The class L consisted of ten 2-4-0T tank locomotives built by the Avonside Engine Co. in 1877. Its boiler was similar to that of the class F 0-6-0ST, but the wheel arrangement with a leading axle was chosen to get better running characteristics in passenger service. The locomotives had small drivers with a diameter of three feet and cylinders of 10.5 by 18 inches. In 1893 and 1894, seven were rebuilt. Three were rebuilt to 4-4-0T by adding a two-axle bogie in place of the leading axle, so that they were now similar to the class L^A. Four also received a larger coal bunker and a trailing axle, so they became 4-4-2T similar to the class L^B.

Soon they were used in other roles since they had become too weak for passenger service. All seven rebuilt locomotives had been withdrawn by 1939. The three unrebuilt locomotives were sold to the Public Works Department shortly after the turn of the century. Later they came to new owners in the industry and finally, all three passed their last years at Portland Cement near Whangārei. All three are still existing and even operational. The photo shows L 508 that was originally numbered L 208.