Testing and fine-tuning are complete on the Line 8 Metro signal system that caused six breakdowns in just 10 days from late June.

The Shanghai Metro operator is confident of a better service

The Metro authority said yesterday that more trains would join Line 8 to ease the increased passenger flow.

However, commuters still have to go through a trial run lasting a year when the signal system will be further tested between Line 8 and its second phase which will open to the public tomorrow.

The automatic signal system, though the most advanced used on Metro lines, should be updated both at the control-center end and on the trains to regulate speed and the distance between trains, according to Wu Hao, a manager with equipment provider Alcatel-Lucent Shanghai Bell Co Ltd.

Alcatel-Lucent, in cooperation with two domestic companies, won the bid to provide the signal system for Line 8 in March, 2005.

The latest signal glitches happened when the software installed on trains failed, which forced drivers to run trains manually, Wu said.

"Some operators have to stay up all night these days to ensure the signal system is in shape," said Zhang Zhiti, an engineer with the Metro's maintenance department.

Ninety percent of breakdowns on Line 8 should be avoided after the testing procedures were completed on Thursday morning, the authority said.

Another move to relieve pressure on Line 8 will see the introduction of new seven-carriage trains in early October. The new trains -- 18 of which will be introduced this year -- can each carry 300 more passengers.

In the interim, the Metro authority said it would monitor passenger levels closely as door malfunction often occurred when crowds squashed into the trains.

As the second phase of Line 8 begins trial runs tomorrow, residents in Pujiang Town will be able to travel to People's Square in about 36 minutes, as compared to roughly two hours by bus.