 Despite the advantages, their complexity resulted in them becoming unreliable, and they were withdrawn in 1977.L41 and L42 were scrapped soon afterwards, but L43 was used for testing purposes for a further three years.The locomotives fitted with GEC controls used an electro-pneumatic controller, with 28 steps, which allowed the four motors to be connected in series, in two parallel-series pairs, and all in parallel as the speed increased.