Railway gauging refers to the size of the cross-section of the train relative to the infrastructure around it. Simply put, gauges ensure that trains do not hit structures such as bridges, platforms, and buildings.

The W10 and W12 gauges are used for freight wagons and containers on the GB rail network. W10 focuses on narrower containers, while W12 provides additional width clearance for larger cargo. These gauges were designed around wagon and container combinations on the network in 2002. They did not cater for some newer wagons.

RSSB research reviewed W10 and W12 to find extra space in these gauging envelopes, allowing allow more combinations of wagons and containers to run. For W10 and W12, a further 64 and 151 container/wagon combinations can be added, respectively. This research also opened more routes to these two gauges, increasing freight’s network access.

The findings are now embedded in railway group standard GERT8073 Application of Standard Vehicle Gauges. Building on this success, a further project is carrying out a similar review of freight gauges W7-W9a and W10a.