Recap.
The Lamma IV, a 24 metre boat owned by Hongkong Electric carrying about 124 staff and their family members, with a crew of 3, travelling to watch Fireworks in Victoria Harbour, collided with the ferry Sea Smooth, in waters off Lamma Island at about 8.23pm on October 1, 2012. More than 100 passengers on the boat fell into the water, and at least 39 are confirmed dead. This is the deadliest boat accident in Hong Kong in 40 years. The Fireworks were scheduled to start at 9.00pm, and attracted around 150 spectator vessels. It was reported the Sea Smooth was travelling around 24 knots and the Lamma IV around 14 knots. Visibility was good. It appears the Sea Smooth Port Bow made contact with the Lamma IV Hull in the area of the Stern Port Quarter, where the Engine room compartment is located. It was reported that the impact caused a hole of 9 sq. metres. The Lamma IV engine compartment became inundated with in rushing sea water, causing the stern to rapidly sink to a depth of 15 metres trapping people inside. Eyewitness reports state the Lamma IV was barely visible as a dark shape after the crash. It’s reported the Sea Smooth stayed for around 5 minutes before leaving the scene. Eyewitness reports state the Lamma IV, sank with it’s Bow sticking out of the water within 5 minutes of the collision.
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The following drawing was published in the SCMP. It illustrates the differences between the two vessels that collided, and shows how the Lamma IV, was very vulnerable to a large breach of the Hull in the Engine Room section, or next aft section, which they have called the Sterntube compartment.
The drawing of the Lamma IV shows Five Bulkheads built into the vessel, each of which would either be a sealed bulkhead with no penetration, or have a watertight door to gain access from one section to the next, such as was likely the case between the Engine Room and the Sterntube section.
In some of the news reports, there has been speculation that watertight doors may have been left open allowing more than one compartment to flood. The investigation will answer that question. If the Sterntube section did as seems likely flood, then there may be additional reasons for that to happen, including additional cracks or openings in the Hull that allowed seawater into that section.
Some survivors have been quoted in the news papers to say that they felt they only had a minute or two after the collision before the Lamma IV aft passenger section was inundated with sea water, and the stern started to slip below the water.
Based on assumptions of the dimensions of the Lamma IV engine room together with the anticipated water flow with a large opening below the water line, I believe it would only have taken around 1 to 2 minutes for the engine room compartment to be filled with more than 80 to 100 tons of sea water.
It is staggering to realise that an opening of less than one square foot, a metre below the sea surface could allow sea water to rush into the vessel at a rate of around 1,000 gallons per minute. Bear in mind that reports mention the opening in the Lamma IV Hull caused by the impact was around 9 square metres.
If there was one watertight door open between the engine room and the sterntubes compartment then at most it would have taken less than six minutes for the compartment to fill with sea water.
These are ‘broad brush’ estimates based on published tables of ‘Estimated Water Flow Rates’, taking into account the size of opening and fall distance. They are also conservative estimates.
With both compartments filled with well over 100 Tons of seawater, and the buoyancy of the aft section removed, the vessel’s stern would rapidly sink, and the vessel upturn into the Bow Up condition as seen in so many photographs.
Anyone trapped in the passenger compartment in the aft section would now be under several metres of water, in a vessel that is vertical, with loose items freefalling down on top of them. A very perilous situation.
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To give some support and context to the above assumptions, there follows below an eyewitness report of the aftermath of the collision as recounted by Chris Head, who was seated on the upper open deck of the Sea Smooth. This was published in the SCMP.
Quote
Teacher and Lamma resident Chris Head, 48, who was sitting outside at the back of the upper deck of the Sea Smooth, relived the moment of impact and the harrowing minutes afterwards when he thought his 12-year-old son was aboard the stricken vessel the ferry had hit.
“Visibility was fine, it wasn’t crystal clear, there was that haze, but you could see quite clearly. The water was calm,” he said.
“I just heard this enormous whack. I thought we had hit the biggest wave of all time. The force of the collision toppled me out of my seat, I ended up on my hands and knees on the deck. My first reaction was that of shock, just simply ‘wow! what happened?’ I didn’t know if we had hit a rock, a reef, a lighthouse or what.
“Then, because I was at the back of the ferry, I could see the other boat and realised what could have happened. All I could see was this very dark, silhouetted vessel limping away, it was leaning over to one side. It didn’t seem to me like a ferry, it was so dark, there were no lights on it. I thought it was a fishing boat.
“I couldn’t hear any shouts for help or screams, nothing, the boat was just so dark.
“Initially we were trying to put on our life jackets, so we were more concerned with that. But after a few minutes, probably about five, I could see the end of the boat – I couldn’t tell whether it was the bow or the stern – sticking vertically out of the water and I thought ‘Shit! This is real’.
Unquote
Lastly take a look at the following photographs taken of the Lamma IV as she was lifted onto a Barge to remove her for further investigation.
The massive tear in the Hull caused by the impact can clearly be seen in the Blue Hull. It is also possible the massive impact on the Hull caused other cracks to open further aft.
These are quite chilling photographs as after looking at these it is not hard to imagine just how quickly the stern section would have filled with sea water and sank.
There is an eyewitness report from ‘gac’ on the Lamma Forumn, who saw the Lamma IV as she was lifted onto the barge. He describes the tear in the Lamma IV to be like in an L shape, with a vertical tear from the top of the Hull down to the chine (foot of the side) linking with a horizontal tear along the chine, as illustrated below. In addition there appears for be an opening at the rear bulkhead of the engine room, likely caused by the force of the impact on the Hull shell plate at the time of impact.
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So in summary the Lamma IV sank so quickly due to the massive breach of her hull. Her fate was sealed the instant the two vessels collided. As soon as the Hull had been ripped open to the extent it was, then rapid flooding and sinking was the only outcome.
Given the force of the impact, any vessel of the same specification and construction as the Lamma IV would surely have had the same outcome.
The tragedy is that the collision took place in the first place, and the Investigation will seek to provide answers to how could that happen, as well as to “Why the Lamma IV sank so quickly”.
The last two Photos are courtesy of contributors of the My Lamma Forumn.
Lastly I’d like to pay my respects to all those affected by this tragic accident with such a sickening loss of life.
Maritimo 48 