Lamma IV would not sink, based on calculations: Ex-ship surveyor

The Lamma IV ferry should not have sunk even if two of its below-deck compartments were flooded, a retired Marine Department ship surveyor yesterday told the commission of inquiry into its October 1 capsize.

But the commission had earlier heard three compartments were flooded due to the absence of a watertight door, which contributed to the ferry's speedy sinking after it collided with the Sea Smooth off Lamma Island on October 1, claiming 39 lives.

Former Marine Department principal surveyor of ships Wong Chi-kin, who had vetted the drawings of the Lamma IV, was asked whether the vessel would sink if both its tank room and steering gear compartment were flooded. "I have seen the calculation [after the incident]. The ship would not sink," he said.

Wong said the ferry's general arrangement and hull construction plans were submitted to the department in 1994 and 1995 respectively. He said Cheoy Lee Shipyards, which built the ferry, had also been asked to submit its damage stability and floodable length calculations, but Cheoy Lee submitted only the former.

A damage stability calculation determines a vessel's capacity to resist flooding damage, while a floodable length calculation determines the length a vessel can be flooded without causing it to sink below its safety line.

Although Cheoy Lee did not submit the floodable length calculation, Wong said officers could exercise discretion, allowing shipyards to submit just the damage stability calculation as the former was outdated.