Westminster Bridge, London
1739-50 The first Westminster Bridge was built having been designed by the Swiss architect Charles Labelye
1854 Construction started on the replacement bridge. Designed by Thomas Page. Overall length of 826.8 ft and a width of 88 ft, it is a seven-arch wrought iron bridge with Gothic detailing by Charles Barry.
1855 The contractor, Mr Mare, was declared bankrupt; although the work was taken on by others[1] they could not complete it so a Select Committee was established by Parliament to examine the issue[2]
The ironwork of the bridge was made by Messrs. Cochrane, of Woodside, near Dudley.
The bridge was described and illustrated in detail by William Humber. See here for description and here for drawings.
The arch becomes rather flat towards the crown, and a most unusual form of construction was adopted. The arches springing from the abutments are made of cast iron, but transitioned to wrought iron boiler plate for the flatter part of the arch. This is in recognition of the vibration and percussion from moving traffic. The length of these central wrought iron ribs varies according to the span of the particular arch, being 52 ft long and 28" deep for the longest (120 ft) spans. The transition from cast iron to wrought iron ribs can be seen in photo 4 above. Also note that cast iron cross members are used between the cast iron ribs, while riveted wrought iron cross members are used between the wrought iron ribs, although it appears that these have been supplemented by fabricated steel members.
Vulcanized india rubber was used in the joints of the longitudinal girders to accommodate expansion.
The original deck comprised numerous 'buckled' (dished) wrought iron plates measuring 7 ft by 4 ft.
The piers are surmounted by octagonal pillars made from immense blocks of Cornish granite from the Cheeswring and Penrhyn quarries, and weighing 20 to 30 tons.
1862 May 24th The new bridge opened for traffic.
"...The north footway of the new Westminster Bridge was opened to the public at 9 o'clock on Tuesday morning, and affords a spacious promenade. It is 14ft. in width, laid in the Stamford hard-burnt terracotta tiles, 12in. square, and bordered on the edge next the carriage-way by a curb of the red granite of the Isle of Mull. The temporary footway and timbering on the lower side of the bridge is being rapidly removed, so that the details of the whole structure will soon be open to public..." [3]
1924 'On Tuesday afternoon last, precisely at three o'clock, all traffic was held up at either end of Westminster Bridge for a period of five minutes. This interval was sufficient to allow the engineers of Messrs. Rendel, Palmer and Tritton to take readings of the loading conditions of the bridge when free from traffic, while the effect of the sudden renewal of normal traffic was also noted. The information gained during this test will serve to complete the work of testing the bridge, which has now been in progress for about five months. The report on the bridge, which is being prepared by Messrs. Rendel, Palmer and Tritton for the London County Council, is now, we learn, well advanced and will be presented shortly.
The Westminster Bridge was opened for traffic in 1862. It was built by Thomas Page, and work on it was begun in 1859. There are seven arches, each formed of seven [15!] ribs, which are of cast iron nearly up to the crown, where to avoid danger from the concussion of heavy loads they are made of wrought iron. The span of the arches varies from 96ft. to 120ft., and they have a height of from 16ft. to 20ft. above high water level. The design of the bridge was made to harmonise, as far as possible, with that of the adjoining Parliament buildings. Despite the greatly increased weight and speed of the traffic using the bridge, we believe the structure will be found to be very well preserved.'[4]