A 'complex' project to improve connectivity across a huge UK region has suffered another major setback, just months after its grand debut.

Back in December 2024, Nexus launched a £362m fleet of new trains across Tyne and Wear, in what has been described as the 'biggest' regeneration in Metro's history. Half of the 46 new trains, which are on order from Stadler, are scheduled to be in service by the end of 2025 - while the remaining will begin running over the next two years.

However, in a huge blow for commuters in the North East, a number of the trains were dramatically withdrawn from service due to a fault last week, on Sunday, June 22. It is believed issues with the air-conditioning units on four trains resulted in water leaks, following scorching temperatures of around 30C.

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This resulted in hefty delays of up to 40 minutes on the yellow line, and 25 minutes on the green line, disrupting travel plans for swathes of locals. One unfortunate passenger, who was using the Metro when the incident occurred, told Chronicle Live: "It was leaking above all the doors. [The] floors were soaked.

"The carriage was packed due to other trains being withdrawn. [I] switched lines at Monument and got on another new Metro and it was happening there too. It was my first time on a new Metro, so not ideal."

Cathy Massarella, managing director of Nexus, and Lucius Gerig, CEO Stadler Switzerland, issued a joint statement apologising to anyone affected by the fault. "Some of our new trains experienced an issue with their heating, ventilation, and air conditioning units, which has meant some water has entered the main saloon," they said.

"As a result of this, we have had to take some trains out of service while we investigate what has happened. We are working closely together to get this rectified as quickly as possible... Please be assured that we are doing everything we can to maintain a good service for customers."

Nexus later explained that all of its fleet is fully back in service, and, as an interim measure, it will monitor its heating, ventilation and air conditioning (HVAC) units to 'minimise the chance and impact of any reoccurrence'. "The fleet introduction is the biggest and most complex project in the history of the Tyne and Wear Metro and the current phase is the most challenging of any fleet transition project," they added. "This is why we are taking a careful and phased approach to fleet introduction to promptly address any arising issues."

The blunder follows an incident back in March where five new trains were pulled for more than a week after the train's doors opened on the wrong side. Again, Nexus reiterated the complexity of its Metro rollout and argued that 'minor technical and operational issues' would likely arise.

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