Our machines look after the tracks to keep trains running smoothly and safely
Tampers and stoneblowers are track maintenance machines that make sure the track is correctly aligned and has a smooth level along the rail. They help to prevent the risk of trains derailing, and ensure smooth, comfortable journeys for passengers and freight trains. These machines generally work at night when no trains are running.
Tamping machines restore the line and level of the track by correcting its vertical (height) and lateral (left or right) profile.
They do this by inserting large tools called tines into the ballast – the stones beneath the track – and then forcing the tines together to move ballast under the sleepers. The tamping machine moves additional ballast under the sleepers to raise the height of the track and can move the track sideways if required.
It is programmed with geometrical data that shows where the track should be, and compares the data with the actual track position using on-board measuring equipment. The machine then calculates the required movements to reposition the track according to the geometrical data.
Some tamping machines can be used to treat switches and crossings (S&C), while others are for treating plain line (straight) track.
We currently contract around 65 tamping machines nationally from the following suppliers:
Regulators are used to correct the track's ballast profile by redistributing ballast to the right areas of the ballast bed (beneath the track) to give the track lateral stability. The even bed of stone prevents the track from moving when under the load of a train.
We currently contract six regulators from the following suppliers:
Stoneblowers do the same job as tampers but work in a slightly different way. First they measure the track to work out where it needs to be lifted to bring it level, and how much it needs to be moved side to side to ensure correct alignment.
After the measurement run, the machine moves along the track, lifting it up at each sleeper and using compressed air to blow extra stones under the sleeper where required to level it up. This tends to give a more durable result than using a tamper, and so can extend the life of the track by many years, saving the railway significant amounts of money. Given their specialist nature, all the stoneblowers are owned by Network Rail.
Did you know?
- Although most of the stoneblower fleet works only on plain line (straight) track, there are three multipurpose stoneblowers, which also work on points and crossings.
- We developed these jointly with machine manufacturer Harsco Rail.
- The multipurpose stoneblowers are the only three machines of their type in the world.
- They have been so successful at extending the life of old points and crossings that we're looking at buying more to replace the old and life-expired plain line stoneblower machines.
Numbers of these machines in operation:
Plain line – 11
Multipurpose – 3