In January 1818, less than six months after it opened, Smith’s Dryburgh bridge blew down in a storm. The form of bridge was blamed by authors like Charles Drewry and Claude-Louis Navier, and cable-stayed designs went on to become a rare eccentricity until their revival in the second half of the twentieth century.
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The failed bridge was rebuilt by Smith as a more conventional suspension bridge design by September 1818, and survived for several decades, although it also eventually failed. It's not entirely clear how old the present structure is.
The current structure is a lightweight, unassuming suspension bridge, with metalwork towers. Contrasting it to the stone towers and overweight deck at nearby Gattonside, it’s a much more delicate structure, although its dark green paint counteracts the lightness somewhat.
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The blocks which clamp the hangers to the cables are a bit odd, resembling large blocks of lego, and certainly not original, judging from earlier photographs. Their sheer size detracts from the elegance that should normally be expected from a suspension bridge.
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I can't say I find latticework towers particularly attractive, and there's something to be said for the more monumental masonry adopted at the nearby Gattonside footbridge. Metalwork is clearly more economic, though.
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They really do show how over-the-top the Gattonside design is. The parapets at Dryburgh are unintrusive (green paintwork aside), nothing more than they need to be, and all the better for it.
Further information:
- Google maps / Bing maps
- Structurae
- RCAHMS
- Description of Bridges of Suspension, Robert Stevenson, in the Edinburgh philosophical journal, 1821
- A memoir of suspension bridges, Charles Drewry, 1832
- Some iron suspension bridges in Scotland 1816-1834 and their origins, Ted Ruddock, in The Structural Engineer, 2003
- Civil Engineering Heritage Scotland - Lowlands and Borders
, Paxton & Shipway, 2007
3 comments:
The present bridge was built in 1911. The heavy pates connecting the hangers to the catenary were a response to local corrosion of the plough rope catenary and were once clamped in place injected with resin. As far as possible the original structure was left intact. One of the problems with the bridge was the rigid connection between the deck and the hangers, which proved to be susceptible to fatigue the present detail incorporating rubber bushes allows for articulation and owing to the particular characteristics of the rubber provides damping against excitation.
William Day - williamt.day@btinternet.com
Could this be the mystery bridge shown on your twitter feed?
https://twitter.com/natlibscotmaps/status/1384061707895574528/photo/1
https://structurae.net/en/structures/dryburgh-abbey-bridge#:~:text=The%20bridge%20at%20Dryburgh%20in,720.
An interesting contemporary account of the failure by the bridgebuilders, in "The Penny Magazine of the Society for the Diffusion of Useful Knowledge".
https://www.google.co.uk/books/edition/The_Penny_Magazine_of_the_Society_for_th/obYw4z_kfBMC?hl=en&gbpv=1&dq=dryburgh%20abbey%20bridge%20penny&pg=PA416&printsec=frontcover&bsq=dryburgh%20abbey%20bridge%20penny
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