According to the city's contract with Canada-based Bombardier Inc., the system's reliability must reach 99 percent within eight months of starting operations, Hau said, and the city will require the contractor to strengthen its reliability testing to achieve the goal as soon as possible.

Operations of the newly-inaugurated line were shut down Friday afternoon when the power supply system apparently malfunctioned.

The failure affected 21 trains carrying more than 9,000 passengers on the Neihu/Muzha line, including 700 who were stranded in three of the trains that got stuck between stations.

The services were resumed at 6 a.m. Saturday.

According to Hau, a preliminary investigation found that the failure was caused by a breakdown of an uninterruptible power supply (UPS) system, which cut off all signals and communications along the line.

The mayor acknowledged that the integration of the new Neihu line built by Bombardier and the Muzha line built by France-based Matra posed a high degree of difficulty, and that glitches in the integration of the two driver-less systems' software may have been behind the recent malfunctions.

The city government has requested Bombardier to send its most senior engineers to Taiwan to help solve the problem, he said.

Hau promised that the city government will investigate the responsibilities of the contractor and related officials and will seek compensation from the contractor after the existing problem is solved.

Also Saturday, Chang Chi-te, commissioner of the city's Department of Rapid Transit Systems (DORTS) , and Chao Hsiung-fei, vice president of Taipei Rapid Transit Corp., apologized to the public for the inconvenience caused by Friday's system failure.

Chang said he will shoulder his due responsibility if the city government's investigation finds that DORTS is to blame for the incident.

Chang explained that the damage to the UPS at Zhongshan Junior High School station paralyzed the entire Neihu/Muzha line because there is only one electric circuit in the Neihu line's power supply system.

The DORTS has requested that Bombardier install a back-up circuit to prevent a repetition of the problem, he said.

On compensation for the affected passengers, Chao said each of the 700 stranded passengers were offered two free bus and metro tickets immediately after they were guided to walk along the line's track to reach nearby stations.

The more than 9,000 passengers who used the service between 3 p.m. and 5 p.m. are eligible to receive five free metro tickets within one week at any metro station, Chao said.

Passengers who claim the free tickets will be required to show their Easycards, which contain records of their rides on the metro system, to confirm their eligibility, he added.

(By Y.F. Low)