 For working on other lines, they were fitted with outside shoes, since most lines used a four-rail system, whereas the CLR only used three.The vehicles were numbered L22 and L23 in 1929, and were scrapped in 1936 and 1937.When the City and South London Railway was being reconstructed in 1922, a number of "padded cell" trailer cars – so-called because of their lack of windows – were stripped out, so that lead-acid batteries and charging resistances could be placed in the resulting space.