page_title: Royal Albert Bridge
section_title: Construction
hierarchical_section_title: Royal Albert Bridge / History / Construction
caption_attribution_description: English: A tide recording machine designed by Isambard Kingdom Brunel to measure the tidal range on the River Tamar at Saltash in Cornwall, United Kingdom, as part of the design work for his Royal Albert Bridge, which was completed for the Cornwall Railway in 1859.
context_page_description: 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 lenticular iron trusses 100 feet above the water, with conventional plate-girder approach spans. This gives it a total length of 2,187.5 feet. 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. Work was carried out during the twentieth century to replace the approach spans and strengthen the main spans. It has attracted sightseers since its construction and has appeared in many paintings, photographs, guidebooks, postage stamps and on the UK £2 coin. Anniversary celebrations took place in 1959 and 2009.
context_section_description: The first work was to properly survey the river bed. On 26 April 1848 a 6-foot (1.8 m) iron cylinder 85 feet (25.9 m) tall was launched into the Tamar. From the bottom of this the bed of the river could be examined to identify its nature and the location of solid foundations. The Cornwall Railway at this time was finding it difficult to raise funds and so most operations were suspended that summer, but a small fund was allowed for Brunel to continue the survey. The cylinder was positioned at 35 different places and a total of 175 borings made.
  In 1853 the tenders for the bridge were considered by the Cornwall Railway Board, and it was decided to let the work to Charles John Mare, a shipbuilder from Blackwall who had built the ironwork for the Britannia Bridge. The fee he sought for building the Saltash Bridge was £162,000, but on 21 September 1855 while constructing the first of the two trusses he filed for bankruptcy. Brunel proposed that the company should complete this first truss itself by its own direct labour, to which the company agreed. A contract for the remainder of the building was awarded to Messrs Hudson and Male.
  Mare's first task had been to establish an erecting yard on the Devon shore with a jetty and workshops. He then proceeded to construct a 37-foot (11.3 m) iron cylinder 90 feet (27.4 m) tall which was to form the work base for the construction of the central pier. This was launched in May 1854 and moored in the centre of the river between four pontoons. The bottom had been shaped to follow the rock surveyed in 1848; once it was settled on the river bed the water was pumped out, the mud within it excavated, and a solid masonry pier built up clear of the water. This was completed in November 1856.
  The landward piers on the Cornish side of the river were completed in 1854 and the girders for these spans were hoisted up to their correct positions. Next to be built was the main truss for the Cornwall side of the river. The lower ties of the trusses formed of chains made from 20 feet (6.1 m) links. Many were obtained from the suspended works for Brunel's Clifton Suspension Bridge and others rolled new for Saltash. The Cornwall span was floated into position on 1 September 1857 and jacked up to full height in 3-foot (0.9 m) stages as the piers were built up beneath it, the central pier using cast iron octagonal columns; the landward one using ordinary masonry.
  With the yard now cleared of the first truss, work could start on the main Devon span. This was similarly floated into position on 10 July 1858 and then raised in a similar manner; it was in its final position by 28 December 1858. After this had been removed, part of the yard had to be cleared to allow the construction of the final landward pier and then the Devon approach spans could be raised up to their final position. The work was sufficiently advanced that directors were able to make an inspection by train on 11 April 1859.
  The Cornwall span had been tested before it was launched. The two ends were supported on substantial timber piers and the remaining scaffolding removed. Static loads of 1.25 and 2.25 long tons per foot (4.2 and 7.5 t/m) were placed on the deck, the deflections measured and any permanent change measured once the road was removed. Now that it was completed, the bridge had its statutory inspection and tests by Colonel Yolland on behalf of the Board of Trade on 20 April 1859. He ran a heavy train over the bridge and measured deflections in the main trusses of 1.14 inches (29 mm) in the Devon truss, and 1.20 inches (30 mm) in the Cornwall one. Overall he described it as 'highly satisfactory'.
caption: A tide recorder designed by Brunel as part of his survey
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