These wagons were built in Great Britain in the 1980s by the Standard Wagon Company of Heywood, using redundant tank wagon underframes. They have a 17′ wheelbase, a length of 27’1″, a gross laden weight of 50.75 tonnes, and a maximum speed of 60mph. The wagons are fitted with hand wheel brakes, air brakes and English Steel Pedestal suspension units. Disc brakes were fitted to one side of each axle, 180 degrees apart.
Some 40 were built in two batches, 20 in 1988/9, and 20 in 1989/90. All were hired to Allied Steel and Wire and were used on scrap traffic to the Allied Steel and Wire works in Cardiff. Some wagons are believed to have been used for internal traffic at Allied Steel and Wire. All were painted black with yellow chevrons on the buffer beam and around the upper angled surface.