Welcome to a chapter of the e-book Disaster Investigation.
1.24 Bilge Pumps running before and after the Accident - censored
It is unbelievable that the Final Report (5) does not describe the bilge pump system in any detail. There is not one word about bilge pumps in the whole Final Report! You get the impression that the Commission intentionally deleted all mentioning of the bilge pump system to avoid pertinent questions about it.
To prevent any ship from sinking there are several bilge pumps fitted aboard and the bilge pumps shall be able to empty - pump dry - any compartment in the hull that is leaking.
The 'Estonia' should have had at least four bilge pumps located in different compartments to enable one, or more, watertight compartments below the car deck in the hull to be pumped dry in case of leakage. The pumps were driven by engines or electrical motors and the latter were fed both from the auxiliary and emergency generators. The pumps should be connected to a bilge pipeline with a minimum diameter of about 136 mm, and each pump should have had a capacity of minimum 105 m3/hour. Probably the actual capacity was much higher.73
Systems engineer Sillaste stated at two interviews immediately after the accident, one of which where the director of the Finnish NMA and the expert of the Commission captain Simo Aarnio (2) was present, that
"the bilge pumps were running"
just after the listing had occurred and that Sillaste had the impression that the 'Estonia' was leaking 1.3. These statements are not included in the Final report (5). Sillaste had probably been called down at 00.30 hrs to start the bilge pumps, but that he could not say - he said that he went down to fix the toilet sewage system - and then he never dismissed the suggestion that it was water on the car deck at 01.15 hrs, which caused the accident. Or the testimony has been edited to make that impression. This writer believes Sillaste was called down to assist stopping a severe hull leakage and that it was Sillaste (and Treu) who started the bilge pumps.
It is not easy to design an idiot proof bilge system, as several pumps shall be able to empty both its own and adjacent compartments. The system can become over-complicated with a too large number of stop and control valves. By not mentioning the bilge system in the hull at all the Commission adds to the uncertainty about its contribution to the accident. Probably large amounts of water - 1 200-2 400 m3/hour - leaked into the hull of the 'Estonia' and later spread through open watertight doors, when the crew did not manage to pump the relevant compartment(s) dry or to isolate the compartment(s) by closing the watertight doors. The result was unavoidable - sudden listing and later sinking on the stern, when the superstructure started to be flooded via the vents on open deck 4 aft or via an open pilot door on deck 2!
The bilge pump system of the hull may have contributed to the accident.
73 The 'Estonia' had total six, electric driven bilge pumps with total capacity 960 ton/hour located in four separate watertight compartments below the car deck, which thus could have controlled a minor leakage. With a major leakage you had to rely on the watertight subdivision and that the watertight doors were closed and allow the damaged compartment to fill up.