Having inherited systems with DC electrification, the LMS built a number of new 3-car electric multiple units.

Similar to the earlier LNWR electric units but with accommodation in compartments (having seating for 40 in first class and 240 in third class[1])), eleven 3-car sets were sent for use on the Liverpool to Ormskirk line, alongside the earlier LYR electric units.

The remainder were used on the Euston and Broad Street DC lines in north London.

[2] In 1932, additional cars were purchased to increase the London fleet to 25 three-car sets.

These ran with the LNWR electric units and additional third class trailers that were marshalled in or between sets to increase train length to seven cars.