The invention relates to an evacuation refuge for a maritime unit meant for maritime purposes, such as for shipping, operating at the sea and/or like, in connection with which there exists at least the said evacuation refuge for people existing on the maritime unit and life boats or like for emergency exit.
It is usual nowadays within maritime operations for e.g. shipping or operating at the sea to place the life boats e.g. on the open deck of ship or e.g. at the side of an oil drilling rig, from where the same may be lowered to the sea by dropping. This causes many problems in practice, one of the most crucial of which worth be mentioning is particularly insecurity during an actual emergency, whereby moving to the life boats takes place in open space totally exposed to the roll of the sea and weather circumstances. On the other hand one crucial problem related to the traditional type of placement of the life boats is that, that the life boats as well as the supporting and lifting apparatuses for the same are continuously under very demanding circumstances, that is why effects e.g. by corrosion can be seen already after a very short period of use. This is why the life boats and the operating apparatuses of the same require regular observation and active maintenance in order to confirm usability of the same during an actual emergency.
The problems described above are furthermore emphasized when speaking of actual maritime units, that are meant for operating at the sea, such as immovable oil drilling rig units. In this type of use such situations may arise for most heterogeneous reasons, that the personnel has to seek shelter and get prepared for emergency exit. This is why present rigs have according to the present stipulations temporary refuges, that may be closed airtight from the surroundings. Such temporary refuges are meant however for a very short stay, that is for a residence lasting about 30 minutes at the maximum. Such rooms are generally in practice usual cabins only, that have not been designed for protecting purposes so, that they could be easily separated airtight from the surroundings or that they would have structures increasing fire or explosion safety. After this time at the latest one must leave the protecting facility in question to the life boats placed at the side of the drilling rig or to the helicopter deck, in case evacuation is possible that way. The situation may thus be such, that the sea underneath and/or a part of the drilling rig is burning, whereby getting to the life boats is impossible because of toxic combustion gases existing in the surroundings or because of high temperatures. In addition to that problems may be caused under such situations also by high roll of the sea and by otherwise disadvantageous weather circumstances so, that helicopter transportations being used typically for emergency exit may not be used.
In Finnish patents numbers 96896 and 100197 there has been presented solutions, that are meant for developing particularly traditional drilling rigs of jack-up type. In this connection it may be stated, that it is nowadays known to use both so called semi-submersible drilling rigs and the type of so called jack-up drilling rigs as described above, which have feet, that may be moved with respect to the frame part of the drilling vertically in order to support the drilling rig to the bottom of the sea during an operating situation. The semi-submersible drilling rigs comprise an underwater part, which supports the actual working deck existing on the sea level. Such a drilling rig is not supported stationary on the ground at all during a drilling situation, that is why the type of drilling rig requires expensive and complicated joint and movement arrangements between the drilling device drilling the ground and the drilling rig, which enable drilling despite the roll of the sea. Both the costs of manufacturing and operating of such type of drilling rigs are multiple, when compared to the same of those drilling rigs of jack-up type described above. One crucial advantage of the type of drilling rigs above compared to nowadays drilling rigs of jack-up type is, however, that because of a massive construction of the same they may be transported in most heterogeneous circumstances, even during a relatively high roll of the sea. In addition to that, they may be used with clearly deeper depths of water than jack-up rigs, which may be used when the depth of water is usually below 150 meter.
The solutions presented in the Finnish patents mentioned above are meant particularly to improve the safety and feasibility of a drilling rig of jack-up type, whereby the former of the same is meant particularly to improve the safety and feasibility of the drilling rig in a way, that the residence unit belonging to the drilling rig is arranged moveable, whereby it is moved at least for the time of the drilling situation essentially away from the drilling unit, advantageously in a direction, that is essentially opposite to the moving direction of the drilling unit.
The latter patent discloses a solution, that is meant to improve the feasibility of a drilling rig of jackup type particularly with a view to the safety of an attachment phase and a detachment phase. In this case under the bottom of the frame part there has been arranged an airspace, that may be discharged for the transportation position of the drilling rig, whereby air is blown to the same in order to achieve an airbed or like, particularly for the time of the attachment and/or the detachment phase.
The risks related to maritime may be classified to the following main groups: cases of sinking, collision, fire, explosion and structural damage. In addition to that typical risks related particularly to off-shore oil drilling are: gas leakages, which cause danger to life due to an explosion or poisoning, oil leakages, yielding of the sea bottom, a pipe damage of the bore, helicopter accident, a threat to terrorism.
The evacuation stipulations for different kinds of risk situations are always slightly differing, but in serious cases they according to the main rule always end up to exiting the rig either by helicopter transportation or by life boats. As an example of the above increasing of hydrogen sulphide to a level of 0,04% may be mentioned. In such a case the rig must be evacuated immediately. When an evacuation is taking place, it is safest to carry it out by helicopters, in case they may be used under those circumstances or if there is enough time to use them. In case use of a helicopter is prevented because of the weather circumstances or because of urgency of the evacuation, people must enter the life boats. Moving to the life boats is always a risk already as such. It has been said, that most lives, that have been lost in sea accidents all over the world are just result of life boat accidents, because fatal accidents have occured while handling the life boats. They may be caused by the bad shape of the life boat or of its treatment apparatus, by circumstances during exit to the boats, by roll of the sea while staying in the boats and to a high degree also by exiting the life boats to the rescuing ship.
Despite the developed solutions according to the patents described above, in which there has been suggested first of all to place the helicopter deck in connection with the upper part of the residence unit above the life boats in a way, that a covered sheltering space is achieved, that protects moving of the personnel to the life boats, and on the other hand also that, that in connection with the residence unit there has been arranged built-in a sheltered emergency exit space, the present art for the part of the life boats has remained unchanged in such respect, that the life boats are completely uncovered at the sides of the drilling rig, so that the problems presented above are related also to the solutions according to the above mentioned patents.
It is the aim of the evacuation refuge according to this invention to achieve a decisive improvement in the problems presented above and thus to raise substantially the level of knowledge in the field. To achieve this aim, the evacuation refuge according to the invention is primarily characterized in, that the evacuation refuge is arranged as a rescue station, that is arranged to be closed essentially completely and preferably airtight from the surroundings and in which long lasting residence is enabled and furthermore inside of which the said life boats or like are being placed.
The evacuation refuge according to the invention improves significantly safety of maritime units meant for most heterogeneous purposes particularly with a view to different kinds of protecting, emergency, emergency exit situations or like. This is first of all thanks to the fact, that the life boats are placed in a space, which is totally protected from the surroundings so, that safe moving to the same is always enabled under most heterogeneous circumstances and surroundings. As an advantageous embodiment the evacuation refuge according to the invention is being exploited particularly in a maritime unit that is meant for operating at the sea, such as an oil drilling rig or like, whereby in connection with the rescue station there has been arranged processing devices for breathing air, such as ventilation arrangements, reserve of breathing air, regeneration and/or filtration units for breathing air, in order to keep the air suitable for breathing inside the rescue station, that is particularly to be closed airtight with respect to the surroundings, which enables long lasting residence in the rescue station. The invention has one crucial meaning in such respect as well, that the life boats, that are totally protected from the roll of sea and weather circumstances, are despite demanding surroundings maintained in good shape, whereby maintenance and service of the same may be minimized without however risking their reliability. One more advantage of keeping the life boats protected is the fact, that also the operating apparatuses of the same are kept in good condition with significantly less maintenance than presently. The evacuation refuge according to the invention improves thus significantly the general safety of maritime decreasing simultaneously significantly also maintenance and service expenses.
Advantageous embodiments of the evacuation refuge according to the invention are represented in the dependent claims related to the evacuation refuge.