The October 1950 issue of The Railway Magazine detailed the reconstruction work carried out following severe flooding on the East Coast main line between Berwick and Dunbar in August 1948. The report describes the replacement of seven bridges, repairs to a damaged culvert near Ayton and reconstruction work near Burnmouth.
The floods of August 1948
ON August 12, 1948, exceptionally severe floods caused serious damage on the East Coast main line between Berwick and Dunbar. The railway was closed completely for nearly 11 weeks, while temporary repairs were executed, and was reopened for goods traffic on October 25, and for passengers on November 1. Although the Great North Road runs at no great distance from the railway, difficulty was experienced in bringing materials and plant to some of the sites, and the preliminary work included the construction of special approach roads. The work of permanent reconstruction was put in hand in the autumn of 1948, and was finally completed on May 21 of this year with the erection of the 71 ft. 6 in. steel girders and concrete decking of bridge No. 130, near Reston, enabling the down track to be laid over it.
Replacing the damaged bridges
On the five-mile section between Grantshouse and Reston, seven bridges carrying the railway over the Eye Water were totally destroyed, and, as a temporary measure, steel bridges of a military type were built to replace them and to restore traffic as quickly as possible. They were erected in such a way that after the reopening of the line to traffic it would be possible to build concrete abutments and wing-walls as substructures for the permanent bridges without causing interference with traffic. This work progressed steadily according to schedule, and on February 19 this year work began on the placing of the new superstructures in position.
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Six of these permanent superstructures are of the deck type, with one pair of steel girders under each line of railway, and the seventh is of the through type with a small depth of construction to give sufficient clearance between the river bed and the underside of the superstructure.
Working Sunday by Sunday
On each of the Sundays between February 19 and May 21 inclusive, with the exception of March 5 and April 9—or on twelve working Sundays in all—the half of each of the six deck-type superstructures, carrying either the up or down line, was replaced. The same procedure in the erection was followed each Sunday.
First, two locomotive cranes removed the girders and the top portions of the steel trestling forming the half of the temporary bridge carrying the up line. The two new steel girders to carry this track—which are of all-welded construction, and with diaphragms fixed in position weighed in all 26 tons—were next brought forward and placed in position. Special dished precast reinforced concrete units in 3-ft. widths were then set on top of the new girders to form a well-deck floor on which were laid the stone ballast and permanent way to carry the up line. On the following Sunday the other half of the temporary bridge was removed and the permanent superstructure erected to carry the down line, the transfer from temporary to permanent superstructures occupying two consecutive Sundays in the case of each bridge.
The seventh bridge
Meanwhile, the seventh bridge, already referred to as of the through type, had been replaced. The work entailing occupation of the line was carried out on the other two Sundays of this period. On March 5, in the first phase, the three main girders, also of welded construction, were placed by railway cranes on a prepared staging to one side of the temporary bridge and the steel joists to form the floor were set in place. On weekdays thereafter the steel joists were riveted to the main girders, and then encased in concrete to form the floor, which was waterproofed by covering with bituminous sheeting.
On Sunday, April 9, in the second phase, the line was completely cut—both up and down tracks being removed by a steam crane—and the new span, complete with deck or floor, and weighing about 350 tons, was slewed with the aid of hand winches into position over temporary runways of steel balls running between old rails. After being rolled into position, the span had to be lowered about 4 in. on to its bearings. This was accomplished by the use of sand-jacks—a simple arrangement of piston and cylinder—by which movements to very fine limits are obtained by the controlled release of sand from an opening in the base of the cylinder.
Reconstructing the culvert near Ayton
In addition to these bridges, the rehabilitation of the railway included the reconstruction of the culvert carrying the Horn Burn under the railway, near Ayton, where the flood waters had been impounded to a depth of some 26 ft. against the railway embankment. At this place, the clay in the 52-ft. embankment had been under water pressure for some weeks before the water level could be lowered and the burn diverted through a temporary culvert. As it was necessary to reconstruct the culvert close to its original position, the hazards of tunnelling through clay in an unstable condition, due to the absorption of water, had to be reduced by the application of electro-osmosis to dry out the material. In this work the Department of Scientific & Industrial Research gave much valuable assistance. The new culvert, 200 ft. long, was constructed with precast reinforced concrete segments, similar to those used in building the London tube railway tunnels, and is being lined internally with reinforced concrete placed in situ to give a finished internal diameter of 9 ft.
Repairs near Burnmouth
Another item in the 1948 flood damage was a slip which occurred in the embankment at milepost 53½, near Burnmouth. At this point the main line runs close to the sea, but about 200 ft. above the foreshore. As a temporary measure, the line was at first moved some 8 ft. to the landward side to permit the passage of trains at reduced speed. Boring operations here proved the presence of rock at reasonable depth below the railway formation, and mass concrete retaining walls and a bridge have now been constructed as a permanent repair. 400 yd. of new retaining wall built on the landward side has allowed the tracks to be re-aligned here for normal high-speed running.
Speed restrictions lifted
The speed restrictions which have operated since October, 1948, over the seven bridges, and between Burnmouth and Berwick-on-Tweed, were lifted when the summer timetable came into operation, and, later, when full speed is also permissible over the embankment at Ayton culvert, a chapter of events unprecedented in the history of railways in Britain will be brought to a close.
