- Left : Tightening the fastenings on mono-block sleepers - Right : Mono-block sleepers in the foreground and twin-block sleepers in the background
- (Photo at left : JJ D’ANGELO)
(Photo at right : ETF-DROUARD)
Sleepers are members made of wooden, metal or concrete. They are placed across the track in order to hold the rails to gauge and transfer loads from the rail to the ballast.