Classification of Railway Sleepers - Advantages and Disadvantages

1. Wooden Sleepers

Wooden sleepers are the ideal type of sleeper. Hence they are universally used. The utility of timber sleepers has not diminished due to the passage of time

Advantages of Wooden Sleepers

1. They are cheap and easy to manufacture
2. They are easy to handle without damage
3. They are more suitable for all types of ballast
4. They absorb shocks and vibrations better than other types of sleepers.
5. Ideal for track circuited sections
6. Fittings are few and simple in design

Disadvantages of Wooden Sleepers

1. They are easily liable to attack by vermin and weather
2. They are susceptible to fire
3. It is difficult to maintain gauge in case of wooden sleepers
4. Scrap value is negligible
5. 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

1. It is more durable. Its life is about 35 years
2. Lesser damage during handling and transport
3. It is not susceptible to vermin attack
4. It is not susceptible to fire
5. Its scrap value is very good

Disadvantages of Steel Sleepers

1. It is liable to corrosion.
2. Not suitable for track circuiting
3. It can be used only for rails for which it is manufactured
4. Cracks at rail seats develop during the service.
5. Fittings required are greater in number

3. Cast Iron Railway Sleepers

They are further divided into two categories:

1. Cast iron pot type sleepers
2. Cast iron plate type sleepers

Advantages of Cast Iron Sleepers

1. Service life is very long
2. Less liable to corrosion
3. Form good track for light traffic up to 110 kmph as they form rigid track subjected to vibrations under moving loads without any damping
4. Scrap value is high

Disadvantages of Cast Iron Sleepers

1. Gauge maintenance is difficult as tie bars get bent up
2. Not suitable for circuited track
3. Need large number of fittings
4. Suitable only for stone ballast
5. 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:

1. Mono Block Concrete Sleepers
2. TWIN BLOCK Concrete sleepers

Advantages of Concrete Sleepers

1. It is more durable having greater life (up to 50years)
2. It is economical as compare to wood and steel.
3. Easy to manufacture.
4. It is not susceptible to vermin attack
5. It is not susceptible to fire
6. Good for track circuited areas

Disadvantages of Concrete Sleepers

1. It is brittle and cracks without warning.
2. It cannot be repaired, and required replacement.
3. Fittings required are greater in number.
4. No scrap value