UK Railways longest running line with class 121 stocks is coming to an end after longest running train in history. Chiltern Railways who operates trains  announced that it  will withdraw its two British Rail Class 121 called  ‘Bubble cars’ on May 19.

Class 121 Bubble cars chiltren

The single-car first-generation diesel multiple units were introduced to British Railways in 1960, and are currently used by CR between Princes Risborough and Aylesbury. The first (Class 121020) was bought from Network Rail in 2003, with a second (121034) joining it in 2011 from preservation. In 2003, Chiltern Railways reintroduced “Heritage” diesel multiple units on its Aylesbury to Princes Risborough shuttle service.

They are the last trains in daily use with vacuum brakes. However, CR says that because of the increase in ongoing maintenance needs they are to be withdrawn and sold. They will be replaced by Class 165s. The Class 121 is Britain’s longest serving DMU, having been in service for 57 years as of 2017.

“We will be sad to see these trains go, as they are a part of railway history and some customers even make special journeys to travel on them,” said Chiltern Railways Engineering Director Matthew Prosser.

“However, the changes are necessary due to the age of the vehicles, and we will ultimately be providing a more comfortable service for our customers.”

CR said a small farewell will be held on their last day in traffic.

Sixteen Class 121 single-car, double-ended driving motor vehicles were built from 1960, numbered 55020–55035. These were supplemented by ten single-ended trailer vehicles, numbered 56280–56289 (later renumbered 54280–54289). They have a top speed of 70 mph, with slam-doors, and vacuum brakes.
Chiltern Railways is a British train operating company owned by Arriva UK Trains that has operated the Chiltern Railways franchise since July 1996. It operates commuter/regional rail passenger services from its Central London terminus at London Marylebone along the M40 corridor to destinations in Buckinghamshire, Oxfordshire and Warwickshire, as well as long-distance services to the West Midlands along two routes. Services on the Chiltern Main Line run from London Marylebone to Birmingham Snow Hill, Stratford-upon-Avon and Oxford, with some peak-hour services to Kidderminster.