Lamma trial told of radar system errors

The Marine Department's radar tracking system is not designed for detailed accident investigation, the trial of two coxswains involved in the National Day ferry collision two years ago heard yesterday.

Yim Kit-ming, an engineer with the department, agreed with some of defence counsel James Turner QC's suggestions when he pointed out the system's deficiencies on October 1. Turner is representing Chow Chi-wai, captain of HK Electric's vessel Lamma IV.

The High Court heard that Hong Kong and Kowloon Ferry's Sea Smooth, which rammed into the port side of Lamma IV, appeared to "sit on the pier" at Yung Shue Wan after the collision that led to the loss of 39 lives.

Yim explained that when the Sea Smooth approached the Yung Shue Wan pier to dock, "the radar echo of the Sea Smooth and radar echo of the land became so close that they merged together".

"When it tried to sort out the Sea Smooth's radar echo from land echo of the Yung Shue Wan pier, it can give rise to the situation that … the Sea Smooth sat on the pier of Yung Shue Wan," he added.

The system was also inaccurate, Turned suggested, in that the position of the Sea Smooth was shown as being 135 metres away from its actual position roughly 11 seconds after the collision. The collision took place about 17 seconds after 8.20pm.

Yim admitted that the Sea Smooth was shown "in a substantially wrong place".