Single bolsters were often used in pairs or as runners beneath extended loads on other wagons. Unexpectedly, BR built more than 8,000, with 4,000 being built unfitted in 1957. They did not last long, with many in internal use and others as match wagons for engineers cranes. Drawing of diag 1/402 in BR Wagons Bartlett et al.
© Paul Bartlett's Photographs