1. TRACK FITTINGS AND FASTENINGS

2. FASTENING SYSTEM
Rail fastening system is a means of fixing rails to sleepers
Used to keep rails in proper position
Important fittings are:
FISH PLATES
SPIKES
BOLTS
CHAIRS
BLOCKS
KEYS
PLATES

3. FISH PLATES
Fishplate, splice bar or joint bar is a metal bar that is bolted to the ends of two rails to join them together in a track
Maintain the continuity of rails & to allow for expansion and contraction of rail due to temperature difference.
Maintain correct alignment of line both horizontally & vertically.
Fishplate is a small copper or nickel silver plate that slips onto both rails

5. BONE SHAPED
FISH PLATE
FISH BOLTS

6. REQUIREMENTS OF FISH PLATES
They must support the underside of rail and top of the foot
They should allow free movement of rails for expansion & contraction. For this They should not touch the web of rail
They should bear stresses due to lateral & vertical bending moments
They should hold ends of rail both laterally in line and vertically in level
They should not wear due to impact, expansion & contraction
Length of fish plate should not exceed 457mm in India.

7. FISH BOLTS
Holes are drilled through plates and web of rails and then fish bolts and nuts are provided in these holes.
Alternate holes are made elongated and oval shaped so that bolts in the rails will not be turned by vibrations.
Holes are made of larger diameter generally 5mm- 6mm to allow for expansion & contraction.

8. Bone shaped Fish plate
Rail
Hole for Fish bolt

9. SPIKES To hold rails to wooden sleepers.
A rail spike is a large nail with an offset head that is used to secure rails and base plates to sleepers

10. REQUIREMENTS The spike should be
Strong enough to hold rail in position & enough resistance to motion to retain its position
Cheap in cost
Deep as possible for better holding power
Easy in fixing and removal from sleepers
Capable of maintaining the gauge

11. DOG SPIKES Commonly used Hold rail flanges with timber sleepers
Shape of head of spike resembles ear of dog ,hence called dog Spike
Section of spike is square – shape & bottom part is either pointed or chisel shaped
Cheapest, easy in fixing and removing from sleepers
Maintain better gauges

12. DOG SPIKES

13. DOG SPIKES Important points to be noted: 1. Driving:
Plays an important role in determining the holding power of spike.
Driven in a staggering manner. If spikes are placed opposite to each other they have a tendency to split sleeper and have less holding power
2. Blows:
Blows to spike should be centric & regular. Otherwise result in larger holes.

14. DOG SPIKES 3. Boreholes: 4. Number:
Spikes driven into bored holes have slightly smaller section than boreholes & have greater holding power than when driven without boreholes and also crushing of sleepers can be reduced.
4. Number:
No. of dog spikes is 2 per each rail.
For heavy traffic ,upto 3-4.
On bridge sleepers, no. is 4 per each rail joint.

15. DOG SPIKES 5. Auger Dog spikes are bored using 13mm auger.
Holes are bored vertically through sleeper
Verticality is essential otherwise connections will be loose , gauge will be widened , hole become widened and sleeper will decay.
6. Plugging
Due to heavy traffic, when dog spikes gets loose it is driven out and hole is plugged with wooden plug.
Another hole is bored and dog- spike is redriven there.
Plugged holes are called spike killed holes.

16. SCREW SPIKES
Tapered screws with V- threads used to fasten rails with timber sleepers.
Head is circular with square projection

17. SCREW SPIKES Holding power is double that of dog- spike
Resist lateral thrust in better way
More costly
Gauge maintenance is more difficult
Driving operations are similar to dog -spikes

18. ROUND SPIKES Head either cylindrical or hemispherical
Used for fixing chairs of bull headed rails to wooden sleepers
Limited use only

19. ELASTIC SPIKES
To overcome the problems of dog- spikes head absorbs the wave motion of rail without getting it loose.
Provide better grip and result in reduction of wear and tear of rail
Commonly used in British railways

20. BOLTS 1. FANG-BOLT Alternative to round spikes
Not in much use due to difficulty in fixing and removing bolt
19mm in dia and of sufficient length to pass through sleeper

21. BOLTS 2. FISH BOLT Made of medium carbon steel
Length of bolt depends on type
of fish plate used
Too much tightening is prohibited as it prevents free expansion & contraction of rails
Nuts are made of sufficient length to provide a good grip on the bolt with square or hexagonal shape

22. CHAIRS AND KEYS
For double headed & bull headed rails chairs are used to support them in position
Made up of cast iron
Distribute load from rails to sleepers
Chairs have been fixed to the sleeper using wooden spikes screws, fang-bolts or spikes
Chair consist of 2 jaws & a rail seat
Web of rail is held in inner jaw of chair and a key is driven between rail and outer jaw of chair

24. RAIL
KEY
CHAIR

26. CHAIRS AND KEYS Chairs are fixed to sleepers using 3 spikes
Keys may be of wood or metal and may be either straight or tapered
Wooden keys are cheap
Initial cost of steel keys is high. But life is about ten times more than wooden keys. So steel keys are preferred

27. STEWART’S KEY
Stewart’s key: steel plate bend in the form of letter E and a steel wedge.
Steel wedge to keep the key tight against rail web and outer jaw of chair

28. BEARING PLATES Rectangular plates of Mild steel or cast iron
Used below flat footed rails to distribute the load on a larger area of timber sleepers
Placed below rails carrying heavy vehicles at high speed

30. BEARING PLATES Advantages:-
Distribute load to sleepers over a large area and prevent sinking of rail in soft wooden sleepers
Prevent destruction of sleepers due to rubbing action of rail, increase life of sleeper
Help in firm and perfect holding of spikes to sleepers which prevent shifting of rails
Better maintenance of gauge

31. BEARING PLATES Disadvantages:- Plates rattle when loose
When any hole for a spike is failed and a new hole is to be made , all spikes in the bearing plate have to be pulled out which affects good hold of spikes.
When bearing plates are loose , they admit moisture and result in mechanical wear of sleepers

32. Thank you…