Over time, railway tracks that once had their sleepers firmly fixed to the ground flex, compress the underlying gravel and develop gaps underneath.
This causes damage to the tracks and increased noise and vibration for the passengers.
Today’s invention is a simple system which could be fitted to a large number of trains.
As a rail vehicle passes over a high-amplitude gap between sleeper and ground, the exact location is recorded.
This allows a later carriage of the same train or even a different one to squirt a pool of liquid cement beneath the sleeper in question.
When this solidifies within the gravel and under the sleeper, the vertical movement is reduced to zero.
It would be particularly smart to wait for a sleeper to be lifted to the maximum by the weight of the passing train and only then inject the cement.