Thicker plating may have bought more time before Lamma IV sank: expert
Damage could have been reduced and victims may have had more time to escape if Lamma IV had been made with thicker metal, says expert
Passengers on the Lamma IV could have had "marginally more time" to escape if the ferry had been built with thicker side plating, a naval expert has said.
The vessel started to sink just 96 seconds after the crash with the Sea Smooth, Australian naval architect Dr Neville Armstrong yesterday told the inquiry into the October 1 accident.
Armstrong said he found it "quite extraordinary" that Marine Department officers used only professional judgment and experience - instead of making full calculations - to approve the ship without a watertight door it was designed to come with.
He said he believed that the ship was built with a side plating of 4.5mm - 0.5mm thinner than in drawings approved by the Marine Department and 0.72mm less than the standard set out in 1995.
"The thinner plating size … may have contributed to the extent of the damage," stated Armstrong in his expert report. Thicker plating would have reduced the size of the holes, he said. "[It] might have provided marginally more time for escape before the vessel sank."
The ship's bottom plating was between 0.2mm and 0.5mm thinner than the 6mm set out in the drawings, but Armstrong said that contributed little to the sinking of the vessel.
According to documents submitted to the commission, Cheoy Lee Shipyards, which built the Lamma IV, had ordered 4.83mm-thick metal sheets for the ship.