The Royal Albert Bridge - a photo on Flickriver

            Saltash, Plymouth

The Royal Albert Bridge is a railway bridge which spans the River Tamar in England between Plymouth, Devon and Saltash, Cornwall. Its unique design consists of two 455-foot (138.7 m) lenticular iron trusses 100 feet (30.5 m) above the water, with conventional plate-girder approach spans. This gives it a total length of 2,187.5 feet (666.8 m). It carries the Cornish Main Line railway in and out of Cornwall. It is adjacent to the Tamar Bridge which opened in 1962 to carry the A38 road.

The Royal Albert Bridge was designed by Isambard Kingdom Brunel. Surveying started in 1848 and construction commenced in 1854. The first main span was positioned in 1857 and the completed bridge was opened by Prince Albert on 2 May 1859. Brunel died later that year and his name was then placed above the portals at either end of the bridge as a memorial. During the 20th century the approach spans were replaced, and the main spans strengthened.

Design
The structure was the third in a series of three large wrought iron bridges built in the middle of the 19th century. It was influenced by the preceding two, both of which had been designed by Robert Stephenson. The two central sections of Brunel's bridge are novel adaptations of the design Stephenson employed for the High-Level Bridge across the River Tyne in Newcastle Upon Tyne in 1849. Brunel was present when Stephenson raised the girders of his Britannia Bridge across the Menai Strait in the same year. From 1849 to 1853 Brunel was erecting an iron bridge of his own; the Chepstow Railway Bridge carried the South Wales Railway across the River Wye and featured a main truss of 300 feet (91 m) with a curving tubular main member and three conventional plate-girder approach spans of 100 feet (30 m), a similar solution to that adopted for crossing the River Tamar at Saltash.

The river is about 1,100 feet (340 m) wide at Saltash. Brunel's first thoughts had been to cross this on a double track timber viaduct with a central span of 255 feet (78 m) and six approach spans of 105 feet (32 m) with 80 feet (24 m) clearance above the water. This was rejected by the Admiralty, who had statutory responsibility for navigable waters, so Brunel produced a revised design to give 100 feet (30 m) clearance, with two spans of 300 feet (91 m) and two of 200 feet (61 m). The Admiralty again rejected this plan, stipulating that there should not be more than one pier in the navigable part of the river.

Brunel now abandoned plans for a double track timber structure and instead proposed a single-track wrought iron design consisting of a single 850-foot (259.1 m) span. As the cost of this structure would have been around £500,000 at 1846 prices (equivalent to £51,510,000 in 2021), he amended the design to one of two main spans of 455 feet (138.7 m) with 100 feet (30.5 m) clearance above mean high spring tide; this was approved by the Admiralty and the directors of the Cornwall Railway.

The two spans are lenticular trusses with the top chord of each truss comprising a heavy tubular arch in compression, which tend to expand in length under load, while the bottom chord comprises a pair of chains, which tend to contract in length under load. By design, these two effects cancel so that there is no net change in length under load. This in turn enables each of the trusses to be supported with no horizontal thrust exerted on the piers, which is crucial in view of the curved track on either side. Between these two chords are supporting cross-bracing members and suspension standards which hang beneath the bottom chord to carry the railway deck which is a continuous plate beam.

That’s enough text… I’ll stop here!

Taken on: November 10, 2022

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The Royal Albert Bridge

1859

Bowstring Suspension Bridge

River Tamar

railways

Cornish Main Line

Great Western Railway

lenticular

iron trusses

Saltash

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Devon

Cornwall

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Sets appears in: • Cornwall Tour - 2022

Groups appears in: • Cornwall • White and Black Photography more » • Historic Bridges • Bridges at Night • Bridges in the UK • Devon & Cornwall • Magic Cornwall • Bridges around the world • Black & White Digital • The Bridge • White/Black • *****FROM MY LENS***** • !!Perfect Composition!! • Bridges, Bridges, and MORE BRIDGES • Cornwall Black & White • Black&White Photo Group « less

Camera: Canon EOS 5D Mark III, f/11.0, 37 sec, 17mm, ISO 400 (more info) (hide info)

Camera:	Canon EOS 5D Mark III
Lens:	EF17-40mm f/4L USM
Aperture:	f/11.0
Exposure Time:	37
Focal Length:	17mm
ISO:	400
Exposure Bias:	0 EV
Flash:	Off, Did not fire
Exposure Program:	Bulb
Exposure Mode:	Auto
Metering Mode:	Multi-segment
White Balance:	Auto
Color Space:	Uncalibrated
Software:	Adobe Photoshop 24.1 (Windows)
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