Overview
The N7s had superheaters and piston valves. They were unusual (for inside-cylinder locomotives) in having Walschaerts valve gear. They were, as London suburban locomotives, fitted with Westinghouse air brakes.
Some were fitted with condensing apparatus for working on the Metropolitan Line and the East London Line but the condensing apparatus was removed between 1935 and 1938.
Read more about this topic: GER Class L77