Engine/generator set


Both photographs courtesy Mark Bennett.

The top view shows a generator coupled to a Sulzer 6 cylinder engine at Derby Works. The lower view reveals the generator in situ in 25064, which had been brought into Derby Works for attention. The entire run of the Class 24/25's carried the British Thomson- Houston type RTB15656 generator.

The early performance of the BTH generators was marred by flashover problems, which was eventually cured by reducing shunt field values, external resistance being increased to reduce no load voltages. Mechanical vibration, the bane of most locomotives, caused problems with resistances fracturing, cured along with many other similar problems, by the their renewal with equipment of a more robust design.

The Class 24's featured a rotatable device for checking of the brushgear on the main generator. Unfortunately the ring was easily jammed by dirt, creating an unpleasant task for the people assigned to inspect the brush gear, especially the bottom brushes, which lay just above the drip tray. For the Class 25's a sturdier chain mechanism was used to rotate the brush gear, the modification was not applied to any earlier machines.

The BRCW Type 2's (Classes 26/27) also carried the Sulzer 6 cylinder engine, but the electrical equipment was different. The Class 26's were supplied by Crompton-Parkinson and the Class 27's by GEC (Whitton).

Page added April 22nd 2000.
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