RAIL FASTENINGS

1
Rail fastenings

• Rail fastening are used to keep the rails in
  proper position and to allow for expansion and
  contraction, maintain required tilt of the rails,
  maintain set the points and crossings properly

2

• Fittings
• Fish plate
• Bearing plate
• Spikes
• Chairs
• Bolts
• Keys

3
Fish plate

• Functions
• Provide full expansion and contraction
• Bear vertical and lateral stress without
  distortion resist wear
• Provide easy renewal and replacement

4
Bearing plate

• F.F rails do not provide adequate bearing area on
  the timber sleepers and hence bearing plates are
  used to distribute the load over larger area
• In case of D.H and B.H rails bearing plates are
  not required
• These plates are fixed to the sleepers by spikes.
  It can be made of cast-iron or steel

5

• Limitations
• Pressure distributed over larger area
• Widening of gauges on curve can be eliminated
• By preventing rubbing action of rail life of
  timber sleeper increased
• When bearing plates are loose, they admit
  moisture and result in increase of mechanical
  wear of the sleepers
• When any hole for spike is injured and the new
  hole is required to be made in such case, all the
  spikes in the bearing plate have to be pulled out
  which spoil the good hold of the spikes

6
Spikes

• For holding the rails to the wooden sleepers,
  spikes can be used
• Types
• Dog spikes
• Screw spikes
• Round spikes
• Standard spikes
• Elastic spikes

7
Bolts

• It can be used for fixing the track components in
  position
• Types
• Fish bolt
• Sloping lips
• Straight lip
• Rag bolt
• Fang nut and bolt

8
Keys

• Keys are used on indian railways for making
  different rail connections
• Types
• Metal keys
• Stuarts key
• Morgan key
• Wooden keys

9
Kinks in rails

• When the end of adjoining rails move slightly
  out of position shoulder or kinks are formed
• Causes
• Loose packing _at_ joints
• Defect in gauge and alignment
• Defect in cross level _at_ joints
• Uneven wear of rail head

10

• Effects
• Obstruct smooth running of trains
• Measures
• By correcting alignment _at_ joints and _at_ curved
  locations
• Proper packing _at_ joints
• Proper maintenance of track periodically in
  respect of cross levels, gauge, alignment etc

11
Creep of rails

• Creep is defined as longitudinal movement of
  rails in the track. Creep is common to all
  railway track, but varies in magnitude
• Measurement of creep

12
Effects

• Sleeper move out of square and out of position.
  This affects the gauge and alignment of track
• If any rail is removed from the track for any
  purpose, it becomes difficult to fix it again at
  proper position
• Rail joints get opened
• Surface of track get disturbed
• Alignment of track get disturbed

13

• Remedies of creep
• Pulling back the rails
• Provision of anchors
• Use of steel sleeper
• Use of good quality of ballast
• By improved drainage
• By increasing sleeper density