|
|
|
|
Read also the book Disasterinvestigation |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chapter 2. What happened Aboard the 'Estonia'2.1 A Sequence of Events based on Passenger StatementsTo establish what happened aboard the 'Estonia' on the night of the accident you must evidently first study the early statements given by all the survivors - passengers and crew. The Sequence of Events and the times in 2.2 are generally based on the German Group of Experts sequence published early September 1996 and partly included in (11). It is based on an analysis of the early statements given by 123 of 137 survivors. The sequence here also considers the virgin statement given by the fire patrol watchman Linde given to Dagens Nyheter 7 October, 1994 1.22. Evidently the statements of some engine crew members are ignored as they are contradictory. The German sequence suggests that the visor fell off after the first abrupt listing took place, which the writer thought already 1994. The Germans suggest that water leakage into the garage caused the abrupt listing. The writer does not believe that 1 000 000 litres of water leaked into the garage undetected. The German sequence was presented to the Commission in September 1996 and you would have expected some sort of reaction from it. However it was filed away and apparently not further discussed. In June and December (11) 1997 the Germans presented witnesses stating that 'Estonia' was leaking below waterline. This is also reported in (12). Several survivors have generally confirmed the times and events considered in 2.2. These events are shown in bold. Other events are inferred by, e.g. the assumed angle of list and/or the assumed (changed) course of the vessel. These events are shown in bold/italic. Events, related second-hand and/or by only one survivor, mainly about assumed visor failure or what was heard but was not seen, are not included. The events are, e.g. that someone heard someone stating that the visor had fallen off, etc. There is also a distinct possibility that someone has spread misleading statements and information. The confirmed events suggest that nobody saw and heard that the visor fell off and pulled out the inner ramp and that water flooded the garage. Therefore the confirmed events are interpreted differently in the last column of the Sequence of Events. There is no proof whatsoever that the visor fell off before the abrupt listing occurred. It is unlikely that there was any water in the garage, when the abrupt listing occurred. The question is therefore - where did the water come from, which was observed on deck no. 1 at 00.56 hrs? The interpretation here suggests that inflow of water below the waterline - a leak - caused the abrupt listing. The NOTEs indicate that the Commission has completely overlooked this possibility. The reason nobody saw or heard the visor being ripped off is that this event took place at 01.12 hrs when the vessel was listing 34° and when it was full panic aboard. This book gives the reason why the visor fell off 2.8. The speeds, positions and courses of the ship during these events are plotted in figure 2.23. The Commission has tried to plot its sequence of events, 4.20 and 4.21. Note January 2001 - since writing the above in 1997 the author has been in contact with several survivors confirming the sudden listing at about 01.02 hrs. Records made public by the Commission also show that the expert to 'edit' the survivors testimonies, Mr. Bengt Schager, was also convinced that the time of listing was at 01.02-01.05. However, in order to produce the false sequence of events it was necessary to change the time of the 'accident' to 01.15 hrs so that Linde's statements could be ignored. It is also clear that the visor was still attached to the ship when it sank. 2.2 Sequence of Events on September 28, 1994
2.3 The Cause of the Loss of Stability The cause of the loss of stability is a shell damage i.w.o. compartments, e.g. frs 85-97 and/or 97-110 (the sauna) on deck no. 0 below waterline followed by inflow of sea water. The damage probably took place at 00.40 hrs. It is regretted that these normally un-attended spaces of the wreck have not been searched by divers to check/identify any shell and consequential interior damage and to see whether the water tight doors were closed on decks nos. 0 and 1 4.8. It is very easy for a diver to go down and check the sauna as an access hole is already made in the port side at deck no. 1! 4.14. 2.4 How to prevent the AccidentIt is not uncommon that ships start to leak below waterline. Water inflow into un-attended compartments below waterline can only be detected by remote bilge alarms. SOLAS does not require such safety features either on passenger/roro-passengerships or cargo ships. Remote bilge alarms can be connected to automatically start bilge pumps and to close water tight doors, when water is detected inside the ship. Had the crew/bridge/ECR been alerted about water inflow at 00.45 hrs, the accident could have been prevented. Formal safety assessments have not considered anything of this 5.10. 2.5 Could more Passengers have survived?It should be clear that the abrupt listing followed by continuous slow increase in the angle of loll made it impossible for most passengers in the cabins to escape as early as 3-5 minutes after the abrupt listing. The only way to survive was to act on your own immediately. Mainly those lucky passengers in cabins, who had been forewarned by water, noise and the modified behaviour of the ship and were awake and managed to reach the stairwells within minutes, seem to have survived together with other persons from the public rooms. The ship's crew could have done othing to assist passengers inside cabins to be rescued. Probably passengers started to drown as early as 01.12 hrs in the starboard outside cabins on deck no. 4. 2.6 Could the Crew have saved the Ship?It should be clear that the officers and crew were in a hopeless situation. The junior officers on the bridge observed the abrupt listing at 01.02 hrs and probably changed course to counter it, which was good. Then they hung on to the control consoles (the list was considerable) and probably called the Master and other senior officers for assistance over the phone. But probably they never made contact - the Master and other senior officers had difficulties to reach their phones and to get out of their cabins. This explains why no Mayday was sent earlier. The bridge officers no doubt forgot or were not able to close the water tight doors, which should have been done immediately, so the vessel might have survived. This is the only fault the writer can find. But already at 01.09 hrs water flowed into deck no. 4 above the garage and then no water tight doors could have stopped the vessel sinking. The writer does not know what emergency procedures were used on Estonia but evidently the procedures did not foresee an abrupt list of first 50° and then back to 15°. The writer believes that the junior officers tried to ballast the ship upright 01.04-01.15 hrs, which was good, while 3/E Treu states that this took place much later (10). Note August 2000 - the writer does not longer believe that the engine crew tried to ballast the ship upright. The writer believes that the engine crew left the ECR immediately after the first sudden listing to save their own lives. In fact it would have been impossible for the engine crew to evacuate the Engine Control Room on deck 1 at 01.25 hours, when the list was >45°, and to reach deck 8 a few minutes later. 2.7 The Master's and senior Officers' ActionsThe 1/O apparently made it to the bridge later and managed to send a Mayday at 01.24 hrs. It is not known if the Master reached or was on the bridge. We do not know at all who were on the bridge 1.22. The Master could have done very little - after 01.09 hrs no action could have been taken to save more lives or the ship. 2.8 The Bow Visor SeparationIt is not possible that the visor fell off before the abrupt list at 01.02 hrs and the writer do not believe that it and the inner ramp were leaking before that time or contributed to the accident. It is hard to believe in a conspiracy (11) whereby the crew noticed that the inner ramp was leaking as early as 00.45 hrs and tried to do something about it with or without the knowledge of Master, 1/O or the bridge/ECR and without reducing speed/changing course etc. In consequence it is concluded here that the garage was dry at least until 01.12 hrs, when the visor separated from the hull and in the process maybe pushed open the inner ramp a little 2.21. It is regretted that for two years the Estonian, Finnish, Swedish Commission on the one hand and the Group of German Experts on the other hand quarrelled about whether (a) the visor locks were damaged first by external wave forces or (b) the visor hinges were damaged first by the weight of water inside the leaking visor, so that, in either case, the visor could fall off, pull open the inner ramp and open the ship to the waves so the garage could be flooded (and then that the inner ramp closed itself!). The Germans changed opinion September, 1996 and state now (11) that the visor/inner ramp only leaked, so that the vessel listed, and that the visor fell off later when the ship listed. 2.19 why this is unlikely! The position of the visor is at 289° to Söderarm - the ship's arrival point. The visor location seems far too South from a reasonable course from Tallinn to Söderarm. For the positions of (i) the visor at time X, (ii) the ship at the 01.24 hrs Mayday and (iii) the wreck at 01.55 hrs to make sense, the visor must have fallen off after the abrupt listing took place at 01.02 hrs and after the vessel turned to port at 01.03 hrs and before the Mayday at 01.24 hrs. A reasonable time X appears to be at 01.12 hrs, when the vessel had 34° list to starboard, 3 000 tonnes of water had already flowed into the vessel below waterline, the vessel was heading straight into the waves, 225°, and the side of the visor was in line with and almost parallel with the water surface. When the 'Estonia' then pitched into the waves, the visor hit the water surface and the sideways impactive/slamming force was 6-10 times greater than any periodic hydrodynamic wave force acting on the visor in the upright condition. This happened about the same time the engines stopped - the vessel then continued one mile south where it stopped in the water. When the impactive force slammed straight into the side of the visor at angle of list 34°, all locks, hinges and other connections were broken in one go after which the visor then crashed down on the forepeak deck and rested against the ramp at the top recess. This may have been heard by the trainee second officer (see FR6.2.1 in (13)). At the next pitching the visor was lifted over the protruding ramp and may have touched the inner ramp 1.9 and tipped forward and was rammed by the bulbous bow. It is of course also possible that the inner ramp was damaged later 2.21. Judging only from photographic evidence of damage to visor locks, hinges and hydraulic pistons it seems perfectly possible that these parts were ripped apart and bent by one sideways impact from starboard to port as outlined above 4.10. Note January 2001 - the writer believes today that the visor was in fact found adjacent to the wreck and was not detached as outlined above. The above description assumed that the visor position 1 560 metres West of the wreck was correct, an assumption which today cannot be considered correct. The visor was naturally removed from the wreck under water ... after the accident. 2.9 The Safety Rules in Force on the 'Estonia'The garage of the 'Estonia' was arranged as per SOLAS II-1, reg. 23-2, 1 (open/close shell door indication), 2 (TV surveillance and/or leak detection) and 3 (manual patrol) to ensure that no sea water could leak into the garage that could lead to major flooding 5.2. The Commission has spent a lot of effort to prove (1) that the door indication was defective, (2) that the TV surveillance was faulty and (3) that the manual patrol was unreliable i.e. that all three safety features to detect water in the garage were not functioning on the 'Estonia' on the night of the accident. The patrol watch man (Linde) has stated from the first day after the accident (in different versions) that the garage was dry at all times (particularly when he left the garage the last time at abt. 00.35 hrs (or 00.50 hrs - i.e. abt. 27 or 12 minutes prior to the abrupt listing took place) and this seems to be true. There is no convincing evidence that the garage safety arrangements on the 'Estonia' did not fulfil the spirit of SOLAS. Even if it were the case, it does not mean that water entered the garage and caused the abrupt list, 50°, at 01.02 hrs. The writer am quite astonished that many Administrations have concluded that the SOLAS rules did and do not contribute to the safety of the ships and that the only solution is that Estonia type ferries shall have adequate stability with 0.5 meter of water on the garage deck through design solutions only, while the inadequate safety rules are maintained. Adding new safety rules on top of other existing safety rules, if the latter are not working, is not a good safety practice. It is to be hoped that some new safety rules, agreed after the Estonia accident, should therefore be revised in due course - the rule about adequate stability with 0.5 meter of water in the garage deck through design solutions only would not have prevented the Estonia accident 5.16! 2.10 The Visor LocksThe Commission has concluded that the strength of the locking devices is the main cause of the accident, 1.15 and 1.21) However; the Commission never recovered the visor side locks during the diving survey 1.14 and the Commission ensured that the side locks were never examined in a laboratory 1.16. Furthermore 2.15 the Commission wrote to the German Experts in December 1996 and stated that the Commission could not prove that the faulty locks originated from the shipyard. The Commission's strategy was clear - blame everything on the visor locks, even if they were never salvaged from the wreck and never analysed in a laboratory, but ensure that the shipyard cannot be blamed for it, as the shipyard will require better proof than what the Commission has provided. Nothing of this was mentioned in the Final Report (13). Note August 2000 - the German Experts wrote several letters to the JAIC in 1995/6 pointing out errors in the Commissions conclusions all of which were made secret by the JAIC. The German letters were not available to the public until March 1998 after the publishing of this book. It would appear that the visor did not fit correctly and that at least the bottom lock must have been damaged and unusable prior to the accident, that the visor and ramp were secured with ropes and that the visor and ramp could not have caused the accident. 2.11 The Position of the VisorConsidering the position of the visor vis-à-vis the wreck the only possibility, that the accident took place as suggested by the Commission, is that, if the visor fell off underway (at 01.16 hrs, course 287/9°) and the garage filled with water, the vessel then started to turn 180° to port (at 01.17/8 hrs with increasing angle of starboard list, port rudder and propeller above water and stopped engines a few minutes after 01.18 hrs!) and returned on counter-course 107/9° to one mile south of the original course where the Mayday was sent 01.22/4 hrs. This manoeuvre is impossible. Forssberg has a different story 1.13. Another story was published in the Final Report, 4.20 and 4.21. 2.12 About Water flowing down from the Garage to Deck no. 1The Commission suggests that water first flooded the garage deck no. 2 in the superstructure, and then that water leaked down to deck no. 1 in the hull to alert passengers. First the water in the garage must have leaked through closed fire doors at the centreline with 20 cms high sills on deck no. 2 into the stairwell. You need about 600 tonnes of water in the garage to reach the top of the sills (20 cms of water in the garage), when the ship is upright or has 1° list to starboard (the ship listed originally 1° to starboard). The free water in the garage would tend to collect on starboard side and to increase the heel, so that the fire doors would be left in a dry position. It is alleged that the vessel's stabilisers managed to counter the heeling moment and keep the vessel upright. Therefore water flowed through a very narrow slit below the fire doors in the garage and flowed down the stairwell to no. 1 deck, out in the corridors and into the cabins on starboard side of deck no. 1, where it was finally observed (at 00.56 hrs). Then it seems logical to assume that the visor had fallen off at abt. 00.45 (and not at 01.12 or at 01.15 hrs). This is impossible, as the ship would then have been abt. 4 miles to the West of the visor position, when the abrupt list occurred (at 01.02 hrs). The whole idea that water flowed down from the superstructure to deck no. 1 is distorted. The Commission refers to statements by passengers that water was seen pouring in all around and between a fire door and its frame in the stairwell. The writer has never managed to identify these survivors nor the statements. The statements do not make sense unless the door was located on deck no. 1 leading to a space to/from deck no. 0 but not at deck no. 2. The idea that water poured down to deck no. 1 from deck no. 2 is as unlikely as the allegation that great amount of water entered the garage in the first place at the forward ramp 1.7. It is unforgivable that the Commission has not considered, where the water on deck no. 1 originated from. A survivor (CÖ - Cabin 1049 1.2) says he was sitting in his bed at about 01.00 hrs smoking a cigarette when he heard strange noises. He dressed quickly (30 seconds) and went out of the cabin. He saw water in the alleyway and when looking ahead from the staircase he saw the water tight doors open. He saw in the alleyway water splashing up as if a valve had been opened somewhere below. The abrupt list occurred when he was further up on his way to the 7th deck. For some reason the Commission ignores this statement. Another survivor (MÖ) is quite certain that the abrupt list occurred 01.02 hrs. Many survivors from all six watertight compartments with cabins on deck no. 1 forward have stated that there was water on that deck before 01.00 hrs. It seems water was noticed in the absolute foremost compartment and in a compartment 50 meters aft at about the same time. How could water have spread so fast so far apart? The Commission decided to ignore the question or to state that the water came from the garage above via one closed fire door. It is very strange, if someone as early as 00.56 hrs noted that water was pouring down the stairwells between decks nos. 2 and 1, that this extraordinary fact was not brought to the attention of the crew. On the other hand water in corridors and in cabins on deck no. 1 starboard side alone may not have been considered too dramatic. Some passengers on deck no. 1 left their cabins early, as they knew that something was very seriously wrong and moved up to deck no. 5 to complain about water on deck no. 1 - not about water pouring down from deck no. 2 in the stairwell to deck no. 1. Some passengers from deck no. 1 went to the open deck no. 7 before the abrupt listing occurred. An unproportionate number of survivors (33% - 46 of 137) had cabins on deck no. 1 (even if it seems that half of them were not in their cabins when the accident occurred). It is absolutely impossible that the water on deck no. 1 leaked from the garage above. 2.13 About Sailing without VisorThe Commission's cause of accident 1.11.3,4 means that the vessel would have sailed without visor for two minutes in the upright condition without nobody noticing it from the bridge. This is confirmed in the Final Report, 4.20 and 4.21. Even if you could not see the visor itself from the bridge, you should be able to see the light inside the garage illuminating the sea in front of the ship in the middle of the night. Nobody saw anything to this effect. The Commission has never commented upon this fact. Note August 2000 - without visor and a fully open ramp >1 800 m3/min of water would have entered the ship's garage and she would have turned turtle immediately. The light went out at least 10 minutes after the sudden listing (no capsize), i.e. the light in the garage would have illuminated the outside sea. 2.14 About Breaking and Breaching of the Visor OutfitIt also means that events like locks and hinges breaking, deck plating being ripped apart, visor flipping up and down, etc. 1.11.1,2,3 must have taken place when no other unusual events were observed aboard long before 00.45 hrs (even if JAIC in (13) says it took place at 01.00 - 01.10 or 01.15 hrs). These events must have been associated with big noises but nobody heard anything (except the visor pounding against the fore peak deck?) It can only be regretted that the Commission made the wrong conclusion when it found the wreck without visor 1.4 and thought that the loss of the visor caused the accident, while it was more probable that the accident had caused the loss of the visor. To repeat the idea for three years or to back it up with doubtful testimonies and publish it in the Final report is irresponsible. 2.15 About impact Loads on the Bow above WaterlineIn 1971 the writer worked for Lloyd's Register of Shipping and was asked to investigate a number of damages to bow structure above waterline on tankers and bulk carriers - plastic deformation of plates and stiffeners. It was found that transient and random impact forces on structure above waterline, similar to slamming forces on the bottom of the ship, were to blame. These impact forces increased in number and amplitude when the angle between the bow shell and waterline (flare angle) was reduced and when the shell plate was flatter (less rounded). The impact load could be ten times bigger than a periodic and hydrodynamic external wave load (but of much shorter duration). When 'Estonia' listed >34° to starboard the effective flair angle was almost 0° and therefore big impactive loads would develop, when that side hit the water surface. The Commission has never considered that the visor was struck off sideways in such way. Instead the Commission has alleged that the visor locks were of poor design and manufacture to transmit external wave loads into the hull proper in the upright condition. The locks were said to be so poor so you wonder, why they had never before been deformed or fractured by less severe wave loading. Poor design, etc. manifests itself onboard by deformation, fractures and malfunction (before total collapse takes place). The suggested poor design never manifested itself prior to the accident. The Commission has said i.a., that the reason for this is that the ship never in 15 years encountered such heavy weather as the night of September 27, 1994 (13), but this is of course not true. Interestingly, one Commission member wrote to the German Experts in December 1996 and stated that the Commission could not prove that the faulty locks originated from the shipyard. 2.16 Stability AssumptionsThe ship was not fully loaded on September 27, 1994. Assume that there were 500 tonnes fuel aboard, a couple of hundreds tons of fresh water, 1 000 tonnes of cargo (cars, lorries, trailers) and 100 ton passengers and luggage and port trim tank full, 185 tonnes, to balance heavy cargo on starboard side. Then the deadweight (dwt) is about 2.200 tonnes and the draft (d) is about 5.1-5.2 meter. Deck no. 1 below car deck is then below the waterline. With its large beam (B) the 'Estonia' had always good, built in stability. The writer estimates the metacentric height GoM to be about 2.1 meter, which is confirmed by other people 4.4. (GoM is a measure of the 'lever' which together with the ship's displacement keeps the vessel upright). The 'Estonia' required approximately minimum GoM about 1.8 meter to fulfil the rule requirements of damage stability. The writer has estimated the lightship weight of the 'Estonia's to about 9 000 ton. The 'Estonia' was a 'two compartment' ship i.e. two watertight compartments in the hull below the garage could be flooded without the vessel capsizing or sinking 5.5. If water leaks into the car deck of the superstructure (figure 2.16.1), the vessel heels about 10° with 600 000 litres on the deck. Fig. 2.16.1B. This water does not flow down to deck no. 1 inside the hull, as the door openings are at the centreline and fitted with 20 cms high sills. The water is always trapped on the side of the sloping deck .  (Translation of Swedish text in figure 2.16.1 above - Water on car deck. 1A. Initial position. 1B. 600 tons of water on the car deck above the heeled waterline. No water flows down to deck 1. 1C. 1200 tons of water on the car deck, which is still above the heeled waterline. 20° list. 1D. 2000 tons of water on the car deck, now below the heeled waterline. 34° list. Water on decks 4 and 5. Righting lever GZ=0. The ship turns upside down. 1E. 90° list at instable capsize. The ship turns upside down in seconds. Centre of gravity G outside centre of buoyancy B! 1F. Final condition. Ship floats upside down on the undamaged, tight hull). You need about 1 200 tonnes of water on the car deck 7.62 meter above the keel to list the vessel about 20° to starboard. This water, 1 200 tonnes, forms a 2.8 meter high wedge with its base against the starboard side and with a lever about 7.22 meter from centreline, which lists the ship (a fair number of trucks and trailers were parked on the starboard side - water filled the space below and beside the trucks and the centre of gravity of the water wedge was pushed inboard). Fig. 2.16.1C. The top of the wedge is many metres from the ship's centreline and almost a meter below the sills of the fire doors, when the ship lists. Some water flows out from the car deck via the existing scuppers. The more water that enters the car deck, the more the 'Estonia' lists, and at a certain angle of heel with a certain amount of water on the car deck she tips upside down 5.5. The reason for this is that the righting arm, GZ, becomes 0 at abt. 34° heel, fig. 2.16.1D, and the vessel then is unstable. The vessel cannot float with list 90°, fig 2.16.1E, which is an unstable position. Then the vessel is on its way of turning turtle with the whole superstructure flooded, fig. 2.16.1F. When the 'Estonia's was turning upside down, she should have floated on the hull with the centreline (and the openings down to deck 1) three, four metres above the waterline, fig. 2.16.1E. Very little water could during that time flow down to spaces below the garage. The volume of the hull below the car deck is abt. 18 000 m3, and that air cannot leak out, when the ship is upside down. As the lightship was only 9 000 tonnes and the dead-weight 2 200 tonnes, there was plenty of buoyancy left inside the ship hull (abt. 7 000 tonnes), so that the 'Estonia' should in the end have floated up side down, if she had capsized with water in the superstructure - fig. 2.16.1F. But she did not do that. She sank! It does not matter if there are errors in the weight assumptions, i.e. if the ship and the cargo, etc. were lighter or heavier, or if the stability was better or worse or the levers were longer or shorter, because the principal result is always the same. You need substantial amounts of water on the car deck in the superstructure to heel the ship 18°, and you need about 2 000 tonnes of water on the car deck to heel the ship about 34°, where it turns turtle in minutes and floats up side down 5.5. Water in the superstructure does not only heel the vessel. The water also trims the vessel either on the bow or on the stern. The water always collects at the lowest point on the car deck, which shifts position, when the ship heels and trims. With 1 200 tonnes of water in the garage the ship trims about one meter either on the stern (1 200 tonnes water aft - the opening in the bow moves up several metres above the waterline and makes further water entry more difficult - or on the bow (1 200 tonnes forward) - which means that the car deck is almost below the waterline forward and facilitates water entry. In the latter case you would expect that the 'Estonia' had turned turtle in a few minutes - as 'Herald of Free Enterprise' outside Zeebrügge 1987 (but 'Herald of Free Enterprise' only ended up on the side as the water depth was 12-14 metres, where she capsized, i.e. she never sank below the water surface but rested on the bottom with the side above water 4.16). It took about 33 minutes for the 'Estonia' to list to 70° after she had first suddenly listed to 15° (witnessed by several survivors). It means that about one hundred tonnes of water per minute should have leaked into the superstructure above the waterline during 30 minutes. It seems quite strange. We know, if the inner ramp was completely open and if the ship trimmed on the bow and if there was speed forward, that the vessel would have turned turtle in a few minutes, alternatively if the water ended up in the stern, that the bow opening would have been about 2-3 metres above the waterline and no or little water could get in. My conclusion is that there was no water in the superstructure. If a watertight compartment in the hull below deck no. 1 below the car deck of 'Estonia' is flooded (figure 2.16.2) with abt. 1 000 tonnes of water the stability, the metacentric height GoM, is reduced by 0.8 meter due to free water surfaces (loss of inertia to prevent the vessel to list). If two compartments are flooded (fig. 2.16.2B) the metacentric height is reduced 1.6 metres and there remains only 0.5 meter of GoM. It means that the ship is still stable, but that she rolls slower. This is the rule requirement. Ships shall survive with two flooded compartments of the hull.  (Translation of Swedish text in figure 2.16.2 above - Water below car deck. 2A. Initial position. 2B. Underwater hull damaged. 300 tons of water in one or two compartments. GoM reduced. 0° heel. 2C. 600 tons of water in the ship. Water spreads through open watertight doors. GoM almost 0. Other compartments on deck 0 flooded. 2D. Ship has heeled (GoM<0) 15° to a new equilibrium (GoM>0), where free water surface effects are smaller. No water on the car deck. 2E. 45° list. Water spreads through open watertight doors and fills compartments on deck 0. Water on deck 4 and 5. Stable condition! 2F. 90° list. The ship does not capsize, when water enters both below and above the car deck. STABLE CONDITION!). If three compartments are flooded (>2 200 tonnes) the initial stability becomes negative and the ship may suddenly list 50°. But because it is only 2 200 tonnes of water in the hull, it becomes stable again, when it has listed a certain angle - fig. 2.16.2D, because the free water surfaces are reduced by the heeling, when the water is pushed up against the watertight car deck. Open watertight doors are temporarily 'on the dry' and no water spreads. Also the righting lever (GZ) is positive at larger angles of heel. That three or more spaces could be flooded on the 'Estonia' during the night of the accident is clear. The watertight doors between all six watertight compartments on deck no. 1 forward of the engine room were open. The following probably happened. First (at abt. 00.40 hrs) one or two compartments (the sauna (11)) on deck 0 were flooded due to a shell damage, and the vessel was still stable - fig. 2.16.2B. When the water reached deck no. 1 (at abt. 00.50 hrs) it spilled out there (fig. 2.16.2C), which was observed by many passengers on deck no. 1, who complained at the reception, which in turn informed the bridge (00.54 hrs) by telephone. SL was sent to check! While a large number of passengers on deck no. 1 started to evacuate their cabins and climb to deck no. 7, the water spread through open watertight doors on deck no. 1, and filled other spaces of the hull on and below deck no. 1. The result was that the initial stability (GoM) became zero and that the ship listed to starboard at 01.02 hrs (fig. 2.16.2D). Then the ship became temporarily stable, when the water could not spread through the watertight doors and the free surfaces were reduced. But water continued to flow in - fig. 2.16.2E, water could again spread through the open watertight doors and the deck house was flooded, so that the ship heeled more and more - 70° at 01.35 hrs - and sank 01.55 hrs. That the ship finally sank (01.55 hrs) and did not, e.g. tip over up side down, was due to the fact that there was a hole in the hull below waterline - fig. 2.16.2F - and plenty of water (weight) in the hull below the car deck, which stabilised the ship. All air in the ship below the car deck and forward of the engine room escaped through the ventilation system, while the angle of heel was less than 90° and the buoyancy was reduced to <12 000 tonnes. The engine room was still dry, but its buoyancy was maybe only 5 000 tonnes, so 'Estonia' could not float on that. Thus she sank, probably with the bow first. Note August 2000 - correction - evidently the 'Estonia' sank stern first - already at 01.36 hrs. 2.17 Elementary StabilityBoth the Commission and the German group of experts think that 'Estonia' capsized and sank due to large amounts of water on the car deck in the superstructure. The Germans (11) are probably right when they suggest, that the visor locks and hinges were worn and badly maintained, but it did not contribute to the accident, as the visor according to the Germans, was struck off after the abrupt listing had developed. The Germans suggest that thousands of tonnes (millions of litres!!??) of water leaked through the badly maintained rubber seals between the visor and the hull and the inner ramp and the hull. The writer does not believe that so much water can leak undetected, while the visor and ramp were still in place, and he does not believe in the Commission's theory. A ship sinks when the hull is damaged below waterline. Therefore all ships have watertight bulkheads to prevent that water spreads, if the hull is damaged. 'Estonia' should have survived with one watertight bulkhead damaged and two compartments flooded. But because the watertight doors were open in the bulkheads, the water spread and 'Estonia' first listed and then sank. This is elementary stability theory. That the Commission has omitted to investigate normal leakage is remarkable. There is not one word in the Final Report (13) that 'Estonia' could have sprung a leak! 2.18 What caused the Leaking?The ship suffered a big impact some time about 00.40 hrs and later there was water on deck no. 1 at 00.50 hrs. Water probably leaked into the vessel below deck no. 1. The writer has no idea of the proximate cause of the leak (Note August 2000 - but see below). Linde said the vessel suffered a hard impact. A small explosion inside a tank or pipe? Explosions are relatively common causes of accidents aboard. The NTSB investigating the TWA Flight 800 accident still does not know what caused that accident, but an explosion is a possible cause. NTSB investigates many different causes. The Commission never bothered to check 'Estonia' for any other damage than the visor, 1.22.10 and 4.8. 2.19 Water in the Garage?The inner ramp was found only partly open 1.11.3. 3/E Treu said he saw water flowing in at the forward ramp at 01.15 hrs on the garage VDU in the engine control room 1.9.1. Treu did not say that he saw the inner ramp completely open, i.e. that he could see the waves and sea through the completely open bow opening 4.23. Assume that the ramp was only partly open, 60-70 cms at the top or 30-35 cms halfway down about 2.5 meters above the garage deck (as it was found). The area of the two wedge shaped openings (P+S) is about 0.82 m², where water can enter (up to 2.5 meter above the garage deck). The garage deck was about 2 metres above the waterline. Assume that the pitching period was about 12 seconds and the relative motion amplitude was about 4.5 meters. This means that the two wedges were below water for about 3 seconds every 12th second - the remaining time the wedges were out of the water! How much water flows in through the wedges in 3 seconds. The loose visor was protecting the openings, so water only flowed in by gravity. Say the inflow velocity was 3 m/s. Then only 7-8 m3 flowed in every 12 second (even if Treu said that water was flowing in all the time!) or 36-37 m3 per minute! Therefore it would have taken at least 15 minutes to fill up the superstructure (600 tonnes) until water reached the sills of the fire doors. But water would also flow out through the scuppers of the garage drenching system. Enough water to capsize the vessel did not flow through the partly open (or leaking as suggested by the Germans) inner ramp. No, we have to assume that the visor pulled open completely the ramp just after 01.15 hrs, say at 01.16 hrs as suggested by the Commission in 1.15.5. It is strange that Treu has never stated that he saw the inner ramp completely open and that Treu never reported his first observation to the bridge. Soon after the whole garage was full of water according to Treu (10) and the ship was listing. Between 01.20-01.25 hrs Treu is in contact with 4/O Kikas on the bridge discussing ballasting the vessel to reduce the listing (sic!). They were not discussing stopping the engines or changing course. With the bow completely open the area through which water enters is, say 15 m², and the velocity is 7 m/s (ship's speed), i.e. 1 575 m3 enter in one minute! (five intakes of 3 seconds) or 3 150 m3 in two minutes. Then the vessel will heel >34° in less than two minutes and capsize, i.e. tip upside down (like the 'Herald of Free Enterprise' 4.16). But the 'Estonia' stopped heeling at 20°! So apparently there was much less water in the garage - 1 200 tonnes - and then the water stopped flowing in. The inner ramp closed up again! The Commission says so 1.15.5. Treu's statement that 'the whole garage was full of water' (above the roofs of the cars) is also strange! If there was 2 000 tonnes of water in the garage, the vessel should have listed at least 34°, but then all the water would have collected on starboard side aft and only the outermost cars aft would be fully below water, and the ship should have tipped upside down. All the cars on the whole port side and the starboard side forward would be dry 4.21. The writer believes 3/E Treu never saw any water in the garage. The writer believes that 3/E Treu was as surprised as the Master Andresson, 2/O Kannussaar and 3/O Tammes on the bridge and Mr. Linde, when the vessel abruptly listed 50° at 01.02 hrs. Maybe Treu was asked to make up his story by someone who did not know how ships behave with water in a superstructure above waterline? 2.20 Water on Deck no. 1!Many survivors saw water on deck no. 1 in the hull before 01.00 hrs and that the watertight doors were open. Deck no. 1 forward consists of six compartments of cabins without toilets. The compartments are divided by watertight bulkheads about 10 meters apart fitted with watertight doors. The public toilets are located in the 2nd and 5th compartment, i.e. 75% of the passengers on deck no. 1 must pass a watertight door to go to the toilet. It is probable that the watertight doors were permanently open at sea in contradiction to SOLAS II-1, reg. 15.7.1.2.3. and reg. 15.9.2. 5.6, but maybe in compliance with reg. 15.9.3. It is possible that sea water leaked into the vessel hull on deck no. 0 below waterline between, e.g. frames 85-98 and/or 98-110 well before 01.00 hrs. Maybe the doors in the watertight bulkheads on deck no. 0 were open, so that more than one compartment was flooded. Later the water started to spill out on deck no. 1 and was noted by many passengers. The water spread through open watertight doors at the centre line into six compartments. The damaged vessel then trimmed on the bow, so the water flowed generally forward. Suddenly the vessel lost its stability due to the free water on deck no. 1 and the associated loss of inertia. All water on deck no. 1 then collected on the starboard side, some water flowed also up from deck no. 0 port side and ended up on the starboard side on deck no. 1 (this is when water ended up in JS' cabin in the foremost compartment on deck no. 1 4.7) and listed the vessel 50°, but as the amount of water was limited and the free surfaces were reduced at increasing angle of loll, the vessel regained stability at 15° list. Water did not spread through the open watertight doors at centreline, which were on 'the dry'. When more water continued to flow into the ship 70° list developed during 30 minutes. Then the vessel slowly sank. Note August 2000 - the writer now believes that the starboard stabilizer fin foundation may have been damaged, due to bad installation welding in February 1994, and due to wave forces, at about 00.40 hrs and a 0.2 m² opening was created. It seems the night of the accident was the first time the stabilizers were tested since installation! Then the whole compartment inside the fin unit was flooded with water - inflow rate about 50 ton/min. Only one or two compartments were thus flooded - the stabilizer compartment and the small, narrow compartment forward - because the watertight doors at the end bulkheads were then closed. After the water had filled the compartments, it started to spill out on deck no. 1 above, where it was noticed by several passengers. The time was then about 00.55 hrs. The bilge pumps were started. However, then for unknown reasons somebody opened the watertight doors on deck no. 0 level (the tank top) and the water spread into more compartments aft - the generators and main engines rooms - and the water disappeared from deck no. 1! The result was loss of intact stability due to free water on the tank top (deck no. 0) in three, four compartments and the ship heeled suddenly 30° to starboard (with help of outside waves rolling the ship) at 01.02 hrs. Then the ship stabilized itself at about 15° heel. The visor was probably not properly locked at departure - the bottom Atlantic lock was probably already damaged and out of function Appendix so the visor was pulled off when the ship sank at about 01.35-01.40 hrs. The ramp was never pulled open by the visor. It too was probably not properly locked upon departure. The cause of the accident was thus a combination of a badly fitted stabilizer fin February 1994 and the crew mishandling the situation - opening the watertight doors. For unknown reasons the Commission would not admit this. When it saw on the videos of the wreck that the visor was missing (the visor must have been just beside the bow), it decided to blame the accident on the visor and the ramp. Note September 2001 - it could also have been the swimming pool recessed into the double bottom that collapsed and caused the leakage. Who has ever heard of a swimming pool inside the double bottom of a passenger ship? The 'Estonia' had one. How and when it was built is unknown, but it was a substantial weakness of the groundning protection of the ship. 2.21 The Inner Ramp DamageThe Commission says that the ramp opened up, permitted water to flood the car deck of the superstructure and closed 1.15.5. The German Group of Experts pointed out during 1997 that this was unlikely, as the ramp was not weathertight in the lower port corner (11). To make the ramp tight, the crew put cloth and rags between the ramp and the frame, which are seen on the video films. Had the ramp been opened up, the cloth and rags should have been flushed away. They are still there - thus the ramp was never opened up. Of course, had the ramp opened up and water had entered the car deck, 'Estonia' would have tipped upside down. She didn't = the ramp never opened. The JAIC believes the rags were flushed in between the ramp and the frame, when the ship sank and when the ramp closed (13). 2.22 Safety in the FutureAll rules and regulations about safety at sea are based on previous accidents and examinations of such accidents. You cannot develop safety rules unless you investigate properly all accidents. The complete failure of the Commission to investigate the 'Estonia' accident chapter 4 has contributed to reduced safety at sea chapter 5. 2.23 Plot of accident
See elsewhere on the Heiwa Estonia web page for un updated sinking scenario.
|
