The second batch, introduced in 1952, was constructed from aluminium, saving weight and one train was left unpainted as an experiment.

Considered a success, trains were left unpainted or painted white or grey to match in 1963–68.

After World War II it was decided to replace the London Underground trains that remained with hand-operated sliding doors.

These included external 'door open' indicator lights,[5] roller destination blinds,[6] fluorescent lighting[5] and a modified way of displaying the internal advertisements and District line route maps.

One of the most noticeable differences between the R38 Stock and the rest of the R Stock fleet was that the R38 cars featured four small windows in the central saloon between the double doors, whereas the R47, R49, and R59 cars featured just two larger windows in the same location.

[8] In 1962/63 one train of R stock featured in early trials of automatically driven trains, prior to the larger scale trials on the Central Line which preceded the use on the Victoria line.

These trials involved the one eastbound District Line train travelling in automatic mode between Stamford Brook and Ravenscourt Park stations.

[6] The Athens-Piraeus Electric Railways showed interest in purchasing 60 cars of R stock, for use in five-car trains, since the dimensions of that system were similar to the District Line, but the deal fell through.