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GWR Route: Birmingham and Henley in Arden Railway
Company
Lapworth to Henley in Arden Branch Line: gwrha2813
The newly completed plate girder bridge over the main
Stratford Road at the northern edge of Henley-in-Arden. The bridge was built in
1906 and the view here is looking south into the town. This bridge carried the
single line which connected the North Warwickshire line to the old Henley
branch line.
The steel plate girder design was typical for the period,
being considered to be the most economic for spans from 15 to 80 foot. The type
used here is termed a through bridge with cross girders supported
on the lower girder flange of the main girders to maximise the road headroom
below. Conventional construction would have two smaller steel girders acting as
rail bearers on or between the cross girders positioned directly under each
rail of the track. The width was then covered with waterproofed steel decking
plates, with vertical ballast plates either side, and on this the ballast and
track formation was placed. Later in the 1920s, transverse pressed steel
troughing had largely replaced this cross girder design on through plate girder
bridges. Close inspect will show that the main girder flange is thicker at the
centre of the span where the bending stress is greater and a number of
additional (double) flange plates have been riveted together to give extra
strength. There will be bedplates under the girders at each end, where these
rest on the abutment bedstones. The main girders have vertical stiffeners at
regular intervals to prevent buckling occurring. Additional steel parapet
plates have also been provided above the outer edge of the main girders to
comply with the Board of Trade requirement that all bridges should be provided
with hand rails or parapets not less than four foot six inches above rail level
with projecting platforms for the escape and protection of platelayers (This
was to prevent passengers alighting from a train and falling over the
parapet).
The steel plate girders for this bridge at Henley-in-Arden
were manufactured by E C & J Keays Ltd of Darlaston and has a cast iron
plate bearing their trade mark and the date in the centre panel. The abutments,
wing walls and pilasters were constructed from blue engineering brick by the
main contractor C J Willis & Sons.
Robert Ferris
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