Hur man utför en sjunkförloppsstudie - 23 april 2006

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 Hur man utför en sjunkförloppsstudie - 23 april 2006

----- Original Message -----

From: Anders Björkman

To: d.vassalos@na-me.ac.uk ; n.barltrop@na-me.ac.uk ; valanto@hsva.de ; Claes Källström

Cc: VINNOVA ; Katarina Stenström Ros ; John Graffman

Sent: Sunday, April 23, 2006 11:54 AM

Subject: Dnr 2006-00547 VINNOVA - Research Study on the Sinking Sequence of MV Estonia

Gents,

I understand that you are now very busy with subject at Swedish tax payers' expense, which please confirm.

I assume that the events just before the vessel started to load water in the superstructure http://heiwaco.tripod.com/epunkt319.htm will be included in the study, but I summarize them anyway:

The MV Estonia was doing 15 knots heading into 4.2 meters waves with a large relative motion forward. The MV Estonia superstructure bow flare was struck several times by heavy 350-700-1000 tons wave impacts that nobody heard (no action taken on the bridge, eg slow down).

You are recommended to test this in full scale on any ferry yourselves. It is very simple. Just ask the Master to head at full speed into heavy waves and notice the first wave impact. You cannot avoid hearing the BANG, feeling the VIBRATIONS in the structure and seeing the BIG SPLASH. Ask yourself if the MV Estonia crew was deaf, etc. allowing the following to happen:

Then various steel structure parts in the MV Estonia superstructure were damaged 10 meters forward of the bridge during at least 10-20 minutes: the visor side (deck 3) and bottom locks (main deck) were ripped off due to wave impacts, the visor moved up-down and damaged its bottom and the ship's main deck due to waves and relative motion, the visor lifting arms were ripped apart at the deck hinges on deck 4 due to wave impacts, the lifting hydraulic foundations were also ripped apart (deck 3) due to wave impacts, the hydraulic pistons and lugs then cut the deck 4 steel plate and a strong deck steel beam web and flange and the visor started to hit against the ramp protecting the superstructure, all ramp hooks and locks were ripped apart, etc.

You are kindly recommended to verify the damages and ask yourselves how they could develop without being noticed by anybody - except as noise from the bow.

Then the visor fell off (time is 01.15 hrs) and the ramp was fully open - the ramp top was then below the waterline and the forward speed was 14-15 knots. Water could enter into the superstructure 2.5 meters above waterline, when the MV Estonia with forward speed pitched the ramp opening below the waves. There is no evidence for this - three crewmembers in the ECR saw the ramp closed at 01.17 hrs, but assume that they are lying (they had of course escaped from the ECR at that time - http://heiwaco.tripod.com/epunk148.htm - after having started the bilge pumps as they were standing in water to their knees in the engine room).

So water started to be loaded on the MV Estonia superstructure car deck (deck 2) and the water ended up inside on starboard side and suddenly listed the vessel. Then the MV Estonia turned 180° port and stopped with the opening away from the waves. There was no capsize (GZ<0, vessel floating upside down) that you would expect with 1 900 tonnes of water in the superstructure side (considering also trim, of course) so less than 1900 tons of water were loaded. You would now expect much water in the superstructure to flow out again through the opening in the bow and the vessel to upright. Evidently no more water could enter through the bow opening at this time as it was high above the waterline! Do you agree?

If you agree, you must conclude that there are some basic errors in the JAIC analysis and evidence of the MV Estonia accident that you shall base your research study on.

Then the MV Estonia started to sink - and maybe you will just concentrate on that in your study? The time is 01.20 hrs and the ferry is more than a mile from the position of sinking after 01.54 hrs. So the MV Estonia was drifting at >2 knots speed while sinking. Do you believe that? See http://heiwaco.tripod.com/epunkt19.htm .

Anyway - the MV Estonia was sinking. The hull below deck 2 is undamaged all the time. All watertight doors are closed at 01.20 hrs. Most water in the superstructure should now flow out through the bow opening (easy to verify by model tests) and only a litte water should remain due to the original stern trim, and this water should flow out through the scuppers. There is no way that more water can enter the superstructure at this time with the bow in lee and speed away from the waves and you should expect the MV Estonia to upright due to the buoyancy of the hull.

But in order for MV Estonia to sink you must now flood at least three, four or five watertight and undamaged hull compartments after which the bulkhead deck comes under water and all the other compartments fill up. How could it take place? I will tell you.

Model tests!

Primo - start to verify the model in calm weather and closed ramp with 0.5 meter stern trim as per MV Estonia original loading condition at zero speed. Car deck is full of trucks and cars. This is fun! Load water on deck 2 (car deck) just by filling the compartment with a hose from above and observe what happens (the ramp is closed); vessel lists and trims more on stern, with 1900 tons of extra water on the car deck (among all the trucks and cars) model turns upside down. Capsize. Evidently the vessel does not float on the deck house decks 4-9 (doors are open aft on deck 4, 5 and 6 and in the side of deck 7, the windows are broken when coming below water) that is flooded completely immediately.

Secondo - verify the model in calm weather and open ramp and zero speed. Load water on deck 2 with a hose and observe again what happens; vessel lists and trims again on stern and capsizes with 1900 tons of water on the car deck. The bow was high over water all times. Same result as first test.

Tertio - repeat the second test in heavy weather, open ramp with opening away from the waves, zero speed (the condition at 01.20 hrs); fill the superstructure with a hose but due to vessel pitching (>trim), you will find that the water flows and sloshes forward and back on the car deck and out through the bow opening in spite of original stern trim. Interesting! The sloshing is in reality very noisy.

Recommendation - when you visit a ferry in heavy weather to check the bow impacts, also put 50 tons of water on the car deck and listen to it sloshing around.

Fourth - open ramp down below waterline, forward speed 14 knots into 4.2 m irregular waves, big relative motion forward (no change of heading during test); after 10-20 pitching movements (1-2 minutes) up/down vessel stops and capsizes quickly.

Fifth - like four but with a 180° change of course prior to capsize; vessel lists but after change of heading we are back to test 3 - and the water flows out through the bow opening due to the pitching.

Six - repeat two but prevent the vessel from capsizing (cheating a little by using an outside support) and allow the model to trim on stern only due to the water in the superstructure until the first opening on deck 4 (apart from the bow ramp deck 2-4) comes below water. What opening is first underwater. Right - the aft vents on deck 4 into the superstructure below. You do not have to fill the superstructure anymore by hose - it fills itself. Release the support and see what happens! Capsize of course! All the water in the superstructure flows to the starboard side again and model turns upside down.

Seven - as yourself how the clock on the bridge, starboard side deck 9, could stop at 01.36 hrs. Did it stop when it came under water? But the vessel didn't sink until 01.54!

Eight - like five but no water flows out through the bow opening for some reason at 01.20 hrs, no capsize takes place and the hull compartments are being flooded one way or another (you shall describe that) and the deck house decks 4-9 comes under water. The vessel is drifting at >2 knots for 35 minutes while sinking. How? How can a sinking ferry drift so fast?

Please keep me informed of your progress of your study.

Kind regards

Anders Björkman, Heiwa Co

(ovan e-brev är obesvarat)

Contact anders.bjorkman@wanadoo.fr 

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