LMS Route: Birmingham New Street to Tamworth

Tamworth High Level Station: mrthl1837

A copy of the 1935 LMS ‘B' plan which shows a number of interesting features. The Wiggington up IB was a searchlight approach-lit colour light. In the early days of colour light signalling, two basic types emerged, the Multi-unit type with a separate bulb and lens for each aspect, and the Search-light type which had one bulb and lens. The aspect shown was determined by the position of a moving spectacle glass, as in traditional semaphore signalling. Approach lighting was applied to certain IB signals and reduced power consumption and bulb wear. The lights in the signal were not illuminated until a train entered upon the track circuit, in advance of the signal controlling the entrance to the intermediate block section. In the case of Tamworth, the Wiggington signal was illuminated by the occupation of TCs 1838-1839. The IB distant was automatically returned to danger upon the passage of the train, and the IB home released by the block instruments. A detonator placer was provided in conjunction with the IB distant, and in the event of the failure of the signal light, this would operate. Normally however, it was held off the rails, and the position of the detonator placer, along with the aspect the signal was showing, the proving of the lamp and the track circuit indications, were all detected in the box. In the event of the TCs 1838-1839 becoming occupied and then clear with 17 (the IB) in the ON position, a train running away on right line alarm bell sounded in the cabin.

Robert Powell Hendry

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