The "H" class wagons were three-plank vehicles of 14' 6" body length, 6' 6" body width with centre-side drop doors. They were originally intended for the carriage of third class passengers in addition to goods and freight, but no evidence exists of them being used for that purpose. However, there are photographs from opening day in 1873 showing the first train had an "H" wagon in use to carry the military band. The wagon was fitted with removable safety railing to head-height for the purpose.

Confident of sufficient goods and freight business, the I.M.R. purchased twenty "H" wagons from Metropolitan for the opening of the line in 1873, followed by a further six from Ashbury to the same basic design in 1877. The Manx Northern Railway purchased twelve wagons of a similar design from the Swansea Carriage & Wagon Co., for its opening in 1879, followed by a further six from Hurst Nelson in 1900. The Manx Northern Railway converted one of its short wheelbase timber trucks supplied by Ashbury into a three-plank wagon in 1901. So after amalgamation in 1904, the I.M.R. had 45 "H" wagons on its stock book, numbered H.1 to H.26, and Hr.27 to Hr.45.

A wide range of wagons were built in-house by the I.M.R. during the first quarter of the 20th century. In 1918, the Douglas Workshops produced a hybrid three-plank wagon H.46, using the running gear from crash-damaged cattle wagon K.15, itself constructed on the old chassis of four-wheel carriage B.5! The "new" wagon had unique brake gear for the "H" class, with centre V-hangers and two-wheel braking.

Records also indicate that the Douglas Workshops built a replacement wagon H.41 in 1925 from a "M" class wagon M.55, the original ex-Manx Norther Railway Hr.41 having been withdrawn and scrapped. However, a 1960 photograph shows 'replacement' H.41 built to an early I.M.R. design and not with the type of chassis from M.55, so its origin is not clear.

In addition to goods and freight, "H" wagons were fitted with wooden frame top railings and used to transport sheep to and from livestock markets when required.

Remarkably, the entire "H" class of wagon was extinct by 1964 and it wasn't until the Supporters' Association rebuilt one in 1998 (after the success of a similar "M" wagon project) that such an item of stock existed on the railway once again. As time and information allows we hope to add some approximate disposal dates and individual photographs for these wagons, anyone who can help with this please contact us!