Gauge is measured 5/8 inch below the top of the rail, between the faces that the wheel flanges ride against. Standard gauge in North America is 4 feet 8.5 inches, and track that spreads wider can let a wheel drop in between the rails, one of the most common causes of derailment. Federal track standards set the maximum wide gauge for each class of track, and inspectors check it with a gauge bar.
Gauge is running 57 and a half through the curve, the ties aren't holding spikes anymore, get a slow order out.
Track people say track is wide or tight on gauge, and wide is the one that puts trains on the ground.
Also heard as
- track gauge
Related terms
Tie
One of the crosswise beams that hold the rails to gauge and spread their load into the ballast.
Superelevation
The amount the outer rail of a curve is raised above the inner rail, measured in inches.
Slow order
A temporary speed restriction on a stretch of track because of its condition, heat or work in progress.
Frog
The crossing piece in a turnout or diamond where one rail passes through another and wheels cross the gap.