Image caption Transport for Wales service has been dubbed "second rate" by critics

Engineers have been working around the clock to fix an "unprecedented" number of trains taken out of service for repairs, according rail bosses.

Commuters have been critical of disruptions since Transport for Wales (TfW) took on the franchise in October.

Thirty-six out of 127 trains have needed fixing, with staff doing 1,000 hours of overtime, rail chiefs said.

TfW said after weeks of problems it began operating a full service from Monday.

"After a number of difficult and challenging weeks with so many of our fleet damaged we are pleased to have returned to a full service today," said Colin Lea, TfW's customer experience director.

Daily traveller Owen Pugsley, 27, said he has been facing "constant delays" on services between Merthyr Tydfil and Cardiff.

"You get cancellations for things like it being too wet," he said.

"How can you not know it is going to be wet in Wales? I don't understand."

He added: "The trains are just appalling."

Engineers have been fitting "wheel-slide protection" technology to the existing fleet to make them "more resilient to autumn conditions", according to TfW chief executive James Price.

Passenger Jessie Howells, 22, took to social media to recount problems after her carriage lights failed, the train's toilets did not work and the conductor could not issue tickets as his machine was faulty on the 08:23 from Cwmbran earlier this month.

Image copyright Jessie Howells Image caption Passenger Jessie Howells posted this on Facebook during one eventful journey

She said passengers collectively "cracked up laughing" after the conductor highlighted the catalogue of problems over the tannoy,

But commuter Gregg Johnston, 38, who travels from Newport to his job at Cardiff University, added: "It's clear we're getting a strict economy service and England is getting first class."

Anthony Smith, chief executive of the independent watchdog Transport Focus, said passengers wanted "reliable services on which they can get a seat and are good value for money".

He claimed passengers in Wales were "travelling on trains well past their sell-by date".

TfW chief executive James Price has promised an investment of £5bn to "transform rail services" over the next 15 years, with £800m for new trains and £194m in station improvements.

"While we have ambitious long term plans to transform our services, ongoing issues caused by recent storms, autumnal conditions and ageing trains have led to an unprecedented number of our trains being out of service recently causing disruption for our customers," he said.

"We recognise how important it is to give our customers the best experience as soon as possible, which is why we are investing £40m in our current fleet to fund a range of improvements including additional services as well as customer experience and accessibility improvements."