Sir – Dr Martin Barnes makes some good points concerning cut and fill on the proposed HS2 route, but he omits to mention the many tons of gravel/ballast that will be needed to provide a base for the track.

However, I must take issue with his comments “trains do not cause any vibration” and “only make much noise when working hard….rising gradient”.

Vibration from trains is caused by a heavy load travelling over a non-rigid foundation. The heavier the load, the more the ground under the train is deflected.

This causes ground waves to travel outwards from the disturbance. And the noise is caused not only by the engine but by the wheels clattering on the track. The faster and heavier the train, the more will be the vibration and noise.

Since most solutions for mitigating the vibration [deep ditches] and noise [high acoustic barriers] are unlikely to be acceptable, the only practical solution to keep the noise and vibration to current levels is to limit the speed of the extra trains to something like 40 miles per hour in the vicinity of housing.

Bob Adams
Oxford