Chiltern Class 165 DMU at London Marylebone

UK: Chiltern Railways is working to present the Department for Transport with options for a fleet renewal programme, with London Marylebone being the only non-electrified London terminal and pressure for the withdrawal of diesel trains continuing to mount, particularly from local residents.

Industry insiders report that this could see at least the 39 two and three-car Class 165 diesel multiple-units replaced.

Built for Chiltern services in 1990-92 as part of the total route modernisation carried out by British Rail, the DMUs were refurbished and fitted with air conditioning in 2003-05.

However, maintenance is increasingly expensive, with the price for an engine overhaul understood to have almost tripled in recent years.

The government has confirmed that electrification of the Chiltern routes is currently not being planned, and the London Underground electrification system which extends as far as Amersham lacks the capacity which would be needed for future Chiltern electric services.

As such, it is envisaged that any new trains will require the use of an alternative form of traction.