The Mayor of London, Boris Johnson, has travelled on the first air-conditioned Underground train.

London Mayor Boris Johnson has enjoyed a test ride on the first air-conditioned London tube train, due to enter service on the Metropolitan line next summer.

There will be 191 of the trains in total, which will eventually be rolled out to the Circle, District and Hammersmith & City lines following its introduction to the Metropolitan line.

However, with the weather this summer likely to be warmer than average – with some areas of the country reaching temperatures of 30 degrees Celsius – the advances made in providing air conditioning on the Underground will come too late for most passengers.

Until the cooling systems are introduced across the network, 83 industrial-sized blue fans will be in operation at 36 locations on the tube network to help increase ventilation.

Mayor Johnson commented on the cooler trains: “These trains are fully walkthrough, boast improved information and security features, are designed to make life easier for disabled passengers and the air conditioning systems will keep passengers comfortable whatever the weather.”

As the oldest metro system in the world, the majority of the underground network was built before air conditioning systems came into place.

Johnson continued: “Cooling the deeper Underground lines remains a considerable challenge. A crack team of engineers at Transport for London (TfL) is focused on doing just that and is concentrating on the Victoria line in particular where we are doubling the capacity of the fans at all of the main ventilation shafts serving the line and adding cooling systems to four major stations.”

In addition to the new train air-cooling systems, London Underground (LU) is also working on the existing ventilation network – this includes upgrading and re-conditioning fans, upgrading ventilation shafts to improve airflow, and installing high-speed ceiling-mounted impulse fans at Marylebone and Lambeth North stations.