Types of rail failure, sketch of rail failure.

 Types of rail failure:-

Following are the types of rail failure

1.  Crushed heads rail failure:-

Crushed heads rail failure are those which have either sagged or flattened. Besides the defect of manufacture, crushed heads are due to,
Sleeping of wheels. Flat spots on wheels which are developed due to skidding of wheels.
Weak supports at the rail end.

2. Square or angular break in rail:-

The rail mein completely broken either in a vertical plane or in an inclined plane.

3. Split heads rail failure:-

  • In this, cracks occur in the middle of the head or pieces are split from the side to the end of the head.
  • If the surfaces of the crack, when opened, a smooth and dark, the defective rail is known as piped rail.
  • This happened either due to cavity formed during manufacture shrinkage of metal when the metal not having been closely welded together.

4.  Split web:-

This is the through crack in the web, through note necessarily runs through the Bolt holes.

5.  Horizontal fissures rail failure:-

These are developed in the rail head. They are more in the form of a fracture and develop gradually.

6.  Transverse fissures rail failure:-

  • It is a cross wire crack which starts from a point inside the head and spreads like contours shape gradually.
  • The broken surface has a smooth oval or round bright spot.
  • This defect is either a manufacturing defect or may occur due to to over straining of metal in service.

7.  Metal in heads:-

The metal in the rail head is forced to flow on the sides due to which the rail head gets widened and depressed.

8.  Horizontal cracks:-

  • These occur at rail ends between head and web.
  • Sach cracks are believed to be due to worn fish plates or insufficient ballast packing under joint sleepers resulting in pumping of joint and consequent fatigue failure of Steel.
  • This defect is either due to fatigue caused by sharing stresses or due to reversal of stresses ( from high compressive to low tensile stresses ) in the rail between supports.
         
Rail failure

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