Railway wagon, British Railways, 20T Weltrol H.C, No B900805, 1950.

The British Railways 20T Weltrol H.C. wagon No B900805 is an example of a trolley wagon designed to transport large and heavy large loads, in this case up to 20 tons. “Weltrol” is an abbreviation of “Well Trolley”, describing the design of the wagon, which has a load-bearing floor at the base of a shallow well formed by the side frames and raised ends. This contrasts with a “Flatrol” or "Flat Trolley" wagon, on which a load sat on substantial, girder-like side frames.

As British heavy engineering declined, so did the use of wagons such as these.