'Crack' in train forces Heathrow Express to replace stock Published duration 29 February 2016

image caption Trains from the Heathrow Connect service have been deployed on the route

All Heathrow Express rolling stock has been taken out of service after engineers found a structural fault on one of its trains.

Trains from the Heathrow Connect fleet have been deployed on the route, while the slower Connect service has been suspended.

Heathrow Express services are running at the same speed and frequency as usual.

But travellers were warned to expect overcrowding at peak times.

Train drivers union Aslef told the BBC a crack was found in the underframe of one train on Sunday.

A spokeswoman for Heathrow Express said the fault was "passable" but that engineers had "decided to test every single train" as a safety precaution.

Heathrow Express director Fraser Brown said: "We are working with Siemens engineers, who manage our depot site and the maintenance of our trains, to understand the extent of this issue.

"When we are aware of what we are dealing with, we will be able to make a decision on when a full service will resume."

Heathrow Express has cut its single fare from London Paddington to Heathrow from £22 to £17 to help compensate travellers who would otherwise have taken the cheaper Connect service, which costs £10.20.

Business First travellers are entitled to a full refund.

'Smelly'

Passengers who wish to travel to one of the stations on the Heathrow Connect route have been advised to take the 140 bus from Heathrow to Hayes & Harlington, followed by a Great Western Railway service to Paddington.

Great Western Railway will run extra trains between London Paddington and Hayes & Harlington.

Piccadilly line tube services to Heathrow are unaffected.

Travellers took to Twitter to complain about the replacement trains.

"Why no mention in hex [Heathrow Express] app?" tweeted @xtianh. "I would have taken an earlier tube! Short train=Cramped. No power = no laptop use - like tube!"

Another traveller, @marcusx, complained of "dirty, smelly replacement trains".