Robert Hudson Ltd of Leeds was one of the main suppliers of narrow gauge equipment in the United Kingdom, supplying a standard range of rolling stock suitable for temporary contractors lines and industrial narrow gauge railways. The 4-wheel wagons were light enough to be pushed by hand, but strong enough for locomotive haulage, so were first choice on operations where wagons had to be man-handled over temporary tracks from a worksite to the more permanent locomotive-worked tracks.
These steel body wagons were mostly built after WW2 when industrial and military narrow gauge lines were in need of replacement rolling stock, often due to the former wood construction stock dating back to WW1 having expired.
The robust steel bodies and smooth surfaces were ideal for handling aggregates, resulting in many still being used today as ballast wagons on heritage railways.