Bath Bridges: 1. Pulteney Bridge

I spent some time in Bath recently to attend an IABSE conference on the subject of "creativity and collaboration". It was a very enjoyable conference, with plenty of material relevant to bridge designers, but I doubt I'll have time to capture any details here.

However, I did get time to visit three of the city's most significant bridges, which I'll feature across my next three posts.

First up is probably Bath's best known bridge, the Pulteney Bridge. This is one of very few historic inhabited bridges still existing in the UK, although at one time there were many, with fine examples in London, York, Durham and Newcastle, to pick just four.

The survivors include the High Bridge in Lincoln, a somewhat unprepossessing structure in Frome, and the well-known house on a bridge at Ambleside.

Approached from the south, Pulteney Bridge is an impressive structure, its three arches sitting astride the River Avon, a splendid backdrop to the crescent-shaped river weir. When first built, it connected the city of Bath to the Parish of Bathwick, an estate owned by the Pulteney family since 1726. In 1769, William Pulteney advanced plans to replace the existing Bathwick ferry with a permanent toll-free bridge, petitioning for the first of two Acts of Parliament.

The initial plan for a three-arch masonry bridge was prepared by Thomas Paty. This did not include the rows of shops which are now the bridge's most notable feature. Robert and James Adam became involved in the project in 1770, and progressed on the basis of an inhabited bridge, a concept which at the time may have been considered a relic of the past, with the well-known British examples being mediaeval in origin. Indeed, Bath Corporation objected to the proposal: "It has been for some years past an uniform practice throughout the Kingdom to avoid and condemn incumbrances of this kind".

Robert Adam's proposals owed much to an unused proposal by Palladio for the Rialto site in Venice, although more practical and less extravagant. Adam designed an entirely symmetrical structure, supporting twenty-two shops, each with an attic and some with cellars hidden within the arch spandrels (the circular cellar windows are a highly visible feature). The bridge was completed in late 1773, at a construction cost of £8,183.

Significant changes to the bridge were made in 1792-1794, to a design by Thomas Baldwin, increasing the height of the shops, knocking some shops spaces together, adding second storey windows and making other alterations. Author Eric de Maré commented on the result of this and other works that "the original house part has unfortunately been pathetically travestied by alterations".

In 1799 and in 1800, flooding cause severe damage to one of the arch piers, resulting in several of the shops being demolished. A design by Thomas Telford for replacement with a single-span cast-iron arch bridge came to nothing, and instead the north elevation of the bridge was rebuilt to plans by John Pinch, which echoed but did not precisely match Adam's design. The difference is readily visible on the road elevations.

Although the bridge was not damaged by flooding again, the rows of shops saw significant alterations during the course of the 19th century. Cantilevered structures began to appear on the external facades of the bridge, like isolated barnacles on the southern face and eventually encrusting the whole of the north face. These provided additional space for shop tenants, and echo the cantilevered structures which still adorn Italy's Ponte Vecchio, and which were common on other inhabited bridges in the middle ages. They seem to be a popular idea in Bath: I spotted them on other buildings elsewhere in the town.

Today, the entire north façade remains cantilevered, its appearance having been largely fixed since the 1870s.

Further alterations were made to the bridge in the early 1900s, with the west end of the southern row of shops being demolished and reconstructed, so that the end pavilion now sits above the arch rather than above the abutment. I doubt that many visitors spot the loss of symmetry, although Robert Adam undoubtedly would.

More recent changes have been with a conservation and restoration ethic, removing the "blisters" from the southern façade and between 1938 to 1951 reinstating parts of the elevations (with work interrupted by war). Further changes to the shopfronts were made in 1975 with a view to more closely matching the original designs.

What I find most interesting about Pulteney Bridge is the contrast and tension between the perfection of form sought by its original designer, and the loss of integrity of the original design over time. I like the extent to which this humanises the bridge; after all, we all acquire an accretion of defects, blemishes and a loss of symmetry as we age. The restorationists may not have got their hands on the jumbled north elevation yet, but clearly would like to gradually obliterate each departure from the original concept as time and funds permit. My guide here owes more to the ideas of Stewart Brand in his excellent book "How Buildings Learn" - that a successful building is one which can adapt to use.

I think the main failing of the original design is commercial - the desire to maximise income by lining every inch of each edge of the bridge with shop units. Compare the Rialto Bridge in Venice, where there are gaps in the retail arcades at the crown, and also walkways outside the shops, so that bridge users can enjoy the river more directly. Even the heavily-built Ponte Vecchio has openings from which the river can be viewed. It would be interesting to see the different reactions which would arise if it were proposed to open up any of Pulteney Bridge's retail units as public space, so that road users can also view the river.

The bridge also makes me wonder about how a modern inhabited bridge could be designed. A criticism often expressed whenever such a thing is now proposed is of the extent to which it inevitably blocks views up and downstream. The proximity of tall buildings to the riverside edge is such that Pulteney Bridge is less guilty of this than it might otherwise be. The question also arises as to how an inhabited bridge can be designed to be adaptable, with the design life of retail units being significantly shorter than the design life of the supporting bridge. Symmetry is much-prized in design, but a bridge which starts life with asymmetrical blisters and blemishes would be an interesting concept.

Further reading:

• Google maps
• Wikipedia
• Structurae
• British Listed Buildings
• Bath Past
• Transport Trust
• British Bridges (Johnson and Scott-Giles, 1933)
• The Bridges of Britain (De Maré, 1954)
• Bridges in Britain (Wood, 1970)
• Pulteney Bridge (Manco, Architectural History, 1995)
• Living Bridges (Murray and Ann-Stevens, 1996)
• An Encyclopaedia of Britain's Bridges (McFetrich, 2010)
• Bridge of the Month (Bill Harvey Associates, 2017)