The class E was a 0-6-2T tank locomotive built for goods traffic on the Metropolitan Railway mainline. It was developed from the class E 0-4-4T by adding a third driving axle and using a single radial trailing axle in place of the two-axle bogie. The photo also clearly shows the steam pipe from the condenser that went from the smokebox to the water tank. Designer was T.F. clark, superintendent of the Metropolitan.

Four were built by the Yorkshire Engine Co. in 1901 and numbered 90 to 93. Although passenger traffic on the mainline had already been taken over by electric multiple units in the following years, goods traffic still relied on steam traction. They were renumbered to L49 to L52 when they were passed on to London Transport in 1933. Their withdrawals were between 1957 and 1964.