Disadvantages of Wooden Sleepers
- They are easily liable to attack by vermin and weather
- They are susceptible to fire
- It is difficult to maintain gauge in case of wooden sleepers
- Scrap value is negligible
- Their useful life is short about 12 to 15 years.
2. Steel Sleepers
Due to the increasing shortage of timber in the country and other economic factors have led to the use of steel and concrete sleepers on railways
Advantages of Steel Sleepers
- It is more durable. Its life is about 35 years
- Lesser damage during handling and transport
- It is not susceptible to vermin attack
- It is not susceptible to fire
- Its scrap value is very good
Disadvantages of Steel Sleepers
- It is liable to corrosion.
- Not suitable for track circuiting
- It can be used only for rails for which it is manufactured
- Cracks at rail seats develop during the service.
- Fittings required are greater in number
3. Cast Iron Railway Sleepers
They are further divided into two categories:
- Cast iron pot type sleepers
- Cast iron plate type sleepers
Advantages of Cast Iron Sleepers
- Service life is very long
- Less liable to corrosion
- Form good track for light traffic up to 110 kmph as they form rigid track subjected to vibrations under moving loads without any damping
- Scrap value is high
Disadvantages of Cast Iron Sleepers
- Gauge maintenance is difficult as tie bars get bent up
- Not suitable for circuited track
- Need large number of fittings
- Suitable only for stone ballast
- Heavy traffic and high speeds (>110kmph) will cause loosening of keys and development of high creep
4. Concrete Railway Sleepers
R.C.C and prestressed concrete sleepers are now replacing other types of sleepers except in some special circumstances like bridges etc. where wooden sleepers are used. Concrete sleepers may be of two types:
- Mono Block Concrete Sleepers
- TWIN BLOCK Concrete sleepers
Advantages of Concrete Sleepers
- It is more durable having greater life (up to 50years)
- It is economical as compare to wood and steel.
- Easy to manufacture.
- It is not susceptible to vermin attack
- It is not susceptible to fire
- Good for track circuited areas
Disadvantages of Concrete Sleepers
- It is brittle and cracks without warning.
- It cannot be repaired, and required replacement.
- Fittings required are greater in number.
- No scrap value
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