Permanent way

 A permanent way is the combination of rails, sleepers, ballasts,fixtures and fastenings, etc.

This term is used to distinguish the finished and permanent track from a temporary track which is laid for temporary work, i.e. for transporting construction material etc on major construction sites.

 

such a temporary track is removed as soon as the construction completed. the purpose of use of a permanent way is to provide the permanent facility for safety and quick movement of normal  commercial  traffic between the starting and destination stations. permanent way costs nearly 40% of the total investment to the railways.

Requirements of  Ideal  permanent   way

 

The alignment of the should be correct.

The track should process sufficient elasticity. It should also possess sufficient lateral rigidity and stiffness so that it may withstand the lateral thrust and centrifugal forces.

The track should be designed that load of the train should be distribute uniformly over it.

the gauge of track should be correct and uniform.

the track should possess high resistance to damage at the time of derailment and its maintenance cost is minimum.

in straight reaches, the rail level should be same while on curves, proper super elevation should be provided.

the friction between the wheels of rolling stock and rail should be minimum

the gradient should be uniform joints, point and crossings should be designed and maintained properly.

facilities of repair, replacement etc of damage portion of track should be adequate.