In their new form the locomotives were similar in outline to the N15 class, though suffered from the expectation amongst crews that they were an improved version of this type.

[2] Maunsell looked at the possibility of converting the LB&SCR “Remembrance” or L class 4-6-4 tanks built by L. B. Billinton between 1914 and 1922.

[1] Conversion into the 4-6-0 tender type, entailed removing the trailing bogie, water tanks, and bunker, shortening the mainframes and fitting new cabs;[1] these were of the side-window variety already used on the Lord Nelson class.

[4] The rebuilding caused a certain amount of controversy among footplate crews, with some maintaining that one could not make so many changes and have a reliable locomotive at the end of the process.

[7] However, the rebuilds gained a reputation for rough riding and relatively poor efficiency when compared to the N15s, and were dissimilar in performance to the original L class locomotives, making them unpopular with crews.

[7] Because of this, the class was used on secondary duties, cross-country and inter-regional trains around Basingstoke rather than the heavy London to Exeter expresses for which they were intended.

[12] After the war, the locomotives were turned out in Bulleid's Southern Railway Malachite Green livery with "Sunshine Yellow" lettering.