Cutter Bridge, Ely

RAPID BRIDGE CONSTRUCTION. DETAILS are published of a piece of engineering construction which reflects great credit upon the staff of the Great Eastern Railway. The Cutter bridge which passed over the River Ouse at Ely was an old timber and cast-iron girder structure which was put up in 1845, but was not considered equal to the heavier rolling stock of the present day. It had, therefore, been decided to substitute for it a bridge of wrought-iron girders, and having, too, a single span across the river, on brick abutments, in place of the three spans and wooden piles of the old bridge. This new bridge was to have 75 ft. on the square and 91 ft. on the skew, and the problem that engineers and contractors set themselves to solve was how to put the one bridge in place of the other with the least possible interference with any of the ordinary trains, whether passenger or goods, the point in question being one of the busiest on the company's system.
The first part of the programme to be carried out consisted in the construction of the new bridge on temporary staging on one side of the line parallel with and clear of the existing bridge, so that it would be quite ready for placing in position as soon as the latter was taken away. This was done, and on Saturday the new bridge, complete in every respect, including the lines of the permanent way thereon, was to be seen standing alongside the main line in readiness for the work of sunday. The ends of the main girders were supported on small "trolleys," and each of these worked on a rail placed on longitudinal timber on the top of the temporary staging, so as to allow of the new structure being eventually drawn into position.
At ten minutes past one on Sunday morning operations were begun. In ten minutes the first rail on the up line had been removed, and in another ten minutes the first girder was being carried off by two locomotive steam cranes working on the down line. The scene was illuminated by powerful Wells' lights, and girder after girder was carried off steadily increasing the gap. The wooden piles which had supported the girders were sawn through above water level, and the "crowns" carried off by the cranes, the lower portions being left to be "drawn" on a future occasion. At last the up line and the greater portion of each of the particular piles on which it had rested had been cleared right away, leaving only the down line and its supports standing. Then came the most interesting feature of the morning's work — the "traversing" or drawing sideways of the new bridge so that it would occupy (until the whole of the old bridge had been removed) the place where the up line had formerly stood. This traversing was done by means of two ropes worked by winches, and, although the massive structure weighed, including rails and timber, something like 120 tons, it was drawn into its half-way position — a distance of 15 ft.— within a minute or two over half an hour. By this time it was nearly six o'clock in the morning, and the actual time taken by the operations referred to was only about 3 1/2 hours. Work was resumed at noon, and the workers, about forty in number, proceeded to clear away the down line. The whole length of girders was removed bodily to one side along temporary piers constructed in the river bed at the same height as the piles supporting the girders, and 3 hours were required to complete this operation. The new bridge was then brought into position, for the remainder of the distance, in half-an-hour; the connections between the rails and with the abutments were completed, and at 8 o'clock in the evening the express from Norwich to London passed safely over the new bridge. The substitution of the new bridge for the old one had taken about 11 hours' actual working, and had involved scarcely 4 hours' interruption of traffic. The work was carried out under the supervision of Mr. Wiison, engineer, and Mr. Morgan, assistant engineer, of the Great Eastern Railway Company, while Mr. Anderson, the managing director of Messrs. Head, Wrightson and Co., and Mr. Young, London manager, represented that firm, who were the contractors. '

The reconstruction work was illustrated and described in some detail in Engineering 1895/12/06.

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