Progress in design and operation of a.c. locomotives and multiple-unit trains

The paper reviews the results of a further five years´ operation of 50 Hz motive power on BR. Individual classes of locomotive are considered, and details are given of the various items of equipment which have given trouble, and of the consequential modifications required. Comparisons are made between the latest class in service and earlier classes, so that the reasons for further changes in the design of this class can be clearly understood. Preliminary details are given of the new class under construction for the extension to Glasgow, and reasons are given for not selecting thyristor control at the moment. The large fleet of multiple-unit trains is reviewed, and various defects and modifications noted. In conclusion, the paper states that, after the bold initial choice of the a.c. system, development was, and must be, based on facts and past performance if a 30-year equipment life is to be achieved.