No 174 Mar 2010 1

www.sihg.org.uk

Pontcysyllte Aqueduct Photo: Graham Horn

The Royal Albert Bridge over the river Tamar Photo: Neil Kennedy See Bridges of Britain, page 8

Published by the Industrial History Group and printed by YesPrint 3 Leafy Oak Workshops Cobbetts Lane Yateley GU17 9LW © SIHG 2010 ISSN1355-8188 Newsletter 174 March 2010 2 Contents 3 Venues / Diary: 27 March to 31 May 4 The Manufacture of Margarine by Anne Lea 5 The Klondike Gold Rush of 1896-99 (part 2) by Alan Thomas

7 Industrial Archaeology Review Vol XXXI No 2 Nov 2009 review by Gordon Knowles

8 Bridges of Britain by Peter Cross-Rudkin report by Mike Davison

9 Industrial Archaeology News No 152 Spring 2010 review by Gordon Knowles

Two enclosures with this Newsletter Programme for the 35th series of SIHG Industrial Archaeology Lectures fill in the form now for a Discount! SIHG Membership Renewal / Application Form

Tom Rolt (1910-1974) Centenary The Inland Waterways Association, of which he was joint founder, is organizing a series of celebratory events - including an enactment of his honeymoon cruise trip in Cressy which he described in his book Narrow Boat. IWA SE Region: www.waterways.org.uk

Surrey Industrial History Group AGM & Conservation Award Presentation Chilworth Gunpowder Mills talk by Andrew Norris Saturday 10 July at 1400 Chilworth Village Hall

SERIAC 2010 South East Regional Industrial Archaeology Conference ‘Wings, Wheels & Water’ Saturday 24 April at Chertsey Hall Organized this year by SIHG Details & updates at www.sihg.org.uk

Surrey Industrial History Group Officers Chairman & SIHG Lectures Organiser: Robert Bryson, [email protected] Secretary: Alan Thomas, [email protected] Treasurer: (vacant) Membership Secretary: David Evans, [email protected] Newsletter Editor: Jan Spencer, [email protected]

SIHG is a group of the Surrey Archaeological Society, Registered Charity No 272098 Castle Arch Guildford Surrey GU1 3SX Group Patron: David Shepherd OBE, Group President: Prof AG Crocker FSA Newsletter 174 March 2010 3 Other IA Organisations

Amberley Museum & Heritage Centre: next to Amberley railway station, West Sussex, www,amberleymuseum.co.uk. Basingstoke Canal Authority: 01252 370073. Chatham Historic Dockyard: Kent ME4 4TZ, www.chdt.org.uk. Cobham Bus Museum: London Bus Preservation Trust, Redhill Road, Cobham, Surrey KT11 1EF, www.lbpt.org. Croydon Airport Visitor Centre: Aiport House, Purley Way Croydon CR0 0XZ, www.croydon-airport.org.uk. Croydon Natural History & Scientific Society: meetings: Small Hall, United Reformed Church Hall, Addiscombe Grove, East Croydon, www.grieg51.freeserve.co.uk/cnhss. Cuffley Industrial Heritage Society: Northaw Village Hall, 5 Northaw Road West, Northaw EN6 4NW. www.cihs.org.uk. Didcot Railway Centre: Access via Didcot Parkway Station, www.didcotrailwaycentre.org.uk. Docklands History Group: Museum in Docklands, No 1 Warehouse, West India Quay, Hertsmere Road, London, E14 4AL, www.docklandshistorygroup.org.uk. East London History Society : Latimer Church Hall, Ernest Street, E1, www.eastlondonhistory.org.uk. U3A: http://fetchamu3a.org.uk/home.htm. Greenwich Industrial History Society: Old Bakehouse, rear of Age Exchange Centre, 11 Blackheath Village, SE3 (opposite Blackheath Station). Hampshire Industrial Archaeology Society (HIAS): Underhill Centre, St. John's Road, Hedge End, SO30 4AF. Hampshire Mills Group: contact 01962 852594. Kempton Great Engines: Feltham Hill Road, Hanworth, Middx TW13 6XH (off elevated section of A316), www.kemptonsteam.org. Kew Bridge Steam Museum: Green Dragon Lane, Brentford, Middlesex TW8 0EN, www.kbsm.org. Lewisham Local History Society: Lewisham Methodist Church SE13 6BT. London Canal Museum: 12/13 New Wharf Road, N1 9RT, www.canalmuseum.org.uk. London Underground Railway Society; Upper Room, All Souls Clubhouse, 141 Cleveland Street, London W1T 6QG, www.lurs.org.uk Windmill: near . Newcomen Society London: Fellows’ Room, Science Museum, Exhibition Road, London SW7 2DD. Newcomen Society Portsmouth: Room 0.27, Portland Building, University of Portsmouth, St James Street off Queen Street, Portsea. Portsmouth Historic Dockyard Railway & Canal Historical Society: The Rugby Tavern, Rugby Street, London WC1, www.rchs.org.uk Rotherhithe & Bermondsey Local History Group: at 1945, £1.50. Time & Talents Centre, Old Mortuary, St Mary Church Street, Rotherhithe Village, SE16, www.kingstairs.com/rotherhithe. Royal Gunpowder Mills: Waltham Abbey, www.royalgunpowdermills.com. Rural Life Centre, Old Kiln Museum, Reeds Road, Tilford, Farnham Surrey GU10 2DL. Shalford Mill (National Trust), Shalford Guildford Surrey GU4 8BX. Southwark and Lambeth Archaeological: Housing Co-op Hall, 106 The Cut. Surrey & Hampshire Canal Society (The Basingstoke Canal): Parish Pavilion, Station Road, Chobham, ww.basingstoke-canal.org.uk. Sussex Industrial Archaeology Society (SIAS): www.sussexias.co.uk. Sussex Mills Group: www.sussexmillsgroup.org.uk. Wealden Iron Research Group: Nutley Memorial Hall, Sussex, (North end of village, West side of A22).

SIHG Newsletter No 174 March 2010 DIARY The 35th series of SIHG Industrial Archaeology Lectures starts on 29 September 2010 on alternate Tuesdays, 1930 - 2130 at the University of Surrey (Lecture Theatre F). Enquiries to programme co-ordinator, Bob Bryson, [email protected]. Maps at www.sihg.org.uk Free parking is available in the evening on the main campus car park. Single lectures at £5, payable on the night, are open to all. The Autumn 2010 Thursday Morning Lecture Series at starts on 23 September 2010. Enquiries to Leatherhead programme co-ordinator Ken Tythacott, [email protected]. As seating is strictly limited, enrolment is for the whole course only; casual attendance is not possible.

Diary March / April / May 2010

April 24 Sat SERIAC. ‘Wings, Wheels & Water’. Chertsey Hall, Heriot Road, Chertsey, Surrey organised by SIHG.

Front cover: Pontcysyllte Aqueduct www.geograph.org.uk/photo/198140; Royal Albert Bridge www.geograph.org.uk/photo/210994. Both photos are licensed for reuse under the Creative Commons Licence and are copyright of the photographers Newsletter 174 March 2010 4

Member’s Talk The Manufacture of Margarine by Anne Lea

Margarine was one of the first products of food inch. The residual cake contained 4-6% oil. technology. Napoleon III offered a prize for a butter Solvent extraction was based on the fact that fat is substitute that could be carried by an army. A soluble in organic solvents such as trichlorethylene. This Frenchman called Meges-Mouries won the prize in 1870 form of extraction is more efficient than mechanical by digesting fatty beef tissue with pepsin from a pig or methods, leaving only about 1% oil in the meal. cow stomach. The product was a success. After only four years, 300 tons per day was being produced in Paris Oils are liquid at room temperature and had to be alone. hydrogenated to turn them into solid fats. Hydrogenation involved the saturation of the double bonds within the For a long time only beef fat was used, then some lard fatty acid molecules. This was achieved by heating the was included. Later, margarine was produced from a oil under vacuum to 120 ºC in the presence of hydrogen variety of fats including whale oil. As improvements and a nickel catalyst. occurred in the extraction, refining and deodorising of vegetable oils, they were included. Fats and oils were Margarine contained a water component, generally extracted from vegetable sources by two principal skimmed milk ‘ripened’ using Streptococcus lactis or techniques: mechanical expression or solvent extraction. Streptococcus cremoris. The fat- and water-based components were emulsified in a churn or votator and a The material was ground or rolled. The meal was then stabiliser was added. The margarine was ‘kneaded’ to heated to increase the output. The expeller or screw produce the desired consistency and was then sent to be press is a very old design but can be made to function packed. very efficiently. It can also be operated as a continuous process. The hydraulic press consisted of a stack of Reference plates. The meal was wrapped in cloth and placed in Food Science and Technology layers between the plates,. A hydraulic ram then by Magnus Pyke, 1970 ¤ compressed the stack with a pressure of 2,000 lbs per sq

Flow diagram of the Solvent Extraction Process used for Soya Beans (simplified)

Evaporator Newsletter 174 March 2010 5

The Klondike Gold Rush of 1896-99 by Alan Thomas Part 2 - The Weary Trail

that they formed the boundary with Canada. This boundary had not been defined before the gold rush started. The distance to Dawson was about six hundred miles. After experience with some of the early stampeders in1897 who carried insufficient supplies to last until the following spring, the Mounties insisted that everyone should carry sufficient food and other supplies to last a year. This amounted to a weight of about a ton, for which wheeled transport was not available over the trails to the passes. Horses or mules were used, at least for the first few miles, but the conditions were so severe that they could rarely survive as far at the tops of the passes, which were only about twenty miles from the coast. The animals were treated with great cruelty; one valley on the White Pass trail is still called Dead Horse Gulch. Most of the supplies therefore had to be carried by the stampeders or by porters from the local tribes (who, being Presbyterians, refused to work on Sundays). Each load could be no more than 100-150 lbs, perhaps less, so many trips were needed. The Chilkoot pass, at an altitude of 3,500 feet, was about 16 miles from the coast at Dyea. There were some rest camps on the way, the last one being Sheep Camp four miles from the summit and above the tree line. The slope became very steep here, up to 35 degrees, and in winter was covered in ice, although it was then rather easier to traverse. An enterprising stampeder cut steps in the ice, eventually 1,500 of them, and charged tolls for their use - so he never needed to go on to Dawson. A cable-way was also established. After each load had been carried up to the At first sight the easiest way to get to the Klondike was to go by sea and river, but apart from the distance and the cost, travel between September and May was impossible because of the freezing of the Yukon river. A complication was that most routes crossed the border between the USA and Canada, with a Climbing the consequent liabilty for substantial customs duties on all goods. Chilkoot Pass An all-Canada route was proposed from Edmonton across the in winter North-West Territory and into the Yukon, but this was so difficult that the first travellers took two years to reach Dawson. A so-called all-American route led from Valdez over a great glacier and through the territory of hostile tribes and was only likely to lead to the avoidance of duties if the NW Mounted Police were unable to catch the travellers. The most popular route was to travel by sea from Seattle, Vancouver or nearby ports to Skagway or Dyea at the end of the so-called Lynn Canal at the north end of the Alaskan pan-handle. From these two places - hardly to be dignified as ports - trails led up the coastal mountains to the White Pass and the Chilkoot Pass respectively. The passes were guarded by the NW Mounted Police who posted sentries and Maxim guns to make the point summit the owner descended again by sliding down the ice, so that eventually a deep groove was worn in it. Up to 35 trips might be needed, taking up to three months. As the route crossed the frontier with Canada, the NWMP collected customs duties at the high rate of 20-25% on most items. If goods had been bought in Canada, no duty was charged provided that they had been transported in bond, but this involved payment of fees to the US authorities - so the traveller had to contribute to one government or the other. The route over the White Pass was lower, only about 2,900 feet, but longer - about 20 miles - and just as rugged as the Chilcoot route. The narrow and precipitous nature of the trail led to many accidents and the stampeders frequently found themselves walking over the bodies of dead horses. Once over the passes the trails led to lakes on a tributary of the Yukon river, from whence travel was by boat. Sometimes a collapsible boat had been carried over the pass, but, if not, it was necessary to build one. Whipsawing (pit-sawing) at Lake Bennett The only material available was standing timber, which had to be Newsletter 174 March 2010 6

wages, and a minority actually looked for gold. Unlike Skagway, which initially was a re-creation of the Old West, Dawson was strictly policed, even to Sunday observances, (but they still had saloons, gambling and brothels). In order to ease the problem of travel over the passes, the White Pass and Yukon Railroad Company was formed in 1898, and on 28 May construction began of a 3-foot-gauge railroad. On 18 February 1899 the line reached the summit of the pass, 20.4 miles from Skagway and at an elevation of 2,865 feet. This involved gradients of up to 1 in 25 - the steepest a non-cog railway can cope with - and very sharp curves, and required the boring of two tunnels and the building of numerous wood trestle bridges. Accomplished in only 8½ months, this was an outstanding achievement. The line reached the lakes on 9 July 1899, and on 29 July 1900 it met the Building the railroad construction gang working south from White Horse. (tunnel and trestle) Thus the total time of construction of the 110 mile line was 26 months. However, in spite of this great achievement, the railroad was too late for the mass of felled and then sawn into planks in a saw-pit. In anticipation of this, among the supplies that had to be carried over the passes were pitch, caulking and nails. Thousands of boats were made in the winter of 1897/8, and over 7,000 set out down-river within a few days at the end of May. They had to cope with three sets of rapids, ending with White Horse rapids, before another lake was reached; then more had to be traversed before reaching the Yukon river and comparatively smooth water. The whole trail was policed by the Mounties, who endeavoured to ensure that the boats and their navigators were fit and competent to make the passage. Once at Dawson, accommodation could be found in the huts built by John Ladue, but in the field it was a question of a tent or a self-built hut using what materials were available. In the winter there was a constant battle with cold and darkness. In the summer, heat was a problem and also swarms of mosquitoes so intense they sometimes stopped horses breathing. Mosquito nets were essential day and night. Having reached their destination, some travellers, regarding the journey in the same light as later climbers of Everest - ‘because it’s there’ - went straight home (above) Engine no 73 (below) View from Carriage on Curve again. Others hung about Dawson, taking work for Photos: Alan Thomas

stampeders. Gold dust was found in the sands of Nome, on the coast of the Bering Strait, in the summer of 1899 and some 8,000 men left Dawson in the first week after the announcement - perhaps thankful to be out of the supervision of the Mounties. Gold can be panned there to this day. The railroad continued in use, as commercial mining companies entered the field, and as deposits of copper and other metals were found. It was also critical to the construction of the Alaska-Canada Highway in the early 1940s, and of other roads including one from Skagway to join the Highway at White Horse and to go on to Dawson and beyond. In 1982 the mines all closed. The railroad also closed, but it reopened in 1988 as a tourist attraction. Up to five cruise-ships call at Skagway in the season, carrying up to 8,000 passengers, having travelled the Inside Passage from Vancouver or Seattle. Skagway has perhaps the greatest concentration of souvenir shops (Continued on page 7)

Newsletter 174 March 2010 7

(Continued from page 6) in the world; the Lonely Planet guide notes that one of them is call themselves rich, but only a few managed to keep their called the ‘Alaska Fleece Company’! wealth. The suppliers of equipment and services were probably more fortunate, if less spectacularly so. The ports from which The railway is open to Carcross, 67.5 miles from Skagway, but the stampeders set out, notably Vancouver and Seattle, most tourist trips end at the summit of the White Pass. A steam particularly the latter, experienced great growth in the gold- locomotive draws trains for the first mile or two before being rush period and this became a foundation of their later replaced by two or three diesel engines. The steam engine, by prosperity. Baldwin of Philadelphia, and the line in general, are similar to those of the extensive network, which formerly, apart from a short preserved stretch, extended south from Denver, References Colorado. Big Pan-out by Kathryn Winslow Phoenix House 1952 It is thought that some 100,000 stampeders set out on the Klondike by Pierre Berton WH Allen 1960 various trails, of whom between 30,000 and 40,000 reached White Pass and Yukon Route: www.wpyr.com ¤ Dawson. Only about half this number bothered to look for gold, and of these only 4,000 found any. A few hundred could

Industrial Archaeology Review Vol XXXI No 2 November 2009 review by Gordon Knowles

This issue is devoted to The Archaeology of the Mill The Last Mill on the Eden: Guardbridge Paper Mill, with an editorial and four articles on differing aspects of Fife by Brian Malaws of the Welsh Royal Commission mills. David Gywn, the editor, sets the scene and states on Ancient and Historical Monuments, and Miriam that this issue looks at examples of the technology of the McDonald of the Scottish Commission, is the result of a mill - essentially a machine for processing raw materials joint recording exercise, coinciding with the centenary into usable products, whether foodstuffs or anything of both bodies. They aimed to foster an exchange of else. The time span considered here ranges from the 6th approaches to, and the techniques of recording, in to the late 20th century; from on the one hand a particular of industrial processes. The paper mill at technologically advanced paper mill in Scotland to a Guardbridge fulfilled several criteria; it was of historical technically conservative saw mill of a small Welsh slate importance, having been on the same site since 1870; quarry. there were many varied buildings and structures relating Colin Rynne, from University College, Cork, writes on to the continuous development of the site; it was Water-Power as a Factor of Industrial Location in Early compact and accessible – and it was still at work. The Medieval Ireland: The Environment of the Early Irish site was unique, yet retained items of standard plant to Water Mill. Important new evidence demonstrates that be found elsewhere, and covered a lengthy period of use. conscious decisions on the location of mills employing It was clear, that, as so often found on industrial sites, it various types of freshwater and estuarine supplies were was the processes, rather than the buildings, that were made as early as the beginning of the 7th century. Early more significant, and so recording was concentrated on Irish millwrights increasingly adopted challenging these. locations and Rynne notes that the availability of water- The final paper is A Slate Saw Mill at Twll Coed Slate power was becoming an important factor in the choice Quarry in the Nantle Valley, Gwynedd by Gwynfor of site for larger monasteries. The article is well Pierce Jones, a Consultant Industrial Archaeologist, and illustrated with diagrams and photographs. My only David Longley of The Gwynedd Archaeological Trust. concern is that his observations on reasons for location A 19th century slate sawing machine from the mill at the seem fairly obvious even without recourse to recent disused Twll Coed slate quarry is to be added to the evidence! National Collection of slate quarrying artefacts at the The title of the next article sums up the content very Welsh National Slate Museum at Llanberis. The well. John Smeaton’s Snuff Mill at Chimney Mills, opportunity was taken to carry out a detailed study of Newcastle upon Tyne; Building Recording and the machine before it was removed and to make a Excavations on the Site of the Former Leazes Brewery. photographic record of the building housing it. Previous Christopher Baglee and John Nolan are architectural surveys have tended to be of the whole of a quarry, here consultants and this is a report on the recent programme was an opportunity to record one significant part in of work. The Brewery was established in 1837 on the detail - a slate-saw table - and the building in which it site of a water-powered snuff mill by Smeaton c 1782 was housed. The machine illustrates how the industry and is possibly the only mill designed by him for this was mechanised in the 19th century and also on the way use. Smeaton was the first to describe himself as a ‘civil it reverted to smaller-scale production in the 20th engineer’ and as a ‘professional’ and thus is of national century after the heyday of the industry in the late 19th significance. The only remaining structure on the site is and early 20th centuries had passed. The saw mill was the Grade II listed Leazes, or Transport House, built central to the process, marking a move away from after 1782 but before 1831 and forming part of the later working with under-capitalised quarrymen-proprietors use of the snuff manufactory. It had been incorporated to highly-capitalised factory scale production, and in this into the later brewery and latterly into Newcastle example also by reversion to a smaller scale production University Jones Marine Engineering Laboratories. unit thereafter. ¤ These were demolished after recording in March 2008. Newsletter 174 March 2010 8

SIHG Lecture Series 9 March 2010 Bridges of Britain by Peter Cross-Rudkin report by Mike Davison

Peter Cross-Rudkin is a member of the Institution of Civil leave the wooden support formwork in position as it was Engineers Panel for Historical Engineering Works and has considered to be unsafe to remove it, but before long the river published a number of papers. He chose to restrict his talk flow dislodged it and the bridge has remained there, mainly to UK canal bridges and railway bridges - a vast structurally sound, ever since! subject in its own right - and he then touched on movable Other railway bridges were described - the graceful Balcombe structures and suspension bridges. The talk was illustrated with viaduct on the Brighton line, with its very particular detailing; a large number of slides. Newcastle’s high level bridge; Ribblehead viaduct, that We were first shown some aqueducts built by James Brindley dominates the Pennine landscape; Whitby viaduct, where in the mid-eighteenth century, typically of brick construction caissons were used to form the foundations in the river; Killin, with 20ft spans. Brindley was a millwright and one could sense which had the first (mass-) concrete viaduct in UK; and that he was feeling his way. The next generation of aqueducts Glenfinnian which was also concrete. In those days the was by William Jessop. In 1792 one with a span of 50ft was concrete was rammed - there was no vibration (which is the built, but it partly collapsed. It is said that Jessop offered to modern method) applied to the concrete. Consequently the pay for the rebuilding. A contemporary of Jessop’s was compaction was often rather poor. Thomas Telford who spent his early years in Shropshire and Gradually cast iron gave way to wrought iron, which in turn designed a cast iron aqueduct - the first successful one in this made way for steel. We were shown a lattice bridge in material. John Rennie, another contemporary, designed the Leamington which later had to be propped; and a box girder outstanding aqueduct that carries the Lancaster canal over the over the river Trent which also needed later strengthening; River Lune. This was a massive structure with five 70ft spans. Stephenson’s box girder bridge at Conway, which proved to He understood better than the other two how to design these have good lateral stability; Brunel’s bowstring girder bridge at structures and used iron rods to tie the sides together, a Windsor; and Chepstow railway bridge, now sadly gone. technique that he recommended to Jessop. Rennie is Brunel’s Royal Albert Bridge at Saltash was built in wrought particularly remembered for his work on the Kennet & Avon iron and was a combination of suspension and arch design. It canal and for structures such as the Dundas aqueduct near was opened in 1859, the year of Brunel’s death. In the case of Bath, which opened in 1805. This takes the canal over the the new Tay Bridge, it was noted that it uses some of the River Avon and also, today, the railway line. steelwork from the old bridge. The first bridge collapsed in The structure for which Telford and Jessop are perhaps best 1879 partly as a result of high wind loading but mainly, in known is the Pontcysyllte aqueduct in North Wales. This is an Peer’s view, because the engineer, Thomas Bouch, did not iron trough carried on masonry piers 126ft over the River Dee supervise it properly. Some slides of the Forth Railway Bridge and is today a World Heritage Site. Several slides of this were also shown. structure were shown. It has spans of 60ft and relies, to an Reference was made to some timber railway bridges, such as extent, on arch action. With this structure the towpath was one in Essex (1848) by Joseph Locke, which is still extant. deliberately built higher than the trough in order to reduce the Also there were several timber viaducts on the Cambrian effort required by the horses. In 1813 the Stratford & Avon railway and the Highland railway, and a wooden road bridge canal opened, but here the towpath was at the same level as the on Speyside. base of the canal, making it difficult for the horses - they had clearly not learnt the lesson. Though not an aqueduct, we were Peter moved on to look at movable structures. In Yorkshire, shown Ironbridge, the masterpiece of 1779, closely associated Selby toll bridge, opened in 1791, is still in use to this day with Abraham Darby the ironmaster. With a span of 100ft, this (though now reconstructed), and the railway swing bridge near is really a ‘timber bridge built in iron’; the connection details Goole (1869) is one of the largest in the world. Telford were copied from carpentry joints. designed a swing bridge over the Caledonian canal, and on the Bridgwater canal there is a swing bridge over the ship canal. In A great number of other, less well known, aqueducts were Argyllshire we were shown a canal bridge that moves described. Examples were a leat to an ironworks in Merthyr longitudinally to allow shipping to pass, and in other places in Tydfil where a tramway runs on top and the leat is below; a Scotland there were many examples of bascule bridges built John Nash design where beam sides have a series of cast iron during the period 1810-20. Also shown were Middlesborough boxes for aesthetic effect; a number of Vierendeel* structures transporter bridge and the Isle of Sheppey vertical lift bridge. with 84ft spans produced in Yorkshire; and a timber bridge that was gradually converted into a cast iron bridge to lengthen In conclusion Peter turned to suspension bridges. In Scotland its service life. It was noted that the designers were often based they realised that a stiff truss was required in order to prevent in the foundries, working closely with Telford and Rennie and oscillations taking hold. He then showed one over the River others. Tweed with a 360ft span. He also showed Telford’s Menai bridge, now totally rebuilt, and the Tamar bridge, recently Peter then moved on to railway bridges. His first illustration widened. In conclusion we were shown modern construction was of the 105ft Causey Arch at Tanfield, Co. Durham. This techniques on the Severn Bridge, each suspension cable having was completed in 1787 and was a very solid structure, carrying 11,000 individual strands, all compacted and wrapped against a coalfield tramway. Later examples were the 1826 brick-built the elements. tram road near Stratford-on-Avon and George Stephenson’s viaduct with 50ft spans on the Liverpool & Manchester canal. Peter’s excellent photos of these classic structures, many still He also showed the Bridgend railway bridge, which goes in use today, brought home to his audience the breadth and under the present day M4 motorway. Wolverton (Bucks) had variety of Britain’s bridge building heritage. the only cast iron bridge used for mainline working. There had *A Vierendeel truss has rectangular openings and rigid been a few famous - or infamous - failures of cast iron and its connections in the elements, unlike the more familiar use for railways was eventually banned. Brunel’s slender brick triangular, pin-jointed arrangement. ¤ bridge over the river at Maidenhead, with its 128ft span and flat 5:1 span-to-rise ratio was described in some detail. This was completed in 1838. Initially the builders were instructed to Newsletter 174 March 2010 9

Industrial Archaeology News No 152 Spring 2010 review by Gordon Knowles

In November 2009 a group of AIA and Newcomen colliery worked throughout the nineteenth and most of Society members visited New Zealand. Fred Barker the twentieth century. Closure in the 1970’s was said to describes the visits made in the North Island. In and be due to a water problem, but in any case the industry around Auckland visits were made to the Tamaki River was in decline by then. At its peak in 1923, a workforce Bridge at Panmure, built in 1864-65 with a 40ft swing of 1,073 was producing coal from four seams. The span; to the radio station at Musick Point and to New smallest seam was closed in 1932 but reopened in 1957 Zealand Steel at Glenbrook where iron from the black as an opencast disposal point, finally closing in 1966. sand dunes has been extracted for some 130 years. The The site became a Heavy Goods Vehicle Training industry still flourishes using local coal and the black Centre until 2009 when all the buildings associated with sand. this were demolished. The nearby Museum of Transport and Technology was The excavations were centred on parts of the colliery next visited, where an Avro Lancaster bomber and a where early plans suggested that a number of buildings Short Solent flying boat were among the displays. Next once stood. The form of these was established after the the Nihotupu dam was visited followed by a trip on the site was cleared. The boiler house foundations and diesel hauled 2ft gauge Rainforest Express Railway. The culverts were exposed as well as those of the fan house. heavy engineering works of A. & G. Price in Thames, Bricks from Leeds and Stourbridge makers were dating from 1871, was next on the list. The firm has identified. In all, five phases of colliery growth and made locomotives, gold mining equipment and pumps; change were identified at Gatewen. it still produces castings up to 10,000kg in weight. The Bruce Hedge tells the story of Dandridges Mill in School of Mines, now a museum; the timber mill at Oxfordshire, where the mill site, dating from Domesday, Waipa, a 1964 hydro power station and a geothermal has recently been fitted with an Archimedes screw to station were next visited. This latter system uses hot generate electricity for the housing to which the mill has water from 61 wells at boiling point driving two turbines been converted. A turbine, made by Hett of Brigg, had of 102.6MW and 90MW, covering about 10% of the been used during the later years of the mill’s working country’s electricity consumption. life. The present mill originally had been used, from Other visits were to railway bridges and viaducts; a 1820, for silk spinning, then in 1839 it was converted for military museum; another hydro electric scheme; a corn milling. By the 1920s production was confined to working Flax Museum and one devoted to geological animal feeds, but in the 1930s the machinery was displays; a floating crane and the Karori dam built in removed, with the exception of the turbine which 1874 which provided Wellington’s first public water survived until the recent development of the site. supply. The visits to the South island will be described During WWII the mill had been used as a shadow in the next issue of IA News. factory where components were manufactured for Robert Carr reports the good news that the 85 year old Mosquito bombers and Magister training aircraft. The paddle steamer Medway Queen is at last to be rebuilt developer wanted to harness the water power once again with a completely new hull, using the same plans and and obtained a grant from the low-carbon funding riveted construction methods as when she was first built. programme. The Archimedes screw operates with a New techniques of riveting have been developed 2.4m head and 360litre/sec capacity. The maximum overcoming current health and safety concerns. She was power output is 4.6kW giving an estimated annual built in 1924 by Ailsa Shipbuilding Ltd. at Troon on the output of 17,000 kWh and an annual CO2 saving of 7 Firth of Clyde and became famous as a Dunkirk veteran. tonnes. The development also includes solar Funding has at last been found, from the Heritage photovoltaic panels and a water source heat pump. The Lottery Fund and public subscriptions, to rebuild her. article does not record what is to happen to the turbine - She was in a terrible state and was beached near to whether it is destined for a museum or a scrap yard. Kingsnorth power station on the Medway. The new hull Among the shorter reports it is noted that the future of should be better than the original. Bob describes the Morwellham Quay copper port in Devon is in doubt traditional methods of riveting and compares them with since the county council withdrew their funding. On a the new techniques. Completion is planned for the more positive note the Lion Salt Works have been autumn of this year. A good webcam, with sound, is taken over by the new Cheshire West and Chester available on www.medwayqueen.co.uk/webcam.html Council and a grant of £4.96m from the Heritage Lottery Richard Scott Jones describes the excavations made last Fund has been confirmed. Work to restore the site is year at Gatewen Colliery, near Wrexham in North under way. ¤ Wales, by Cambrian Archaeological Projects Ltd (CAP). The work was funded by the developers of the site. The