[1] The locomotives worked on the Fell mountain railway system and had four horizontal driving wheels between the frames, gripping a centre rail and providing the extra adhesion needed for the climb.

After the Second World War, the locomotives were starting to show their age, and the New Zealand government was looking for a way to cut the time between Wellington and the Wairarapa.

The last revenue service for the H class was on 29 October 1955, when locomotives 199, 201, 202, 203 and 204 hauled a Carterton Show day excursion train up the incline on the return journey to Wellington.

After the closure and dismantling of the line, in February 1956 all of the H class - except H 200 which had been out of service for some time with a collapsed internal steam pipe - were towed to Hutt Workshops.

At the opening ceremony for the Rimutaka Tunnel on 3 November 1955, the then Minister of Railways John McAlpine gifted locomotive H 199 to the town of Featherston.