This wagon was designed during WW2 to carry the large, heavy, cargoes that both civil and military wartime repairs and new construction required. The loads may have included such items as ship's propellers and electrical transformers. With a 20 Ton maximum capacity, 61107 is one of eleven of these wagons built between January 1944 and June 1945 to diagram 1682 and order No. L1887. One of this type was allocated exclusively for work with the Civil Engineer's department of the Southern Railway while the remaining ten, including 61107, were commercial traffic vehicles.
This wagon is an example of the design work of Oliver Bulleid, the final Chief Mechanical Engineer of the Southern Railway. The wagon is constructed from steel castings welded together. This method of construction resulted in a weight saving of at least 12% over similar wagons fabricated from riveted steel platework. The castings were made at the English Steel Corporation's foundry at Sheffield and the wagon was assembled at the Lancing (Sussex) workshops of the Southern Railway.
Originally, short transverse timber baulks were fitted to the bodywork above the wheels. Two removable longitudinal baulks were then fitted to these. The carrying capacity varied according to where the load was supported, up to a maximum of 20 Tons. As built the wagon was fitted with volute springs, which are a flat plate wound into a rising coil. This arrangement could be fitted into a shorter length than conventional laminated (leaf) springing.
The wagon was later transferred into departmental service with the Chief Civil Engineer of the Southern Region of British Railways, becoming DS61107. The open floor of the well was plated over and the timber baulks were removed. It was now a "Flat Trolley" (telegraphic code "Flatrol SA") wagon. Later, in the 1980's/90's, it was fitted with additional steel plate decking, stop blocks and cargo hitches to allow tracked excavators to be safely carried and held down. The volute springs were replaced in later years by round steel coiled springs which, unlike volute springs, are not self damping. The resulting lively ride required these vehicles to be limited to a maximum speed of 25 mph in their latter days of main line service.
In its final years of service DS61107 was based at Three Bridges Pre-Assembly Depot, being one of a pool of Flatrols of various designs used to carry tracked excavators to work sites. In the run-up to the privatisation of British Rail, the methods and amount of track renewal altered, resulting in the closure of Three Bridges P.A.D. and the redundancy of many departmental vehicles. DS61107 passed into the ownership of Mainline Freight which, after privatisation, became part of English, Welsh and Scottish Railways.
As the method of construction of these vehicles is of such significance, DS 61107 was designated under the Railway Heritage Act 1996 by the Railway Heritage Committee in February 2000. When EWSR withdrew the vehicle from service in 2001, it was given to the Bluebell Railway Trust, with the expectation that it be displayed publicly when possible.
Initially on the Bluebell it continued in service as a Flatrol, carrying tracked excavators for various civil engineering projects on the railway. It has subsequently been used to carry a locomotive boiler. In time, to return it to SR condition, new volute springs will be manufactured for it and the BR modifications will be removed.
Recommended reading:
An Illustrated History of Southern Wagons - Volume Four, by Messrs. Bixley, Blackburn, Chorley and King;
Published by The Oxford Publishing Company, 2002. ISBN 086093 4934.
This book may be available from the Bluebell Railway shop.
