Welcome to a chapter of the e-book Disaster Investigation.
3.5 The Collision Bulkhead
Behind the ramp there should apparently have been a partial collision bulkhead in the superstructure between decks 2 and 3, which was not there. Most ferries in the Baltic 1994 had no such collision bulkhead on the car deck, a fact which the Commission managed to censor completely.
The collision bulkhead was of course fitted in the hull below the car deck - it was aft bulkhead of the fore peak tank, and it could not extend above the car deck for practical reasons.
They (administrations, ship owner, shipyard) instead considered - after the accident, of course - that the ramp was the (extension of the) collision bulkhead (and that the visor was the fender structure to deform in case of a collision). The logic is correct, even if a weather tight ramp cannot ever be a bulkhead. Another structure, a two meters high collision bulkhead on top of the car deck behind the ramp 2,5 meters above the waterline had hardly increased the safety in a collision in either protected or open waters. In collision all bow structure is deformed aft and what you are worried about is, if hull compartments aft of the fore peak are flooded. In the case of the 'Estonia' the first compartment aft of the fore peak was a very small bow thruster room and further aft were two tanks.
You could say that the 'Estonia' had two or three collision bulkheads below the car deck.
Thus in a collision only very small compartments below the car deck could be flooded and it would hardly change the trim of the ship. A collision bulkhead above the car deck in the superstructure would therefore not increase the safety of the ship in collision followed by flooding of the fore peak!
The collision bulkhead in the superstructure is described in chapter 3.6.3 of the Final Report (5) - the collision bulkhead below the car deck in the hull is for strange reasons not shown at all. It is correctly concluded that the collision bulkhead was not required by the Finnish administration for the intended original traffic, i.e. protected coastal trading between Stockholm and Mariehamn, where the SOLAS-rules were not applicable (in spite of the fact that it was an international voyage). This is hinted at in chapter 18.1 of (5).
It is then a fact that, when the trade was changed 1993 to short international voyages on open seas between Tallinn and Stockholm, the Estonian administration did not request any modifications, e.g. that the existing collision bulkhead i.e. the aft bulkhead of the fore peak should be extended above the car deck in the same position.
No Changes or Improvements made
The reason was that the Estonian administration did not require any modifications or improvements of the 'Estonia', when the flag and trade were changed, e.g. a collision bulkhead, correct lifesaving equipment, safety and evacuation plans adapted to the new conditions, watertight subdivision in the hull, etc.
These simple facts are not pointed out in the Final report! No simple facts are pointed out in the Final report. The Final report is only a fairy tale about deficient ramp locks manufactured 1979 causing an accident 1994.
The reason was of course that the Estonian accident investigators were the same people who should have had ensured in the first place that the SOLAS-rules were applied at the change of flag 1.7. The fact, that the collision bulkhead was missing on top of the car deck, was an opportunity, that the Commission used to falsify the course of events, i.e. water had entered into the superstructure at the fully ripped open ramp (false statement) and had not been prevented to enter the car deck by the collision bulkhead (at is was not there). That the collision bulkhead was not there, or had been replaced by the ramp, due to the Estonian administration, was not worth pointing out.