Keadby Railway Drawbridge

This bridge is a unique sliding railway drawbridge. It is located on the railway line between Doncaster and Scunthorpe where the railway crosses the Stainforth & Keadby Canal.

Due to its large size and low level, it is very difficult to photograph in its entirety. The railway crosses the canal on a very large skew, this makes the use of a sliding bridge possible.

General View of the Bridge from the Canal

The previous bridge was a swing bridge with its pivot located at the other side of the canal to the drawbridge. Some of the remains of the foundations for the swing bridge can still be discerned. One of the main reasons for using a sliding bridge was to facilitate replacement of the old swing bridge, minimising disruption to rail services.

The sliding bridge was constructed in 1925 by Sir William Arrol of Dalmarnock (Glasgow). The structure and much of the mechanism remains original. An interesting feature of the bridge is that it is battery operated. Whilst the bridge is not in use a set of 64 batteries, similar to those used in submarines, are being trickle charged. The bridge is operated using electrical power provided by the batteries. The batteries act as a back up system and they provide DC power to the motors which was originally controlled using a tramcar type of controller.

The bridge comprises an open riveted steel framework which is rectangular on plan and which the railway passes over on a skew. In the railway opened position is supported on the nose abutment, the front wedges and the rear wedges.

Control of the bridge is by a railway signalman from the adjacent signal cabin. An interlock with the railway signalling system ensures that the bridge cannot be opened unless rail traffic is prevented from crossing the bridge.

The main actuators of the bridge are a set of hydraulically driven lifting jacks, two sets of electrically driven wedges and an electrically driven winch haulage drive which operates through an open gearbox with a six foot diameter differential gear. The operation of the bridge is shown diagrammatically in the animation.

Animation of Opening Mechanism

We have carried out a detailed inspection of the machinery of the bridge and have recommended improvements which can be made whilst retaining the existing method of operation and much of the existing equipment.

Lifting Jack

Water Operated Buffer