Blog 164 -"Marine Musings" - The Sinking and Salvage of mv ‘Tricolor’
- ranganathanblog
- 2 days ago
- 8 min read
The Sinking and the Salvage of ‘Tricolor’
She started life as the Nosac Sun, a vehicle carrier, built in Japan in 1987.
(I had been on a near-elder sister ship the Nosac Taishan in 1986, a brand new vehicle Carrier, out of Sumitomo Yard).
The Nosac Sun in 1994
My ship, the ‘Nosac Taishan’ in 1986
Soon, she was taken over by Wilh Wilhelmsen of Oslo and renamed Tricolor, as all Wilhelmsen ships’ names started with T.
The Collision
She collided with the Kariba on 14th Dec 2002 in thick fog and sank in the English Channel. The time was 2.15 am.
It would be more appropriate to say that the Kariba collided with her, when the latter turned to starboard to avoid a ship ahead and rammed into the Tricolor almost perpendicular to the Tricolor, just aft of the Bridge.
The Tricolor sank in minutes.
The Norwegian Captain, Swedish officer and 22 Filipinos (officers and crew) managed to abandon ship and were picked up by the Kariba and a passing tug. The Third Engineer had a miraculous escape from a tilted and flooding ship, escaping through the elevator shaft.
Why did the Tricolor sink in a few minutes, when all would say that she would remain afloat for hours?
One of the weaknesses and vulnerability of a car / vehicle / truck / super carrier or ferry is the permeability of her internal compartments.
Most ships - whether container or bulk or tanker - have several water tight compartments that are vertically designed to restrict her flooding.
In those kinds of holds, on an average one would have - in case of flooding - a surface area of 40 mtr (W) x 30 mtr (L) in each hold.
In a car carrier, the compartment watertight divisions are less vertical and more horizontal. In the event of flooding, you can have as large a surface area of 40 mtr (W) x 100 mtr (L) of surface area, thereby changing the permeability of the compartment.
Even below the weather deck, which are divided into water tight compartments, the ‘Free Surface’ Effect’ is vast.
Car Carriers are football field sizes of open areas from the weather deck upwards and marginally smaller spaces, sub divided, on decks below the weather deck.
Just to look at it practically, in a real life situation of flooding and encountering bad weather, a comparison is made for a bulk carrier and a car carrier, both average sized, one compartment flooded and facing bad weather.
The bulk carrier will have a sheet or wall of water, 30 mtrs L, slamming against the side of the ship for a length of 30 mtrs, with each roll.
In a car carrier, the sheet or wall of water will be nearly a 100 mtrs long, slamming into 100 mtr length of hull, with each roll.
Which do you think will capsize first?
When the Kariba rammed her port side and opened her vast cargo spaces to the water, the Tricolor immediately listed heavily to port and continued doing so as she took in more and more water.
There was speculation that the water tight doors were not shut off. Later dives established the following:
One of the doors was found mostly shut, but the hinge locking pins were found hanging out of the recess.
A second, much heavier, door had gone off the rails.
One of the ‘safe’ practices on board all ships is the closing and securing of all water tight doors before departure every port.
In spite of warning beacons being deployed, two ships struck her in her sunken condition.
Lying sunken, two ships collided with her.
The Dutch ship Nicola ran atop her hull on 15th Dec 2002 and had to be pulled out.
The Turkish ship Vicky struck her on 01st Jan 2003, but she refloated with the next tide.
The sunken Tricolor at low tide
The damaged bow of the Kariba
The Tricolor’ collided and sank at one of the busiest traffic locations in the world, in the English Channel, in French waters, in 30 metres of water.
Due to the half sunken wreckage being at a spot where 18% of the world’s trade passed, it was feared that more accidents will happen. England, France and the neighbouring countries pitched in with hazard lights, round-the-clock patrolling of the area and issuing navigational hazard warnings to approaching ships. But this had to be only a temporary measure.
The wreck needed to be removed. Re-floating her was considered and abandoned.
The only way forward was to cut the vessel into pieces and transport the pieces away.
It had to be done without polluting the area and without it being an impediment to the environment.
First came the de-bunkering, the process of removing the various oils on board. The removal of most of the fuel and other oils was comparatively easy, although about 500 tons remained.
Then came the process by which they cut the ship into 9 sections. The engineering and the technology used to do the cutting will always be remembered.
Basically a chain saw, but to an unimagined scale. A diamond studded wire.
Two rigs activated the diamond tipped wire cable. Although the weather had interfered in the work several times, the first cut went on uninterrupted the first cut piece righted and put on board barge bound for Zeebrugge.
Although the cutting seemed to be the impossible task - for an engineer -, pollution seemed to be the primary threat to the environmentalist. An anti pollution ship was deployed in the area to calm the nerves of this group.
The cutting started on 22nd June 2004 and was completed on 19th July 2004.
Nevertheless, it took several months more for the debris in the Channel to be cleared.
The ship had been carrying about 2500 high end cars and hundreds of container ~ truck combination and heavy machinery. During the cutting, thousands fell into the sea while others stuck to the hull or deck and were lifted out with the cut sections.
Each cut section deposited on barge
I am always a victim of ‘espirit de l’escalier’. After publishing my article, I always feel I could have done better.
Hence, I am adding a section on
Water Tight Doors and Vulnerability
Right from my junior days, I have always been wary of Water Tight Doors and the role they play on a ship’s safety.
By the time I had become Chief Engineer, it had become a full blown obsession.
Bulk Carriers had, by their very construction, very few Water Tight Doors of any consequence which were below the Weather Deck.
Some ships - not bulk carriers - had a side opening for bunkers, picking up the pilot, any barge activity etc, that were handled through these two openings, one port, one starboard. They would be just about 2 metres from the waterline. I would insist that these be opened, if necessary, only at the appropriate sections of time, with a person on watch if opened.
Then there were the General Cargo vessels, with Lower Holds, Lower ‘Tween Deck, Upper ‘Tween Deck etc. You could keep the hatch covers of the ‘Tween Decks open and load into the Lower Hold. Once the ‘Tween Deck covers were on, you could load into that space, including the side spaces.
The ‘Tween Deck hatch covers’ were, mostly, hydraulic with hydraulic rams.
To facilitate approaches for maintenance and checking cargo, you could enter from the Engine Room through a Water Tight Door and enter a corridor like tunnel on both sides, port and starboard. When you open the next water tight door, you would be in the ‘Tween deck spaces of the cargo holds. You could weave your way around the cargo, inspect the hydraulic oil levels, oil lines and hydraulic rams.
On one such ship, immediately on sailing out - I had just joined in that port - on the basis of the last Chief Engineer’s report that there were several hydraulic oil leaks in the ‘Tween Deck spaces - I took a heavy torch and entered from the Engine Room side into the first hold. I wasn’t too happy with the negligence of the oil leaks.
However, I continued into next hold. Which was when I realised that the Water Tight Doors were all open. On observing a more immediate danger, I walked all the way up the port side, turned at # 1 Hold and walked back all the way down the starboard side, back to the Engine Room. From the ER, I called up the Captain and asked him to come down immediately. I took him along the same path and it was only after reaching the forward hold that he realised why I had called him - all the Water Tight Doors were open. Shocked, he called the Mate and the crew to shut all doors.
I insisted on an emergency safety meeting, where it was found that these doors were, most often, not closed. Having joined the ship only a day ago, I harshly told all the persons responsible - including the captain, Mate and crew - that I do not want to be a victim because of their negligence in assigned safety duties, after having vividly described what would happen if another ship was to ram us, flooding just one of the holds or ‘Tween Deck spaces.
For the rest of my tenure, I kept a constant watch.
From then, I built up a reputation of either being vilified because of my no-nonsense approach when it came to safety or venerated as safety standards would pick up.
The reason why I narrate this particular incident - when there were many others to relate - was that the sister ship of the one that I was on, sank with all hands in a mid Atlantic storm. She had been carrying, like us, heavy steel coils in the Lower Hold. She lost all power from all her generators and, having sent out a ‘MayDay’ signal, was never heard from again.
In the Inquiry and investigation set up - which I heard about later - it was assumed that the heavy steel coils had become loose and, having smashed through the hull, holed her. She had taken in water and sank. Why she sank so quickly, not even giving enough time to launch a lifeboat - there were no queries about it.
I was not asked, although I had my theories about a. The power loss and b. The quick sinking.
The Water Tight Doors would have been left open, allowing free access for the water gushing in from the breached hull to go into adjacent holds quickly, sinking her in minutes.
This incident happened very early in my capacity as Chief Engineer. Post that incident, whether vilified or venerated, I would take it upon myself to check the water tight integrity of the vessel after every departure, tired as I was. After the advent of walkie talkies, it became simpler to alert the responsible persons, the Captain included.
There would be a general sense of alertness and responsibility from then on, as soon as my name appeared on the list of new joiners.
Container vessels are also prone to such sinkings by neglect, as most container vessels have a wide passage running on port and starboard sides, with Water Tight Doors at each section. By entering this passage, you could enter any under deck cellular container space by the simple expedient of opening another Water Tight Hatch set on a vertical bulkhead.
Car and Truck Carriers, Super carriers with stern ramps, ferries - these are three of the most vulnerable to sinkings because of the vast areas of uninterrupted deck spaces.
These ships, twenty years ago, had to be physically checked to ensure all the locks were in place for the Stern Ramp and Water Tight Doors. Electronics and computerisation have eased the drudgery involved somewhat, with limit switches, sensors, relays and displays.
Finally, the reason why I wrote this article. The Nosac Sun - later named Tricolor - was a near sister to the ship I had taken over from Sumitomo Yard in 1986, the Nosac Taishan. In 2003 ~ 2004, the Captains of the ships I was sailing on would call me to the Bridge to point out the near submerged wreck. When I no longer saw the wreck on later transits through the English Channel, I came across news reports that she had been cut into eight sections. The ‘hows’ haunted me - hence the article.
AR
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