ALMOST EXACTLY four years ago, on June 28 2002, the California Public Utilities Commission formally approved the use of Advanced Automatic Train Control on the Bay Area Rapid Transit network in Oakland and San Francisco.

Being developed for BART under a $40m contract awarded to Harmon Industries in 1998 (RG 6.02 p311), the communications-based train control system was expected to allow higher speeds and 90sec headways, permitting up to 30 trains/h through the Transbay Tube compared with the current 24. A trial installation between Fruitvale and Lake Merritt was declared a success, and the equipment was to have been rolled out across the network by the end of 2004.

On June 16 BART announced that it had filed an $80m federal court lawsuit against GETS Global Signaling, as Harmon's successor, claiming it was 'abandoning its contractual responsibilities to design and deliver' AATC. BART said it had invested about $80m so far; half for equipment and half in engineering staff time. Much of the hardware has been installed but the software is still missing. Board member James Fang said it was not clear whether any of the work can be salvaged.

BART President Carole Ward Allen claimed that GETS GS had 'refused to honour its contractual commitment' and had effectively abandoned the project. GE spokesman Patrick Jarvis denied the accusation, and blamed BART for delaying completion. Not least of the issues is the complexity of trying to commission AATC whilst keeping services running with the existing signalling. Jarvis said GE was preparing its own legal action against BART, but gave no details.