Creep of Rails
It is a horizontal movement of rails in a track. It can be minimized but cannot be stopped.
Causes Of Creep|
There are three main causes of Creep
- Wave motion of trains.
- Expansion and contraction of rails due to variation in temperature.
- Due to starting, accelerating, slowing down (decelerating) and stopping of trains.
- When train passes on a track, the portion of rail length under the wheel of train will under more stresses and little depression will exist.
- As a result, this depression will cause (set) a wave motion in the rail or track
Direction Of Creep
Alignment Of Track:
Creep is more on curve track than on a tangent portion (straight track).
In upgrades tracks, Creep will be less and in down grades track Creep will be more.
Direction of movement of trains:
Creep will be more in the direction to which the loaded train moves more.
Extent Of Creep
- Creep does not vary at some constant rate. (it is not constant)
- Creep does not continue in one direction only.
- Creep for two rails of the track will not be in equal amount.
Result Of Creep
- Expansion gap is reduced, buckling of track take place.
- Sleepers are moved out of a square.
- Crossing points get disturbed.