HOW TRAIN TRACKS ARE LAID
This feat of engineering keeps long carriages in-line and fixed to the ground
WORDSAILSA HARVEY
Railway workers ensure the ballast is levelled out
BENEATH THE TRACK
How each layer of a railway’s substructure plays a role in its safety and stability
1 SUBGRADEA section of natural ground is compacted and levelled to make a stable base for the layers above.
2 FORMATIONThis is a protective layer, made of sand or stone dust, which stops any wet earth from rising towards the track.
3 SUB-BALLASTA layer of crushed stone separates the ballast from the soil and assists with water drainage from the track.
4 BALLASTMade from strong stone like granite, this layer supports the weight of passing trains, spreading it evenly across the ground.