Railway structures
What it is
Track, formation, bridges, culverts and platforms that carry trains.
How it works
Rails spread wheel loads through sleepers and ballast into the formation.
Diagram: Indiacon original, not to scale.
Main components
Rails, sleepers, ballast, formation, culverts, bridges, platforms, overhead electrification masts.
Key codes
IRS codes, RDSO guidelines. Cited by number only; get the text from BIS or the issuing body.
Notable projects
Bairabi–Sairang line, dedicated freight corridors, Etihad Rail (UAE).