GB-London: T1185 - RSSB Research into the maximum current limit at standstill

NOTE: This notice was updated on 28 August 2019 for the following reason: Please note that the tender submission deadline has been extended from 26th September to 10th October 2019.(Electrifying the railway is not economically viable across all parts of the network.

As a result, the industry is exploring the development of on-board battery technology as part of the solution to meet the phase down targets of diesel only trains.

Batteries will need to be charged at various locations on the network and will need to be charged whilst stationary.

Currently railway power supply system design is undertaken using the train timetable and rolling stock consumption.

This is normally done to ensure that the timetable timings can be met and in terms of standards compliance, voltage at pantograph and maximum current, are in accordance with the ENE TSI and GLRT1210 for AC subsystems and GLRT1212 for DC subsystems.

The current at standstill is to provide for the normal operation of the railway, for example hotel loads and rolling stock systems.

Power for charging batteries has not been considered historically.

Going forward, with an increased number of bi-modes that are planned to be procured as well the government intention to replace diesel only trains by 2040, it is prudent to look at the limits for current at standstill and determine the future need and what is able to be supported on traditional electrified routes.

Infrastructure managers have been approached regarding the maximum current limit at a standstill in order to charge onboard batteries, whilst the trains are stabling on sidings or at stations.

Whilst interim guidance has been given, and some stakeholders are now pursuing bespoke charging solutions, there is a need to develop a harmonised set of rules that can be widely applied.

Specified limits with rationale and guidance would enable the development of battery technology on trains around a standardised interface The intention is that this research will comprise of laboratory testing of high currents applicable to 25 kV AC OLE (Overhead Line Equipment) and 750 V DC third rail under a variety of conditions, and for a range of durations in order to provide guidance on safe levels of current at standstill.

These tests will establish a set of current limits for 25kV AC OLE and 750 DC third rail systems.

This would assist in building a better business case for intermittent electrification and hence aid in creating a detailed route map to decarbonisation)