tenfoot

The gap between the two pairs of tracks on a four-track railway.

If there's a train coming when you're doing pway work, then you should wait in the tenfoot until it passes, not the sixfoot.

sixfoot

The gap between a pair of adjacent railway tracks, where they are running in opposite directions. The actual distance can be anything up to twelve feet depending how fast the trains run, but it's always called a sixfoot.

Standing in the sixfoot is like standing on the lane-marker of a road; you shouldn't get hit when a train passes, but you'll be really close.

We were working in the sixfoot when the ballast gave way under us and I fell into the fourfoot - good job my mate pulled me clear before the train came.

pway

Short for "Permanent way" - the physical bits of a railway line, and the place that people work.

If you have the certificates for pway work, you can be sure of a job for life - there are never enough pway people.