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2.2 The Way to the MV Estonia Accident
The ship did not fulfill all SOLAS requirements regarding the extension of the collision
bulkhead above the bulkhead deck, that is, the vehicle deck. According to JAIC it was
common amongst the Finnish and Swedish maritime administrations to accept the ramp as
an extension of the collision bulkhead, even when the ramp was located too much forward in
the bow and not as required by SOLAS. This was a practical solution for the ferries traveling
in the coastal waters between Finland and Sweden. According to Luhmann (2008) this
exemption, however, should have been withdrawn by the authorities for the new trade
Stockholm-Tallinn, as part of the route was located outside coastal waters.
A much more relevant point in the course of the accident is the interlocking between the bow
visor and ramp, which was common in the Baltic ferries in the 1970s and 1980s. In a Ro-Ro
passenger ferry like MV Estonia the ramp can be interpreted as the extension of the collision
bulkhead. The collision bulkhead is a watertight transverse bulkhead in the fore part of the
ship extending to the bulkhead deck. Its purpose is to prevent ingress of sea water in case of
breach or rupture on the ship shell at the bow. Thus the collision bulkhead together with its
extension is meant to be a second barrier against ingress of sea water.
Approval of such a bow arrangement by the maritime authorities, in which the failure of the
bow visor leads to damage to, or the failure of, the extension of the collision bulkhead (i.e.
ramp) exposing the vehicle deck to open sea, is not only in conflict with the purpose of the
SOLAS regulations, but shows also limited understanding of issues related to ship stability.
Technically the interlocking of the ramp with the bow visor may be regarded as an
unfavorable design detail with respect to ship safety, in particular if the ship and the system
of bow visor and ramp are or were in a poor maintenance condition.
Such designs were, however, common in the Baltic ferries in the 1970s and 1980s until the
MV Estonia accident. The SOLAS requirements accepted in 1995 after the accident explicitly
require the extension of the collision bulkhead to be so arranged as to preclude the
possibility of the bow door causing damage to it in case of damage to, or detachment of, a
bow door.
Also the requirements of the different classification society rules concerning bow visor
strength were very unspecific at the time of the MV Estonia’s design and construction. This
reflects also the state of knowledge on the magnitude of the wave loads at the time the MV
Viking Sally, that is, later the MV Estonia, was built. The design load criteria applicable and
used in construction of the bow visor structures of the MV Estonia were thus not adequate,
with the knowledge of today.
The hull form of the MV Estonia was not very good in view of sea loads. It had an extreme
bow flare just (0-2 m) above the waterline at the bow. Above the knuckle line the flare is not
extreme, but it is still considerable. This bow form certainly contributed to the high wave
impact loads the vessel experienced in heavy seas. The bow visor extends also somewhat
below the knuckle line.
The MV Estonia running on the more exposed Tallinn–Stockholm route was subject to higher
wave loads than most other Baltic ferries running between Finland and Sweden. It may also
have run slightly faster in trying to keep its schedule in bad weather. The nautical officers on
the bridge did not reduce speed when they got the information on the strange noises or the
heavy metallic blows from the bow. The reduction of speed would have radically reduced the
wave loads on the bow and, if the ramp was already open, also reduced the inflow of water
on to the vehicle deck. Had the crew acted otherwise, the accident would probably not have
been fully prevented, but it is very likely that the number of lives lost would have been
reduced. Due to the incorrect loading in Tallinn the port side heeling tank was full. As the
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