I THE ARUP JOURNAL

2/1995 Front cover: Lille TGV station roof and fa<;:ade (Copyright SNCF - Direction de THEARUP l'AmenagemenVMichel Denance) Back cover: Satellite image of the Thames and London (Photo: Department of JOURNAL Transport/Engineering Surveys) Vol. 30 No. 2 Editor: 2/1995 David J . Brown Art Editor: Published by Desmond Wyeth FCSD Ove Arup Partnership Deputy Editor: 13 Fitzroy Street Helene Murphy London W1P 680 Editorial: Tel: 0171 636 1531 Tel: 01714653828 Fax : 0171 580 3924 Fax : 0171 465 3716

Eura Iii le: Euralille is a massive trade centre at Lille in north east France, the TGV station roof 3 whose construction was brought about by the selection of that city Sophie Le Bourva as the hub of the Paris-London and Paris-Brussels TGV rail lines. Jane Wernick Amongst several Arup commissions connected with Euralille, the firm was appointed to design the structure and cladding for the roof and fa9ades of the new TGV station constructed as a central component of the complex.

The Tees Ove Arup & Partners Newcastle designed the structure for this Barrage Bridge 7 eight-span tubular steel arch bridge, conceived as the visual focus Neil Carstairs of the new tidal barrage which is a key feature in the regeneration David Stevens of a derelict former engineering works at Stockton-on-Tees. The design deliberately recalls and celebrates the area's importance in the history of iron and steel engineering.

A strategy for the Arups were asked by the Government Office for London to River Thames 11 undertake a detailed study of SOkm of the Thames, from Hampton Michael Lowe Court to Greenwich, in order to make recommendations for Corinne Swain enhancing the riverfront environment, protecting areas of historic importance, promoting high quality new buildings and landscaping, and generally improving access and amenity.

The Western This new privately-financed immersed tube road tunnel is the third Harbour Crossing, 15 link between Hong Kong Island and the Kowloon mainland. Ove Hong Kong Arup & Partners Hong Kong are acting as the Western Harbour Eric Poon Tunnel Company's project co-ordinators, with responsibility for David Snowball overseeing the work of the contractors and design consultants as well as liaising with Government and other bodies involved.

The Pavilion, Ove Arup & Partners Manchester carried out the structural Blackpool 19 engineering design of this conversion of the former Lewis's store Steve Burrows on the seafront at Blackpool, next to the Tower, into a mixed-use Rick Houghton trading/leisure building. The project included the creation of a new Mike Robinson 2400m2, two-storey space at the building's heart.

St. Mary's Car Park, Through careful attention to layout. lighting, finishes, and security, Sunderland 21 this award-winning building has been described as setting new Ray Noble design standards for safety and convenience of customers. Ove Malcolm Shaw Arup & Partners Newcastle were responsible for the project management and the structural, civil, and building services engineering design.

2 THE ARUP JOURNAL 21 1995 Euralille: the TGV station roof Sophie Le Bourva Jane Wernick

Amongst several commissions stemming from the masterplan for the Euralille centre (see 'Background' below}, Ove Arup and Partners International Ltd . were appointed as the Ma'itre D'oeuvre particulier for the roof of the TGV station, including the structures, the fa<;:ades and the cladding. This contract was for an 'M2 plus' mission, which meant in effect a prime agency role for all phases of the work from concept design to completion. In the development of the structural design for the roof, Arups worked closely with French Railways (SNCF}. RFR were sub-consul­ tants for the design of the roof covering. The station is on the left of the aerial photograph below, straddled by the boot-shaped Credit Lyonnais and World Trade Centre buildings. To the right is the large wedge-shaped Euralille Centre, and in the distance on the right the oval Grand Palais.

1.

Background the much larger and more Elements of Euralille steel and glass roof which allows 2 Robert Pugh ambitious scheme of Euralille. By the end of 1994, 250 ooom of the trains to be seen from the city; A mixed private/public client body new development and associated capacity 15 OOO passengers called SAEM Euralille was formed in infrastructure, comprising the first per day. Origins of Euralille spring 1988, and an architectural phase of the masterplan, and • The World Trade Centre Tower - Lille, in north east France, is the competition launched to masterplan including the new station, had been 20 OOOm' of office space. built (Fig.1). This comprised: country's second largest metro­ the 70ha site identified for the new • The Credit Lyonnais Tower - politan district, with some 1.5M TGV station and associated • The Euralille Centre - 100 OOOm' 15 OOOm' of office space. inhabitants. Historically focused on commercial development. of commercial space for retail , • The Rue Corbusier Viaduct - coal mining and its attendant indus­ The Dutch architect Rem Koolhaas recreation, ottice, and residential tries, this socialist heartland with a use, with underground parking for 0.5km of elevated dual with his firm , Office for Metropolitan carriageway. large immigrant population had high Architecture (OMA), supported by 3500 vehicles. unemployment following the demise • The Lille Grand Palais - Ove Arup & Partners, won the • The TGV station - c500m long , of 2 of its traditional industrial base. competition in November 1988. which some 300m is covered by a 50 000m entertainment. Following the January 1986 agree­ conference, and exhibition centre. ment between England and France 2. Lille as the hub of the TGV network. • Multi-storey parking garages - to build the Channel Tunnel, signed 1500 spaces. by Franc;:ois Mitterand and Margaret The TGV now links Lille with Paris Thatcher in Lille itself, the Mayor of and Brussels in an hour, London in the city, Pierre Mauroy, saw oppor­ two hours, and soon Amsterdam tunities for local regeneration flow­ and Cologne in two hours (Fig.2}. ing both from the Tunnel and from Lille has become, as Rem Koolhaas the northern European and cross­ has described , a 'virtual city' of Channel TGV (Trains a Grande 1OOM people. Vitesse) system launched at the same time. A former Prime Minister Frankfurt Arups' involvement of France, Mauroy formed an asso­ 3h10 Ove Arup & Partners have ciation called 'TGV - Gare de Lille'. contributed to three aspects of mobilising the city and the region to Euralille: canvass for the TGV route between • Masterplan feasibility, Paris and the Tunnel. After furious design development, and lobbying, the then French Prime developer specification: Minister Jacques Chirac announced (building, civil , geotechnical, fire, in December 1987 that Lille had and traffic engineering}. been selected as the hub of the • Li/le Grand Palais: Paris-London and Paris-Brussels (building and geotechnical lines. This rail-linked centre of gravi­ engineering). ty for Northern Europe's major cities thus became an ideal location for • TGV station.· trade and commerce and for multi­ Arups' work on the masterplan and national companies, and the Mayor the Grand Palais will be described used the fact of the station to initiate in a forthcoming Arup Journal.

THE ARUP JOURNAL 211995 3 History and architectural choices The architecture of railway stations has a rich history. Their identity was created in the 19th century in the wake of the headlong expansion of steam railways when daring designers celebrated technology and archi­ tecture by using exposed structures to create a bold generation of train stations. About 10 different station configurations were created in Europe and the United States in the 19th century, and remained in vogue for three or four generations. In the 20th century, however, there has been little innovation. In addition, the importance of train stations in cities decreased as a result of the degra­ dation of the train's reputation as the world's fastest terrestrial means of transport. However, the TGV has reinstated this pre­ eminence and, as the SNCF began to develop 3. Another archetypal 19th century French railway station: the Gare du Nord. Paris, in 1847. the network, the opportunity of reviving the The two bays shown still exist; the area into which the TGV trains now run was a later addition, to the right. old position of stations in cities was offered. It was the occasion for the SNCF to think again Various schemes were studied. The final east side of the station and at the level of the about what a station building should be, so design has a smooth, curved metal roof roads serving the station. The main passenger under the impulse of the TGV and of its newly­ which seems barely to touch the transverse concourse, with all the functions of the station appointed chief architect M. Dutthilleul, arches supporting it, the intention being that (ticket hall, circulation, shops customs zone, a charter for the railway architecture was the roof should appear to float above the etc.), is at the intermediate level, whilst the produced in 1987. station like a flying carpet. lower level, which matches the lower ground Its key points were: Structural description level of the piazza on the west side of the ( 1) Stations should look like stations, by The concrete station beneath the roof was station, has two platforms with two tracks referring to and using the existing designed by the SNCF's own architects and each, and the tracks for non-stopping trains archetypes as the background to the engineers, and has three levels which align in the middle. new designs. with the different ground levels around it The arrangement of the tracks determined (2) The archetypes should be expressed via (Fig.4). The highest, which is the main the geometry of the concrete structure, and a contemporary architectural vocabulary, entrance, is at the height of the ground on the the available lines of supports for the roof. expressing the construction techniques. (3) Stations should make people dream. 4. Transverse section. (4) Stations should remain in cities. (5) The organisation of the station should be 'Floating' roof easily understood via its volume. All this, as well as some more local factors, led to the main architectural aims for the Lille station: • The station should be linked to the archetype of the Orsay Station in Paris Entrance level (now Musee d'Orsay), i.e. it should be organised longitudinally, with the platform and the hall being part of the same Main concourse level volume, covered by a vast metal and glass roof. ··· ... • The station should be opened towards (./:\... the city like a 'balcony' and be a Stopping !, Th~ough Stopping showcase for the trains. trains trairis trains i. i.,•...... ) • Obstructions to passenger movement ·,; ·· should be minimised and sightlines kept clear at concourse and platform levels. The space should remain as free as possible of structural supports. Quai Londres Quai Paris • The roof should emphasise the quality of light in this northern region of France. • The roof should be inspired by 19th century metal and glass roofs and be as close as possible to M. Duthilleul's ideal of 'a fine lace floating above the train'. These initial intentions inspired the design decisions for the structures and cladding.

The 50m wide by 300m long roof (Fig.5) is cut into two parts by the road which crosses West the station. The roof is wave-shaped, the curves reflecting the nature of the spaces that it covers: high above the main concourse and lower on either side to shelter the spaces without blocking the views towards the city. The roof is supported by 26 pairs of steel arches, spanning 26.71m and 18.4m respec­ tively, and spaced every 12m longitudinally. This spacing follows the concrete structural 5. Axonometric of complete roof structure. grid, which itself corresponds to the dimen­ The Le Corbusier Viaduct divides the building into two unequal parts between grid li nes 14 and 19. sions of the train carriages. 4 THE ARUP JOURNAL 211995 Fire engineering Behaviour of steel Therefore for the purposes of the fire protection measures. Fire Paula Seever Steel loses its strength as structural analysis on the stability of protection cladding was considered temperature increases and the the roof, it is assumed that the arch undesirable for architectural reasons , In common with many countries in consequences of this loss need to fails and carries no load. The analysis so the alternative was to increase Europe and elsewhere in the world , be studied to understand the stability concentrates on the behaviour of the thickness of the steel in the France does not require that struc­ of a building under fire conditions. the columns. column. tures which support a roof only be The Regles FA 'methode de previ­ The second fire considered was one This makes the column stronger and fire-resisting . In the Lille station sion par le calcul du comportement in a passenger carriage. This is reduces the applied stress. It also structure, however, a rather special au feu des structures en acier'' assumed to be fully involved in fire, increases the critical temperature at problem arose. In France there are gives an engineering calculation with the windows broken and the which the column fails , and allows it particular regulations designed for method for this. In the UK, equiva­ roof intact. to heat up more slowly so that it may lent documents would be BS5950: the protection of high rise (IGH) build­ 2 Flames could emerge and engulf not reach the critical temperature ings which also impose restrictions Part 8 and its associated hand­ over the duration of the fire. book. The Regles FA give the the adjacent edge columns for a on structures nearby. In particular period of 30 minutes. The analysis Accordingly, where the additional they should have two hours' fire critical temperature Tcr at which failure of steel members would showed that the columns would protection was needed the column resistance to prevent fire spread . reach temperatures above the critical wall thicknesses were increased by The World Trade Centre and Credit occur as a function of the applied stress. The Regles also determine temperature for the load which they 5-10mm. In this way the standards Lyonnais towers which span the roof carried. In the case of the locomotive required were achieved , in that (Fig.10) fall under the IGH regula­ the loads which have to be taken into account for fire studies. fire the columns as designed would the structure would survive the fire tions, so the roof below the towers fail. In order to ensure that the but without compromising the and the structure supporting it at To assess the fire behaviour of the columns can survive the design fires architectural uniformity of the these points had to have two hours' structure of the station , a study was it was necessary to propose some column lines (Fig .7). fire protection. As far as the steel undertaken in collaboration with the structure was concerned this would fire laboratory of the CSTB in Marne have necessitated the application of La Vallee. This study fell into three 7. View along the Quai Landres, with the support structure for the Credit Lyonnais on the left. The station structure beneath is some suitable cladding material. principal steps: strengthened to survive a fire but without introducing cladding which One possibility which was consid­ ( 1) Development of design fires compromises the architectural unity of the column lines. ered was the provision of a separate (2) Analysis of effect of fires on structural system suspended from individual steel elements to the tower to support the roof imme­ determine which members fail diately below and on either side of the tower. However, this solution (3) Analysis of the structure under presented a number of potential the fire load case assuming failed difficulties in its implementation, members as calculated in (2). not least of which were its impact Two possible types of fire were on the architecture of the roof below identified which could, in principle, the towers, and the cost involved. seriously affect the steel. The first A fire engineering approach was was a locomotive fire scenario, therefore sought. This sets out to developed by CSTB, in which motor identify what the regulations are oil is assumed to burn . On either of seeking to achieve and to explore the Quai Landres platforms it would alternatives which would meet the be possible for flames to engulf required fire safety standards whilst steel members which form the arch. satisfying the other constraints on The adjacent column would also be the design. The alternative pro­ affected by radiated heat. The arch posed was justified on the basis of members engulfed in flame will technical evidence and calculations. become extremely hot and will fail.

preventing buckling of the arches in their own Roof cladding plane. Out of their plane, the arches are The choice of roofing system had to restrained against buckling by the elements contribute to the 'floating ' feeling as well as that connect them to the roof, and by fixity at provide natural lighting to the station con­ their feet. Member end connections were course. Penetration of light is achieved by the made using steel castings welded onto the incorporation of thin strips of glass following ends of the elements, high strength steels the transverse curve (Fig .8), supported by being used for the rods to keep dimensions curved steel troughs which are in turn carried as small as possible. Since the ties are not by the longitudinal beams. Expanded metal prestressed , they can only carry tension . panels are placed above the troughs to give which means that the structure is non-linear. a smooth, curved surface, with the troughs The analyses of the structure were carried themselves clad with rockwool to provide out using Fablon , Arups' in-house program, sound insulation. No thermal insulation was 6. Interaction between transverse to check element stresses, stability and required. Below this complex skin, a layer of and longitudinal structures. deflections. Also, a wind tunnel study was perforated aluminium panels completes the carried out by the Building Research system. The amount of perforations also To aid the impression that the roof is floating , Establishment in England and was used in varies across the cross-section to enhance the number of connections between the roof certain cases to reduce the code forces. the feeling of the curve. and the arches is kept to a minimum. The arches are made from slender tubes which are stiffened in their planes by an arrangement of ties. The arches support longitudinal roof beams that are also stiff­ ened , out-of-plane, by an arrangement of crossed ties (Fig.6). The connections between the arches and the roof beams are 8. ~ not made in the plane of the arches, but on Elevation of east m either side of them , via the crossed ties , fac;:ade, with inside of »> c which also enhances the 'floating roof' roof clearly visible. " appearance. Longitudinal stability is provided ..g » z by zones of cross-bracing in the roof and > pairs of cross-ties between columns. Across ,- the building, stability is provided by the arches ~ and their non-prestressed ties , the latter also i 5 Fa9ades Conclusion The tac;ades. in comparison, are simpler. Although the total construction of the station They are all open at the top and do not touch took seven months longer than originally the roof (Fig.9). Three different structural planned, it was opened, in May 1994, well in systems were used, one cantilevering from time for the arrival of the first Eurostar trains the ground with vierendeel trusses. one on a at the end of 1994. horizontal torsion member which is attached The construction budget had been set at to the columns of the main structure, and the about FFr90M (£10.?M) at the end of the last as a structurally stiff plane pinned at the design development phase. The contractor's bottom and supported at the top by the roof bid price was FFr76M (£9M), and the final beams.The cladding is made of glazing panels price has remained within budget. of about 1.6m x 2.4m and supported on their vertical sides only by aluminium extrusions. References ( 1} CENTRE SCIENTIFIOUE ET TECHNIQUES DU BATIMENT. Regles FA: methode de prevision par 9. End glazing exterior where the Le Corbusier 10. Below:The Credit Lyonnais (left) le calcul du comportement au feu des structures en Viaduct divides the station: The gap between the tops and World Trade Centre (right) acier. Document technique unifie. CSTB, 1983. of the fac;:ades and roof structure is clearly visible. straddling the TGV station. (2) BRITISH STANDARDS INSTITUTION. 855950: Part 8: 1990. Structural use of steelwork in building. Part. 8. Code of practice for fire-resistant design. BSI. 1990. Credits Client: SNCF Region Nord Architect: SNCF APG (M. Duthilleul) Engineers: Ove Arup & Partners Andrew Allsop, Mike Banfi. Chris Barber. Paula Beaver, Sean Billings. Simon Cardwell . Brian Duck, Ed Forwood , Lesley Graham. Sophie Le Bourva. Alistair Lenczner, Alain Marcetteau. Sean McGinn, Craig McOueen. Chris Murgatroyd, Strachan Mitchell. Neil Noble, Jane Peel-Cross. Peter Rice, Adrian Robinson. Uzzle Sironic. Darren Sri-Tharan. Jane Wernick. Derek Woodcraft Steelwork contractor: NV Buyck Roofing contractor: Laubeus SA Illustrations: 1, 11 : NAI 2, 4, 6: Trevor Slydel 3: Mary Evans Picture Library. 5: Derek Woodcraft. 7: Photo Poteau 8: Sophie Le Bourva 9, 10: Peter Mackinven

11 . Interior of the station looking down on the main concourse.

6 THE ARUP JOURNAL 2/1995 The Tees Barrage Bridge Neil Carstairs David Stevens

Introduction 1. In September 1987, the then Prime Minister. Architect's Margaret Thatcher. took a 'walk in the wilder­ competition model. ness' at a derelict engineering works in Stockton-on-Tees in the north of England. She promised government assistance to develop the 100ha site. and it later became one of the 11 flagship sites of Teesside Development Corporation (TDC).

The River Tees is tidal here, and TDC de­ North River South cided that a key element should be a bar­ approach crossing approach rage, so that the unsightly mudflats exposed bridge Pavilion bridge Pavilion bridge at low tide would always be covered. In late 1990 the Napper Collerton Partnership won a competition organised by TDC for the archi­ tecture of the barrage, the centrepiece of which was an elevated tubular steel arch bridge. Ove Arup & Partners subsequently Canoe won the fee competition for its engineering slalom pass design organized by Montgomery Watson 2. General arrangement of bridges. Ltd ., the main consultants. who subsequently appointed Arups as sub-consultant for this element of the work. 3. Design development. Architectural concept The architects' concept incorporated four main principles: • To create a structure to signal the area's regeneration. celebrating the importance of the barrage and the crossing. The bridge would be an event both in itself and as seen from adjacent bridges. Concept • To build it in structural steel, to reflect the great Teesside tradition embodied in the local Transporter and Newport Bridges. • To make a dynamic visual contrast between the massiveness of the concrete barrage piers and the airy filigree tracing of the bridge. Using such a principle it would complement rather than dominate nearby recreational uses of the restored landscape. First solution • To carry the steel motif across the adjacent navigation channel, access roads, fish pass, and canoe slalom, until natural ground level is reached. It was concluded that a simple structural concept, drawing on the examples of early ironmasters. would best achieve the archi­ tectural principles, with each span a series Final solution of tubular steel arches, supporting circular infill members. The other main components Arches and infills of the competition entry were masonry-clad The first task was to determine the structure's gave a long length of connection, and the pavilions at each end of the river crossing, behaviour and the fabrication method. Cold tubular appearance of the smaller tube was and a tower of lights on the central pier bending of tubes to the radius required for lost over this length. A constructive dialogue announcing and celebrating the entrance to the infills was impractical, as was forming a between the engineer, who knew what was the Teesdale site. structural connection between two tubes ide­ possible, and the architect, who knew what Scheme design ally touching at a single point with a common he wanted, led to the circles being separated Ttie main bridge has four 17.Sm spans. At tangent. A cast steel solution was thus devel­ at the joints, and a flat 'plate' section intro­ each end the road crosses the roof of the oped. with the nodes cast separately and duced between them to form the connection. barrage pavilion and then an approach joined with tube-to-tube butt welds. A simple The number of infills was reduced and a bridge with two identical 17 .Sm spans. The computer model showed, however, that both clear space left between them, to maintain bridge is 160m long overall and carries a the arch ribs and the circular infill members the structure's 'transparency' (Fig . 3). single carriageway road. The arches rise Sm needed to be significantly larger than in the Articulation to clear the navigation channel and service competition entry. The addition of casting At the piers the tubular arch members are roads (Figs. 1 & 2). radii where the two tubular sections 'touched' joined together and pinned to the supports This concept had to become a structure using purpose-made knuckle leaf bearings. meeting highway loading requirements. TDC 4. Final arch make-up. The form of the steelwork. with no vertical specified that the bridge should carry the element at the piers, meant that the bridge highest standard loading specified by the had to be made continuous with no move­ Department of Transport so that future indus­ ment joints, which also- reduced the risk of trial development would not be restricted by water containing road salts leaking on to the its capacity. This was some 10 times the structure. Combining fixed supports and design load of the customary use, in roofing, continuous deck meant that a change in the of such unusual tubular structures. The road Tubular bridge's temperature, normally accommo­ which crosses the barrage links the once­ bracing dated by sliding bearings or bending of slen­ derelict site into the local road network. der columns. would cause significant stress. THE ARUP JOURNAL :>/1995 7 Arch spacing Computer analysis Nine combinations of temperature and sup­ The architect had a pair of closely spaced A few years ago a model sufficiently complex port settlement were combined with each of arches at each side, which put all the load to represent this bridge could only have been these, giving a total of 279 loadcases to be onto the inner arch. To minimise member analysed on a main frame, and even that enveloped by the program. Even after design sizes the four arches had to share the load. would have given no insight into the struc­ completion , when loadcases which gave Introducing bearings between deck and ture's behaviour. Today the power of desktop stresses within 10% of the governing stress­ arches was considered, but the number computers and their programs make such es were examined, it was not possible to jus­ required would have been expensive and analysis possible, and crucially, the results tify reducing the number of loadcases or to would have led to future maintenance diffi­ may be displayed graphically. The curved identify a small number of critical members. culties. Instead the pairs of arches were sep­ parts of the bridge were modelled by short While the computer can indicate the most arated to give spans for the concrete deck of straight elements, with additional moments critical loadcase and element from the thou­ 2.75m and 3.6m, which allowed the trans­ included in the design check to compensare sands of possibilities, the designer still has to verse steelwork supporting it to be omitted. for this inaccuracy. At the nodes the plates be confident that the behaviour of the model Horizontal bracing members were used were modelled by triangulated trusses for will match that of the structure. Since hand between the pairs of arches rather than rigidity (Fig.5). calculations for such a complex model were cross-bracing . A decorative parapet, echo­ impractical, a close study was made of the ing the circular motif, was supported on force and bending moment diagrams and, shaped precast cantilevers, but since this above all, the deflected form of the model would not meet vehicle containment stan­ under the critical loadcases. dards, a separate standard parapet was provided beside the highway. Design stresses In the initial analysis, live load effects domi­ Buildability nated and member sizes had to be Introducing flat plates at the joints allowed a increased. After this the effects of changes in change from the all-cast solution. The main 5. Basis of computer model. bridge temperature became more significant. arch ribs would be circular hollow sections Further member size increases were counter­ bent to the required radius, with the horizon­ 6. Make-up of critical member stresses. tal deck support and bracing as straight cir­ productive because an increase in stiffness cular hollow sections. in one member increased the stresses in all the others. It was therefore decided, once its The infill sections would each be cast with a availability was assured, that grade 55 steel solid circular cross-section, either with the should be used for the rolled tubular mem­ plates integral with the casting or butt-weld­ bers. This gave an increase in capacity with­ ed on later - significantly cheaper than the out a corresponding increase in stiffness. all-cast solution. Fig .6 shows the proportion of dead, live and After further refinements on cost grounds, the temperature loads contributing to the critical final solution, using the most economic solu­ T = Temperature O = Dead L = Live stress in the different elements. A non-linear tion found by the contractors that preserved buckling analysis was used to determine the the tubular appearance, was to fabricate the effective length of the arch members; this bridge from the following components: Loadcases gave a small reduction in limiting compres­ • Straight tubes for the top boom and bracing Live loading on a highway bridge is domina­ sive stress below the yield stress of the steel. • Cold bent tubes for the main arch members ted by moving heavy vehicles. so load effects Concrete deck design are normally determined from influence lines Design of the reinforced concrete deck is • Induction bent tubes for the larger infills (In for the critical elements. this process successive short sections of conventional. The heavy longitudinal bars, tube are heated to red heat by an induction However for this structure it was impossible acting compositely with the steelwork, have coil, bent and quenched.} to predict which elements would be critical to be provided over the full length of the for sizing members under a combination of deck, not just the supports. The contractor • Solid castings for the smaller infills with axial load and bending. 31 loadcases were decided to use conventional rather than per­ attached plates analysed to represent the vehicle crossing manent formwork to avoid having to thread • Castings for the lower half of the knuckle half the bridge in regular increments. these bars through projecting steelwork. leaf bearings • Plates for the upper half of the bearings and the remaining connections between the tubes. The final design contains 360T of tubular steel, and 280T of plates and cast steel. Detailed design Initial analysis showed that the bridge steel­ work behaved unusually. In the final design, over half the thrust in the arch at the support was transmitted through the infill members into the deck at midspan. The proportion of vehicle load carried by a single arch depend­ ed on the position of the axles on the span. To quantify these effects, a space frame model of the whole bridge was developed. 7. Below, the completed bridge in its industrial setting. 8. Concrete barrage piers.

81 1;i ..J <( z a: ::, !;J 0. ::, a: <( w ..:c 8 Corrosion protection Steelwork The exposed steelwork is protected by a sprayed metal coating and 250µm of acryla­ 10. ted rubber-based paint. Regular inspection Casting in and maintenance will give the best protec­ progress. tion. rather than applying a special coating and then ignoring the bridge for a long time. The fully welded construction seals the tubu­ lar member voids against water ingress, and thus gives protection. Specification The OoT's Specification for Highway Works was used for all the bridges in the project, but it is not sufficiently flexible to cover all the works needed for this unusual bridge. Arups have used cast steel members as key struc­ tural elements in a number of buildings in the last few years. and the specification devel­ oped for these projects was incorporated in the contract documents. The standard spec­ ification's requirements for weld testing are written for the fabrication of plate girders (requirements for destructive testing of run­ off plates from flange butt welds are not appropriate to the barrage). Again a specifi­ cation developed for roof structures 1n build­ ings was adopted and incorporated in the contract documents. Requirements for mate­ rials normally relate to the as-rolled material, 13. but there was concern that the heat treatment Arch and quenching inherent in the induction erection. bending process would affect the toughness of the steel. Further destructive and non destructive testing of the bent tube was therefore specified.It was necessary to limit the stresses due to changes in temperature to which the bridge will be subjected during its life. The site welds which establish the continuity of the structure had to be made 15 The bridge under construction early 1994. when the air temperature (and so the tem­ perature of the steelwork remote from the welding operation) was between 5 and 15°C. Fabrication and erection The combination of tubes, solid castings and thick plates in such unusual shapes was a challenge for the fabricator. 24 end (half arch) and 20 internal (double half arch) frames were produced over about six months. Full penetration butt welds on tubes

9 Detail of pinned arch supports.

up to 50mm thick were required . and welding ers, and erected by 70-31 OT mobile cranes activity dominated fabrication, taking 35 OOO standing on the bed of the diverted river, with hours in all. Grade 50 and grade 55EE rolled proprietary trestling at mid-span giving tem­ steel were used, and A4 (modified) cast steel porary support. After the line and level of the which gave equivalent properties to grade arches had been checked the main butt 50. The induction bent tube needed further welds in up to 25mm thick tube were made. heat treatment after testing to ensure ade­ These had to be in a specific sequence and quate toughness. The metal-inert gas (MIG) subject to ambient temperature restriction. process was used for all welds, with an elec­ which meant some night welding. Manual trode containing 2.5% nickel. Extensive pre­ metal arc (MMA) techniques were used for all heat and controlled cooling was required site welds and the fabricator had a welding throughout. 100% non-destructive testing technician on site throughout. Fillet welding (NOT) on butt welds and 40% on fillet welds, of the cross-bracing between arches gener­ carried out 48 hours after welding , was spec­ ally followed the main -butt welding. The full ified . In addition immediate post-weld NOT paint system was applied to all site-welded by the fabricator allowed early identification areas, including shot blasting, metal spray­ of defects. The weld procedures used meant ing, and spray application of topcoats. that the defect rate was very low. The pre­ Throughout fabrication and erection, a high fabricated arch frames were brought to site level of planning, supervision and quality as special loads on purpose-adapted trail- control was provided.

THE ARUP JOURNAL 2/1995 9 Barrage pavilions concrete beams to prevent overturning of the Conclusion At each end of the barrage there is a two­ base adjacent to the navigation channel. This Designing the River Tees Barrage Bridge storey pavilion building. The south pavilion base was founded 9m below finished ground was a fascinating challenge, and its con­ houses the control equipment for the barrage level, on the base of the channel formed for struction taxed the contractor's ingenuity. and navigation lock, the hydraulic power the river diversion, and contained voids to Without modern computers, the design packs for the barrage gates, and the offices reduce the soil bearing pressure to an would have been much more difficult. Whilst of the staff operating the barrage. The north acceptable level. The south abutment was not the cheapest solution to the problem of pavilion, which contains a plant room for the conventional, but at the north abutment the crossing the barrage, it will give the Teesside barrage, is predominately for public use with road crossed another building's roof, formed Development Corporation a distinctive cen­ a restaurant, a rooftop belvedere from which from a 250mm thick slab spanning trans­ trepiece for their flagship project. to view the barrage and river, and a base­ versely onto 1m deep longitudinal beams. Reference ment with a viewing window to the fish pass. Barrage footbridges, (1) Department of Transport. Design Manual for The road over the barrage is carried by the lifting bridge, and tower of lights Roads and Bridges. HMSO, 1992. roof of the pavilion. The reinforced concrete Pedestrians and cyclists are at river bank Acknowledgments roof slab in this area is 600mm thick and sup­ level, so a low level route across the four river John Franklin, Tarmac Construction ported on four sides by reinforced concrete spans and the navigation channel was need­ Keith Temple, Westbury Tubular Structures walls. The limits on allowable openings in ed. The former are four identical 14m long Credits these walls were a significant constraint on simply-supported footbridges, of twin univer­ Client : the planning of the layout of the pavilions. sal beams with a steel plate deck. The deck Teesside Development Corporation Elsewhere the pavilion structure consists of cantilevers outside the beams, supported by Design/build contractor: 250mm thick slabs supported on reinforced shaped transverse plates at 1. 75m centres. Tarmac Construction (Civil Engineering Division) concrete beams and columns. The pavilions The gap between the beams forms a service Main consultant: are supported by an extension of the barrage duct for hydraulic and electric power to the Montgomery Watson (UK) Ltd raft foundation . The concrete structure is internal barrage piers housing the gate Sub-consultant and bridge designer: concealed by masonry cladding which con­ mechanism. 6m long access manholes in the Ove Arup and Partners Martin Butterworth, trasts with the exposed concrete of the bar­ footbridge decks allow replacement of Simon Cardwell, Neil Carstairs. Graham Gedge, Andrew Kirton. Stuart Hunter, Nick Memdew, Ian Miller, rage piers, while emphasising the solidity of hydraulic pipework. The navigation channel Paul Morley. Chns Murgatroyd, John Read, David Stevens the pavilion against the light steelwork of the is crossed by a steel lifting bridge which can bridge. Precast concrete units, matching the be raised by a single hydraulic jack to an Sub-consultant and architect: road bridge cantilevers, provide a visual link angle of 80°. Two plate girders support a The Napper Collerton Partnership between the approach bridges and the main steel trough deck which can carry vehicles Sub-contractor for bridge structure: river crossing. up to 7.5T to service the south pavilion on the Westbury Tubular Structures Bridge foundations island between the navigation channel and Illustrations: the barrage. Parapets for these bridges 1: The Napper Collerton Partnership The barrage piers support the river bridge, 2-6: Sean McDermott pavilions, and the ends of the approach match the decorative handrails on the main road bridges. 7: Alan Proudlock (Photography) Ltd. bridges. The remaining foundations for the 8, 9, 16: Bob Tyson approach bridges are buried pad footings. The tower of lights is a single tubular steel 10-15: Cleveland Colour Labs On the north side one footing had to extend mast, tapering from 350mm to 610mm diam­ underneath the concrete channel of the eter, 29m high, stabilised by guys formed canoe slalom, and the channel was strength­ from Macalloy bars up to 34mm diameter. ened to span across the footing when it The mast and guys support reflective globes settled. On the south side the two footings and plates, while the light source is at the had to be tied together by a pair of buried tower base for maintenance access.

16. Barrage footbridge.

10 THE ARUP JOURNAL 2/1995 Introduction These background investigations • building heights, urban form and The design strategy The River Thames is one of examined: landscape structure of different The main elements are shown London's major assets. It has played character areas along it. in Fig 3 overleaf. These are: a vital role in the capital's history • the history of development along the Thames A continuous photographic survey • identifying focal points to act and is an important visitor attraction. as magnets for activity and Yet to many it is an underused • the evolution of was also undertaken to provide a complete record, in 1500 images, of transport interchange resource. and is often perceived as decision-making bodies riverside development and environ­ • improving the quality of a barrier and a psychological • the river management regime dividing line between North and ment conditions. This presented urban design and architecture • the planning policy context. severe logistical problems to the South London. • creating a robust Arup photographer in terms of landscape strategy In June 1994, the Secretary of State Information was also assembled in access, glare, and how to display for the Environment announced that map form on: 100km of river bank, but these were • improving cross-river he would be launching a study of • distribution of riverside land uses overcome with perseverance. pedestrian access the Thames between Hampton Court and development opportunities The study's conclusions were • encouraging general Palace and the Royal Naval College environmental improvements. at Greenwich. 'A visionary document • accessibility along the banks and produced in two parts: is needed .. . promoting a high quality from the River's hinterland, and • a design strat&gy Focal points of activity of design and landscape along the traffic use of the Thames itself (the creative elements) 14 key centres of tourist and leisure activities were identified. These gen­ River'. he said. The study invitation • areas of heritage and ecological • draft strategic attracted 76 teams, subsequently importance along its length erally have good public transport planning guidance facilities, often including a pier for reduced to eight for the proposal • key landmarks visible from it (the procedural output). and interview stage. river services and a bridge crossing. Richmond is an example of an Arups was one of the few firms able 2. existing focal point, where the open to offer the full range of planning Design guidelines showing recommendations on urban fabric , space in front of the development and design skills, and was commis­ relalionship to river, and building scale and massing. . and the boating activities create a sioned by the Government Office for strong sense of place; whilst at London in August 1994 to undertake Urban fabric Undesirable Recommended Canary Wharf. for example, a major a detailed analysis of the River, new focus of riverside activity could prepare overall design principles, be created, linked to the water­ and make recommendations for based recreational opportunities at draft planning guidance. An inten­ Limehouse Basin. The strategy sug­ sive four-month period lay ahead for gests that there should be a series a team that incorporated skills in of places with which people can town planning. urban design, land­ associate, perhaps identified with scape architecture. transport plan­ some form of marker or structure - ning, economics and tourism. akin to a River 'bus stop' - the The aims of the strategy were to: design of which could be the sub­ • raise public awareness Ject of an architectural competition. Relationship to river Urban form • enhance environmental quality Undesirable Recommended It is crucial that both new develop­ • protect areas of historic ment and the existing townscape do importance justice to their riverside location. • promote high quality design of Some development in the past has new buildings and landscape turned its back on the River or • safeguard river-related blocked public access to the employment generating uses riverside. To illustrate practical approaches, the Arup strategy • improve access to the River. includes a series of design The study was to be strategic in guidelines (Fig.2), illustrating the nature, providing an overview of importance of: Building scale and massing opportunities arising within the • permeability of new development SOkm stretch, rather than Undesirable Recommended to maintain circulation and visual considering the development contact with the River potential of particular sites. • building forms that reinforce Background analysis the River edge During data gathering, the Arup team consulted many organisations • buildings in scale with the interested 1n the Thames, via discus­ River and in contex1 with sion groups, meetings, and events. surrounding development Fieldwork was largely undertaken • avoidance of disruptive from boat trips. building silhouettes. THE ARUP JOURNAL 2/1995 11 3. The Arup Strategy Plan.

South Bank/ Charing Cross

Westminster Kew/ Brentford

Batterse Chelsea

Putney/ Fulham

Marble Hill Landscape Pedestrian accessibility The River acts &s a unifying feature There are stretches of the linking the green spaces along it, River with very limited access like beads on a necklace. These between banks. The Arup strategy vary from informal woodland highlights the potential for new in the quieter upstream sections, bridge links between Gharing Cross/ particularly between Hampton Court Embankment and the South Bank and Kew, to the planted edges Arts Centre, and between St Paul's associated with the formal embank­ Cathedral and Bankside Power ments 1n the metropolitan core. Station (in its new incarnation for the The Arup strategy suggests that a Tate Gallery). There is also scope stronger landscape framework for improved pedestrian access in should be established to raise the the Kew Gardens-Brentford area, quality of civic space along the possibly by ferry. Access from riverside. This would be particularly Brentford, Hammersmith and Kingston appropriate for integrating areas of Wandsworth town centres could be mixed architectural style and quality, enhanced too, as well as from the as on the Southwark riverside office centre at Canary Wharf. (Fig. 5). This approach would not, of course, be appropriate where old ~,, \ .,.,,, ~ warehouses and their modern coun­ ,,,,,,,, '..,,,, terparts rise vertically from the River ~ 1 Hampton .,_ G) Seething Wells edge, as in parts of Docklands. Court '~

4 Creating a vibrant riverside, particularly at the focal points of activity.

12 THE ARUP JOURNAL 211995 Canary Wharf/ General environmental Planning guidance St Pauls/ Limehouse improvements The second part of Arups' recom­ Bankside Tower/ ,,, ... ,, A range of improvements are sug­ mendations covered ideas for draft Butler's Wharf ,, ,, gested as an integral part of future strategic planning guidance for the ..,:, '-:.... : - opportunities to enhance the River. Thames - not only the main study • These include a proposal to develop area, but also the downstream a corporate signage system for the stretches from Greenwich to the sea. Thames, selective use of public art This guidance produced was com­ - and sculpture in scale with the River, plementary to the Thames Gateway and co-ordinated street furniture. Planning Framework produced by Also recommended is the prepara­ the Government in 1994. tion of a lighting strategy for the Strategic planning guidance for the urban stretches of the River. Thames will be a new form of advice A sense of drama can be achieved to local authorities in preparing Dock with good accenting of historical development plans and determining landmarks, and festoon lighting planning applications, and this study ~ / ..l defining the River edge, as at is the first time consultants have 0 2 3 4 5 km ',,,,,,.,,,•' Victoria Embankment (Fig.1). been used to draft such strategic or ----===::::::,----====---- Greenwich More could be done to enliven the regional guidance. riverside including illuminating and The focus for it is to improve the painting some bridges, and to consistency of the policy framework Legend improve security on parts of the for the Thames, a problem that riverside walk. stems from having 13 local authori­ ,,, .. ,, Focal Points of Activity - Existing .... , ties with a river frontage between ,,, ,, Hampton Court and Greenwich. In ...... Focal Points of Activity - Proposed all cases, except Richmond which .. controls part of both banks, the River acts as a divide. Potential for increased River Activity Enhancement 5. Opportunities A strong treeline would provide 1. Hampton Court Park Buildings up lo 3 storeys (approx 10m) greater coherence to buildings 2. South of Kingston Road Bridge along the Southwark riverside. 3 Ham Lands 4. Kew Gardens Buildings up to 6 storeys (approx 20m) 5. Brentford 6. Duke's Meadow Buildings greater than 6 storeys (20m+) 7. Mortlake 8 Corney Reach 9 Hammersmith 0 Key Landmarks - Action Required 10. Barn Elms 11 Fulham Palace Gardens 12. East side Putney Bridge ~ Key Landmarks 13. Gargoyle Wharf Site 14 Fulham Public Open Space 15 Wandsworth D 16. Nine Elms Informal Woodland - Solid 17 Tate Gallery Informal Woodland · Paroal 18 Albert Embankment Formal Plant,ng 19 South Bank Centre 20. St Paul's frontage @ Enhancement Opportunities 21 Bankside 22. West side Tower Bridge 23. Wapp1ng I ~~ I Increased Accessibility Desirable 24 Millwall 26. Deplford Creek Q Thames Path - Significant Missing Links

0 Working Wharves

6. Western Riverside, Wandsworth: a modern. well-designed waste transfer station including an elevated section of riverside walkway.

THE ARUP JOURNAL 2/1995 13 Several policy topics were analysed Southwark Environmental Trust to freight , but have been under threat, Credits including: provide a section of path in the particularly in the upstream sections. Client: • mismatch of boundaries on Central London stretch. There is also The strategy also recommends Government Office for London protective designations such as potential for increased cycle use planning protection for smaller Planning and Design Team : Areas of Nature Conservation along the River. In some places, elements of river heritage, for Ove Arup Partnership Importance for example, it is possible for a example the steps and stairs that Lorna Andrews, Adrian Gurney, separate cycle path to be provided can be lost through new develop­ Corinne Swain (planning), Michael • different ways of signifying the inland of the riverside walkway. It is ment. It suggests that planning Lowe, Graeme Smart (urban design), special character of the riverside encouraging that since the study authorities should consider adding Tom Armour, Cla1re Matthews • need for inter-borough liaison in was completed, the Department of such features to a local list. Some of (landscape architecture), Bernadette protecting key River-related views Transport has supported the London these ideas have also already been Baughan, Hugh Collis (transport), Boroughs' proposals for a Thames included in revised strategic Jeroen Weimar, Paul Whitehouse • use of development briefs to cycle route in the Transport Policies planning guidance for London, (economics and tourism), encourage mixed uses and high and Programme (TPP) settlement issued for consultation by the Sir Jack Zunz (engineering and design design standards. for 1995/96. Government in March 1995. adviser). Jon Carver (graphics), A separate document containing Peter Mackinven (photographer), Two examples of planning policies • Protecting river infrastructure Jo Scott (secretarial). are: This is an area where planning draft strategic planning guidance for policy needs strengthening . the Thames will be published by the Illustrations: • Thames path Government Office for London later 1, 5: Michael Lowe All the local authorities have given Retention of wharves is critical to this year and will be subject to a 2: Michael Lowe!f om Armour unanimous support to the creation keeping open the option of formal period of consultation. 3: Jon Carver of a continuous pedestrian route supplying building materials to 4, 7: London Rivers Association along both banks of this section of London by river, as well as taking Thames Advisory Group 6: Corinne Swain the Thames. Planning authorities away waste products, and at the The Secretary of State for the have actively sought ways to time of study only 15 working Environment has appointed an provide new stretches of riverside wharves remained in this stretch. advisory group of leading architects, walkway as planning gain when journalists, developers and environ­ The Arup strategy recommends mentalists to take forward some of granting planning permission on that a system of safeguarding is new development. the initiatives included in the Arup included in planning policy around strategy. The Arup team made a At the time of the study there all remaining wharves, and that presentation to its first meeting, were only four significant missing any proposal involving the loss of chaired by John Gummer with two gaps in the Thames Path, and the essential river infrastructure other Ministers, in early March 1995, Countryside Commission is actively becomes a departure from the and the Thames Strategy was seeking to negotiate new corridors development plan. formally launched by the Secretary of access here. Essential infrastructure should also of State in May. It will, it is hoped, Innovative engineering solutions are include piers, landing stages and provide the context within which possible in some locations, as where boatyards. The latter are crucial for imaginative ideas and practical Arups are currently assisting the maintaining tourist boats as well as proposals will come forward .

7. Well-used riverside spaces with strong landscape at Coin Street and the Royal National Theatre on the South Bank.

14 THE ARUP JOURNAL 2/1995 The Western Harbour Crossing, Hong Kong K O W L O Eric Poon David Snowball

Western Introduction Harbour Anyone who knows Hong Kong will Central Business District with the Crossing be aware of the problems of traffic west of the Island); and the toll plaza congestion, particularly if they have on the West Kowloon Reclamation tried to cross the Harbour at peak (Fig.3). The landfall in Kowloon is times of day. The Cross-Harbour part of a major redevelopment, Tunnel was opened in 1972 and now not only to accommodate the new carries over 120 OOO vehicles a day, highway and rai,way infrastructure H O N G which makes it one of the busiest but also for housing, commercial tunnels in the world. A second one premises and public recreation - was opened to the east in 1989, and all on land that did not exist as part of a major infrastructure three years ago. scheme aimed at alleviating cross­ Skm harbour congestion. This now carries some 90 OOO vehicles per day and already the approaches are blocked at peak times. 1. Harbour road crossings. Almost as soon as the Eastern Harbour Tunnel opened, the Hong t To N.W. New Territories Kong Government commissioned a o Skm \ and China feasibility study for a third crossing, to the west (Fig .1) . This would not only relieve pressure on the other two, but also act as a strategic link to the NW New Territories and China, via the Shenzhen-Guangzhou Superhighway, as well as to the new Chek Lap Kok Chek Lap Kok Airport further west. Airport Invitations to tender to finance , construct, and operate the Western Harbour Crossing on the basis of a 30-year franchise were issued in February 1992 for return the follow­ ing July. The Western Harbour Tunnel Company was successful in its bid and an agreement was even­ tually signed with the Hong Kong Government on 2 September 1993. Tung Chung Central & However, such is the pace of things Development Wanchai in Hong Kong that work had already Phase 1 Reclamation started a month earlier! The total Phase 1 cost is HK$7.5bn (including finan­ cing) and construction is planned to 2. Overall Airport Core Programme. be complete by 30 June 1997. 3. Site plan. Outline of the project The Western Harbour Crossing is one of 10 Airport Core Programme projects defined in the 'Memorandum of Understanding' -- Contract Boundaries -- Project Boundaries between the UK and Chinese Governments dealing with the estab­ lishment and funding of the new Airport (Fig .2).These include Chek Lap Kok itself and the MTRC Airport Express line (in both of which Arups have ex1ended involvement in various roles), as well as the 1377m­ span two-level Tsing Ma suspension bridge, part of the Lantau Fixed Crossing . The Western Harbour Crossing is, however, the only one of the 10 to be privately funded and therefore has not been subject to the recent uncertainties surrounding the Government-sponsored projects. It consists of three principal elements: the tunnel underneath Ocean Terminal Victoria Harbour; the approach roads at Sai Ying Pun on Hong Kong O SOOm Island, which include a grade SAi YING PUN separated interchange with Route 7 (the major trunk road connecting the

THE ARUP JOURNAL 21 1995 1 5 The franchise concept sponsor companies (shareholders), The Build-Operate-Transfer (BOT) who amongst them must have franchise concept is well known in experience of operating such a Hong Kong , as it had been used in facility. Responsibility for design and an embryonic form for the original construction is given to a major con­ Cross-Harbour Tunnel, nearly 25 tractor or a joint venture of several years ago. More recent examples companies. The contractor(s) are include the Eastern Harbour sometimes members of the Crossing, Tate's Cairn Tunnel, and sponsoring group, although this is Route 3 Country Park section (where not the case with the Western Arups are involved). BOT projects Harbour Crossing . The contractor(s) have gained favour in many parts of in turn employ design consultants. the world , notable cases in the UK It will be usual for a group of banks being the Channel Tunnel and the and financial institutions to share the Dartford Bridge. The principle is that risk of providing capital. the franchisee offers to finance , The shareholders of the Western build and operate the facility for a Harbour Tunnel Co. Ltd. are China set term during which he levies International Trust & Investment charges to users to secure a rea­ Corporation, the principal overseas sonable return on his investment investment arm of the Government and borrowings. At the end of the of the Peoples' Republic of China; franchise period the facility is hand­ Wharf Holdings, Kerry Holdings, and the Project Agreement and precisely participation in the equity, but suf­ ed to the Government in good work­ China Merchants. These companies defines the delegated powers. thus fice it to say that the experience of ing order. The concept is an attrac­ have major interests in both China putting NKJV effectively in the posi­ the Western Harbour Tunnel Co. tive one to Government as there is and Hong Kong in property, infra­ tion of the franchisee in dealing with shareholders suggested contractor no investment of public money. In structure and energy projects, ship­ Government. As required by the participation should be avoided addition the franchisee assumes all ping and transportation. Expertise on Project Agreement the Company and the Company should appoint the responsibilities for procuring the tunnel operations is provided by the has appointed a consultant to check its own 'watchdog ' to look after project. and has a single interface Cross-Harbour Tunnel Co., a sub­ both the design and works construc­ Shareholders' interests. with Government. Major infrastruc­ sidiary of Wharf. The Western tion and act as engineer under the ture projects such as highways, tun­ This led to the establishment of a Harbour Tunnel Co. has let a con­ contract with NKJV. Project Co-ordination Team and the nels and bridges lend themselves to tract for design and construction to this approach as it is comparatively The contractor has been deliberately selection of Ove Arup & Partners in a joint venture between Nishimatsu placed in a powerful position to get September 1993. The pos1t1on of the easy to prove their 'fundability' to and Kumagai Gumi (NKJV). prospective lenders, and to collect a complex job done on time with team within the overall structure is revenue by way of tolls. Project management minimum confusion over authority shown in Fig.4. and lines of communication. NKJV The Project Agreement between The role of the Project Co-ordinator The preparation of a franchise bid is Government and Company makes has an enviable recent track record: a com plex matter and there is not is to represent the Company in tech­ the latter entirely responsible for Nishimatsu were lead contractor and nical and contractual matters, attend space here to deal with more than delivery of the project on time to a major shareholder for the Tate's the key principles. The starting point all principal project meetings with standard acceptable to Government, Cairn bored tunnel in Hong Kong Government, the contractor. and the is the project brief put together by and for subsequent operation during (opened in 1991), and Kumagai Government as the basis for inviting engineer/checker. to monitor and the remainder of the 30-year fran­ Gumi participated in the Sydney report on progress. Arups' role also bids. This explains Government's chise period. The agreement allows Harbour tunnel (opened in 1992) general requirements in respect of includes liaison with the Company's Government to nominate two and Hong Kong's Eastern Harbour Business Manager and the General the project and the franchisee 's Directors to the Company Board, Crossing , both immersed tube tun­ organisation. and sets out detail Manager of the Cross Harbour and approve all designs by dele­ nels. Kumagai is a major sharehold­ Tunnel Co., to assist in the establish­ design, construction. operation, and gated authority to a representative of er in the former and has a minority maintenance requirements. ment of commercial, operating, the Director of Highways. holding in the latter venture. But get­ maintenance and public relations No single organisation would The Company has delegated its ting the job done sometimes leaves policies and procedures. Perhaps normally have either the capacity or obligations and authority for design other objectives not completely ful­ the most interesting but sometimes experience to bid for or undertake a and construction to the NKJV, filled, and confusion of interests can frustrating part of the role has been franchise project alone. The usual retaining only certain legal and arise where the contractor is also a to see that the Tunnel Company arrangement, followed on the financial obligations to itself. The shareholder in the group of sponsor operations and maintenance require­ Western Harbour Crossing, is a joint contract with NKJV, a lump sum companies. This is not the place to ments are adequately covered in the venture to spread the risk between fixed price, embodies the whole of argue either for or against contractor design. Whilst the Government brief for the project provided general requirements and standards, it could not possibly deal with the myriad - Hong Kong Government t\ ...... , details which might vex the operator. The client -. . In an ideal world these would have t : . been agreed with the contractor dur­ Scott Wilson Kirkpatnck ~ Western Harbour Tunnel Shareholders ing the preparation of the franchise Company Ltd . 11 Checkers and Engineers . bid. In practice time was short and I Lenders . Team The Franchisee ' only the essentials were included . Ove Arup & Panners M;ss - Harbour Tunnel '· (and priced for) . This left the details Co Ltd . Project Coordinators to be hammered oui during the . , agement Company I . . approval and design development ' I I stages. The Tunnel Company tack­ ' N1shlmatsu - Kumaga, Joint ~- -1 Maunsell - Acer ' led the problem by arranging for the ' Venture .....--, Parsons Brinkerott JV ' ·- General Manager of the Cross ' NKJV - Project Management I Consultant Team I '------Team Harbour Tunnel Co. to work with I Arups to define operational needs for the designers. Maintenance N,sh,matsu · Gammon JV tl Kumagar Gumi Co Lid I GEC (Hong Kong) Ltd expertise was added to the team by N1s1himatsu Gammon I Immersed Tube Tunnel II M&E I the early recruitment of a Tunnel Construction Construction Co Lid Lid Engineering Manager. The incorpo­ WKR Route 7 SYP ration of these detail needs has A~proach Road been made against the background amps Interchange and Toll Plaza and of a lump sum construction contract AWaroach amps where changes are usually difficult I 4. Project organisation. and expensive to make, but with goodwill on both sides many of the requirements have been met.

16 TliE ARUP JOURNAL 2/1995 5. Left: Casting basin: tunnel units batch 1 under construction June 1994. The business of the Company is All the Directors have many other reviewed through a hierarchy of interests and an unwritten rule has meetings. A relatively informal been adopted whereby no meeting review of key issues is made each lasts longer than one hour - a week by the Chairman , Managing superb discipline to focus the mind Stage 1 Stage 2 Stage 3 Director, Business Manager and on the really important matters! Bulk dredging Trim trench Mound construction Project Co-ordinator; the Executive Much of Arups' effort is directed Committee of the Board meets each towards monitoring progress and month to make a formal review of preparing reports. Although NKJV progress and receives reports from prepare a monthly report, the the engineer/checker, Business Company was concerned to make Manager and Project Co-ordinator; an independent assessment of and the whole Board convenes each project status. To this end Arups quarter, when both Business appointed a Programme Control Manager and Project Co-ordinator Manager who had previously worked make formal presentations of the on the Sydney Harbour Tunnel, and financial and progress status of the so brought first hand knowledge of project, highlighting critical issues. this type of project to the team. The tunnel 6. Above and below: Tunnel construction sequence. The crossing is designed as a dual three-lane highway with an ultimate Stage 4 Stage 5 Stage 6 Stage 7 capacity of 180 OOO vehicles a day, Sinking unit Sand placing Back filling Rock protection although the daily flow when it opens in 1997 is expected to be Sand placing barge under half that. The tunnel is being constructed as a 1.3km long reinforced concrete immersed tube Rock blanket between ventilation shafts on either General fill side of the harbour, with short cut­ and-cover sections on the landward sides, bringing the overall length between portals to 2km. Sand foundation Longitudinal ventilation ducts are Concrete pads provided on both sides of the 100m immersed tube section with cross­ min wmm WWmin min connections to the road tunnels; the cut-and-cover tunnels have overhead ventilation ducts. The immersed tube consists of 12 units, each approximately 113m long x 33.5m wide x 8.5m high. They are being fabricated in three batches of four in a casting basin at Shek O on the south side of Hong Kong Island, 7. Tunnel construction excavated below the floor of a To sinker stage 4: cross-section. partially worked out quarry close to the sea (Fig .5). When each batch is Ballast tanks complete the basin is flooded and the units towed to a temporary Concrete pads mooring for final fitting-out and thence to the harbour. The entrance channel to the casting basin is then / closed with a floating caisson gate Dredged line to allow the basin to be pumped out for fabrication of the second batch. The units are sunk into a prepared trench dredged from the harbour 8. Tunnel unit 1 being floated into position at ventilation shaft (Hong Kong side), 15 March 1995. bed (Figs.6 & 7), from which marine muds are removed and replaced with sand up to tunnel founding level to limit settlement. The logistics of the marine works are considerable, as it is necessary to make several diversions of the shipping fairway through the harbour to allow dredg­ - ing and sinking of the units. Planning is made more difficult by the need to co-ordinate the works with the Airport Railway tunnel, also an immersed tube, which runs close to the road tunnel. Moving the units is an impressive sight as each dis­ places 35 OOO tonnes and requ ires four tugs to manoeuvre it. The first batch left the casting basin in January 1995 and the first unit was sunk into position on 15 March 1995 (Fig.8). The ventilation shafts and cut-and-cover tunnels at each landfall are constructed by the top-down method using diaphragm walls, sunk to sound rock head. THE ARUP JOURNAL 2/1995 17 The shafts are major elements in themselves, being some 38m in diameter with road level 20m below ground and diaphragm wall cut-off approximately 40m lower. A 'dock­ ing bay' is constructed in cofferdam on the seaward side of each shaft to receive the immersed tube units. 9. Each shaft will support a ventilation Part of model of building to house the tunnel fans for grade-separated providing fresh air or to exhaust interchange between smoke in the event of a fire and tunnel approaches associated transformers and and Route 7 switchgear. At the time of writing (note tunnel portal in both shafts are complete and the upper left of picture). building superstructure on the Hong Kong side is under construction. The approach roads The highway works at Sai Ying Pun on Hong Kong Island stretch 2km from the end of the Rumsey Street Flyover to Belcher Bay, where land is still being reclaimed and will not be available to the contractor until mid-1995 (Fig.9). Progress monitoring by Arups activity no more than 1% of the take part in the variety of tasks This long thin site lies alongside A review of contract documentation project total. Thereby errors in involved in building a new company Connaught Road West in a heavily revealed that neither the construc­ weighting assessment are limited. literally from scratch . Working with populated residential area and tion contract requirements nor the The progress of each activity in the Business Manager. the Arup poses the type of problems to the contractor's monthly reporting would team has devised a tailor-made contractor which are typical of this the programme model is up- provide clear information on the dated monthly as a percentage document control system, assisted kind of work. Complex traffic and progress of the works. Indeed the the development of public relations utilities diversions are required to completion. Progress is assessed , form of lump sum contract adopted whenever possible, by identifying policy, are helping to recruit key allow sections of the jig-saw to be meant the Tunnel Company had operations and maintenance staff, pieced together, whilst keeping con­ the achievement of key events and very little detailed information on the measuring the actual amount of are initiating proposals for auto­ struction noise and dust to tolerable make-up of the contract sum. tolling and carriage of telecommuni­ levels. The contractor's problems in work done. Information on progress There was thus a need to develop a is also obtained from the monthly cation links to enhance operating constructing some 17 separate efficiency and revenue, and are bridge structures, 15 of which are system of progress monitoring, and reports of the independent design to this end a model was developed and works checkers as well as the briefing visiting groups from China currently in hand, have been and other Asian neighbours - to compounded by some rather patchy with the following objectives: contractor. Monthly progress is compared with the target pro­ mention a few of the current tasks. ground conditions. The land upon • to provide a baseline programme Experience has shown that Arups which much of the work is being for assessment of the progress of gramme, and the results presented graphically on a summary bar chart has a lot to offer companies in a done was reclaimed about 1O years the project similar position. It is to be hoped ago and in places deep pockets of and cumulative progress curves • to track critical paths, hence in the franchisee's monthly reports. that this will be the first of many marine mud have been found , some allowing identification of likely such commissions. 20m thick. As there are assumptions and problem areas and adverse trends judgements made in establishing Credits This has required deep barrette or • To forecast the achievement of the programme model and in bored piled foundations for the Client: key dates, payment milestones assessing the monthly progress, the Hong Kong Government structures and a ground treatment and the final completion date predictions of project completion are programme where approach ramps Franchisee: • To allow presentation of the results not intended to be absolute. Western Harbour Tunnel Co. Ltd. are located. Treatment generally It is more important to watch the consists of installing 'wick' drains on of monthly progress monitoring in Project Co-ordinator concise, simple terms for the progress trends than the monthly a close pattern grid and surcharging figures themselves. Ove Arup & Partners Hong Kong Ltd . the affected areas to accelerate franchisee's monthly and Eric Poon, David Snowball settlement. quarterly reports. In addition to the progress monitor­ (permanent site team) ing of the Western Harbour Crossing Toll plaza Primavera Project Planner (P3), a Daniel Leung, Sinny Lo, Pat O'Neil, project planning and control Project, monitoring of the progress Grant Robertson, Agnes So, Both the contractor and the Tunnel of interfacing Government projects Company set up their principal computer software, provides the Paul Suet!, Andrew Wolstenholme. basis of the progress monitoring is also carried out to assess their Damon Yuen (Hong Kong) offices on the West Kowloon effects on the opening of the tunnel. Reclamation site, close to the toll model. The model was developed Allan Delves (London) by summarising activity sequences The Project Agreement requires the plaza area, where work started in Advice and help on a variety of issues autumn 1994. This will accommo­ in the contractor's works programme Tunnel Company to make a monthly has been given by Frode Hansen date 20 traffic lanes, some of which within each cost centre so that the progress report to Government. This (consultant to Arups in London). will be equipped with auto-toll logic links and date constraints were distills information from NKJV's Ron Cookson, Stephen Lam, Wilkie equipment to allow subscribers to maintained. Each summary activity report and includes the independent Lam, and Tony Read. was coded by cost centre and assessment of project status and a pass through without stopping - Illustrations particularly advantageous to the bus geographical area for aggregation projection of the completion date. The Arup Team also issues a quar­ 1-4, 6,7: OAP Hong Kong companies. The Tunnel Company for reporting purposes. Graphics Group/Trevor Slydel administration building will be con­ To pr.esent progress concisely and terly report for the Board , which is 5, 8. 9: Peter Yiu , structed close to the toll plaza, and simply in terms of percentage lavishly illustrated and produced to Western Harbour Tunnel Co. Ltd. will house the control room where completion , it was necessary to a high standard by Arups' Hong traffic flow, toll collection and tunnel assign weightings to the summary Kong Graphics Group. Last but by environmental conditions are activities of the programme model. no means least a quarterly report is monitored, and from which action These were derived by assessment prepared to satisfy the lending can be directed to deal with any of major quantities or cost estimates Banks, which has to be certified by emergencies. To the north of the toll and allocated as a resource value in Arups as an accurate record of the plaza there is an interface with the Primavera. Cumulative curves of the project's status. Government Contract for the West weightings can be generated to Involvement with a project of this Kowloon Expressway. Work has provide the target progress curves nature and size. itself a part of the recently started on the Kowloon for the project. The programme gigantic group of Airport Core Station (Arup design) of the Airport model contains about 550 summary Programme projects, is exciting Railway, which is immediately adja­ activities with the maximum enough . However, a fascinating cent to the toll plaza. weighting allocated to any individual aspect of Arups' role has been to 18 THE ARUP JOURNAL 2/1995 The Pavilion, Blackpool Steve Burrows Rick Houghton Mike Robinson

Introduction This exciting and unusual project involved partially demolishing a large steel and concrete-framed building, as well as major structural remodelling of the internal features and construction of a complete new fac;ade to improve appearance and durability - and all while the ground floor retail units remained in occupation and trading. Construction was completed in September 1. Brickwork detail on the refurbishment. Appointment route 1994 and the refurbished building (Figs.1 & 8) Ove Arup & Partners Manchester were first appointed by Grant Thornton to report on the is now fully occupied. 2. The original buildings c.1960. Major tenants include Top Rank who operate building's condition. The structural survey an 1800-seat bingo hall and Woolworths, who was mainly external and revealed extensive have used the project to renew their trading damage to many of the exposed elements: presence along the promenade of the most cracking and spalling of the concrete, the popular seaside resort in Europe. result of chloride contamination corroding the reinforcement and encased rolled steel sec­ History tions. Following issue of the survey report to Up to 1962 this prime island site next to prospective purchasers, Arups were then Blackpool Tower was occupied by traditional appointed by the new owners, Chartwell seaside resort promenade buildings (Fig.2) , Land, for the structural engineering design including the Palace Theatre. Lewis's Ltd. associated with their redevelopment proposals. bought and cleared the site to make way for their flagship store in the north west of England; the new five-storey building, completed in early 1964 (Fig .3) . boasted air-conditioning, restaurant, cafeteria and hairdressing services - every aspect oozing modern boldness and optimism. For many years its appearance. with its green glazed honeycombed screen wall . divided opinions. but love or hate it, it is difficult to argue that the brash statement it made was not appro­ 3. priate to the seafront character. In 1991 , with The famous postcard the demise of Lewis's as a trading company, showing the new Grant Thornton were appointed receivers to Lewis's store.shortly oversee the sale of their assets. including alter completion the building and site at Blackpool. in 1964.

4. New two-storey void created at first floor level.

THE ARUP JOURNAL 211995 19 B.54m Proposal The measured survey had to be used with Chartwell were very much driven by the ' caution. Many of the dimensions related to __3 05 x 457 x 112 current retailing strategy to limit upper floor --i- column casings later found to be eccentric to trading. Basically, the building had too many i inverted tee the structural columns, due to rainwater floors, and with demand for office space lim­ pipes and ducting, and in some places • Typical slab panel I, ited and future demand at best uncertain, the access to the structure had been virtually 1 most cost-effective solution was to remove the ~>< I' ~., A , A impossible because of 30 or so years of roof, fourth floor, and most of the third floor. accumulated merchandise, display units and Not all the development was to be refur­ ~!) + ~, ~ general junk in stockrooms. Thus during the bished for retail use. Chartwell identified the design it was decided to revise the building possibility of offering some two-thirds of the ~ , ~ I grid dimensions in line with the original steel­ 2 work setting-out. first floor, 2400m , for leisure use. This space I 215 RC slab I had to be flexible to attract as many potential I O The fact that the original skeleton was a steel tenants as possible. and this was addressed frame, fabricated and erected to relatively by providing a two-storey high void over half -¥ ------close tolerances, enabled much of the this area (Fig.4). Demolition also entailed 5. remodelling to be developed and drawn with removing a large area of second floor. so that Typical construction of original confidence that details would work, prior to a total of four levels of floor were removed in composite floor beam. above: plan on typical bay any investigations on site. As a result the this area. Radical change to the external and below: section A-A. design team was able to keep comfortably appearance was also fundamental to the ahead of site progress, and significant brief, with emphasis on improved durability. 5/8"0 MS links changes were mainly avoided. Out went 'modern' reinforced concrete and in @150C/C Existing structure came traditional brick masonry, ironically Though many fundamental structural aspects mimicking the style of the original buildings. of the original design were deducible from All this sounds quite straightforward - but the limited number of construction drawings, work had to proceed while the ground floor at this early stage several questions re­ tenants continued trading, a restriction 0 mained unanswered. Enquiries of the local applying to about two-thirds of the building

,,<' Temporary A "roor B r------1 i : '. ~------"' '' /I ------r ------~ ------r - - - - - ~------,------~ '. I I I I : I I '' '

... '

c A 1 Install temporary waterproofing generally at second floor 2 Erect scattold

B 1 Commence Phase I demolition works to upper floors 2 Begin internal remodelling, new stairs, escalators, etc

C 1 Erect roof steelwork and make watertight 2 Remodel perimeter concrete profiles to accomodate new masonry 3 Complete demolition works to create 2 storey void (Phase 2 demolition) 4 Complete internal modelling and reclad facades

7. Sequence of refurbishment works.

20 THE ARUP JOURNAL 2/1995 St. Mary's Car Park, Sunderland

8. Ray Noble The 1995 refurbishment. Malcolm Shaw

Introduction St Mary's Car Park, south of Sunderland's fine Wearmouth road and rail bridges, marks the entrance to the city centre. It represents a new concept in car park design, with para­ mount importance given to quality, safety and security for both people and their vehicles. The emphasis is on user friendliness. the steel beams and the concrete casings. The works imaginative and sensitive design with good Given the speculative nature of parts of the Mr. Pilkington. who described himself as a vehicular and pedestrian access. and high 'pioneer in composite construction', loaned project and the usual unknowns of refurbish­ standards of lighting, security and finishes. the original report on full-scale testing of a ment, Chartwell opted for a management two-span beam specifically commissioned type contract. As prime agents. Ove Arup & Partners were fully responsible for the complete design. prior to the design of the store. Together with The five main packages were temporary tests on site samples. the report confirmed waterproofing, demolition, roof steelwork, The project manager's role , and structural, the load-carrying adequacy of the floor beams. concrete remodelling, and masonry cladding. civil, mechanical and electrical services Slabs were a little more straightforward. It is a tribute to the careful planning and design, were all undertaken in the Newcastle However, with span-to-effective depth ratios execution of the demolition that there were office. The Napper Collerton Partnership as high as 45: 1, many panels did not comply no serious injuries during the contract. were architectural sub-consultants. and with modern standards. This manifests itself. Some 18 OOOT of material were broken up quantity surveying duties were shared by not unpredictably, as fairly large long-term and removed. Arups and Bucknall Austin as sub-consultant. self-weight and creep deflections. although Work began in early 1993 and was com­ Continued overleaf: these are difficult to detect without surveying pleted in time for 1994 Christmas trading. equipment or conveniently placed puddles of During the works, the management contrac­ rainwater! Long-term effects, however, had tor had to deal not only with normal site taken place and subject to the new load issues. but also be comforter to the various requirements the slabs were found to be tenants and their particular needs. Principally adequate from basic principle analysis. this involved informing them of works, Remodelled building design progress. and effects on their property. With the rest of the team , Arups developed a Conclusion work sequence to minimise impact on the Such a challenging project exposes the ground floor trading tenants and the public · engineer to many problems not usually (Fig .7) . To keep down costs and temporary encountered on a typical new building. works, the new roof at second floor level was Successful completion of the £5.3M Pavilion designed to act as protection to the existing has given Blackpool promenade a refreshing structure during demolition, and permanent facelift and a change of facilities for both protection to areas of second floor now locals and the many visitors. This change to converted to roofs. The mesh reinforced the seafront will also boost the local postcard concrete screeds used performed so well industry, as Britain's most popular holiday that no significant repairs were needed prior 'Wish You Were Here' demands a retake!. to final asphalting and laying of insulation. Credits The intricate polychromatic brickwork Client: proposed by the architect demanded a Chartwell Land, Meon Projects rationalised approach to ensuring its stability. Architect: Cold-formed stainless steel channel sections Leach, Rhodes & Walker with horizontally-spanning cavity construc­ tion provided the most cost-effective design Structural engineers: Ove Arup & Partners Steve Burrows, Mark Green , solution. Careful consideration of special Rick Houghton. Andrew Marsland. Mike Robinson, brick shapes and bonding arrangements Graham Scull. Rob Silvester. George Suthers was required to ensure flexural continuity Services engineers: without resorting to excessive quantities of MEDA bed-joint reinforcement. Management contractor: Internally the replanning determined that Tilbury Douglas none of the existing staircases or lift shafts Illustrations: were suitable for reuse . These features were 1, 8: Peter Mackinven variously modified, including infill, partial 2: Ove Arup & Partners infill, widening. and conversion from escalator 3: E.T.W. Dennis or lift shaft to staircase. Many new openings 4: Studio D Photography were also created for the three new lifts, two 5. 7: Trevor Slydel new escalators, and 10 new staircases. 6: Rick Houghton Extensive perimeter concrete works were also needed for the necessary profiles and support of the new masonry cladding. These included recasing steel columns affected by chloride contamination and corrosion. and providing upstand parapet walls and new support plinths at first floor level. Although in situ reinforced concrete usually offers the most flexible material for structural modifications to existing structures, all the new staircase and lift shaft framing was designed using steel for maximum prefabri­ 1. St. Mary's Car Park : a new concept cation and rapid progress on site. Concreting in design both for vehicles and pedestrians. was generally limited to infilling openings and Secure. brightly lit and user friendly. trimming new openings. THE ARUP JOURNAL 2/199:i 21 St. Mary's Car Park, Sunderland (cont.)

2. Stone dressed brick work detail, metal security grilles to the lower floors can be seen at right.

4. Aerial view: two metal-clad arched roofs span the parking areas. pedestrian bridge is in foreground .

Design criteria Structure In establishing the design criteria Arups were The structural arrangement is the key to the particularly concerned to avoid the problems overall design, which incorporates clear­ and deficiencies of multi-storey car parks span, open-plan floors with uninterrupted built since the 1970s; those in Sunderland views, improved circulation, and little con­ city centre, for example, are greatly under­ cealment for thieves. Its basis is a series of in used due to vandalism. theft. fear of mugging, situ concrete frames at 16.Sm centres, and and poor vehicular access and circulation. minimal use of internal SOOmm diameter The aim was also to establish a high quality columns. The external columns are on a Sm architectural style appropriate to the city's grid set in the line of the external walls. The in improving image. The architecture evolved situ frames support a floor comprising 16.Sm as an expression of form and structure using long precast concrete beams at 2.Sm cen­ traditional means of scale, proportion, detail tres and precast concrete decking with in situ and materials. Elevations are brick-clad with topping. Downstand beams are minimised. appropriate stone dressings, and articulated The joints between the in situ frame and by the expressed Sm perimeter structural grid. precast elements are cast monolithically, Double-height openings with contrasting ext7nding the life of the building and reducing decorative brick spandrel panels establish a maintenance costs. The floors to the parking strong vertical scale. Metal grilles provide areas are laid to falls to facilitate drainage, security to the lower two floors, while glazing with gullies cast into the floor slab/column to a new pedestrian bridge built over the ring junctions and discharging to downcomers road at second floor level, and to the curved located at column positions. A central in situ curtain walling of the main staircase and lifts reinforced concrete ramp, 6.Sm wide with a provides contrast with the robustness of the slope of 1: 10, provides vehicular circulation brick detailing. A metal-clad roof formed from between floors. Reinforced concrete shear two shallow curved arches. reflecting those walls at the corners of the building supply of the Wearmouth Bridge, spans the main overall stability. The structural design was parking areas. developed in conjunction with the building services and security requirements. The 2.Sm structural grid was designed to coincide with parking bay widths, allowing integration with luminaires at regular intervals.

5. Glazed pedestrian bridge over ring road at second floor level provides direct access to city centre shopping area.

3. Pedestrians leave the car park by staircase or glazed lift to the footbridge.

22 THE ARUP JOURNAL 2/1995 6. Night view of the brightly lit car park. Wearmouth Bridge is seen left of picture.

Servicing, layout, and operation Another integral factor in the scheme was Conclusion Lighting levels have been carefully consid­ consideration of access points for both Site work began in October 1992 and the car ered to create a bright, but glare-free, safe vehicles and pedestrians. The users would park was operational by Christmas 1993. The environment. with good vertical illuminance be mainly shoppers relying on short-term total project cost was £5.4M , a high propor­ to ensure that facial features are well lit. visits of around two hours or less, and the tion of which was devoted to security, archi­ Lighting uniformity is achieved by eliminating total of 484 spaces, including 20 for disabled tectural, and maintenance considerations. dark corners and patch areas. users, are arranged on four levels of parking. The design is now seen as not only setting Internal dimensions are significantly above new standards for car parking in Sunderland Vehicular circulation areas and parking bays standard minimum requirements. Parking but is accepted by the local authority as are naturally ventilated through openings in bays are 2.5 x 5m, with an aisle width of 6.5m establishing levels of civic design in the city the external fac;;ade . However, a roof-mounted to allow unimpeded parking. The headroom that others must emulate. The car park has mechanical extract system augments air is generally 2.2m. Security reasons led to now been in operation for 18 months, during quality to pedestrian circulation areas, lift there being one point of entry and exit for which there has been no reported vandalism, lobby, and main staircase. vehicles at ground floor adjacent to the con­ assault, or thefts from vehicles or of vehicles The layout incorporates control rooms at both trol room, with pedestrian access via the new themselves - a testament to the safety con­ the ground floor vehicle access and the footbridge over the inner city ring road. scious design and client management of the pedestrian access to the footbridge. The The link this forms between the car park and facility. The convenient and efficient 'Pay-on­ ground floor control room houses monitoring the shops marks an extension of the city Foot' system* allows a current throughput of equipment for the extensive CCTV monitoring centre pedestrian network. Access is again some 9500 cars per week; the high percent­ system, which covers all entry and exit enhanced by the use of two glazed lifts age of women users clearly indicates the points, the car parking areas, the main stair serving street and bridge level, in addition success of the design philosophy. and lift lobby, and the pedestrian access to a staircase. over the footbridge through Green Street The designers recognise that design per se *Pay-on-Foot system Arcade to the city centre. Security is further is only a starting point and that the quality of • Customers pay only for time used. enhanced as the two fire escape stairs to management is vital to its continued success. • Computerised logging and payment, the north elevation have doors linked to an However, the adoption of vandal and graffiti­ hence maximum revenue. internal alarm system which operates in the resistant finishes assists in the maintenance • Valid ticket required on exiVentry via control case of misuse. of this facility. The main staircase and lobbies barrier and rising kerb, hence enhanced security. The user friendliness of pedestrian routes is being fully tiled and all exposed concrete • Veh icle counting system incorporated. improved by the incorporation of large painted with anti-carbonisation paint en­ • Financial audit data information provided. glazed areas to the main staircase - hances future performance and mainten­ • Operational security with minimal manpower. designed to department store standard - and ance. The City operates the car park with full­ in the incorporation of two scenic lifts on the time security guards and a manager, and Awards south elevation. This enables clear views the well fitted-out ground floor control room, • Gold Award: both within the car park and to the outside, mess room, and money counting facility now National Secure Car Parks Scheme, sponsored by private industry and the reducing criminal opportunity and increasing form the control centre for the whole of Association of Chief Police Officers (1994) customer confidence in their safety. Sunderland's car parking operations. • Robert Stephenson Award: Design and Concept Category, promoted by the Institution of Civil Engineers Northern Counties Association (1995) • Regional Award: 7. Parking bays: open plan floor provides uninterrupted views with minimal use of internal columns. Norwich Union Safe Car Parks Scheme (1995). Credits Client: Sunderland City Council Project manager and consulting engineer: Ove Arup and Partners Yasmeen AI -Boutie, Andrew Goodfellow, Jennifer Gunn, Nigel Hamson. David H,llcox. Nick Memdew. Garry Miller, Ray Noble. Steve Pearce. Cohn Peart, Malcolm Shaw, Steve Shaw. Scott Wallace Architectural sub-contractor: The Napper Collerton Partnership Quantity surveying sub-contractor: Bucknall Austin Main contractor: Laing (North East) Ltd. Illustrations: 1, 3. 5, 6: Sally Ann Norman 2: N.E. Studios 4: Harry Marsh Ltd. 7: Ian Bambrick

THE ARUP JOURNAL 2/1995 23