Question

Explain why rails on a railway track are fixed to large wide wooden sleepers.

Answer 1

There are many reasons for sleepers placed below railway track

• Iron rails are fixed over wide wooden sleepers to reduce pressure received from the train by increasing the area of contact, because if surface area increases pressure decreases and vice-versa, they also transfer the loads to the ground underneath. They have one more role which is to hold the rails with correct width apart.
• Iron rails are fixed over wide wooden sleepers because metals have a tendency to expand on heating so if rails would be fixed over any metal then the metal would expand by the heat of the sun and then the rail would become loose which could cause problems in the track
• Wooden or concrete are kept beneath the railway line so that there is less weight of the train on the ground and rail route line may not sink into the ground.
  
  The wooden sleeper is made from a variety of softwood and , oak, jarrah and karri being popular hardwoods, hardwood railway sleepers are generally much more durable and naturally longer lasting.
• Sleepers are provided for to maintain exact gauge distance between rails and to transfer and distribute the load of train to the ground. Sleepers provide an elastic medium between rails and stone ballast to carry vibration of moving train.