Nuneham Viaduct
A short article written by an unattributed author, taken from the October, 1908 edition of the Great Western Railway Magazine
NUNEHAM VIADUCT, NEAR OXFORD.
Nuneham Viaduct. - The viaduct illustrated in the frontispiece carries the line between Oxford and Didcot, constructed under the Oxford Railway Act, 1843, over the River Isis,or Thames, near Culham station, 57½ miles from Paddington. Originally a timber structure stood at the place, but was replaced in 1849-50 by a viaduct - or rather viaducts, for separate structures carried the Up and Down Line - formed of continuous plate girders, supported on cast-iron screw piles, carrying a timber decking, with cross girders and rail bearers.
PART ELEVATION OF ORIGINAL 7-SPAN TIMBER VIADUCT. Owing to the increase in the number and weight of trains in recent years, the screw piles, or columns, were unequal to the task of supporting the river spans and were continually sinking. On several occasions the girders were lifted and packed up to a true alignment, but the sinking continued, and in the early part of 1906 a decision was come to that the reconstruction of this portion of the viaduct should be taken in hand. No trouble had been experienced on the land spans, and it was only necessary to reconstruct those crossing the river.
In reconstructing, advantage was taken of the opportunity to remove the three sets of piles or columns situated within the width of the river, and to build in place of them a single pier in brick and concrete faced with brick. Ornamental relief is given to this pier above water level by stone dressings and by two 10-feet arched openings.
A similar pier is built where the new structure adjoins the old at the western end; and the abutment at the opposite end has been faced to harmonise. The river pier was built inside a coffer-dam of ordinary type and was carried down 11 feet below the river be to the Oxford clay.
The superstucture of the new portion of the viaduct, therefore, consists of two spans of 90 feet length, each of which is formed with two bowstring girders outside, 37 feet apart, with a hog-back plate girder centrally between, the whole being completed with cross-girders, rail bearers and steel-plate flooring. As this will be seen from the frontispiece the new structure is effective and attractive in appearance.
A start was made with the reonstruction in March, 1906, and the new piers were in readiness to take the steel-work before the end of the year. Meanwhile the main girders had been built up complete alongside the permanent way at the London side, it being possible to transfer them to the new piers and place them in their final position, approximately, without disturbing the old structure. On Sunday, December 11th, 1906, the six girders were conveyed from their temporary positions and placed on the new piers between the hours of 7.0 a.m. and 3.0 p.m., by the aid of two 20-ton steam cranes. The work was carried out between trains and altogether invilved the handling of about 180 tons of steel-work, the totlal waight of metal in the finished bridge being about 325 tons. Single line working on the Up side was introduced on January 6th, 1907, permitting of the demolition of the old Down Line structure and completion of half of the new viaduct. Trains were transferred to this new portion on February 10th, 1907, and the second half proceeded with, this being brought to a completion and double line working restored on March 16th, 1907.
VIADUCT RECENTLY DISPLACED
Transcribed by Colin and Daniel Taylor, 2022
