Lowmac designs achieve the lowest possible deck height, so as to allow the carriage of tall loads, such as machinery or road vehicles. This is a very long wagon for a two axle design, but bogies could not have been provided without restricting the length of the low deck, which is 15 feet long and only 1 foot 3 inches above rail height. The wheelbase is 25 feet 6 inches, and the wheels are comparatively small at 2 feet 9 inches diameter. As built, this wagon was vacuum braked, but continuing use in the 1990s led to the additional fitting of a through air brake pipe, seen fitted along the outside of the frame.
The wagon was built with a wooden deck, shown removed to give access for repairs to the steelwork required after half a century of use.
This type of wagon was not required in large numbers, and British Railways built just 510 similar wagons. The design may be a derivative of a Great Western machinery wagon.
D. Rowland, British Railways Wagons: the first half million, London 1996.
