In October 1951, The Railway Magazine reported on seven new battery locomotives being placed in service by the London Transport Executive. The article examined their use in maintenance, cable-laying and construction work, including operations when the normal power supply was interrupted.
London Transport Battery Locomotives
Seven new locomotives for London Transport
SEVEN new battery locomotives are being placed in service by the London Transport Executive for hauling trains equipped for maintenance, cable-laying, and construction work, and for emergency duties when the normal power supply is interrupted.
The satisfactory performance of an earlier series of nine locomotives supplied before the war has led to the main features of the design being retained in the new locomotives, all of which have electrical equipment designed and manufactured by the General Electric Co. Ltd.
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Operating requirements
Both the pre-war and post-war locomotives are designed for a severe and unusual service. They are capable of operation from the normal conductor rails when the supply is available, or for running on the battery on sections where the power is off. The batteries are also charged from the conductor rails.
On track-laying operations, two locomotives in multiple-unit must handle a 200-ton construction train at 30 m.p.h. on the level when running on the 600-V. conductor rails system, or at 15 m.p.h. when supplied from the batteries. On reaching the section under construction they must be capable of inching the train forward on rough track up gradients as steep as 1 in 30. During cable-laying a single locomotive must handle a 100-ton train and be capable of being driven continuously at speeds as low as 3 m.p.h.
Motor control and electrical equipment
The characteristics required have been obtained by using three combinations of the four motors—all in series, two series pairs in parallel, and all in parallel—together with multi-notch resistance stepping and suitable resistance ratings. All three combinations are obtained on the one controller handle, which provides a total of 28 notches.
In the latest locomotives it has been possible to provide a battery of 1,008 amp.-hr. capacity, as compared with 768 amp.-hr. in the pre-war series, thus giving a higher factor of availability. The main motors are of a standard L.T.E. design as supplied by the G.E.C. for other duties on London Transport railways, but have been slightly modified by the L.T.E. to give them characteristics similar to those of the motors in the earlier locomotives. It is therefore possible to operate the pre-war and post-war locomotives in multiple if required. The motors are rated at 210 h.p. (1-hr.) and 150 h.p. (continuous).
Design responsibility
The locomotives and the equipment have been designed under the direction of Mr. W. S. Graff-Baker, Chief Mechanical Engineer (Railways), London Transport Executive.
