It is the sort of clever design solution of which the great Victorian engineer himself would have been proud.

Trains running along the south west coast on Isambard Kingdom Brunel’s Great Western Railway have long suffered from sea spray and salt water corroding and damaging vital equipment.

But a deceptively simple design change is set to ensure the trains can handle the worst of the weather.

The problem is particularly acute along stretches such as Dawlish, in Devon, where the track famously runs alongside the coast on its way to Exeter.

A new generation of ‘Dawlish proof’ trains is set to be rolled out along the route with the promise they will be able to withstand the worst the south west can throw at them.

Several of the trains which currently run on the line suffer from a crucial design fault in which their brake resistors, which dissipate energy during braking and turn it back into electricity, sit in a sunken well on the roof where rain and sea water collects during storms, damaging their working parts.

While the existing 40-year-old High Speed Trains have not been affected, the Voyager fleet operated by Cross Country, which operates between Penzance and Scotland via Dawlish and Bristol, have repeatedly suffered from the problem since they were introduced in 2001.