The lack of a watertight door did not lead to the rapid sinking of a Hongkong Electric launch that claimed 39 lives in last year's National Day maritime disaster, a retired Marine Department principal surveyor told the South China Morning Post.
Wong Chi-kin, a former general manager of the department's local vessels safety branch, is challenging a naval architect's opinion that a missing watertight door between the vessel's steering gear compartment and the tank room had contributed to the speed with which the Lamma IV sank after a collision with the ferry Sea Smooth. The vessel started to sink just 96 seconds after the crash with the ferry.
Wong claimed the rapid sinking was due to the force of the collision that caused flooding in more than one below-deck compartment.
Dr Neville Armstrong was invited by the commission of inquiry, led by Mr Justice Michael Lunn, to give an expert opinion on the collision between the boat and the ferry on October 1 last year.
On Wednesday, Wong filed a judicial review application with the High Court that he hopes will overturn the commission's report, which found serious failings on the part of the department over the disaster.
Released in April, the 186-page report says: "It was Dr Armstrong's opinion that if a watertight door had been fitted to the access opening in the bulkhead between the steering gear compartment and the tank room, and if the flooding had been to two compartments only - that is the engine room and the tank room - the Lamma IV would not have sunk immediately, rather it would have become stable and [still] afloat after about one and three-quarter minutes from the time of the collision."
Wong, who had been with the department for 32 years, disputed Armstrong's view. He said the expert's claim was based on "too many assumptions".
"Even if the missing watertight door had been in place, the boat would have sunk due to the severe damage," he said.
The surveyor said the design of the boat had met the city's "one compartment flooding standard". That means if one single below-deck compartment is flooded, a boat will not sink.
He claimed the rapid sinking of the Lamma IV was because its steering gear compartment, tank room and engine room were all flooded at the same time.
The marine veteran said since the evidence given in the inquiry was unfavourable to the department, it had asked the British Maritime and Coastguard Agency to scrutinise the Lamma IV's watertight subdivision arrangement. He said the agency confirmed that the locations of the boat's watertight bulkheads were acceptable according to British rules.
He said the agency had also confirmed that the steering gear compartment and the tank room were considered as a combined compartment - which did not need to be separated by a watertight door.
But the agency's views were not accepted by the commission as they were submitted after the evidence stage of the hearing.
After the 50-day inquiry, the commission also concluded that improperly secured seating on the vessel's upper deck played "a contributing part" to the heavy casualties sustained.
"The standard required … that the seating be 'properly secured', required that it be so secured for purposes of safety not only in normal operating conditions, but also in circumstances of a collision, having the likely range of consequences flowing from the latter event," the report says.
Wong said that the seating on the upper deck came loose because most of the passengers were gathered there at the time of the collision. Therefore, there were greater external forces inflicted on the seats.