UP TO £20M is being spent on changing signalling equipment on London Underground's Jubilee Line, which will be replaced in just three years time when the signalling system is upgraded.
The work is necessary to accommodate an extra carriage to increase capacity on the line, from January 2006, a date which London Underground has brought forward from the 2009 timescale set in 2003.
But new signalling equipment will have to be ripped out ahead of a newer, more reliable signalling system which will be installed in 2009.
The £20M cost also includes relocating the gates at the end of station platforms, communication equipment, and closed circuit television.
The total project cost for adding the seventh carriage on to the Jubilee Line train is £160M, of which £110M covers the cost of the new carriages.
Contractor Tube Lines is responsible for maintaining and upgrading the Jubilee line and has completed the civil engineering and signalling work on time.
Last week it began testing extra carriages to the 59 Jubilee line trains which will boost the line's capacity by 17%.
London Underground said the extra spending was necessary to bring forward capacity increases.