I THE ARUP JOURNAL

I

3/1994 Front cover: The auditorium of the new Glyndebourne Opera House. (Photo: Martin Charles) Back cover: The central courtyard in Phase 2 of Lloyds Bank headquarters. Bristol. THEARUP (Photo: Peter Cook)

Vol.29 No.3 Editor: 3/1994JO URNADavid J. Brown L Published by Art Editor: Ove Arup Partnership Desmond Wyeth FCSD 13 Fitzroy Street, London Deputy Editor: W1P6BQ Helene Murphy 3 Engineering Glyndebourne Opera House, built in 1934, became inadequate an opera house: for modern use, and has now been replaced by a new 1200-seat the new Glyndebourne theatre which opened on its predecessor's 60th anniversary. Stas Brzeski Ove Arup & Partners were responsible for the building's structural, Derek Sugden services, controls, fire, civil, and transportation engineering, John Thornton whilst Arup Acoustics were acoustic designers for all aspects of John Turzynski the project. including the new auditorium.

10 Cape Town's South Africa's rejoining the international community has led to a Olympic Games bid concerted effort to host the 2004 Olympic Games, the choice Mark Bostock lying between Johannesburg, Durban, and Cape Town. A team Des Correia led by Ove Arup Incorporated managed Cape Town's bid, Cliff McMillan preparing a sports plan and cost estimates, dealing with Ugo Rivera consultations for the technical proposals, and carrying out an economic benefit analysis. It secured the nomination in January 1994 and now goes forward to be considered by the IOC in 1997.

15 Governor Phillip Tower, Sydney Ove Arup & Partners Australia were the structural and civil Bill Thomas engineers, and Arup FaQade Engineering provided the faQade Neil McClelland consultancy services, for this new 64-level office tower on a sensitive site in Sydney. Additionally, detail drawings were provided for the three 100m2 glass roofs over the foyers, as well as the tall stainless steel and glass screens in the entrance area.

19 Lloyds Bank, Arup Associates designed both phases of this new corporate Canon's Marsh, Bristol headquarters on a Sha riverside site in one of Bristol's most Stuart Mercer historic areas. There is a close visual relationship between the Terry Raggett faQades of the two phases, but whilst the crescent-shaped plan Peter Warburton of Phase 1 embraces a new paved public amphitheatre. the circular form of Phase 2 encloses a 40m diameter green courtyard for the Bank's employees.

2 Engineering an opera house: the new Glyndebourne Stas Brzeski Derek Sugden John Thornton John Turzynski

sightlines and create the required acoustic; layout of the building is based on circular the fabric must provide good acoustic isola­ forms, which are used to soften its impact on tion ; and the ventilation system should be the site. Recognizing that the auditorium and inaudible. Also, theatre and lighting equip­ stage areas have the same requirement for ment have very specific needs. (These are acoustic isolation and generate similar the technical criteria; the architectural plan­ widths, they are contained by an oval-shaped ning, too, has its own demands). massive brick wall , the 'fortress wall'. At one Apart from the requirement that only one sea­ end is the auditorium, at the other the back son should be lost during construction, stage, and between lie the side and centre Glyndebourne presented another challenge: stages with the flytower above. how to relate to the House and gardens, and Around the fortress wall is wrapped the an­ maintain those qualities which make cillary accommodation: dressing rooms, 'Glyndebourne' unique. offices, and circulation space. Primary ser­ The concept vices distribution is located in this zone . Whatever success the design has stems from There is a basement. The area behind the the simplicity and clarity of the overall con­ proscenium contains plantrooms, stage 1. Glyndebourne in 1934: Organ Room (left), cept of the building, which works for all dis­ Theatre (right). equipment and dressing rooms , whilst in front ciplines at all levels. The diagram may seem there is a ventilation plenum beneath the Introduction obvious but a study of other theatres soon auditorium, cloakrooms for the public, and The new Glyndebourne Opera House opened reveals that its clarity is exceptional. Such plant rooms for the front-of-house areas. The on 28 May 1994, the 60th anniversary of its simplicity is not easily achieved and relies on back stage plantrooms supply air to the the complete integration of architectural, predecessor, with the same opera, The auditorium via two huge concrete ducts. Marriage of Figaro. The original building, con­ engineering, and acoustic design. Instead of trying to reduce the impact of the new Opera Noisier plant such as boilers and chillers are structed by Sir John Christie in the grounds in a separate refurbished brick out-building. of Glyndebourne House (Fig.1 above) near House by fragmenting it, like Glyndebourne Lewes in East Sussex, was not only too small House itself, the Hopkins' chose to create a The rehearsal stage too is outside the main for current demand, but suffered from poor single compact building and then reduce its envelope next to the loading bay, in which acoustics and sightlines, had inadequate visual bulk, both by cutting into the hillside another stage can be built if necessary. The ventilation, and sub-standard back stage and through the detail of the design. contours of the site are such that the rehear­ facilities. By 1987 his son , Sir George Christie, The design is a natural consequence of sal stage is almost completely underground, had begun to plan a new Opera House; after choosing a horseshoe-shaped auditorium for revealing its presence only by a low brick wall approaching nine architects and asking two the intimate atmosphere it creates. The whole topped by a band of glazing and a lead roof. to develop proposals, he appointed Michael Hopkins & Partners early in 1989. Arups became involved in all aspects of the engi­ neering and acoustics design apart from Energy centre theatre equipment and production lighting. Fortress wall Bar, shop and box office The brief called for an increase in seats from 830 to 1150 and an improvement in technical Stage and Ambulatories Backstage \J flytower over standards. Sir George Christie was quite 2. clear, however, that music, theatre , and an Concept intimate atmosphere took precedence over diagram. technology. He did not want a building where the technology became an end in itself. Basement Clarity and integration plant room The design of an opera house is complicated. The problems of long spans over stage areas Rehearsal and the support of balconies and flytower are stage obvious, but there are many more: the form and detail of the auditorium must give good

3. The new Opera House looking westwards toward the South Downs.

8l ;;i_, z "a: ::, Q Q. ::, a: "w ...:,: 3 Brickwork and the fortress wall cities built houses onto the outside of Outside the fortress wall , exposed precast Glyndebourne House is a collection of mellow cathedrals and castles. This structural prin­ slabs with an in situ topping are supported on redbrick and stone buildings with gardens ciple reinforces the architectural concept. precast beams which span between the and lake, set in the Sussex Downs. The new fortress wall and brick piers. The outer ends Opera House not only had to relate to these The Hopkins' work p,laces great emphasis on of the beams appear through the walls and physical characteristics, but also recreate the the honest use of materials, but brickwork in piers to make the construction legible and particular ambience which Glyndebourne large contemporary buildings is normally add detail to the brickwork. Brick spandrel has. In part this is created by the setting and relegated to a cladding skin or a facing for panels span between the piers as flat arches the tradition of picnicking in evening dress in precast units. This is betrayed in the bonding carrying their self-weight. Precasting was the gardens. It also lies, like the picnic, in the patterns, the use of the bricks in unlikely situ­ chosen both for speed and for quality of contradiction between sophistication and ations, and the location of mastic-filled move­ finish ; also, in the case of the accommodation simplicity. In the old Opera House a complex ment joints. These are required by the expan­ structure, its form reflects the use of timber art was performed at its highest level in a sion of brickwork and the lack of flexibility of and cast iron in earlier brick buildings. The building which could best be likened to a modern cement mortars as much as by the concrete mix was selected for its light colour large church hall . Some people were con­ need to absorb differential movements be­ and contained a mica-rich sand to give it cerned that its acoustic qualities should not tween frame and cladding. Nevertheless sparkle. Precast panels were also used to be lost but these in fact were poor with a dry such joints would have undermined the visual form the ceiling over the auditorium and sound and noise from aircraft using Gatwick. integrity of the load-bearing structure and led create the recessed lighting gallery. These to ditticulties in detailing. They would also elements play an essential role in the audito­ Early in the design the architects considered have been difficult to locate structurally and using flint walling , a local material, but settled rium acoustics: apart from providing the mass undesirable acoustically, so the older tech­ necessary as part of the double-skinned on brick as more appropriate. The hand­ nology of lime putty mortar, which is more made bricks not only related its construction acoustic enclosure, their sculpted form tolerant of movement, was adopted. The reflects and diffuses sound . to the House, they also introduced a quality other distinguishing feature of modern brick­ and scale of detailing which further reduced work, bonding patterns resulting from cavity Above the precast units, the primary roof its impact and recreated the simplicity of the construction, was avoided by building solid. structure consists of radial steel trusses old building. cantilevering into the centre from the peri­ Auditorium, ancillary meter where they are supported on the The fortress wall required mass to achieve its accommodation and roofs acoustic performance and , apart from under balcony columns and tied-down by the fort­ Within the auditorium the balcony structures ress wall . Above the trusses are double­ the flytower, the vertical lo~ds are not particu­ are of exposed precast concrete units larly high, since above basement level the skinned , lead-covered plywood panels. The stitched together by an in situ spine beam , mass of the lead and build-up of the panels is building consists of single-storey spaces with balanced on a ring of columns. and re­ long-span roofs, or three-storey accommoda­ used for acoustic insulation . The trusses for strained at the back by the fortress wal l. (This the back stage are also radial , but in this tion . This led to the idea of constructing the follows the same structural principles as the fortress wall out of load-bearing brickwork, case the centre of the system lies on the back Mound Stand and Compton and Edrich Stands wall of the flytower rather than over the space. double-skinned around the auditorium itself at Lord's.) for acoustic isolation. It was then logical to add the enclosing accommodation as a The exposed thermal mass helps to smooth Continued on p.9 dependent structure, in the way mediaeval temperature fluctuations in the auditorium. 5. Main entrance (Organ Room in Glyndebourne II> House is on the left).

Bricks and mortar "4 4. Brickwork detail on arch.

The bricks had to be similar to those employed at Glyndebourne for its An arch was constructed at CERAM 's used in Glyndebourne House. as well good water-retention properties, laboratories using the chosen bricks as satisfying engineering require­ workability and availability. It is pro­ and lime putty mortar in the agreed ments, and their selection involved duced by hydrating or slaking the bonding pattern. The arch was but­ considerable research. The final lime (calcium oxide) with water to tressed in a similar manner to those choice was a Selborne hand-made, produce calcium hydroxide. The on the building, and was loaded in a re-pressed brick, made from gault reaction is exothermic, vigorous and predetermined sequence. Strains clay extracted from a deposit mined potentially dangerous. The putty is and movements were monitored at for many years. They are a modified stored under water, the longer the relevant points such as springing imperial size, 220 x 106 x 60mm, to better, for increased plasticity and point, extrados centreline and intra­ match those in the walls of the bonding properties. dos centreline. The arch withstood House. Compressive strength is the applied load without undue dis­ 2 Modern cementitious mortars (which 27.5N/mm with an irreversible mois­ incorporate unhydrated dry lime) set tress and with displacements close ture movement of 0.37mm/m - by the action of hydration with water. to predicted values. classified as low by CERAM Building The mortar sets throughout the depth Bricklaying commenced with the con­ The maximum length of continuous Technology. Water absorption is of the joint and, like most cement­ struction of sample panels for the 14.3%. brickwork on the building is just based compounds. is accompanied approval of bricks, joint profile, under 1OOm around the front of the The facing bricks have a textured by shrinkage. blending and colour. Th is was a use­ Opera House. In other areas, per­ surface produced by coating with In contrast, true lime mortars set by ful testing ground to establish work­ forations in walls for doors or other sand before firing . Both these and the action of carbonation at the ing procedures for the main building. openings reduced this length. The the common bricks are made of the exposed surfaces of a joint. Atmos­ The cross-bonded flat brick arches potential long term irreversible mois· same clay and have the same pheric carbon dioxide is absorbed span up to 2.9m between skew­ lure expansion of the bricks has been mechanical properties, thus avoiding into the mortar and the calcium backs built into the piers. They are estimated as about 24mm, which problems of differential movement hydroxide present is converted back 334mm thick and 536mm high, are does not account for moisture move· between facings and commons to calcium carbonate in a lengthy unreinforced, and incorporate a rise ment which occurred over the bonded together or in adjacent process known as induration. The of 25mm. They support their own months the bricks were stockpiled in leaves of cavity walls. depth of setting is relatively shallow, weight and a brick spandrel panel the open. This strain was considered acceptable, taking into account the Knowledge about the manufacture, and the core of a mortar joint remains above. The bricks tor each arch were restraint that was provided by the use and behaviour of lime mortar, plastic. It is this softness that permits made from a single column of clay. floor slabs and beams. chosen to avoid the need for move­ the masonry to absorb stresses Each brick had a unique number, ment joints, is not widespread , and caused by movement. Any cracking and complete arches were delivered The use of load-bearing brickwork an investigation was carried out, that does occur is small and dis­ on a single pallet. with lime putty mortar on a building including a visit to The Lime Centre in tributed along and across a wall. In Although the arches are relatively of this scale has not been seen for Hampshire to gain practical experi­ effect, movement joints are created lightly stressed there was concern many years. The investigations, tests, ence. Lime for mortar is produced by at every bed and perpend joint. that they might be prone to move­ and trials were an essential part of burning chalk or limestone (calcium The lime putty was delivered in tubs, ment and, with negligible tensile developing the design and under. carbonate) in a kiln at about 900'C to and the mortar mixed on site using strength, exhibit unwanted cracking. standing the techniques required for produce calcium oxide. Two types of gauging boxes and mortar mixers: A load test was carried out. both to construction. In the end, though, the lime are used for mortar: lime putty or the proportions were 1: 2:9 (white PC : answer this question and to assess design depends on engineering dry hydrate. The former was lime putty : sand). the comparatively weak mortar. judgement.

4 THE ARUP JOURNAL 3/1 994

The acoustic

The brief Design and analysis: Sir George Christie's brief was simple the 1:50 scale model and direct, but very difficult to As the design developed, it became achieve: he asked for a sound which clear that Hopkins' auditorium would combined the clarity of the old house not include any 'carpets and curtains' with a 'resonance' that would flatter and a minimum of absorbent the orchestra and singers. Like many secondary fixings, so the volume per acoustic briefs it illuminated two seat could be relaxed a little. fundamental criteria which are However, the 8m3 per seat did virtually mutually exclusive. Through­ decrease to just below 7m3 per seat out the history of opera there has as expected, indicating a mid­ 6. Acoustic scale model showing been an argument about whether convex reflectors installed for impulse testing. frequency reverberation time of 1.4 words or music are of primary impor­ sees. Anthony Whitworth-Jones, the tance; the French with their literary General Director of Glyndebourne, 7. Auditorium roof showing use of structural ribs for sound tradition favoured the words, whilst diffusion and 'jelly-mould' sound diffusing form of vertical precast sections. placed great emphasis on clarity. He the Italians were more concerned considered the Coliseum in London with melody, harmony and timbre. and the Bayreuth Festspielhaus with This dichotomy is still with us today RT s of 1.5- 1.6 sees to be too rever­ and its resolution, achieving that berant. Both these auditoria, but delicate balance between words and particularly the Coliseum. lack short music, was the starting point for the powerful side reflections. With the geometry of the Opera House as a short powerful side reflection, an RT response to Sir George's brief. of 1.4 sees - still somewhat more reverberant than most opera houses Setting the standards - was considered to be appropriate. At the earliest stage, after the With the geometry and seating Hopkins' appointment but before that finalized, a 1: 50 scale model was of the theatre consultant. some dis­ constructed in Arups' Model Shop, cussions took place whilst the with the first roof and ceiling scheme. auditorium still had the vestigial fan­ shaped form of the John Bury brief'. Four were tested before the archi­ tects were convinced about a design, This did not inhibit the setting of which incorporated a 'flat dome', a geometrical standards to achieve the common feature of many opera preferred acoustic. Auditoria for houses. Sound waves focus in a music, whether concert halls or opera similar way to light, and this design houses. invariably fall short of the avoided the focusing problems asso­ volume per seat necessary to ciated with many earlier schemes. achieve the appropriate reverbera­ The model was also essential in tion time (RT); defined as the time exposing focusing from the drum at taken for a sound to decay through high level. This was corrected by the 60dB, RT is still considered the prime introduction of convex panels. Slotted criterion for measuring the quality of lift-off panels were also introduced to sound within an enclosed space. Its allow the inclusion of small areas of value at different frequencies is also absorption to deal with certain focus­ very important to the quality of the ing and to allow for a limited degree sound. It is directly proportional to of fine tuning. volume and inversely proportional to the absorption of all the surfaces. Extensive work was carried out in the model to define the final geometry of Volume decreases as the architec­ the balcony fronts - fundamental in tural concept is developed and achieving , after the direct sound, the detailed! In addition, clients and strong early reflections which provide architects find ways of increasing intimacy, clarity and envelopment. seat numbers as the design and The detailed geometry was resolved sight-line analysis develops. in the model to achieve this without Initially, Bm3 per seat was the volume focusing effects. The profiles reflect fixed to achieve the preferred RT; for sound down into the stalls at the clarity, a maximum 17-1 Bm between sides, with a subtle change in profile balconies was set to ensure strong towards the back of the auditorium, early side reflections; whilst for and are slotted to provide acoustic acoustic and visual intimacy, the transparency where focusing would furthest seat was to be a maximum of occur. 30m from the stage riser. To ensure an orchestral sound of 8. Derek Sugden firing a .38 revolver The quality of any acoustic is during initial acoustic tests in December 1993. some richness and warmth, a 20- immeasurably enhanced by a quiet 25% increase in RT at low frequen­ background. To achieve this a cies is needed. This is quite un­ double skin wall and roof construc­ common in most opera houses, tion of sufficient mass with the where orchestras sound dry and appropriate cavity was specified, rather 'boxy'. It was most rewarding together with an air-conditioning that Hopkins' design of the audito­ strategy that would ensure a back­ rium without an architecture of ground noise level of PNC15- second and third fixings was funda­ approximating to the threshold of mental to achieving this aim. The hearing. soffits are of exposed concrete, the

6 THE AAUP JOURNAL 3/1994 main floor is a stiff composite layer tural scheme, together with the aban­ with a minimum thickness of 40mm, donment of a proposal for sliding and all the balcony fronts are of very proscenium boxes and subsequent rigid solid pine, with a geometry that change in geometry of the sliding adds to their structural stiffness and bridges - part of the original John so ensures a minimum of bass­ Bury brief - resulted in a decrease absorbing resonance. This was a to the overall length of the pit. To most important aspect of the acoustic compensate for this, the distance design. between the orchestra rail and stage There was extensive acoustic input riser was increased to 4m. into the seat design in addition to the Following the test concert, the close work with the mechanical London Philharmonic Orchestra, with engineers to achieve the specified c.75 players on modern instruments, noise attenuation. The seats were tested various configurations of the tested in a laboratory with and with­ orchestra for Figaro and Peter out auditors. Following the first test, Grimes, under conductors Bernard adjustments were made to certain Haitink and Andrew Davis. The rostra aspects of their construction to geometry, particularly at the back of achieve the specified absorption the pit, was resolved both for sight coefficients. These modifications lines and comfortable seating. were confirmed in a final test. The other Glyndebourne band is the Predictions and Orchestra of the Age of Enlighten­ measurements ment, about SO-strong, who play on Measurements in the model pre­ original, and thus less powerful, dicted a mid-frequency RT of 1.4 instruments. In view of this, it was sees, with 1.7 sees at 125Hz. A test desirable that all their players should concert with full audience was held sit forward of the stage riser, but with on 28 March 1994, where measure­ the growing demand of orchestral ments gave an average mid-fre­ players for increased space and the quency reverberation time of 1.25 presence of the safety net this was sees with 1.65 sees at 125Hz. The not possible. However, with the clarity index was high throughout the adjustable pit lift slightly below the auditorium and the impulse traces preferred stalls level the OAE can be were of 'text book' shape. accommodated with the brass and The orchestra pit woodwind placed under the safety 9. The auditorium. One of the central problems for an net or edge of the cantilever. acoustician in the design of an opera Coda - art or science house is the balance between pit and Acoustics is often referred to as a stage sound. The orchestra pit of a 'black art', but it is no more nor less modern opera house must be able to an 'art' than any other branch of engi­ 10. Semi-circular backstage area. house and adapt to a wide repertoire, neering. Engineers, like architects, from the orchestras of the Renais­ work from precedent, but primarily sance operas of Monteverdi and from intuition, using calculations as a Cavalli, through Haydn and Mozart, guide to what they want to do, and to Verdi, Wagner and Richard with detailed analysis as a supporting Strauss, and on to Birtwistle and tool. Acoustics does perhaps differ, beyond. in that the choice of an acoustic is In the last 200 years the orchestra highly subjective, whereas the overall has changed out of all recognition stability of a structure is not a matter and the instruments have become of taste or opinion. A quiet back­ enormously powerful. Conductors ground, however - one of the most have a love affair with that great lush important qualities of a great acoustic sound favoured by many recording - is not a matter of opinion, although engineers and producers. The power even on this subject we can argue of the human voice may have how quiet we should make an increased somewhat, but there is no auditorium. This aspect of acoustics, comparison with the size and power the setting and achievement of sound of a modern orchestra. insulation and sound attenuation, was The brief for the orchestra pit was not one of the great success stories at precise about the maximum number Glyndebourne. Rob Harris of Arup of players. There is a tradition at Acoustics observed that it was the Glyndebourne which encourages first auditorium we have measured young singers, and to achieve the that achieved PNC15 at the first test delicate balance between stage with no modifications or 'tinkering' sound and pit sound with a large necessary. modern orchestra, a maximum dis­ tance of 3.6m between the orchestra • John Bury was the theatre designer and rail and the stage riser was agreed. It consultant who prepared the drawings for the competition brief. He had designed a was always the intention to place the series of Glyndebourne productions for more powerful instruments of a Peter Hall, including Figaro, Rdelio, and modern orchestra on descending Carmen. and had been auditorium rostra under a limited cantilever consultant to the original Edinburgh section of the stage. The final struc- Opera House.

THE ARUP JOURNAL 3/1994 Auditorium Early on, modelling studies were carried out in conjunction with Cam­ ventilation system bridge University's Department of Theoretical Physics and Applied Choice of system Mathematics. A 1: 25 perspex model Flytower The design of the ventilation system of the auditorium, stage arrd flytower for an auditorium is distinguished by was inverted in a water bath, with two key features: the large concen­ coloured saline solutions of various 12. tration of occupants within a relatively densities used to represent hot air Auditori um small proportion of the overall movement. The choice of a displace­ ventilation volume, and the absolute importance ment ventilation system was con­ principles. of the system's acoustic performance. Return air firmed and important data obtained ductwork riser The decision to ventilate the audito­ for subsequent use in the design. rium by a displacement system sup­ System design plying air at low level under the seats To meet the PNC 15 noise limit, plant and extracting at high level was is located at a distance from the natural and intuitive. Systems supply­ Underground auditorium and, in addition to exten­ concrete ducts -----I!:=;:==== ing air from above must overcome sive attenuation, very low air velo­ the natural upward airflow resulting cities have been used in all dis­ from buoyancy forces generated by tribution systems to avoid noise were imposed : the ability to allow Temperatures were recorded at vari­ the heat of the audience. Falling fresh generation. The ventilation system is seats to be removed to locate ous locations and tracing smoke air becomes mixed with rising hot air integrated with the building fabric cameras for video broadcasts. and used to examine the flow of air so that heat and odours are recircu­ wherever possible. Four 50m long, the resilience of the performance of throughout the auditorium and stage lated to the occupants. In contrast, 2m x 2m concrete ducts buried in the the outlet to the Glyndebourne tradi­ area. The results showed an accept­ displacement ventilation comple­ ground beneath the backstage areas tion of placing coats under seats. able correlation with the predictions ments the natural air flow pattern. connect the ventilation plant to the On completion of the tests and stud­ of the earlier scale model test. Cooler, fresh air supplied from below auditorium. Air is injected into large ies, the integrated seat pedestal air The real proof came with the first use replaces stale rising air so that the plena beneath the floors of the stalls outlet was chosen. A detailed simu­ of the auditorium for a public perfor­ occupied zone is constantly purged and each of the circles, and enters lated load test at an acoustic labora­ mance, at the 28 March 1994 test with conditioned air and local re­ the auditorium through air supply out­ tory followed . A block of 24 seats with concert, which lasted approximately cycling is eliminated. There is no lets integrated with the seating sup­ air supply pedestals was built above 90 mins. Temperature measurements need for higher air velocities to over­ port pedestal. The orchestra pit is a plenum pressurized by a fan . A compared favourably with the design come the natural air movement, so similarly supplied, but with a flat grille lamp bulb was placed on each seat predictions and reports from there is less likelihood that noise will served by a separate plenum con­ to represent the heat generated by members of the audience and result. A benefit of the resulting nected to a branch of the main sys­ the audience, and detailed air tem­ orchestra were positive. The acoustic increased cooling etticiency is that tem. The exposed structural concrete perature and velocity measurements performance of the system has been air is supplied at higher temperatures within the auditorium provides a sub­ were taken, as well as further confirmed both by measurement and than required for ceiling supply stantial thermal cooling store which acoustic measurements. by its inaudibility to the human ear. systems, so refrigeration running smooths temperature swings by costs are reduced. System tests Conclusion absorbing and releasing heat energy. The heat load test was repeated on Testing at successive stages in the 11. Seating with acoustic absorbent Choice of air outlet site at full scale during commission­ design, construction, and commis­ base, mounted on integrated Various auditorium air outlet types ing trials. Lamp bulbs and convector sioning process underpinned initial air supply pedestal. were considered, both integrated heaters were distributed throughout design assumptions, confirmed detail with the seat support and separate. the auditorium to simulate the heat design parameters and, finally, Each outlet was tested to prove its air generated by a full house - equiva­ proved satisfactory system perform­ flow and acoustic characteristics and lent to about 1250 domestic 100W ance. The successful outcome con­ examined to ensure that it could be lamps. Sufficient theatrical lights firms the importance of testing in accommodated within the space were rigged and operational to repre­ situations where attention to detail is available. More unusually, two further sent the heat given off by production paramount in achieving the end criteria peculiar to Glyndebourne lighting during a performance. result.

13. Fabric canopy, designed by Arups, over the foyer entrance.

8 THE ARUP JOURNAL 3/1994 ii,. Continued from page 4: Primary truss The trusses span from the fortress wall to a semicircular torsion beam hung from the fly­ Roof slab/table top tower roof. the semicircle being used to Steel leg/ create a skylight. The side stage roof trusses tubular column simply span from flytower to fortress wall. Hangers In these areas the acoustic requirements are less than over the auditorium so the ply and Wind posts ----,----r-, lead roof is the only skin. thus allowing the 1..++--1-+-+--- Outline of steelwork to be seen from below. The roof of auditorium roof the rehearsal stage also consists of exposed Steel plate steelwork with lead/ply panels. Like other shear wall parts of the design the steelwork continues Side stage girders the contrast of simplicity and sophistication. the design being based on simple back-to­ back angles and tie rods. The sophistication Proscenium arch lies in the organization and the refinement of the details. The roof over the accommodation uses timber and steel flitch beams to intro­ Concrete leg/ duce a more domestic scale. shear wall The exposed brick, the finely detailed precast concrete, the reclaimed pitch pine balcony fronts and panelling, and the bare timber floors have a tactile quality which creates a particularly restful atmosphere in the audi­ torium. This is enhanced by the apparent absence of services. not easily achieved in a building without applied finishes . Air is sup­ plied through perforated seat pedestals. lighting is recessed into the precast concrete. and conduits are cast-in. The back-of-house Side stage areas were detailed with the same attention; great care was taken over the co-ordination of services. brickwork and concrete. conduits were cast-in wherever possible and final routing was simple. A fairly robust approach was adopted for the actual detailing and selection of fittings. 14. Flytower structure. Flytower The largest single piece of structure and the most conspicuous element of the building is Construction Timetable the flytower, its size following inevitably from Construction started in March 1991 with an Architectural appointment: February 1989 that of the stage and the height of the pros­ enabling works contract to divert existing site cenium. Originally it was to be elliptical and of services. After the close of the 1991 season Scheme design approval: December 1990 brick construction, but as the design de­ work began in earnest with the demolition of Start on site (Phase 1A): 27 July 1991 veloped the shape changed to a rectangle as much as possible of the existing building with curved front and back walls. As well as without affecting the operation of the main Start on site (Phase 1B) : 5 August 1992 softening the shape, the curves create part of the opera house in the 1992 season. Completion and handover: 31 December 1993 spaces for the curtains, a staircase. smoke Work then proceeded on the structure behind extract plant, and dimmer rooms. However, the proscenium until after the 1993 season First night: 28 May 1994 the curved torsion beams required to support when the rest of the old opera house was these walls were very large and would have demolished. Credits been an unacceptable intrusion into the Client: Before work started there had been concern Glyndebourne Productions Ltd. auditorium above the proscenium. The de­ over the problem of removing 33 370m3 of sign was changed so that the walls were sus­ Architect: excavated chalk through the narrow country Michael Hopkins & Partners pended from roof top trusses. which also lanes. This was solved by a slight modifica­ helped speed construction. A grillage of ex­ Consulting engineers: tion to the topography of one of the adjacent Ove Arup and Partners Jeremy Brasington. Pat Clowry. posed steel trusses is carried by four steel fields . The Christies seemed to delight in the Barney Jordan. Rob Kinch, Clare Murphy, Steve Peel, columns supported on concrete shear walls , Caroline Ray. Mervyn Rodrigues, David D Smith. John Thornton. 10m deep hole, literally outside their back John Turzynski (structural) two of which form the proscenium. The grid door, as a sign that their project was under floor and stage equipment are suspended John Berry. Sias Brzeski. Martin Greenblat. Carolyn Gallehawke. way, but it cannot have been easy for them to Nigel Tonks, Graeme Walker (mechanical) from the grillage as well as the front and rear live with a large, complicated, fast construc­ Joe Patel. Alex Perkins. Chris Taylor, An dy Worsick (electrical) walls which are formed of lead-clad timber Bob Bassah, David Carroll. Tony Minchinton (public health) tion project in their garden. panels and precast concrete units; similar Bob Cather, Chris Murgatroyd (AR&D). Nicos Peonides (Controls) Chris Barber (Arup Fire), Adam Chodorowski (Arup Geotechnics) side walls are supported by storey high The choice of load-bearing brickwork for a Vaughan Sutton (Transportation) trusses. project to be built in a very short time might Acoustic consultant: The House in the garden seem perverse when speed is normally asso­ Arup Acoustics Derek Sugden, Rob Harris, Raf Orlowski, Part of the attraction of Glyndebourne is ciated with steel frames . However as a simple Helen Thornton strolling around the grounds before the per­ labour-intensive activity it is well suited to Theatre consultant: formance and during the intervals, one of working in many areas at the same time. Theatre Projects Consultants which is long enough for people to eat in the Moreover. the extensive use of precast Cost consultant: Gardiner and Theobald restaurants or picnic in the grounds. This, concrete helped speed the work. Other key Construction manager: and the fact that the season takes place in factors were the simplicity of the ventilation system and the fact that almost all structural Bovis Construction Ltd . the summer. creates opportunities which a Illustrations: more conventional situation cannot. The components were self-finished, which mini­ mized the fitting-out time . 1, 15: Courtesy dining room is in a separate simple brick Glyndebourne Archive building, while outside the auditorium the Glyndebourne is a special building both in 2, 12, 14: Dennis Kirtley walls of the circulation areas consist only of the quality of its design and the feeling that it 3. 5, 9-11 , 13: the piers with balustrades between. This will be there for a long time . Many people Martin Charles helps reduce the solidity of the fai;:ade as it have remarked on the enthusiasm of those 4, 6: Peter Mackinven looks out to the House and gardens. Another who worked on its construction . Perhaps it 7: Ove Arup and softening device is the PVC-coated polyester was these things which generated the enthu­ Partners canopy (left: Fig .13) which links the building siasm or perhaps it was just that men could 8: Richard Davies with the bar, shop and box office attached to see the skill of their hands in the finished the original dressing room block which was building, something increasingly rare as con­ retained. This creates additional circulation struction becomes an assembly process and space sheltered from the English summer. finished surfaces are machine-made. THE ARUP JOURNAL 3/1994 9 1. Table Bay Harbour: Waterfront and central business district

...... _, /J / cape Town 2 0 0 4

Introduction firms were invited to make submis­ During the course of the Study, how­ kingdom). It is a tourist paradise that During the past few years certain sions. Some 40 teams did so, includ­ ever, it changed the bidding process has not realised its potential inter­ people - among them Sam Ram­ ing one led by Arups, and this was and a decision was eventually only nationally because of South Africa's samy, President of the National selected in September 1992 to assist made in January 1994. To involve polrtical isolation. All indications are Olympic Committee of South Africa the Cape Town Olympics 2004 NOCSA more in the cities' proposals that tourism will increase dramatically (NOCSA) and Raymond Ackerman, a Steering Committee in establishing and to allow the latter to demonstrate over the next 10 years, and that the prominent Cape Town businessman the feasibility of hosting the Games. their capabilities, each had to host a Olympic Games will be a major - became aware of the prospect of (This formal client body now com­ NOCSA Council meeting in 1993 and stimulus to this. Because of the an African city being favourably con­ prised the broadest possible cross­ make a presentation to it - Cape Cape's special environmental sidered by the International Olympic section of interests in the Western Town in April, Durban in August and qualities and the strength of the Committee (IOC) to host the 2004 Cape - sporting, community, busi­ Johannesburg in November. The ecology movement in Cape Town, the Olympic Games. Africa is the only ness and political.) If hosting was technical bids were submitted at the Steering Committee is committed to continent never to have had the found to be feasible, the next step end of November and the final pre­ an Environmental Charter. Games on its soil, and political events would be to secure NOCSA's sentations were made on decision­ This will ensure that any development, there in the early '90s, including South nomination. day: 29 January 1994. for tourism, industry or the Games, Africa's rejoining the international Arups' role was to manage the entire This extension of the period placed will be co-ordinated within its frame­ community, have created some bid process: prepare the sports plan particular strain on Cape Town's work so that impact on natural assets enthusiasm for the suggestion. and capital expenditure estimates, financial resources and its consul­ will be controlled . South Africa's three largest cities, deal with the consultation process for tants, partly because it was the one The city is the centre of the second Cape Town, Durban and Johannes­ the technical proposals, and carry out bid to be entirely private sector-led most powerful province economically burg, started preparations to bid, so an economic benefit analysis. The and funded, but also due to the timing in the new dispensation in South NOCSA decided on a formal com­ Feasibility Study, completed on set by NOCSA Having disclosed the Africa - a focus for likely investment petition between them. One South schedule between October 1992 and depth of their thinking in April, Cape and industrial growth. It is a desirable African city could thus be chosen with April 1993, concluded that it was Town had to maintain the momentum city: people want to live there, it has a full national support to compete for feasible for Cape Town to host the and lead for another eight months. trainable potential workforce, and the Games. Games and that in fact the city could Environment, location there are well-developed educational Cape Town City Council produced an put together an irresistible bid to the and features facilities including three universities audio-visual presentation outlining the IOC in 1997. Arups were subse­ 'The fairest Cape' is famous for its and two technikons (major technical benefits and opportunities of hosting quently also employed to prepare the natural beauty: for Table Mountain colleges). It has a well-developed the Games, and formed an interim technical bid documentation for (Fig.1), for the beaches around the primary road network and rail infra­ committee including sporting repre­ NOCSA. and to present the technical Peninsula, for the wine farms within structure, plus good transport and sentatives and businessmen. It was and economic case. 100km of Cape Town, and for the communication links to the rest of decided to commission a formal NOCSA had indicated that it would famous 'fynbos' (the local generic Africa and other continents. Being in feasibility study, and professional make its decision by mid-1993. name for the shrubberies of this floral the European time zone would be an 10 THE ARUP JOURNAL 311994 '4 2. An international National IOC ideals destination. vision The •pproach 3. .... Feasibility study. Regional A.-, Regional needs potential " Synergy and opportunities

Olympic requirements

Major satellites Northern (I::) __ I Corridor O Khayelitsha ~ f) Philippi CB~ ...... · 7··--- 0 UWC/Pentech Southern .. 4. Corridor Main Centre, Needs and Wingfield opportunities. • Minor satellite 5 . .... - New opportunity Transport.

advantage for the 2004 Olympics because all the summer Games between 1980 and 2000 will have been in the Eastern or American zones except for Moscow and Barcelona. It is endowed with out­ Ourbanville standing medical facilities , including 0 South Africa's first sports medicine faculty. So far as sport itself is con­ cerned, Cape Town has a strong tradition which includes hosting inter­ national events like the Argus Cycle Tour (with 20 OOO competitors, the Stellenbosch largest event of its kind in the world), the Two Oceans Marathon, the Cape­ lo-Rio Yacht race and athletics. rugby and cricket events. Finally, it is a centre with a rich his­ tory, a liberal political tradition, and cultural diversity, which has led to its inhabitants being described as the rainbow people'. and hence the pro­ 6. Cape Town's Olympic plan. posal dubbed the Rainbow Games'. Cape Town's tradition of relative peace and stability contrasts with the violence affecting most of South The objective was to capture the syn­ developmental objective, the Games people of the region greater mobility Africa in recent years, and naturally ergy that exists between the Olympic had to be planned to bring benefits to and access to employment oppor­ political stability and peace are pre­ requirements and the regional needs, these areas. tunities. After examining more than 20 requisites to staging a successful opportunities and potential, and at the Cape Town's transport infrastructure sites as possible Olympic venues, the Olympics in South Africa. same time to utilize the Olympic (Fig.5) is at present focused on Arups-led team decided to locate the ideals, linked to a national vision. to moving people to and from the CBD. main Olympic complex at Wingfield, A developmental strategy create an approach that would be with sub-nodes at Philippi, From the outset the Steering (The 300 OOO+ morning peak capa­ unique and irresistible (Fig.3). city makes the commuter rail system Khayelitsha and the adjacent Committee recognized that the bid University of the Western Cape and process should be based fundamen­ The Cape Town metropolitan region Southern Africa's largest.) By locating comprises two zones of historical the proposed Olympic venues near Peninsula Technikon campuses tally on a sound developmental (UWC/Pentec). strategy if the concept was to enjoy affluence and development, one run­ these road and rail corridors, it will be the vital support of the community ning north-south down the peninsula possible to provide the necessary These nodes will be strongly linked by and the future Government. This and the other east-west from the cen­ transportation efficiency between the transportation system, enabling meant that: tral business district (CBD) (Fig.4). them, and at the same time ensure the Olympics to reinforce develop­ Between these, some 2M people - that the Olympic planning process ment already proposed there by exist­ • It had to be African and community increasing rapidly as a result of acts as a catalyst to co-ordinate the ing initiatives. At the same time, all based. inward immigration - live in relative development of the system over the existing sporting facilities in the • It needed to address income poverty on the Cape Flats south-east next 1O years , transforming it from its region would be utilized to their maxi­ redistribution and empowerment. of the CBD, many in informal settle­ present CBD focus to a metropolitan­ mum, either as competition or training • It had to be feasible. ments like Khayelitsha. To achieve the wide looped service, giving the venues (Fig.6).

THE ARUP JOURNAL 3/1994 11 • 7. Olympic Stadium . .,. 8. Wingfield Olympic Centre ~ T 9. Khayelitsha Sports Centre. =Cope Town WtNGFlELO OLYMPIC CENTRE . ~ Cope= Town .. , 1 OLYMPIC STAOIUII 2 Ol.'t'IIPIC vtUAGE J ATKl.ETES' f AQUTIES 4 ATHLETES' PARK 5 WA.RIIMJP TRACK & fACIUTIES 6 vtP STADIUM eHTRY 7 OUTSIOE: 8AOA,OCA.S1' ZOHe I PU8UC CONCOURSE I PROPOSED RAILWA'f STATION 10 ElOSTING RAIL.WAY STATlON' 11 TEMPORARY OLYMPtC PARKIHO {5000 CARS) 12 ME04.A CENTRE - FUTURE IHOUSTRlAL 13 ME.()l;A Yiu.AGE 14 LAKEIWETU,NOS 15 EXlSTING AHO PROPOSED PARKLAHO 16 SPECTATOR RAMP/CONCOU RSE 17 CEMETERY II fU1\lRE HOUSNO 11 EAAl.Y HOUSING DEVll

KEV 1 FOOTBAU. STADA.M 2 80:XJHGHAU 3 SHOPPING AND STADtUM ctRCUS <1 SHOPPING S PRACTICE PtTCHES 9 CARS ...... 7 CARsn>RA.cncE 9 MAIN STATION 10 EXISTING ttOUSU-iQ 11 EXISTING WOOD & PARKLAND

The Wingfield site offers everything a immediate mixed use development of Guiding principles in the choice of all Proximity to the road and rail network main Olympic complex could need: a the site to provide lasting benefits to the venues were accessibility, use to ensures that 17 of the venues will be 300ha, open, publicly-owned site the community, made the proposals the maximum of existing facilities, within 15 minutes' travelling time from which, without problems of conges­ particularly potent (Fig .8). promotion of local sport development, the main Olympic complex at Wing­ tion, can be planned for optimum The facilities at Philippi and integration into communities, and pre­ field , and virtually all within 30 Olympic use as well as for after-use, Khayelitsha will reinforce the pro­ and after-use. The training venues minutes (Fig .11). This will ensure a strategically located 12km from the posed Western Cape Metropolitan also present opportunities both to compact, efficient, Games plan. city centre and in its growth path, and make maximum use of existing facili­ Development Framework, delivering The strategy has built-in flexibility to with a magnificent vista of Table sorely-needed facilities to the Cape ties and to introduce modest facilities Mountain. into communities where need exists. review the siting of venues as the Flats communities. A football stadium detailed Olympic planning proceeds. Wingfield will have the world-class and boxing arena, serving as a multi­ A few comments on certain of the pro­ Olympic stadium for 80 OOO specta­ purpose indoor complex after the posed venues are appropriate. To The equestrian cross-country event tors (Fig.7), and two indoor arenas, Games, are proposed at Khayelitsha avoid the cost of two new indoor halls will be held at Vergelegen, one of the for which concept designs were (Fig.9), whilst Philippi will accommo­ tor gymnastics and basketball, which Cape's most beautiful wine estates. prepared of state-of-the-art facilities date baseball and wrestling . Here, the require seating for 20 OOO and 25 OOO It is worth noting that the Cape is the that then could be transformed into a Olympic structures will form part of a spectators, Arups proposed using the only area in Africa likely to be permanent multi-feature sports development node, with job creation existing Newlands Rugby Stadium declared immune from African Horse centre. as a primary objective. (Fig.10) by rooting it temporarily and Sickness within the next few years, The compact arrangement of the pro­ The UWC/Pentec facilities will utilize partitioning it into two indoor halls. thereby avoiding the problems which posed athletes' and media villages existing management capacity, and Preliminary discussions with the any other African city would create for and media facilities, all at walking dis­ the connections of those institutions rugby authorities on the implications this particular competition. Yachting tance from the stadium and arenas, with the communities to ensure that of this have met with a favourable will be in Table Bay harbour against plus the potential to use the Olympic they will serve the grassroots sports reaction , but the proposal will need the backdrop of Table Mountain thrust as a catalyst to stimulate needs on a long-term basis. further detailed consideration. (Fig.12), whilst the proposed venue

12 THE ARUP JOURNAL 311994 Accommodation Capital expenditure The accommodation plan is designed The estimate of gross capital expen­ to provide a suitable range for all the diture over the 10 years leading up to estimated 208 OOO visitors expected the Games is R5.9bn (£1100M). The on any day of the Games. The famous largest item in this is infrastructure - Victoria & Alfred Waterfront will pro­ roads , railways and airport - vide the IOC and other Olympic followed by the sports facilities and dignitaries with a setting in Table Bay the villages. The infrastructure expen­ harbour unequalled in the world . diture will be on projects necessary 10. ~ Cruise liners will be used to the for the development of the region , Newlands utmost for other VIPs and corporate most of which have already been Rugby sponsors.Currently it is proposed that proposed independently and will Stadium. . 25 OOO beds in 27 vessels will be enhance the new Government's accommodated in the harbour, but on reconstruction and development the advice of those experienced in programme (Fig.13). The impact of 18 the corporate sponsorship trends of the Olympics is to ensure their co­ Travel times 16 17 the Games internationally there are ordination and in some cases to "'~14 plans to increase this by utilizing advance the expenditure in time. The ~12 other harbours and anchorages . Olympics process is an extremely .;'.10 11 powerful force for co-ordinating The large range of holiday homes and ~ 8 capital expenditure across the region, ~ 6 guesthouses throughout the Western involving local authorities and pro­ § 4 Cape, together with the Cape's vincial and national agencies such as z 2 tradition of hosting visitors in private 3 0 the rail , road and airport authorities. 0 homes, will be exploited to the 0-15 16-29 30-49 50+ The power of this co-ordinating effect 11. utmost. The projected increase in lime (minutes) A compact is already evident and has been tourism over the next 10 years will Games plan. particularly significant in the political enhance the accommodation stock and policy vacuum which has existed significantly. Also, because of the in South Africa. These benefits will timing of the Games, the large stock continue to be significant over the of education residences in the Cape next few years while the new pro­ will also be available. vincial and local authority structures One of the Olympic villages at come into effect. Wingfield will accommodate 15 OOO The proposed expansion of Cape athletes and officials and the other Town's airport, very small at present 15 OOO media people. These are because of regulations only recently envisaged as private developments removed with it being accorded inter­ and will serve as well-located and national gateway status, will increase 12. crucially-needed housing afterwards. Yachts in Table its capacity to approximately 11 M Bay Harbour. Costs and finance passengers per year by 2004. This is The costs associated with hosting the in line with the airport authority's Games are divided into those of projections for demand-driven growth arising from increased tourism and Rand(M) Rand(M) bidding, the operating budget and Olympic costs Non-Olympic costs the capital expenditure programme. business activity. Housing 874 Infrastructure 3670 Bidding is estimated at R60M (£18M) It is proposed that approximately Sports 1037 Contingency 100 (1993 figures) . The economic analysis R1 .8bn (£330M) of the capital expert· Infrastructure 220 Total 5901 concluded that tangible benefits diture would have to be under con- ' 2131 Sub-total would flow from this process alone, struction or committed by late 1996 to making the bid worthwhile even if the ensure a credible South African bid to Games were not secured in 1997. the IOC. Most of this expenditure will be on necessary infrastructure pro­ These economic benefits arise jects. About R300M (£55M) of it will primarily from the tourism boost be for sports facilities. the priority fuelled by the publicity associated being those which will best fulfil com­ with the bidding process. This will munity needs. This will ensure that by translate into additional business, new Infrastructure 1.400 Infrastructure 2.490 13. late 1996 six of the proposed Olympic 1994-1997 (A t751M) 1998·2004 (A 4150M) Capital costs. construction projects such as hotels venues will be virtually up to Olympic and a convention centre, generating standards, 21 will be under construc­ additional jobs. tion or fully committed, and only six for rowing and canoeing is on the The small coastal strip stretching a will be bid- dependent. The latter will Berg River at Paarl. about an hour's few hundred kilometres from Cape The proposed operating budget for the Games shows an operating include the most costly, like the main drive from Cape Town - a location Town is one of the world's six floral stadium. and those facilities which relatively free from wind. kingdoms, with an exceptional variety revenue of US$1 .25bn (£830M). This has been based on careful analysis least meet immediate community Finally, as far as football is con­ of flora . of the budgets of other cities which needs. In this way, it is proposed to cerned. it is proposed to take as This timing is optimal climatically, have hosted or bid for the Olympics produce a bid which will be totally many matches as possible to the coming at the end of the rainy Cape over the last 12 years. Although convincing to the judges and IOC enthusiastic fans throughout South winter and before the summer south­ projection of costs and revenues 1 officials and demonstrate Cape Africa. at venues such as Durban. east winds prevail. 30 years of climate O years hence must be treated with Town 's commitment to the necessary Johannesburg and Port Elizabeth, records for that time of year were caution, allowance has been made for infrastructure and facilities. with one of the pools and the finals in analyzed, and it was concluded that prevailing trends; for instance. some Cape Town. the climate will be satisfactory for Economic benefits reduction in US television revenues is The key to the economic benefits to Timing and climate both athletes and visitors, with mild temperatures, ideal humidity, rela­ expected. though European and be derived from Cape Town hosting Many considerations influenced the Japanese revenues appear to be tively long daylight hours, little rain the Olympics is the unique synergy choice of late September to early increasing. and sea level altitude. that exists between Cape Town's October for the Games. This timing , tourism growth potential and the the same as Sydney's for the 2000 Records show that windy days can A lower provision for revenue from ticket sales has been assumed Olympics. The Olympics will help to Games. suits world television require­ occur within the period of the Games, drive tourism growth by projecting the ments, athletes' international sched­ but the probability of acceptable because of the need to encourage local attendance. world class assets of Cape Town as a ules, and domestic priorities such as limits being exceeded is low. tourist paradise for a decade as it academic holidays. The main stadium, where wind effects The budget indicates an operating emerges from the period of inter­ It also offers the unique advantage of on athletics records could be an surplus, most of which will be national isolation. Also the tourism spring in the Cape, with its famous issue, will be designed to minimize ploughed into the development of the growth will generate the demand wild flowers . the effect. Olympic facilities. which will drive the development of THE ARUP JOURNAL 3/1994 13 hotels, tou rist facilities, the airport and transportation. Growth scenarios with 6,000 and without the Games were based 1994-97 1998-2004 2005-2008 on inputs from many players involved with tourism. A 15% compound 5,000 With Games 9.8% 16.5% -1.9% annual growth rate is indicated for Realistic 8.7% 11 .0% 7.9% that with the Games, which is pro­ Do Nothing 6.2% 6.4% 6.5% 'yi 4,000 bably a conservative estimate. 8 14. Economic benefits derive from the 8. With Games The tourist growth scenarios. l!? -- difference between this growth and g Realistic ·;;; -- what might happen if no concerted 3,000 5 Do Nothing campaign was mounted and without -- the benefit of the Olympics (Fig .14). They serve to accelerate the growth 2,000 which might otherwise occur with a well-managed tourism strategy. Evidence from other Olympic cities 1.000 L--L._ .L_--1._ _!__L._-L._.L_--1._ _!__!..._.....L._.L_--1._...l.....J shows this benefit continues several 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 years after the Games, with tourism in the couple of years after higher than 12,000 ~------~------in the Games year itself. Total Contribution ~ (Rmillions) 10,000 The economic benefits derived from Macro direct and indirect spending by 48,091 visitors accrue not only to the Western 8,000 Micro •>----"'o Cape region but to the national 9.300 ,.: economy. Arups estimated the gross 15. resulting economic benefits to be Annual gross economic contribution . R48bn (£1 0bn) (Fig.15). Even the State is a winner: it is calculated that revenues from taxes and other sources amount to R8bn (£1 .Sbn) over the period - this in return for a 2,000 gross capital expenditure of less than R6bn (£1 .1bn). Extremely important is the job 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 creation potential of this increased economic activity. South Africa faces 250,000 .------~ high and drastically increasing un­ :,;"' employment which is unlikely to be R g alleviated in the medium term even 200,000 1------~ :gm -=------! with improving economic growth , Macro because most formal businesses and Micro industries do not generate significant 150,000 16. job opportunities. Construction and j E Annual employment. tourism are the industries with maxi­ z::, mum potential to generate new jobs at modest cost, and these are the beneficiaries of the Olympics and the tourism development. Arups estimate up to 200 OOO new jobs will be gener - ated by 2004. Fig.16 shows the pro­ gressive growth over the 10-year 0 period as a result of the Olympics. 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Community involvement Arups' work involved an enormous Committee, the list of Patrons, many • a compact technical Games plan Credits amount of community consultation. of whom have been actively involved which should enable Cape Town to Client: This was especially necessary in the bidding process, represents a demohstrate to the IOC its ability to Cape Town Olympics 2004 Steering Committee because of the unique political Who's Who of South Africa's leader­ host the Games efficiently ship and personalities. The formal Leader of Bid Team: climate in which the bidding process Ove Arup Incorporated Marl< Bostock. endorsements included in the bid • the unique synergy between to date was undertaken. The priorities tourism and the Olympics which Des Correia. Michael Lew,s, Cliff McM,llan, Ugo Rivera, document are from a large cross­ Soza Zware, JIITI Read (corrmuocallOOS), James Burland, of communities are for basic facilities enable economic benefits to accrue which will improve their quality of life section of South African interests. Michael Lowe, O,pesh Patel, Graeni Sman (urban which justify the support of business design), Andre,, Allsop (wind studies), Jane Osborn, - shelter and social infrastructure for The sponsors who funded the bid are and Government for the Games lvone de F,gueuedo (adrnnistrallOn and report education and health. It has been national and international companies, p,oducbOn) necessary to demonstrate to these household names in South Africa, • the developmental strategy which Other Team members: communities, who may suspect that will ensure community support for the M.L.H. Architects & Planners, Hawkins, who showed commitment to Cape Hawkins & Osborn, Price Waterhouse the Olympics represents an unneces­ Town's bid despite their business Games and its compatibility with the reconstruction and development Meyernel sary expenditure of public funds on interests in the other cities involved. Marketing and PR consultants: potential white elephants, the programme. Corporate Image benefits to be derived in terms of Conclusion The announcement on the evening of The process of preparing the IOC bid Sub-consultants: reconstruction and development. That Prol. David Dewar (regiooal developmeot needs), this process has been largely suc­ 29 January 1994 by Sam Ramsamy of has already started and Arups are John Donaldson (sports events), l'lefre Tredoux cessful is a commentary on the NOCSA's nomination of Cape Town deeply involved, although the precise (lounsm), Reg Patte

14 THE ARUP JOURNAL 3/1994 Governor Phillip Tower, Sydney Bill Thomas Neil McClelland

Introduction In 1982 the New South Wales State Govern­ ment called for proposals to develop a vacant block of land in the heart of Sydney's financial precinct, overlooking Sydney Cove and the Opera House. The site once contained the first Government House of Australia, also the first permanent building in the colony. It had been built in 1788 by Arthur Phillip ( 1738- 1814), the first Governor of NSW, and had subsequent additions to satisfy nine Gover­ nors, one of them the infamous Captain Bligh of The Bounty. Surprisingly the land remained undeveloped after demolition of the old premises in 1846. s1idg-e~ Governors Place ·'_.,r-f Commemorative / I museum site

Core area

"Title boundary"

Governor Macquarie Tower Site

1. Site plan. 2.

A design - with which Arups were involved - was accepted for the site, but community pressure was brought to bear for an archaeo­ logical investigation. To the delight of the conservationists and embarrassment of the bureaucrats, the stone footings of the first Government House and additions were discovered. This naturally threw any plans to develop the site into disarray, and close to a decade passed before a competition was held for a commercial development, adJacent to the original site and containing a museum of the history and foundations of the first European development in Australia. Together with the successful architects, Denton Corker Marshall, Arups again became involved, this time as fa9ade engineers as well as structural and civil engineers. The building The commercial development, aptly named Governor Phillip Tower (GPT), is a 64-level The tower forms part of a total development, entrance foyer and between the zinc blades landmark office building, soaring 250m encompassing an entire city block bounded are three glazed roofs supported by delicate above its foundations to join the tallest on by Bridge, Phillip, Bent and Young Streets, in stainless steel cable trusses. Between GPT Sydney's imposing skyline. It has 38 office which there are five integrated elements: GPT and the adjoining Governor MacQuarie Tower floors , typically 38m x 52m with a floor height itself, Governor Macquarie Tower, Governor's is a sandstone-clad loggia with three glazed of 4.05m, giving a total nett lettable area of Place, the Commemorative Museum and the entrance screens supported by vertical cable approximately 55 170m2, serviced by four existing heritage-listed terraces along Phillip trusses. banks of lifts for medium, medium high, high, Street and Young Street. The tower fa9ade is a panellized strong-back and sky rise zones. The tower contains three The first office floor of GPT, at level 21 , is 40m system of polished granite, glass, and stain­ double-height floor plantrooms at levels 30, above Young Street, offering tenants superb less steel fins with metal inlays. The latter 51 and 62, whilst below street level there are city and harbour views. Beneath this level the define a three-storey square grid pattern 10 basement floors extending under the full tower sits on a series of zinc-clad blades over which has been further accentuated by the width of Young Street for 650 car park spaces a magnificent entrance foyer finished in sand­ distinctive stainless steel clad fins terminating and plant facilities. stone with a polished granite floor. Above the above the tower roof.

THE ARU P JOURNAL 3/1994 15 Structure demands necessitated a scheme for a located in slots and pass clear through the The brief rectangular tower overhanging the housing . core. Specially manufactured bearings allow Despite the floor area, the seNice core ideally for rotational freedom and relative vertical It was an important aspect of the client's brief needed to be only 12m wide. The major movement at the connection between core that both the Young and Phillip Street challenges posed in satisfying this proposal and truss, whilst providing horizontal restraint terraces and the important remnants of the were : to stabilize the truss chords. footings of the original Government House remained undisturbed, with historical • to provide a structural system integrated Erection of the transfer trusses was seen as artefacts recovered from the site preserved in within the architectural form to support an the most critical stage, and a study was the Commemorative Museum. However, as Sm overhang of the eastern fa9ade over carried out to determine the optimum time well ·as preserving the site's history, the the Phillip Street terraces solution for assembly and erection of this development of the new office building had to • to develop a lateral stability system in the steelwork. This document formed part of the proceed on a sound commercial basis, with east-west direction to augment the very structural steelwork tender package - for the following major requirements: slender service core information only, the builder being ultimately responsible for his own erection procedures. • Design and construct a state-of-the-art, • to provide, within the design, structural sys­ It is interesting to note, however. that the quality building. tems and techniques to help the builder eventual erection procedure was in principle • Maximize the site development rights. achieve the shortest possible construction the same, with the exception of cranage. 2 program. • Provide a nett lettable area of 1400m per The transfer trusses were assembled on a typical floor and maximize floor efficiency. Transfer structure temporary platform at street level. As soon as • Provide 12m of column-free space from the The most striking feature of the tower is the the service core and steel box columns were external fa9ade to the face of the central Sm overhang, but in addition the columns on constructed to level 21 , the trusses were service core to allow for optimum tenancy the northern fa9ade needed to be relocated winched up through temporary slots left in the planning. transversely to avoid the important remnants core and rolled across to their final location, of the first Government House footings. The each truss being lifted in less than a day. A • Deliver the project in the shortest possible transfer structure had to be located beneath time. composite steel-concrete floor was con­ level 21 to give the required clearance above structed at level 21 which subsequently acted The ideal building form would have had its the terrace housing, and be able to transfer a as a platform for starting work on the typical three central fa9ade columns striking through total weight of 12 OOO tonnes . To minimize the floors. This jump-start system saved 15 the Phillip Street terraces. but the briefs material used and maximize speed of con­ weeks on the construction programme. struction, steel was chosen in preference to reinforced or prestressed concrete. Each of the four trusses is 36m long, 12m deep, and weighs 250 tonnes (Fig.4). Each was cambered 20mm and its tension mem­ bers prestressed in two stages during con­ struction to reduce absolute movements of the truss and hence minimize their effect on the ta9ade. The trusses are supported on steel box columns 1.2m square which spring from foundations ?Orn below level 21 and freestand 2Sm tall within the foyer walls. Preliminary investigation during the design of the transfer system showed that the trusses and supporting box columns needed to be independent of the core to avoid transfer of vertical forces from one element to the other, owing to differential vertical displacement. Further, under wind action, coupling of these Belt truss elements would have resulted in large trans­ fers of wind moment and hence axial forces from the core to the columns. To overcome these undesirable effects the trusses are

3. Structural scheme, viewed from the north.

Steel box 4. columns Transfer truss in workshop. 5. Transfer trusses supporting typical floors over terraces (bottom left). 6. Outrigger/belt truss connection 3. at plantroom level. 5. 4. 6.

16 THE ARUP JOURNAL 3/1994 Lateral stability system walls in the plantroom to achieve a stiffness There is no triangulation of the middle truss Architectural planning requirements dictated comparable to that of a steel truss. Such a panels, so deflections due to asymmetric that the service core be limited to the con­ division in the plantrooms was too restrictive loading are controlled by the prestress in the stant 12m width, east-west, over its full on the planning of the building services and cables, the level being set so that no height. In the north-south direction it reduces was therefore ruled out. elements experience compression buckling in stages from 36m to 20m . For the building's Three-dimensional analysis of the building under any load combination .. The prestress overall height of 250m this resulted in aspect using the ETABS computer program showed also provides inherent stability so no lateral ratios of approximately 21 :1 and 7:1. For the that the combined core and outrigger system bracing is required . core alone to resist wind forces, a maximum had the following effect when compared with The roof glass was designed using a non­ aspect ratio of approximately 14: 1 was re­ the core acting alone: linear finite element analysis package; subse­ quired for the necessary strength and • reduction of 40% in the tip deflection quent testing confirmed the calculated stiffness to control stress levels, drift and deflections as well as the safety requirements accelerations, so clearly the east-west dimen­ • reduction of base bending moment in of the overhead glass.The glazing consists of sion was inadequate for this height. The the core of approximately 20% double glazed units with internal channel options considered to solve the problem • change in the first mode of vibration spacers, the channels enabling a partially were: to a lower amplitude excitation captive but flush glazed system. The glass is • Increase the width of the core. • reduction in the induced wind set in a purpose-designed aluminium suite ·! • Provide a tube-in-tube system by modify­ accelerations to a less perceptible level. which allowed easy replacement of individual ing the fac;:ade with additional columns. glass units. Cladding The flimsy unstressed trusses were assem­ • Strengthen the core with outriggers Arup Fac;:ade Engineering were appointed as connecting it and the fac;:ade columns. bled at ground level in a lifting frame, the cladding consultants for the project, with a same one being used for each roof bay. The The first two options were ruled out because brief to assist the architect and project aluminium members were attached , all the they invalidated the brief and architectural manager with aspects of the cladding and to glass apart from edge units was installed, requirements, so the third became the monitor the performance of the cladding and the almost-complete roof was lifted into preferred solution to be investigated. To subcontractor. This included the following position and the trusses stressed. Support compensate for the core's slenderness, pairs tasks: deflections had been carefully calculated, as of steel outrigger trusses span the width of • Review design calculations had the drop in the trusses when depropped. the building coupling the fac;:ade columns and shop drawings for performance. The actual deflections were as predicted. and core. These are 6.5m deep, and are • Review testing of prototype located in the plantrooms, independent of the cladding panels for air and water floors , at levels 30 and 51 . Each truss weighs infiltration and structural performance. 90 tonnes. The bending stiffness of the whole building footprint is thus mobilized to resist • Carry out QA factory inspections wind forces. All shear or horizontal forces are of panel production. retained in the crosswalls of the core with the • Carry out site inspections of panel fac;:ade columns, providing a push-pull installation. reaction. To mobilize effectively the external columns, 8m deep belt trusses cross the east A separate commission was also given to and west fac;:ades and form part of the Arup Fac;:ade Engineering to help select the stabilizing system. Each truss weighs 135 granite for the main tower. tonnes. This included site visits to a quarry in India The outrigger trusses were intentionally offset and a close monitoring of the stone strength from the core crosswalls so as not to throughout production. constrain the wall locations and hence affect Foyer roofs and loggia screens the core planning. They pass through the Arup Fac;:ade Engineering carried out full core and are only connected to the major design and documentation to the level of longitudinal walls through steel inserts cast-in shop drawings for the glazed roofs over the to act integrally with the core structure. entrance foyer to GPT and the screens in the The estimated long-term differential shorten­ loggia between GPT and Governor Mac­ ing between the perimeter columns and the Quarie Tower, together with their tensioned service core is 30mm. Movements of this support systems. order, if not allowed for, would result in signi­ Foyer roofs ficant loads being attracted to the outrigger The foyer roofs consist of three 10.5m x which as a result would become over­ 10.5m bays. Each is supported by five cable stressed. To control this differential move­ trusses spanning from the building core to ment, flatjacks and steel wedges were in­ the main perimeter column lateral support corporated at the junction of the outrigger beams. The truss consists of 23mm diameter truss to the belt truss column. This enabled duplex stainless steel rods kept apart by the connection to be released and re-wedged stainless steel struts. Stainless steel castings at a number of stages during the construction were used for the nodes connecting the period . Finally, the flatjacks were grouted up cables, struts and glazing. Though they to form part of the permanent connection. allowed for architectural expression, the use The choice of steel versus concrete for the of castings did not prove to be expensive system was investigated initially. Concrete and, in addition, they solved the problem of outriggers would have had to be full height in-plane cable crossover. ... a. 7. Plan showing glass roofs and screens. Foyer with glazed roofs and cable trusses. ~ 9. Close-up of foyer roof bay.

--- --' Glazed I foyer I roof , -- - ., Side screen Loggia entrance ~ screen '---!---.__-~

THE ARUP JOURNAL 3/1994 17 12. Screen truss strut and connection detail, showing 19mm truss rods and 9.Smm glazing rod.

13. Cable truss node casting.

14. Stress distribution in foyer glass.

Loggia screens Conclusion 10. Loggia screen to exterior (Farrer Place). The loggia area provides a common entrance The landmark GPT project was completed on space for GPT and Governor MacOuarie budget and within the two years and nine Tower. The two main entrance screens. 12m months programmed construction time. and 9m high and each 8.5m wide, have three Experience on the project showed that for vertical trusses, whilst the side screen, 12m high-rise buildings up to 70 storeys where the 11 . Courtyard loggia screen. high and 8.5m wide, has two vertical trusses. service core alone is too slender to resist The vertical glass joints and truss nodes are wind or earthquake forces. the introduction of at 2 m centres. The entrance screen trusses outriggers to mobilize the total footprint of the are of similar configuration to the foyer roof building should be investigated. Two levels of trusses, one of the design requirements outriggers appropriately located in the tower being the re-use of the roof truss castings. would generally suffice. It should be noted. Whereas the roof glazing has continuous sup­ however, that this solution may not be appro­ port, the screen glazing is supported on cor­ priate if extreme lateral forces such as those ner patch fittings attached to the truss via a associated with typhoons exist. stainless steel cruciform casting, the only new casting for all of the screens. The screen A jump-start system can, under certain cir­ trusses also have a 9.5mm diameter vertical cumstances, result in significant time savings glazing rod which takes the dead load of the to the overall construction programme. The glass. Again, the asymmetric loading is marginal increase to the structural cost is mainly resisted by a prestress in the 19mm generally well off-set by the saving of the diameter rods with some help from the verti­ builder's preliminaries associated with the cal glazing rod (See Fig .12). time saving and earlier rental returns. The foyer roofs and loggia screens demon­ Local stresses around the glass patch fittings strate that with careful analysis and design, were checked using finite element analysis. It innovative but relatively inexpensive glass was found that standard proprietary glass roofs and screens of large area and high patch fittings were unsuitable, as the charac­ 'transparency' can be built. teristic high deflections of the cable trusses Credits and the rigid connections of the proprietary Client: fixings resulted in excessive local stresses in State Authorities Superannuation Board the glass at the fixings. Various combinations Architect: of compressible washers and gaskets were Denton Corker Marshall considered but they all proved unsatisfactory: Structural engineers: the only solution was to use a true pin con­ Ove Arup & Partners John Nutt, B,11 Thomas, Chezy Tang, nection. This was a considerable problem as Ch11s Smith, Jim Forrest Arups were only asked to carry out this part of Fa9ade engineers: the design at the last moment and the cast­ Arup Fa<;ade Engineering John Perry Tristram Carfrae. ings were already under production . The Neil McClelland M,ke Gwodz Pro1ect manager: solution was to use a standard pin joint that is Colin Ging an Partners common in mechanical engineering applica­ Buildef' tions, and the pins proved to be easily Grocon obtained and inexpensive. All the trusses for Curtain wall sub-contractor: one screen were assembled on lifting frames Permasteelisa and simultaneously stressed. Careful analysis Foyer roof and loggia screen sub-contractor. was again needed for the support deflections Hudson Pacific as a good knowledge of the support stittness Illustrations: is crucial for calculating the required pre­ 1, 4-6, 8, Photos: John Gollings. stress. The predictions were complicated by 2, 7: Dennis Kirtley. the fact that all the truss supports were differ­ 3: Tristram Carfrae. ent, both between the screens and within the 9-13, Photos: David West. screens. The glass was installed once the 14: Neil McClelland. trusses had been stressed, the glazing rods being prestressed to remove the glass weight deflections in the trusses.

THE ARUP JOURNAL 3/1994 1. Aerial view of Canon's Marsh.

Planning brief Although various redevelopment proposals were made earlier. it was not until 1984 that the City Council produced a Planning Brief with a strategic plan for a comprehensive approach to the area's regeneration. This proposed that Canon's Marsh should be­ come Bristol's main centre for the arts, leisure. and recreation. and envisaged the creation of a series of public pedestrian routes and spaces linking it both to the City and ultimately to the other side of the Floating Harbour via a ferry and a new bridge. The Planning Brief did not support ottice­ building in Canon's Marsh. but with little progress due to lack of public funds for the activities envisaged, the City recognized that a corporate building for a major company was the only realistic way forward. provided that certain undertakings on its impact and contribution to the area could be agreed. After extensive negotiations between Bank and City, as well as a public enquiry over the closure of Butts Road which divided the site, Arup Associates produced a development strategy including proposals for all the building forms plus public spaces along the quayside. Outline Planning Permission was granted in April 1987. Amphitheatre The design team considered it vital that the new development should not be restricted by Lloyds Bank, Canon's Marsh, Bristol ownership and road boundaries inherited from the area's previous dockyard function Stuart Mercer Terry Raggett Peter Warburton and that, wherever possible, the buildings should be sited and formed in response to the new regeneration opportunities. In parti­ Introduction and to respond to the dynamic changes then cular, these included a progression of com­ With the increasing office rents in Central taking place in the banking business, a sophis­ plementary civic spaces not evolved from the London during the mid-'80s and the expiry of ticated, advanced technology building was needs of the past but anticipating those of the leases on several of their City offices, Lloyds needed. with a high degree of interior flexi­ present and future. To achieve successful Bank decided to relocate and group their bility for either open or cellular office spaces external spaces on a site for which public retail banking activities together on a single throughout. expectation was high was thus paramount. site outside the capital. In November 1986 The site and largely determined the building form f6r Arup Associates were appointed to design Canon's Marsh is an area of flat. reclaimed, Phase 1. this new headquarters building on land at low-lying land, bordered to the north by The City wanted a major public assembly Canon's Marsh in the centre of Bristol. In May higher ground where Bristol Cathedral stands, space on the quayside, at the key point of the 1988, the two seven-storey tobacco bond and beyond by Brandon Hill and Park Street Rivers' confluence, and so a 60m radius, warehouses that had dominated the site with their dominant respective silhouettes of crescent-shaped, open-air amphitheatre was since the 1930s were demolished, so that the Cabot and University Towers. The re­ provided, with the public's relationship to the construction could commence. mainder is enclosed by the historic 'Floating waterside enhanced by lowering the harbour The brief Harbour'. The site itself covers some Sha in a wall within the amphitheatre's limits. Stepped, Offices for 1400 staff were required, plus vari­ Conservation Area overlooking the conflu­ precast concrete seating units are ranged ous support facilities, all adding up to a gross ence of the Rivers Avon and Frome. This along its outer edge, and a semicircular stage area of 23 450m2, with some 650 car-parking forms the focal point of the old Dockyard, was formed at the original quayside level spaces. The development was required in whose industries used to cover most of around a listed structure - the Weathervane two equally-sized phases, the first designed Canon's Marsh but had, with the advent of Tower - at the focus of the crescent. Large to stand alone in case the second was never modern shipping in the post-war years. de­ ramps provide direct routes for both the dis­ built. To satisfy the demands of Lloyds Bank's clined rapidly, resulting in semi-dereliction abled and public utility and emergency organization and communication operations, over much of its area. vehicles to the amphitheatre. The City has ambitious plans for this space to be the main assembly point for spectators of waterside activities such as powerboat rac­ ing, concerts. music festivals, regattas, and firework displays. It is clear of obstructions so that large groups of people can congregate, and anchorage points are integrated with the paving to allow temporary structures such as seating stands and marquees to be erected for special events. The lowered level also pro­ vides safe access onto the ferry, a landing point established for official and ceremonial occasions, as well as floating pontoons to extend the usable level out onto the water for particular events.

2. Phase 1 and amphitheatre viewed across the 'Floating Harbour'. THE ARUP JOURNAL 3/ 1994 19 3. New view of the cathedral between Phase 1 and Phase 2 .

• 4. Detailed elevation of Phase 1. 5 . ... Phase 2 courtyard

6. Site plan 1 Main entrance 2. Restaurant 3. Phase 1 4 Amphitheatre 5 Phase 2 6. Quayside 7 Future building 8 'Floa11ng Harbour' 9 Surface car park

8

20 THE ARUP JOURNAL 3/1994 Building form 7. Main entrance hal l. To define and visually enclose the amphi­ theatre, Phase 1 is crescent-shaped. Although an unusual geometry for office buildings, this is an architectural form not uncommon in Bristol, most notably in Georgian terraces in Clifton and the City Council House. The Plan­ ning Brief stipulated opening up a new sight­ line of Bristol Cathedral across the harbour, as well as preserving all existing views. Be­ tween them , these factors determined the limits of the crescent form. At the southern end , the Phase 1 building is within 20m of the dockside, a spatial restric­ tion that provides a 'threshold ' through which the public pass from the amphitheatre to the further series of quayside spaces. A future building envisaged by the City on the space between the northern end of Phase I and the quayside will , in due course, provide a similar 'threshold' to the amphitheatre and so complete its visual containment. The building is limited to three storeys, to keep within the height constraints laid down by the planning authority. To avoid deep office spaces, it is divided along its linear axis into two parallel office floors of 12m span, each arranged on either side of a full-height , top-lit galleria forming an internal street separating and serving the two office areas and containing all the secondary circulation. The brief requirement for two distinct phases meant that the massing of a large single monolith could be avoided. Phase 2, although not so restricted by site boundaries or sight­ lines as Phase I, is circular in plan to comple­ ment its neighbour: the radial forms give a common yet distinctive identity to the two phases. They are set some 20m apart, with the main entrance located in this space in a single-storey structure, permitting a new sightline to the Cathedral. The converging convex forms create a generous approach and natural focus to the main entrance to the north, and an ideal location for restaurant facilities looking south onto the quayside. Phase 2, also of three storeys, is some 80m in diameter, with primary internal circulation arranged around its inner perimeter serving Car parking/delivery sense of place and orientation as well as to 15m-deep office spaces on one side and Harbour Way, a new road on the western foster a corporate community. Introducing overlooking an internal open landscaped edge of the site, provides access to a 325- spatial hierarchies within offices creates clear court on the other. This green 'private' court­ space surface car park and connects territorial boundaries and can thus overcome yard, over 40m in diameter, provides an Canon 's Way to the existing 'A' shed as well the greatest single objection to modern 'open' important counterpoint to the hard-surfaced as, ultimately, to future development on an office interiors - the invasion of group and 'public' space of the amphitheatre, and is adjacent redundant Gas Board site . A new individual social territories by 'outsiders' intended to ensure that Phase 2 is not con­ north/south public walkway to and from the wandering through on routes with no clear sidered by staff as the 'poor neighbour' to quayside runs between this car park and definition. These routes do not require the Phase 1. Phase 2. A secondary staff entrance on the same sophistication of lighting, electrical The ground floors of both Phases are raised latter's west side provides access from this servicing, air-conditioning , or sub-division some 1. 8m above the quayside level to avoid walkway into the Phase 2 offices. capability as the office spaces. This provides any possibility of flooding. The resulting A further 217 spaces are provided in a cir­ an overall cost benefit for the office spaces, defining the working zones within which terrace defines a natural line for the new cular car park beneath Phase 2, accessible boundary to the Lloyds Bank site and creates on the north from a ramp by the main columns should be avoided if possible to provide maximum flexibility. an effective and natural separation between entrance. Lifts and stairs give direct access the private functions of the office spaces and from th is car park to the office levels above. The main entrance hall, containing the waiting the public domain. area, reception counter, and visitors' wash­ 18 spaces of visitors' surface parking are Phase 2 quayside rooms, is circular, with a central glazed roof arranged on both sides of the main entrance lantern from which two radiating primary cir­ The present large quayside space in front of forecourt. A fu lly-enclosed, three-bay truck culation routes originate. These give direct Phase 2 will accommodate two buildings dock inside Phase 1, with immediate vehicle access to the respective main cores in each under City ownership intended to promote access off Canon's Way, serves both phases Phase. In Phase 1 this route follows the cres­ and encourage the tourist and leisure activi­ by means of an underground link to distribute cent form , with views focusing on the ties in the area. A 250m2 single-storey struc­ goods and services. Phasing and costs of Weathervane Tower in the amphitheatre. In ture for a restaurant/fast food facility is envis­ excavation in ground with a high water table Phase 2, it follows the radial geometry of the aged at the eastern end, with a 2500m2 made it impossible to put the truck docks plan with views directly into its open land­ two-storey building set alongside the existi ng anywhere other than near the main entrance. 'A' shed sited at the west. An original pro­ scaped courtyard . Along these enclosed posal for extensive tree-planting in th is open However, the potential problems of such routes, three-storey high side-lit atria space quayside area as a visual contrast to the close proximity have been overcome by the signals the thresholds of the respective office amphitheatre, so enhancing the variety of complete enclosure of the delivery bays, buildings. The staff restaurant is accessible spaces, was rejected by the City on the careful design, and good management. directly from the main entrance. grounds that space was needed for public Internal circulation Phase 1' s main service core, containing pas­ activities. The quayside area therefore has a Large buildings, particularly those with com­ senger lifts , service risers, and washrooms, series of areas defined by limited tree plant­ plex working communities like big corporate frames the route, opening out to create a cir­ ing to enable the erection of marquees and offices, should provide a spatial organization cular top-lit space at its intersection with the seating for these major public events. Time and comprehensible structuring of both pri­ galleria. The circulation routes on the upper will tell if this was the right decision. mary and secondary circulation to create a two floors take the form of galleries along the THE ARUP JOURNAL 3/1994 21 edge of the galleria with bridges across the The screen sits on a 1.8m high Terrace An aluminum-framed walkway for mainten­ space connecting to the staircase at the formed in split-faced precast reconstituted ance access at second floor level also gable ends. granite blockwork with a matching precast visually obscures the 1.5m high aluminium coping, on a base of piers in rusticated St spandrel panels of the curtain wall and offers Similarly, the main service core in Phase 2 Maximin saw-faced limestone with Euville solar shading to the office windows below. frames the axial route from the main entrance, stone plinths. These piers are linked at first Polyester powder-coated, aluminum, full­ but intersects with the secondary route on the floor level by an interlocking series of precast height, clear double- glazed curtain walling outer edge rather than the centre of the build­ lintels and column bases using white cement spans the two upper office levels, with lroko ing. Here, a three-storey conservatory con­ and Balladon aggregate and having a tooled timber-framed windows in the openings tains a reception area with a staircase to all finish. Through their depth and solidity, the between the piers on the ground floor. the perimeter circulation levels above. Two piers provide an important visual weight to secondary cores housing service risers and the screen at its base as well as being the Although the overall development pro­ stairs are located off this perimeter route. By 'threshold' separating the public quayside gramme was extensive, the construction time variation in volume, light and outlook. the areas and the private office spaces. The available for the two individual Phases was articulation of these circulation routes creates ground floor internal height is 300mm greater very short. The prefabricated curtain wall ele­ a natural progression from entrance to work­ to compensate for the more limited outlook at ment made it possible to enclose the building station. intended to make the overall building this level. at an early stage to provide a weatherproof easily understood and efficient to use. environment for services installations and A two-storey high, double-column. similarly interior fit out to proceed, while the more External fa~ade precast colonnade surmounts the piers. traditional construction of the colonnaded The extensive views across and beyond the These are set at approximately 4.5m centres screen and masonry walls could continue at Floating Harbour, as well as of Bristol Cathe­ to provide scale and rhythm to the fa9ade, their pen pace and so achieve the perceived dral and Brandon Hill, suggested that the which a curtain wall with its mullions at con­ hand-made quality appropriate to the offices should be fully glazed, particularly stant 1.5m centres to suit the internal office surrounding conservation area. above ground floor level, to satisfy the expec­ planning module fails to give. The twin tations of staff relocated from London. How­ columns impart an apparent transparency Structure ever, large areas of glazing on the outside when viewed at right angles from the interior. Canon's Marsh is an historic landfill site and were not considered appropriate, given the giving the views sought by the staff, whereas has seen many cycles of industrial activity. dockside landscape setting in the heart of a the colonnade visually closes from oblique The fill , generally 2-4m thick, contains rem­ city whose most prominent buildings are in external viewpoints to create the illusion of a nants of these activities and so varies in stone. This urban context, and the significant solid but articulated masonry wall , as sought quality and type. The underlying natural strata function of the building in forming major pub­ by the planning authority and public opinion. comprise a thinnish crust of firm to stiff clay lic spaces, necessitated an appropriate 'civic' above softer alluvial deposits which in turn quality in response to the surroundings. A lead-finished, timber-framed canopy is overlay Keuper sandstone at about 12-14m supported by a twin steel column-and-stay depth. Following the design team's similar approach assembly, fixed to an acid-washed. precast for Legal & General's new building at Kings­ concrete capital linking the tops of the double The concrete-framed warehouses had been wood1 - where a free-standing landscaped columns. This canopy provides solar shading founded on the clay crust with massive pergola screen was adopted as an extension to the upper office floor; its eaves, 12m above spread footings . A much simpler and more of its rural context - an articulated masonry the quayside level, reduce the building's predictable approach was chosen for the screen was constructed in front of the offices' apparent scale as well as conforming to the new buildings, which involved driving pre­ glazed curtain wall , as an extension of the height limitations stipulated by the planning cast, 300mm square section piles into the Lloyds Bank building's urban role. The same authority. A precast parapet unit set back on sandstone. Small section piles were chosen type of masonry screen was used to unify the the line of the main building completes the to make it easier to avoid existing obstruc­ fa9ades of both Phases. elevation. tions, and precasting overcame problems 22 THE ARUP JOURNAL 3/1994 8. Phase 1 galleria. The shear walls of the Phase 1 cores were arrangement gives an even illumination on the sides of the ceiling rib and provides the 9. Route leading to Phase 2 from constructed in concrete with blockwork inter­ main entrance hall with courtyard beyond. nal walls. This proved time-consuming and desired cut-off angle of light from the lumi­ tied up resources. In Phase 2 the cores were naire to eliminate surface reflections at desk 10. Phase 1 ribbed in situ reinforced concrete constructed as structural steel cages with level and on VDU screens. Control is by a ceilings with precast cantilever walkways. concrete accommodation platforms having a Oelmatic system with individually program­ 11 . Phase 1 masonry details. void-to-platform ratio of about 1: 1. All but the mable control cards in the spines of the light­ external walls are fabricated from metal stud­ ing fittings. On both sides between the rib 12. Meeting area, ground floor, Phase 2. work and the link building between the two and the fitting , preformed, self-finished 13. Phase 2 offices and precast cantilever Phases is of in situ concrete. acoustic panels limit sound reflections into walkways overlooking courtyard. the office space. Ottice partition can be fixed Dock water to both the luminaire and the acoustic panels The heating and cooling system uses the on the 1.5m internal planning module. By dock water, the temperature of which varies integrating the lighting, acoustic panels, and from 19°C in summer to 0°C in winter. When air extract ducts between the ribs, the cost the water is below 12°C it is used to cool the and programme time for installing a conven­ computer rooms . In summer, when the out­ tional suspended ceiling was avoided. side air temperature is above 18°C, it is used to reject condenser heat from the refrigeration The restaurant and main internal circulation plant. In spring and autumn, it is used as a routes are lit by low voltage dichroic lamps to heat source for the refrigeration plant eva­ emphasize the different quality and function 13. porators so that the plant can operate as a of these spaces. heat pump. In winter, the heat pump co­ All power, data and telecommunications efficient of performance cannot compete with cabling for the office is run in the raised floor free heat from the cogenerators. Should the to a regular grid. Instead of using traditional dock freeze over, gas-fired boilers meet outlet boxes in the raised floor, a special cir­ demands. cular brass casting was developed for the The intakes are in deep water between the controlled passage of cables into the central surface level refuse and the bottom sediment. spine unit of the desking system. Trays incor­ At the suggestion of the local Dockmaster, a porated into this spine allow cables to be fully reversing design was installed: as the neatly supported and adequately segregated system is reversed, the strainer on the ex­ from the floor void to the desk-mounted haust, which was the intake, is automatically equipment. The service spines are concealed flushed clean. To use the dock water, a way­ by panels that can be easily removed by leave was necessary to penetrate the dock service personnel. wall and a licence to extract the water was Conclusion needed from Avon River Authority. The Lloyds Headquarters has brought a sig­ Mechanical services nificant improvement to the prime site in the The major plantrooms in Phase 1 are located historic docklands and has acted as an under the galleria space and at roof level important catalyst to the future development above the central core. In Phase 2 they are of this largely derelict area. The City of Bristol along the outer edge of the underground car has now adopted a new strategic plan retain­ park and behind screen walls at roof level. ing a predominance of arts and recreation Service cores at the ends of the office areas use but with a balance of commercial and feed conditioned air into a 600mm raised residential development. It has the agree­ from the high water table. The suspended floor plenum, from where it enters the space ment of all interested landowners and a great ground floor was raised above flood level through adjustable twist air outlets. These can deal of public support. and constructed of precast units spanning be relocated simply by transferring the floor Finally it is interesting that, despite the reser­ about 11 m between the pile cap strips. tiles that incorporate them to suit any new vations and objections of Bristol's conser­ office layout. Around the external perimeter, The basement construction for the car park in vation groups during the planning stage, fan coil units in the floor void provide heating a major opinion poll on the City's architec­ Phase 2 comprised a 600mm piled raft, thick­ and extra cooling; flexible connections allow ening to 900mm under the line of the principal ture undertaken by the BBC in summer these also to be repositioned to suit new desk 1994 established that Lloyds Bank is clearly office column structure. The potential prob­ layouts. The units incorporate a damper lem of flotation under maximum flood con­ the Bristol public's most favoured post-war which, during cooling, takes air from the ditions is counterbalanced by the dead building. plenum and directs it up against the glazing. weight of construction, with the tension References Air is extracted through ducts integrated with anchorage of the precast piles providing a (1) BONNER, M. and FERGUSON, D. Legal & the luminaires and passed to header ducts factor of safety for exceptional conditions. General, Kingswood: Architecture in landscape. within the raised floor above, which connect The Arup Journal, 27(4), pp.3-9, Winter 1992-93. The client had liked the concrete radial rib to the main air risers in the service cores. (2) BONNER, M. and RAGGETI, T. Leslie & God­ construction integrated with lighting and Air enters the ottice space at 18°C-22°C win. Farnborough, The Arup Journal, 20(2) , pp.2-8, extract systems used at the Leslie & Godwin Summer 1985. 2 depending on the outside air temperature. building, Farnborough , and this approach Through the stabilizing effect of the exposed Credits was developed further at Canon's Marsh, to concrete troughs, conditions in the occupied Client: optimize the structural opportunities pre­ Lloyds Project Construction Co. Ltd. areas are maintained within the comfort for Lloyds Bank pie sented by floor supply ventilation and the bands without the need for terminal unit requirement for clear span space: nominally Designers: thermal control. The machine ottice cooling Arup Associates 12m and 15m for Phases 1 and 2 loads, from 20W/m2 average to 40W/m2 peak, respectively. Architects + Engineers + Quantity Surveyors can be simply accommodated through pro­ Landscape architects: In situ, post-tensioned radial ribs run between vision of twist air outlets. Peter Swann Associates perimeter beams on circular concrete columns Heat recovery is provided between the ex­ Management contractor: at 4.5m centres. The ribs were cast off high haust air duct and the air intake in the plant­ Bovis Construction Ltd. quality reinforced glassfibre moulds to pro­ room. The kitchen, restaurant, and computer Illustrations: vide a finished surface for painting. Multi­ rooms have separate air-handling plants. 1: Sealand Aerial Photography. strand post-tensioning tendons were used, 2, 5, 9: Peter Cook. Electrical services 3, 12, 13: Roger Ball. stressed in two stages and subsequently 4, 7: Rupert Truman. grouted to form a fully-bonded system. This Two diesel generator sets in each Phase pro­ vide 100% standby power capacity, supply­ 6: Declan O'Carroll avoided the need to camber the floors and 8: Jonathan Moore. the moulds, and allowed a faster turn round of ing heat and electricity to the building during 10, 11 : Helene Binet. moulds - and thus fewer of them, lower cost, the winter months. When tariffs are favour­ and a quicker erection sequence. The ten­ able, electricity is also exported into the dons were designed to balance the loads South Western electricity system. imposed by the next level of construction, Continuous linear air-handling luminaires in thereby avoiding the need for backpropping. the ceiling troughs between the ribs incor­ Precast ribs were considered, but the inner porate smoke detectors, emergency lighting, city location inhibited their economic use. and sprinkler heads. These were specially However, cantilevered precast walkway units designed for the ottice spaces and provide do form the primary circulation balconies. an average 450 lux at desk top level. This THE ARUP JOURNAL 3/1994 23