A total of ten small tank locomotives were grouped together under the name "South London Tanks", which showed a few differences and were built by Craven for operation in the southern suburbs of London. The first was number 212, built in July 1865 and intended for the line between South Croydon and Victoria station. It had an inside frame with inside cylinders and water tanks on the sides and under the cab. Since the tanks had a total capacity of only 645 gallons, in July 1868 another 155 gallon tank was integrated into the front of the frame, extending below the cylinders.
Also in July 1865 followed number 213, which now had an outside frame and belonged to a standard Craven type. It was slightly heavier than the 212, but only had a cylinder diameter of 15 instead of 16 inches. The 214 and 215 followed in November, which had a total of three water tanks in the frame instead of the side tanks. Otherwise they had a lot in common with the 213. In April 1866 Nos. 17 and 216 to 218 were built, again largely identical to the 213 and having side tanks but with larger water and coal supplies.
Number 230, which was completed in October 1866, showed greater differences. The wheel sets were hinged in an inside frame, while there was still an outside subframe. It had a larger boiler and, like the 212, a cylinder diameter of 16 inches. The 231 delivered in the same month showed even greater differences, which had a bogie instead of a trailing axle due to significantly increased supplies.
Most locomotives have been renumbered over the course of their service life. There were no major rebuilds to the locomotives. However, they were only expected to have a relatively short life, as all were scrapped in the first half of the 1880s.
