See photographs of the new Tyne and Wear Metro train undergoing testing in Switzerland

Testing of the Class 555 model has been taking place on the Rigi Bahn, near Lake Lucerne, commonly regarded as one of the most scenic stretches of railway in the world.

The initial tests were being undertaken ahead of the train being transferred to Velim, in the Czech Republic, for final “dynamic testing on a large testing track”.

The new £362 million fleet of 46 trains will boast features including air conditioning, wifi and phone charging points, and should also be 30 per cent more energy efficient.

Speaking in December after disruption caused by the first winter cold snap, Nexus’s managing director Martin Kearney said the new fleet “cannot come fast enough” after the company’s ageing trains struggled in the freezing temperatures.

The first of the 46 new Metro trains, which Nexus has on order from Stadler, will be arriving in the North East “in just a few weeks”.

They will then undergo further testing on the Metro network along with driver training ahead of entering passenger service in the autumn.

A Nexus spokesperson said: “We are really excited to be counting down to our first new Stadler Metro train arriving in the region in a couple of weeks’ time.

“There are two trains completed which have been sent to a vast test track in the Czech Republic to go through a rigorous process of dynamic testing. The second train to move over there was stabled at Rigi in Switzerland.

“The first new train will arrive in the region and will then enter a further testing and training phase. This will be a chance for our drivers to do some training on the real thing before it enters service for passengers.

“These trains mark the start of a new era for Metro. They will deliver a step change in comfort and quality, and will cut energy consumption.

"They will have modern features including a step-change in accessibility, providing an automatic sliding step at every door of the new trains, making travel easier for Metro’s 50,000 wheelchair passengers as well as people with children’s buggies, luggage or bicycles.”