The test train ran through much of 1935 and 1936, and was tried on nearly all of the electrified tracks on the Metropolitan line and the District line. Once the concept had been proved to be reliable, the train was also used in passenger service. Besides the regenerative braking, the acceleration was found to be particularly smooth. When the decision was taken to proceed with the new system on the O and P stock, the test train was dismantled, and the equipment was fitted to three battery locomotives built by the Gloucester Railway Carriage and Wagon Company, which were part of a batch of nine vehicles supplied between 1936 and 1938. The equipment was particularly suitable for battery locomotives, as the lack of starting resistances reduced the amount of power wasted when starting and stopping frequently. At slow speeds, conventional control systems would often overheat, but the metadyne-equipped locomotives could pull trains weighing 100 tons for long distances at speeds as low as without problems. However, the complexity of the equipment, and the difficulty of maintaining the metadyne machine, resulted in the locomotives not being used sufficiently, and they were withdrawn for scrapping in 1977.