PLANS TO increase service frequencies on London Underground’s Jubilee and Northern Lines have been put back by Transport for London. The improvements are part of the Railway System Enhancements (RSE) programme, formerly the World Class Capacity scheme.

The provision of 10 extra trains for the Jubilee Line and 17 extra trains for the Northern Line under the JNAT (Jubilee and Northern Additional Trains) procurement was abandoned in autumn 2017 as a cost-saving measure, with TfL focusing on infrastructure and signalling enhancements and increased fleet utilisation to deliver additional capacity.

On the Jubilee Line, the aim is to operate up to 32 trains per hour (tph) between West Hampstead and North Greenwich at peak periods, up from the current 30tph. This improvement is now scheduled for mid-2022. On the Northern Line the programme is to deliver a rise from 30 to 31tph on the Morden branch and 26 to 27tph on the Bank branch, now planned for delivery in autumn 2021 concurrent with the opening of the Northern Line Extension from Kennington to Battersea (p60).

A paper to TfL’s Programmes and Investment Committee meeting on 23 October explained agreement has been reached with Alstom, which maintains the Northern Line’s 1995 stock fleet, to make an additional train available for service. This will be achieved through changes to maintenance processes enabled by the installation of a new wheel lathe at Morden train maintenance depot. It says track works to support faster train speeds have been substantially completed, while an update to the signalling system software is now planned to be implemented in spring 2020. The report says there is an opportunity to bring forward the frequency increase on the Morden branch to mid-2020.

Power upgrade works on the Northern Line are also planned to address poor asset condition, provide additional service resilience and enhance network power capacity for service increases on the sub-surface lines after the Four Lines Modernisation (4LM) programme is delivered. This is split into two packages of works, with the first including replacement of life-expired coupling transformers at Stockwell substation, upgrades at Whitechapel and Mile End substations to reduce the load on coupling transformers at Mansell Street and to upgrade the high voltage network between Stockwell and Clapham Common substations. A second phase comprises upgrades at several substations and cable reinforcement works along the Northern Line to provide additional resilience.

On the Jubilee Line, enhancements in 2018 saw an increased in the duration of the 30tph peak service in both peak periods. Work planned to allow a further increase includes investment in the 1996 stock fleet to improve reliability and availability, with a new wheel lathe to be installed at Stratford Market depot in autumn 2020. A feasibility study is also nearing completion for introduction of a real-time on-train condition monitoring system, reducing the likelihood of service affecting failures. The improvement will also require signalling system modifications through a software upgrade by supplier Thales, with plans to enter into a contract in early 2020. This upgrade could also include the introduction of a train coasting functionality to improve energy efficiency.

More trains at West Hampstead: the delivery aspiration is now mid-2022. A 1996 stock Jubilee Line train calls on 16 August 2019.
Philip Sherratt