THE STRATEGIC Rail Authority (SRA) last week backed a new signalling system which will take longer to install and so save fewer lives than its less sophisticated alternative.
It confirmed that it wanted to abandon installation of a lower grade version of the European Rail Traffic Management System (ERTMS) in favour of a more advanced version.
This is not expected to be fully installed until 2025 and could cost over £6bn to put in on the UK's high speed lines alone.
Figures published by the SRA last week predict that between 2012 and 2052 the preferred system will prevent 74 deaths, while the more basic alternative would save 83 as it could be in place more quickly.
High speed line installation of ERTMS will be delivered by 2015 - five years later than demanded by the Uff-Cullen inquiry into signalling following the Ladbroke Grove and Southall train crashes.
The government had originally backed the simpler version of ERTMS, but last week came under pressure to reject this on the basis that it would reduce capacity and drive more people on to the roads (News last week).
The ERTMS programme board last week recommended the adoption of the more ambitious system. Board members come from the SRA, safety groups, freight and train operators, trade unions, government departments and ERTMS technical specialists.
Although the less elaborate option would cost less to install, the chosen version is expected to work out £8bn cheaper over the 40 year period.
These savings depend on figures given in the report that conclude from initial modelling that the system could deliver a 10% increase in capacity. This research was unavailable to the Uff-Cullen inquiry.
Adoption of the system depends on ongoing research by the ERTMS programme team to model the true level of increased capacity. The report warns that as yet the model does not apply to the whole network.
Installation of the system involves erection of trackside beacons and a two week refit for each train. Work on the West Coast Main Line (WCML) fitting a train protection warning system will not be entirely redundant, as some of the infrastructure can be re-used.
INFOPLUS www. nceplus.co.uk/magazine/ rail
Which signal is which?
The European Rail Traffic Management System (ERTMS) uses mobile phone technology to keep train drivers continually updated on future signals.
Trackside digital radio transmitters send information to a train's on-board computer. This monitors the train's speed and applies the brakes if it is going too fast or approaching a stop signal too quickly.
The Train Protection Warning System (TPWS) also being installed on parts of the network uses induction loops in the track bed and a pick-up antenna attached to each train. If a train passes a signal at danger an electrical impulse is sent to the train, making it brake. Installation requires more extensive trackside work, increasing risk to workers.
Automatic Train Protection (ATP) is a generic term that covers forms of train management systems that can automatically bypass the driver. It includes ERTMS and TPWS.