RailThe steel bar the train's wheels roll on. Two run side by side.
TiesThe beams laid across under the rails, of wood or concrete. They hold the rails the right distance apart. In Britain they are called sleepers.
BallastThe bed of crushed stone the ties sit in. It spreads the load and lets water drain away.
SubgradeThe prepared ground the track is built on, under the ballast.
GaugeHow far apart the inner faces of the two rail heads are.
The rail itself: 3 3
HeadThe top of the rail, which the wheels roll on. It is shaped to resist wear.
WebThe narrow middle of the rail. It holds the head up above the foot.
FootThe wide, flat bottom of the rail. It sits on the tie plate. It is also called the base.
What holds it together: 3 3
Joint barA steel bar bolted across the joint where two rails meet. It holds the ends in line. Also called a fishplate.
Tie plateThe steel plate between rail and tie. It spreads the load and protects the tie.
SpikesSteel spikes driven into the tie, their heads gripping the rail's foot. Newer track often uses clips instead.
How this list was compiled: Read 2026-09-27. (1) Wikipedia, Railway track, https://en.wikipedia.org/wiki/Railway_track : rails, sleepers (railroad ties in American English), ballast and the underlying subgrade; flat-bottomed steel rails spiked, screwed or clipped to timber or concrete sleepers, with crushed stone ballast beneath; tie plates that spread the load, and cut spikes widely used in North America; rail joints held by fishplates (joint bars). (2) Wikipedia, Rail profile, https://en.wikipedia.org/wiki/Rail_profile : the head is profiled to resist wear, the foot to suit the fixing system, and the web holds the head above the foot. (3) Wikipedia, Track gauge, https://en.wikipedia.org/wiki/Track_gauge : the gauge is measured between the inner faces of the rail heads. (4) Wikipedia, Standard-gauge railway: 1,435 mm (4 ft 8½ in), used by about 60% of the world's lines. (5) Wikipedia, Track ballast: packed between, below and around the ties to bear the load, hold the track in place and help drainage. Licence: own work
The drawing: Drawn for this site by script, 2026-09-27. Own work, nothing traced. Licence: own work
How it works
These are the parts of a railroad track in three views: cut across, from the side at a joint, and one rail close up. Start with the 5 main parts.
Read the full guide
From the ground up
The subgrade is the prepared ground. On it lies a bank of crushed stone ballast, and the ties sit in the ballast. The two rails are fastened across the ties, the gauge apart.
The rail and its fixings
A rail has a head the wheels roll on, a narrow web and a wide foot. The foot sits on a tie plate and spikes hold it down. Where two rails meet, a joint bar is bolted across the joint.
Tie and sleeper mean the same thing: tie is the American word, sleeper the British one.
Questions and answers
What are the parts of a railroad track called?
The rails, the ties (sleepers) they are fastened to, the crushed stone ballast the ties sit in, and the subgrade underneath. Tie plates, spikes and joint bars hold it together.
What is the gravel under railroad tracks called?
Ballast. It is crushed stone packed between, under and around the ties to carry the weight of trains, hold the track in place and help water drain away.
What is the gauge of a railroad track?
How far apart the inner faces of the two rail heads are. About 60 percent of the world's railroads use standard gauge: 1,435 mm, or 4 feet 8½ inches.