GWR Route: Banbury to Wolverhampton

GWR Route: North Warwickshire Line

Birmingham Snow Hill Station: gwrbsh1769

Official Great Western Railway Drawing of the signals for both the down platform line under the canopy and down main line protruding from the canopy above the down platform line (note the loading gauge arc). The drawing is dated 5th August 1936, but little has changed since the original construction, with the exception of the addition of the two white diamond symbols which indicate that track circuit supervision has been installed. Photograph gwrbsh1745 shows the rear of the down main line signals which protrude over the tracks and photograph gwrbsh1768 shows the down platform line signals under the canopy. This drawing shows differences between the two groups of semaphore signal arms;
1) Those external to the canopy over the track have conventional wooden arms with a slight taper, but are only three foot long. This allowed the signals to located closer together and lower which improved sighting for trains entering the station from Snow Hill Tunnel (see gwrbsh1744).
2) Those under the canopy are the same length, but the arms are metal and their pivot point has been moved towards the arm’s centre to fit in with the clearance required under the canopy. The spectacle lenses are also smaller. Both groups of signals have subsidiary ‘Calling On’ (CO) signal arms below the main signals. The arms of these signals are only twelve inches long to reflect their relative importance. ‘Calling On’ Signals were provided to authorise a driver to proceed forward cautiously into the section ahead as far as the line was clear. Normally a ‘Calling On’ signal was not lowered until the train was brought to a stand at it (Rule 44 - 1933).

Robert Ferris

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