5 plank opens & 16 ton minerals. British Railways formed the 'Ideal Stocks Committee' to create a standard range of goods wagons. While the committee noted the advantages of having higher payload wagons reality was that 12 ton wagons were rarely loaded to capacity. The final recommendations for open merchandise wagons were for a wagon similar to the final LMS and RCH designs with a 17ft6in steel chassis but improved with robust corrugated steel ends. For mineral traffic a standardised version of the 16 ton steel bodied wagon was designed, with over 200,000 built in the 1950s to replace wood framed ex-private owner coal wagons, many of which were in poor condition following WW2.Ex-private owner wagons in British Railways service are listed with the 1923 wagons.