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Introduction
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Read also the book Disasterinvestigation |
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The 'Estonia' had a steel hull full of 18 000 m3 of air below the watertight car deck - the top of the hull. The ship was floating in the water on this steel hull as per the principle of buoyancy of Archimedes established circa 252 BC. The weight of the steel hull and all weights loaded on top of the hull was about 12 000 tons, so there was a margin of 6 000 m3 of buoyancy below the car deck. This margin was necessary to enable two sub-compartments of the hull to be flooded (in collision!) without causing the ship to sink and to provide stability, when listing. Thus only about 5.1 meters of the hull was below water, when the 'Estonia' was floating. The margin of 6 000 m3 provided a 'free board' of the hull of about 2.5 meters. The top of the hull was thus 2.5 meter above the water. On top of the hull the 'Estonia' had a weather tight superstructure (marked red in the figure above) where you loaded trucks and cars - the car deck or garage. |
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Alleged water on the watertight car deck of 'Estonia' was thus inside the superstructure 2,5 meters above the waterline and could not flow down into the compartments of the hull below. Water (2 000 tonnes!) inside the superstructure on the car deck (extra moving cargo!) could only heel the 'Estonia', until she tipped upside down at about 34° list, when all the 18 000 m3 of air became trapped inside the upside-down-turned underwater hull. Water on the car deck could never force out those 18 000 m3 of air, when the ship was upside down. The 'Estonia' should have floated on that, slightly compressed, air after having capsized. This is a fact, which the Joint Accident Investigation Commission (JAIC or the Commission), an Estonian, Finnish, Swedish tripartite commission never understood and still does not understand! The Final Report does not even mention the air below the car deck.It is very easy to prove with calculations that the 'Estonia' could not have sunk with water on the car deck. The JAIC has not done the correct stability and water inflow calculations. It is even simpler to show with model tests, that it is impossible to sink the 'Estonia' with water on the car deck. Fill the car deck and see how the model turns upside down - then try to sink it! It is not possible! The JAIC never did any model tests of the sinking.
The Commission had quickly told a completely different story within three weeks of the accident, and one day before finding the visor 1 570 meter West of the wreck. The same story was repeated in the Final Report of the 'Estonia' accident (13), i.e. that poor locks of the ferry's bow visor caused the accident. The visor locks were broken by the wave loads, the visor had been ripped off in heavy weather, while the ship was underway on a westerly course Tallinn/Stockholm, water had entered the superstructure at the forward ramp and flooded the watertight car deck and the vessel had rapidly lost stability and ... sunk. The crew was not to blame too much. (This was quite obvious because you could not blame the crew for the design of the locks!). The Master had visited the bridge at 01.07 hrs, when all was in order (while at the same time heavy waves were ripping off the visor!) - 4.2. On October 24, 1997, Lloyd's List had published a statement by Mr. Laur that the final report should be published in early December 1997 and that there was no room for doubt (sic), what had caused the accident.
However, the JAIC theory is simply wrong. If the 'Estonia' with forward speed had lost its visor and pulled open the inner ramp, so much water would have quickly entered the superstructure, that the vessel would have been un-steerable and would have proceeded straight forward while listing to 34°, when she should have turned upside down in totally less than two-three minutes, 2.16, 4.16 or 5.5. She would then have floated upside down on the undamaged underwater hull. This did not happen - survivors said that the 'Estonia' first listed abruptly almost 50° to starboard and, then, came back to a new equilibrium at circa 15° list, 3.16, and that it took a rather long time before the vessel was on the side and then sank. To founder in such a manner is easy to associate with a massive leak below waterline and flooding of several compartments of the hull connected by open watertight doors. The Commission has never bothered to investigate this cause of accident.
Why do I publish this book more than three years after the accident? Why did I not contact the Commission and why did I not discuss the matter with the members of the Commission in the spirit of IMO resolutions A.440(XI) and A.637(16) of free exchange of information and public hearings? Unfortunately the Commission refused to discuss anything about the accident with any outsider and all meetings were kept secret for 38 months. I met a member of the Commission, Börje Stenström, as early as end of October 1994 at the IMO, where we both were engaged to develop better rules for oil tankers, and told him that the 'Estonia' could not have sunk due to water on the car deck in the superstructure. Stenström went pale and refused to discuss the matter. I met Stenström several times 1994/5 and he avoided carefully to discuss the 'Estonia'. In October 1996 Stenström informed that he never wanted to see me again(!). In April 1995 the Commission published its Part Report 1.17 and then I wrote to the Commission pointing out the message in this book. The Commission filed my letter in act F69 and never replied. Over the years I have attempted to discuss the matter with the Commission and it has always refused. In the summer 1996 I corresponded with an expert of the Commission, Bengt Schager 1.18, who said that the Commission had investigated the technical suggestions in this book and had concluded that they were not relevant or wrong. Asking for further details was met with silence. August 7, 1997 I met the head of the Swedish delegation of the Commission - Ann-Louise Eksborg - in her office at Stockholm who promised that, of course, the Final Report was going to clarify the questions raised in this book, e.g. how the hull was flooded, so that the ship sank. Of course, the questions were not even raised in the Final Report. August 14, 1997 I met the JAIC stability expert, Dr. Michael Huss 1.18, and asked him how the 'Estonia' could have sunk with water in the superstructure. Dr. Huss refused to answer and left the meeting after accusing me of being 'conspiratorial'.
Was it a Freudian slip on behalf of Huss? The reason I investigate the 'Estonia' accident is that I have designed six converted ro-ro passenger ferries for service in the Red Sea and that I am interested to know why the 'Estonia' sank. Many people, knowing my work, asked just that question. How and why did the 'Estonia' sink? When designing a ro-ro passenger ship, damage stability is very important. The old rules required only that the ship remained upright with two compartments of the hull flooded and without sinking with minimum extra, residual stability (area below the GZ-curve) provided by the hull and, maybe, the superstructure. The new (SOLAS 90) rules requires that the ship must have additional residual stability after the worst possible accident. However, in neither case was water on the car deck inside the superstructure considered, because it was not a conventional damage stability case. Water on the car deck above the waterline is only extra weight 'loaded' on the side of the garage tipping the vessel upside down (the hull is undamaged) - never sinking the ship. Increasing the built-in damage stability of a ro-ro passenger ship would never prevent tipping the vessel upside down. The 'Estonia' did not suddenly tip upside down - she listed 50° and then found a new equilibrium at 15° list and then took a long time before sinking 3.16. Why? The answer is obvious - the 'Estonia' had positive residual stability and was leaking below the waterline flooding the hull! The fascinating fact is, that the Commission always insisted that the 'Estonia' was not leaking below the waterline - the hull was allegedly intact. Why was the Commission insisting on water on the car deck of the superstructure sinking the ship, when everyone should know that water on the car deck could not sink the 'Estonia' (only tip her upside down)?
During the summer of 1996 I was not fully aware of all the other information presented in this book now. Then I wrote down my alternative cause of the 'Estonia' accident based on first principles of intact stability, damage stability, periodic and transient hydrodynamic wave loads on a bow above waterline, behaviour of ships with free water in a superstructure above waterline and in damaged compartments in the hull below waterline, the information given by Mr. Linde to Swedish newspaper Dagens Nyheter in October 1994, that the visor was found one mile West of the wreck 1.13, etc. The theory was simply that the 'Estonia' had lost its stability due to inflow of water into the hull below the waterline (leakage) and turned into the wind (South-west) and that the visor (in the superstructure) had separated later from the ship, when the 'Estonia', with a substantial list to starboard, had hit the flat visor side straight into the waves 2.23.
The first draft was sent to Mr. Bengt Schager for comments. Mr. Schager friendly added some useful information to my theory but told me that all was wrong. He said that the Commission had investigated my theory (all alternative causes) and that it was wrong.
I refined the draft and sent it to the biggest Swedish newspaper, Dagens Nyheter, which published it on August 15, 1996. The same day the Commission told Swedish news agency TT that the article was 'un-intelligent gibberish based on un-scientific methods by an un-reasonable person'. The rhetoric confirmed my certitude that the Commission was not serious in its work to find the truth of the 'Estonia' disaster, 'wie es eigentlich gewesen ist'. Therefore I continued to improve the scenario, a summary of which Lloyd's List published in November 8, 1996. After that I received a lot of information and various documents used in this book, which further support my suggested cause of accident. The German Group of Experts gave very valuable information, i.e. a completely different time of the first abrupt listing and a completely different description of the listing itself based on survivors' testimonies. All that information fitted nicely into my theory.
You would expect that the IMO and various National Maritime Administrations would be interested in the details of the 'Estonia' accident. IMO reacted quickly in 1994 and a Panel of Experts made at least 30 changes to the SOLAS safety rules based on the conclusions of the Commission in March and April 1995 and these were adopted by the IMO Marine Safety Committee as regulations to enter force from July 1, 1997. Never before had so many safety rules been adopted in such a short time. But were they any good? Correspondence with the relevant parties was disappointing - it seems nobody was prepared to stand up and defend, or just explain the logic behind the new safety rules. The reason is simply that there is no logic behind the new safety rules chapter 5 and that nobody is prepared to say so. This prepares the ground for conspiracy theories chapter 6. I do not believe in any conspiracy. I think that the crew of the 'Estonia' forgot to close the watertight doors in the hull, when 'Estonia' sprang a leak. I believe an incompetent Commission never thought of the possibility that leakage of the hull below waterline sank the 'Estonia'.
Dagens Nyheter asked the Commission twice in editorials during 1997 to investigate or just comment upon my theory. The Commission decided to ignore the requests. Many people wonder why the Commission is so afraid of investigating a water leak below waterline of the hull as the cause of the accident. Many ships that sink at sea were leaking, so it is a logical risk to investigate.
I hope that this book contributes to several things. First that there is a new dive survey of the 'Estonia' to establish, if the vessel has a hull damage on starboard side forward below the waterline (in the bottom or in the vertical side), and, if so, that a new accident investigation is done. Second that the IMO review all the safety rules chapter 5 that were quickly (and badly) amended after the 'Estonia' accident based on the assumption that there was water on the car deck. Third that the IMO issues new rules how international accident investigations should be carried out, as the 'Estonia' investigation ignored all rules and conventions.
Anders Björkman, M.Sc., Naval Architect, anders.bjorkman@wanadoo.fr
6, rue Victor Hugo
F 06 240 Beausoleil, France
January 1998
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