Question: if the train made vibrations how far would it travel and affect

Natalie Wride answered on 16 Jun 2016:

Hi James!

This is a great question 🙂 All trains will cause the ground to vibrate – even when were driving on the road in our cars it causes vibrations in the ground. That’s one of the reasons we get pot-holes in the roads.

The problem with high speed trains is that these vibrations will be bigger and potentially cause more problems. Our cars can handle driving over pot-holes (as long as they’re not too deep!) but high speed trains are sensitive to this movement – especially because they’re travelling at such fast speeds! Even the slightest bumps in the track at 400 km per hour can make passengers feel sick and have an uncomfortable journey on the train.

You’re right though! The vibrations don’t just happen as the train drives over the ground but also in front of the train – up to 30 metres in front. There’s a risk that you could get an effect called ground vibration boom (similar to sonic boom in aircrafts). This can happen when the vibrations in front of the train haven’t calmed down before the train drives over the ground and causes more vibrations – you get even bigger vibrations because you have two lots together!!

If this happens there’s a risk the train could derail under the vibrations so Engineers are working really hard to come up with a design that makes sure this doesn’t happen 🙂