The 10 foot wheelbase version of the standard SR 12ton open wagon. 1400 of these wagons were built between 1935 and 1937, using second-hand "worn-out" spoked wheels and rated to carry 10tons. Although the wheels seem to have been the only parts that weren't new, the wagons were referred to as "Rebuilds Type 4". By 1939, most had been fitted with new wheels (probably all of the 3-hole type) and were uprated to 13tons during the war years. During the BR era, they were rated at 12tons.

The kit has "one-piece" floor and solebars. The end and headstock are in one piece, with separate buffers.