PERTH WATERWORKS – CONSERVING ONE OF THE WORLD’S EARLIEST CAST IRON FACADES.
Dr David S Mitchell & Christopher McGregor
Presented at the Association for Preservation Technology Conference, Atlanta 2009
Whilst James Bogardus has generally been credited with inventing the cast iron façade form of pre-fabricated construction, the $1.6 M conservation of an unusual Scottish building in 2004 / 2005, and the research undertaken by the authors challenges the validiy of this. Perth Waterworks may well be one of the earliest and most important cast iron structures, hitherto largely unknown.
The use of cast iron for structural columns, beams and spandrels was by the 1820’s reasonably common in Britain and the United States. Sir William Fairbairn (1789-1874) has generally laid claim to the first complete iron building via the three storey flour mill he designed and shipped to Turkey in 1839. This was not however a fully cast iron constructon, instead using wrought iron plates for walls. A fully cast iron lighthouse was constructed in London by Cottam and Hallen in 1844 before being shipped to Bermuda. It utilised the bolted internal flange principle used extensively in cast iron building construction thereafter.
Bostonian Daniel Bager, the pioneer of cast iron façade construction on a mass market basis wrote that he was ‘the first person who practically used iron as a building material for the exterior’ of a structure, refering to an 1842 Boston Shopfront he had erected. Badgers’ shopfront, Fairbairns Mill and Cottam and Hallems lighhouse were all later than Adam Anderson’s Perth Waterworks.
James Bogardus (1800 -1846) has generally been credited with inventing cast iron architecture. The authors would submit that whilst he certainly popularised the material and the technology on a large scale, he did not invent cast iron façade construction. That title may lie at the door of Adam Anderson, the Perth schoolmaster. Bogardus was an inventor, and his move to cast iron buildings was prompted by the two major New York fires in 1835 and 1845.
Cast iron construction was seen as fireproof construction, and Badger established his foundry beside the Columbia Ironworks and the foundry of Daniel Badger in New York, 1848. The modularity of the cast iron components were such that from a limited number of patterns, high volumes of identical components could be cast and assembled quickly. The secret, was of course in the design, the essence of all prefabricated buildings. His first cast iron building was the Milhau pharmacy of 1848 on the West side of Broadway, a five story façade erected in three days.
In the years that followed, Bogardus designed and erected a profusion of cast iron buildings, notably the Sun Building in Baltimore.
Whilst the work of Bogardus was sixteen years later than Anderson, there are some potentially interesting connections. These may of course be cirumstantial, but perhaps there is something more to be learned. Bogardus had married Margeret Maclay in 1831, a Scots immigrant to the united States and daughter of influential Baptist Minister Archibald Maclay. His fine engineering work sustained them in the early years of their marriage. He met John Wylie Thomson, another Scot from Kilmarnock who arrived in New York in 1832, the year that Perth Waterworks was completed, and who was to become his trusted busines partner. We know that Bogardus left America for Britain in 1836 1, for a planned short period to protect his overseas patents. He secured high quality engraving work, however, and remained in Britain for four years. He was joined by his wife in 1838 who wished to visit her family and that of Thomson, in Scotland. It was on a trip to Italy before they returned to New York in 1840, that Bogardus is identified as forming his plans for cast iron architecture ;
‘ It was whilst in Italy, contemplating there the rich architectural designs of antiquity, That Mr Bogardus first conceived the idea of emulating them in modern times, by the aid of cast iron’ 2
Given the Scottish connections with Bogardus and his sharp engineering and inventive mind, it might not be too much of an extrapolation to suggest that Bogardus was certainly aware of the erection Perth Waterworks. Anderson notes that in 1837 the King of Prussia has asked for outline drawings of the building in order that an identical structure be erected in Berlin. Whilst to date no record of such a building has been determined, if the king of Prussia was to learn of it, surely a man in Borgardus’ position would also ?
Perth is situated at the heart of Scotland, some forty miles north of Edinburgh. The river Tay bisects the town, one of the finest salmon rivers in Scotland with a steep runoff from the surrounding catchment (Figure 1).
Figure 1 : Mid Nineteenth Century view of Perth showing Waterworks (Image from D S Mitchell private collection)
Perth Waterworks is an A Listed structure which identifies it as a building of national or international importance. There are around forty thousand listed structures in Scotland, from grade C to A (highest) as designated by Historic Scotland on behalf of Scottish Ministers. Historic Scotland served a number of functions during this project, a statutory consent role for the conservation works undertaken, and as a key funding partner for the project.
As early as 1751 Perth town council proposed pumping a water supply from the Tay, but it was not until 1762 that a timber piped supply was installed, replaced thirty years later in lead. In 1810 The Perth Water Commisioners requested that Adam Anderson evaluate the options of providing a water supply.
Anderson was then local schoolmaster with an interest in science matters. Anderson conducted extensive water sampling, and discovered that general abstraction from the land adjacent to the river brought water that was contaminated from the alluvial deposits borne downstream by the river. However, when sinking a nine foot cast iron pipe into the bed of the Tay itself, he discovered that he could penetrate a clay band beneath the river bed where the staticial pressure forced the water level in the pipe well above the river level, and raising good quality drinking water. Further evaluation identified that the river had eroded through the clay band on Moncreiffe Island on the Tay, and this was selected for the extraction point.
Andersons logic was simple, yet highly effective. Filter beds would be lain on Moncreiffe Island and the water pumped to a high level storage tank or cistern. A deep well would be constructed beneath the ground. The base level of the reservoir was set at four feet above the the level of the highest outlet point in the town to ensure that the water supply would not fail. He designed an additional mechanism to ensure that supplies were maintained to those properties which might be considered marginal (Figure 2).
Figure 2 : Operational Sketch of Perth Waterworks by Adam Anderson (c. 1830). Image courtesy of Perth and Kinross Council Archives.
Anderson first selected a site adjacent to Grey Friars Graveyard, proposing a relatively plain structure given its location. The local residents were unhappy about the prospect of the water supply for the town being in such close proximity to the graveyard, and a new location on the corner of Marshall Place and Tay Street selected. Given the prominent location, Anderson re-designed the building in the ionic order (Figures 3 and 4).
Figure 3+4 : Anderson designs drawing for Perth Waterworks, c. 1830 (Image copyright of Dundee Library)
Firms submitted tenders for the pipework and the cast iron façade work separately. Eleven ironfounders tendered for the casting and erecting the façade work, some of which recorded a manufacture and installation timescale of six months from order 3 . Whilst Scotland was to become the location of a large and specialised collection of architectural ironfounders in the latter half of the Nineteenth Century with famous firms such as Walter MacFarlane & Co, McDowell Steven and George Smith’s Sun Foundry exporting structures around the world, there were few specifically architectural ironfounders in Scotland at that time. The notable exception was Carron Company, founded in 1759 as the first large scale industrial operation in Britain. It is somewhat surprising that Carron does not appear on the tender list, although one of their engine men later applied for the Perth engine man post.
St Johns Foundry in Perth was the lowest bid at £980 which was accepted. A dispute over specification later developed with Anderson, and the firm withdrew it’s bid, citing the death of the foundry manager who had agreed the contract originally. The contract for both the façade and the steam engine was subsequently awarded to the Dundee Foundry 4.
The filter beds were excavated four feet below the river bed with a gravel base. Eight foot walls were built in open stonework to allow water percolation. The beds were capped in flat fine jointed stone to prevent surface water seepage. The entire construction was then buried beneath clay and gravel to offer protection in spate conditions. A masonry well was constructed in the centre of the bed from which a cast iron pipe ran to the bank, and a cast iron trap was constructed to trap sediment . The river pipe had a bore of one foot with a one inch wall thickness, and coated inside and out with India rubber dissolved in linseed oil and coal tar. Anderson designed the system such that the pipe could be flushed towards the filter bed using water from the cistern.
The cast iron wells were sunk to a depth of twenty three feet below the engine house floor, and four feet below the river bed. This allowed the wells to fill largely under their own pressure. Anderson notes that
‘The unremitting exertions of fifty or sixty men with a couple of large pumps in an inclined position were barely sufficient for removing the water, as it flowed in from every side’ 5
The foundations were constructed to take a load of nine hundred tons in Perthshire sandstone and lime, undertaken by the firm of Cameron and Galletly at a cost of £3127 6. The primary cylinder of internally flanged cast iron supported a domed roof atop which was mounted a cupola. A steam pipe was run from the boiler house around the internal face of the cistern to prevent freezing in winter. A steam engine was incorporated to assist water movement. A beam engine was supplied by the Dundee Foundry Company in 1832, with another from Russell of Kirkcaldy the following year.The Dundee Foundry Company are not known for their architectural work, but are recognised for producing engines, notably the Stirling Maxwell engine in later years. As previously indicated the 1830’s was before the architectural ironfounders had become established generally in Scotland.
Perth waterworks opened in 1832 to considerable acclaim. By the 1860’s the works were no longer considered adequate to meet the needs of the burgeoning population, and a reservoir was constructed at Wellsfield. The waterworks became a pumping station to supply the new reservoir. The Commissioners planned to dismantle the ironwork in 1872 to raise funds, but public outcry prevented this. The sole plates of the reservoir and the associated masonry were dismantled and raised £100 in sale. In the same year a new boiler house and office building was erected on the site. In 1878, eighty unemployed men were taken on to dig a new well within the round house and construct foundations for new engines supplied by Boulton and Watt’s famous Soho works.
A further supply was run into the building in 1888 from a new filter above Perth bridge, and a new engine room erected in 1898 to house a triple expansion engine from Glenfield and Co to pump water to the new Muirhall reservoir. Another pumping engine was installed in 1904.An attempt to sink an artesian well was commenced in 1916, but abandoned the following year at a depth of 450 feet. The original two beam engines were removed in 1928, not having been used for thirty years. The site finally closed in 1965 when a new waterworks came online to serve the city.
A campaign was launched in 1967 to save the building by the newly formed Perth Civic Trust, with extensive correspondence between the Trust, the Town Council, and the Ministry of Public Building and Works (the predecessor of Historic Scotland). Interestingly a ‘specialist report’ from Robertson and Robertson of Perth Foundry in 1964 considered the ironwork to be ‘in a remarkably good state of preservation’ 7 but then notes that the frieze section is insecurely fastened and currently held on with wire ! The foundryman does note that bolts were falling off the structure. Morris and Steedman Architects were appointed to convert the building into a tourist information centre, which was completed in 1974. the tradition of technological innovation continued, as the showpiece of the building was a 360 degree scenic projection made possible by fourteen slide projectors.
The original engineering expertise required to cast radiused panels in relatively thin section to form a perfect cylinder, as well as the highly decorative work, was considerable. The radiused panels which form the core of the building were cast in grey iron with internally faced flanges on four sides. These flanges are tapered inwards to effect a better seal. The jointing detail varies from location to location but essentially comprises a wrought iron fitting strip with cast iron cement infill. In some locations leather strips had been used where a fitting problem had occurred. Cast iron cement was invented by William Murdoch, a Scot who worked closely with James Watt and Mathew Boulton 8 . It comprises cast iron filings mixed with sal amoniac (ammonium chloride) which sets hard in the joint, and was used extensively in the jointing of pipework in both steam and water pipes.
The original proposal for the dome was relatively utilitarian due to it’s planned location next to the graveyard, but the current prominent location prompted a more decorative approach. Ionic pilasters and decorative corbels and friezes were cast and bolted through the primary structure to create a more decorative building, including the city crest. References to the paintwork are somewhat conflicting, one specifying that the ornamentation should be a darker colour than the rest of the dome, another that it should be ‘shaded as the stone below’ which matches another quote noting that it would be painted ‘in imitation of ashlar’ at a cost of £13.50 9 . The second approach would appear to be the one employed and ties in with later cast iron façade decoration where the cheaper cast iron could be made to appear like finished ashlar.
The original decorative scheme was unfortunately destroyed in the 1972 restoration, when the structure was coated in a rubber – type paint which caused subsequent problems due to its lack of permeability to moisture.
The 1970’s project adopted a repair in situ approach, with key aspects being ;
ïThe later pumping house to the front elevation demolished to present the site in it’s original configuration.
ïThe masonry to be extensively cleaned.
ïStress fractures to the primary panels repaired by the ‘Metalock’ TM process of cold metal stitching.
ïOther fractures repaired using mild steel flat bar drilled and tapped to the cast iron panels.
ïLimited re-bolting within flanges (the reasons for which became apparent later).
ïRecasting missing or damaged components of the structure in fibreglass.
ïReplacement of damaged stone.
ïReplicating the original urn from Anderson’s drawings, again in fibreglass.
In the 1960’s structural steelwork was added to the interior of the dome to provide structural support to the cast ironwork This work was undertaken by Frederick Braby and Co Ltd of Glasgow, who were themselves manufacturers of architectural ironwork of note in the 19th and early 20th Century.
Thirty years later Perth Council had concerns over the structural stability of the structure, particularly the profuse failure of flange bolts.
Following a major restoration project which involved completely dismantling the building, the building re-opened to it’s current use as an art gallery in late 2005 and we would hope that it will now become more widely recognised for the role it has played in the development of cast iron façade construction, and that it is truly a building of international importance.
1. Margot Gayle and Carol Gayle, Cast Iron Architecture in America (New York : WW Norton & Co, 1998).
2. John W Thomson, Cast Iron Buildings – Their construction and advantages (New York, 1856)
3. Perth Water Commisioners Archive, PCPE20 Bundle 5, Perth & Kinross Council Archives.
4. Perth Water Commisioners Archive, PWCPE20 Bundle 9, Perth & Kinross Council Archives.
5. Anderson quote…………….
6. Perth Water Commissioners Archives, PWCPE20 Bundle 4, Perth & Kinross Council Archives.
7. National Archives of Scotland Papers NAS DD27/4253.
8. Samuel Smiles, Lives of the Engineers, 3 Vol (London, 1862).
9. Perth Water Commissioners Archives, PEWCPE20 Bundle 11. Perth & Kinross Council Archives.
Perth City Archives and the National Archives of Scotland for access to archive documents, Moses Jenkins, Researcher with Historic Scotland TCRE Group, John Sinclair of Allen Gordon & Co, Heritage Engineering, Casting Repairs, Historic Scotland for supporting the writing and presentation of this paper.