Northern Line

MQT on 2015-01-21
Session date: 
January 21, 2015
Question By: 
Andrew Dismore
Labour Group
Asked Of: 
The Mayor


My constituents have commented on the rough ride of the newly-signalled and controlled trains, compared to the previous much smoother control by drivers. Did you specify acceleration and deceleration limits in the specification of the new system, as the trains hunt around their correct speed? Can the new system be fine-tuned?


Answer for Northern Line

Answer for Northern Line

Answered By: 
The Mayor

The Northern line signalling system has now been modernised, delivering 20 per cent more capacity with a frequency of up to 26 trains per hour on the Bank branch, and up to 24 trains per hour on the Charing Cross branch during the busiest time. This is up by 4 more trains per hour in the peak and off-peak compared with just a year ago. The track on much of the line has also been replaced and improved, which has led to a better ride quality for customers.

Acceleration limits were specified to maximise the full performance of the Northern Line 1995 Tube stock as per the trains' original designed performance which is in line with other modern Tube stock on the Jubilee, Central and Victoria lines. The deceleration limits remain the same as they were when the trains were manually driven.

Faster trains directly enable increased capacity to the benefit of passengers. The quality of ride for customers is something TfL accurately measures across the network against clearly defined limits at a minimum of every eight weeks. When the new signalling was first introduced on the High Barnet branch there were some ride quality issues, which were improved by fine-tuning the train's operating system. TfL will continue to monitor performance on the line and make adjustments as required.