WO2000032464A1

WO2000032464A1 - Lifeboat system

Info

Publication number: WO2000032464A1
Application number: PCT/NO1999/000360
Authority: WO
Inventors: Nils Gausvik; Ulf Tolfsen
Original assignee: Umoe Schat-Harding As
Priority date: 1998-12-02
Filing date: 1999-11-30
Publication date: 2000-06-08
Also published as: DE69924405D1; EP1135290A1; NO985630D0; ATE291548T1; NO310606B1; AU1698700A; EP1135290B1; DE69924405T2; ES2241345T3; NO985630L; WO2000032464A8; DK1135290T3

Abstract

A lifeboat system for a surface vessel, comprising davits (4, 6), control/release devices (9), and possible power devices (9') for davits (4, 6) and lines (8) for lowering of a lifeboat (1) to the surface. The novel features of the lifeboat system comprise: a preferably U-shaped main frame/cassette (3) comprising a horizontal main beam (30) in the inner rear edge with one horizontally extending fixed telescope part (40, 60) of the davits (4, 6) arranged in either end of the main beam (30), with the main frame/cassette (3) being arranged to in the lifeboat's ready stored position essentially to surround the lifeboat's (10) bow, stern and one side, telescoping outer davit beams (41, 61) arranged for running between an entirely contracted position and an extended position on the inner fixed telescope parts (40, 60) so that the lifeboat (1) is guided through an opening (21, 21') to an evacuation/boarding position outside a ship's side (114) and with the main frame/cassette (3) being arranged for placement of the entire lifeboat system as a unit in a lifeboat storage room (20) in a vessel, preferably via an opening (21, 21') in the ship's side (114).

Description

LIFEBOAT SYSTEM

This invention relates to a lifeboat system comprising a lifeboat and davits for lowering the lifeboat to the sea surface.

Statement of the technical problem.

During evacuation of vessels due to average or fire, lifeboats or rafts are used. The most essential advantages of rafts are that they are of little weight and occupy little space during transport and in ready state. Rafts are inflated by means of integrated containers of C0₂ when a desire arises to use them, or automatically by means of a sensoric release mechanism reacting on pressure or water. One of the disadvantages of rafts is that they have no propulsion engine or steering capability. Further they give very limited protection against water and cold and they easily capsize, particularly in strong wind combined with waves .

Hardtop-covered and so-called partially hardtop-covered lifeboats give a better protection for the passengers and are futhermore capable of being manouvered by means of their own engine. It is necessary to have lifeboats and/or rafts having room for all the passengers and the crew of a vessel. The International Maritime Organization (IMO) -standard requires that passenger ship lifeboats shall be partially covered. The cover serves as protection from wind, precipitation, cold or heat, sunrays, splashing from waves, and water filling. By cargo vessels of several types and platform installations at sea, free-fall-lifeboats are used more and more. Such systems, however, require special standards of instruction and physical capability of those who shall use the system. Further, free-fall systems require much space, also measured relative to conventional lifeboat systems. This makes use of free-fall systems less relevant for passenger ships. Storage of lifeboats on a lifeboat deck in the way presently done on modern passenger ships with ordinary davits (see Fig. lb) requires much space. Most lifeboat systems comprising lifeboat and davits in their assembled state raise between 4 and 6 metres from the lifeboat deck. This is due to the lifeboat's own height from the keel to the pilothouse, altogether usually building more than 2.5 metres, and also that the lifeboats are held at least two metres above the deck in order for unhindered passage for passengers below the lifeboat keel. Furter the launching arrangement much space for storage and launching. The lifeboat "steals" valuable deck area and space volume of the ship. Further the lifeboats hinder free outlook from cabins and living-rooms on the concerned decks. On board some fast running passenger vessels only inflatable and more protecting lifeboats. This is dua to existing lifeboat systems weight and space requirements is incompatible with the vessels requirement to design, speed and loading capacity.

With the present davit-carried lifeboats as described above, considerable transport costs arise for shipping the lifeboat between the lifeboat manufacturer and the shipyard building the ship. Transport of the lifeboat system usually takes place in a disassembled state, i.e. that the lifeboat, davits, winches and possibly a power accumulator are shipped separately. The lifeboats' outer dimensions as height and breadth often require that they are transported as deck cargo, which implies that they must be unloaded and reloaded in intermediate harbours. Damage during loading, reloading and unloading is therefore a risk for conventional lifeboats. Work with assembly and mounting of a davit and lifeboat with equipment on the shipyard is extensive and complicated which several connection points. This work is usually outside the lifeboat manufacturers responsibility and can entail problems as misassembly.

Lifeboats are usually exposed to weather and sun and are exposed to deposits of salt, sand and dust. Normally this will entail maintenance as cleaning of the lifeboats, repeated greasing of wires, sheaves, pulleys and blocks; washing or sandblowing and painting of davits. All sea spray in hot climate entails rapid evaporation and leavs considerable amounts of salt at every surface. Such mainenance in the present open systems is work-intensive and expensive.

Lifeboats shall be able to being launched even on strong heel, even in a situation with the ship being "dead" and there is no available energy from the mother ship. Today this is solved in two principally different ways; In the obviously more space demanding but technically simplest solution, the davit is designed with respect to the lifeboat and the ship with such a geometry, elevation and centre of mass that gravity force alone is required for launching. In the less space demanding, but technically far more complicated solution, the davit is driven out by means of stored energy from a hydraulic accumulator. These hydraulic accumulators are assembled according to the known art in a work-intensive operation.

Known art in the field.

An example of modular lifeboat systems is found in GB2229402 "Self-launching accomodation modules in off-shore environments" describing a living quarter module being releasable and which can be launched as a covered lifeboat.

The module is in the shape of a living quarter giving complete living, cooking and mess localities for the crew. The module is arranged on a carrier frame arranged for vertical displacement on vertically arranged guide rails on the ship's side so that the modul in normal use is situated above the deck, usually on the outside of the platform or the vessel. In an emergency situation the guide frame with the module is guided downwards in order for the module to reach the sea. The module contains propulsion means so that it can move away from the possibly averaging vessel or platform. However the module requires much space and a system comprising an outboard support frame and vertical guide rails.

A less practical example of compact rescue modules is illustrated in US4356789 "Emergency evacuation system for offshore oil platform" which is a patent on closed container-like rescue capsules arranged on rescue stations on the outside of a petroleum platform. The rescue capsules are provided with a lift eye in the top. This lift eye is arranged for being caught by a hook of a crane on a rescue vessel or a neighbour platform coming for assistance, so that the rescue capsule may be hoisted over to the rescue vessel or the neighbour platform. The resque capsules are also provided with lines for lowering down though an opening in the deck. The disadvantages of the system are obvious. Among others, it cannot be ascertained whether any rescue vessel will come to assistance, or that the rescue vessel will manage to lift over all the rescue capsules in due time.

Another GB2108054 "Method and apparatus for rescuing the crew of a ship or a sea platform" describing a lifeboat station with a lifeboat with an ejection mechanism from a closed lifeboat storage room under a deck and below the waterline of the mother vessel . This may be an advantage if an oil fire takes place at the sea surface. The lifeboat is arranged in a frame which is arranged to push the lifeboat out through a hatch in the ship's side after the lifeboat has been closed and the storage room has been filled with water. Admittance to the lifeboat takes place throug a hatch from the deck above the lifeboat storage room. The disadvantages by the lifeboat system illustrated in GB 2 108 054 is among others that if the ejection mechanism should fail then there is no way to return after the lifeboat storage room has been filled with water. The hatch in the ship's side may be damaged and thus impossible to open so that the lifeboat is not allowed to be entirely released. If the ejection mechanism does not guide the lifeboat entirely out of the lifeboat storage room and the vessel has a low heel towards the side where the acual lifeboat is situated, it may be difficult to get the lifeboat away from the averaging mother ship. Moreover, one may not open the lifeboat storage room's hatch if the pressure from the outside is not entirely balanced.

Another example from the known art is GB 2 186 547: "Ship davit system" describing a device for taking cargo onto a vessel, and lowering the cargo, with a deck partially consisting of a roof-shaped upper deck extending in the entire breadth of the ship, and being integrated in the main structure of the ship, with two separate guiding frames extending in the entire breadth of the ship in the upper deck or by the stern edge of the upper deck, with a davit is movably arranged on sheaves in the main frame. These davits are arranged to be extended straightly out from the vessel's side through the side of the upper deck. The lightboat described in the the GB-publication is an open lightboat, and not a covered lifeboat. The davits in the GB-publication is arranged in a fixedly arranged guiding frame in an overlying ship deck, and the lightboat is placed standing on an open lower deck, and not arranged in a lifeboat storage room. The separate guiding frames for the davits are arranged above the lightboat 's position in its ready-for-use attitude on deck. The guiding frames constitute a fixed built-in part of the overlying deck and constitutes no part of an integrated lifeboat system. Thus the guiding frames are not possible to replace. The davits are arranged for independent operation outwards and inwards with respect to each other. Each davit may be used as a crane for loading and unloading. This implies that the davits of the GB- application comprises more movable parts and more control devices and is thus vulnerable and complicated to control in an emergency situation. Another lifeboat system is described in US 1 133 700: "Life-boat device" (patent applied in 1914) describing a ship with separate large lifeboat rooms having space arranged for passengers to enter covered closed lifeboats. The lifeboats are illustrated as being completely cylindrical and occupy a small part of the lifeboat room.

The lifeboat room has horisontally hinged upper and lower large hatches . Through elongated slots in the lower edge of the upper hatches there are arranged fixed, long davits shaped as runways for sheaves on the lifeboats' upwards extending rods. In the US-patent's claim 2, line is written " .. and the said cover devices having slots suitable for admitting the said ways so as to permit the said cover devices to be closed while the outer portions of the said ways remain in such position so as to overhang the side of the ship." These runways are not extendable davits, but fixed, and always extending outside of the ship. The lifeboat system according to the known art is also not to replace as a unit. The evacuation and the boarding of the lifeboats takes plase inside this lifeboat room, and the room is due to this reason, and due to the extensive runways on the davits and the hook mechanism, and a separate inner boarding deck, considerably much larger than a lifeboat storage room according to the present invention. In the US- patent the fixed davits are all over overlying with respect to the corresponding lifeboat, and not arranged generally in the same elevation and surrounding the bow and the stern of the lifeboat in a very space economic arrangement as with the present invention. A davit system is shown in DE 198 08 491: "Boots-Davit" describing in a german patent publication defining an extendable beam having in its outer end a hinged beam which in turn holds the lifeboat . The hinged beam can be locked in the folded-in position with the lifeboat is kept in a ready position above the lifeboat deck. The lifeboat is brought into boarding position by the ship's side by running the carrier beame outwards and thereafter releasing the hinged beam. The lifeboat is not arranged for arrangement in a lifeboat storage room in ready position below a lifeboat deck. The davits are also not arranged for arrangement in the same lifeboat storage room. Boarding of the lifeboat can take place from a balcony in the ready positon or from the deck in an evacuation position. DE 198 08 491 constitutes part of the technical art with respect to davits being telescopically extendable in a direction straight outwards from the ship's side.

The purpose of the invention.

On the background of the above, one of the problems which gave rise to the invention, is to make room for lifeboats having sufficient passenger capacity in a limited space, in a system arranged for simple and safe boarding, and rapid, efficient and safe lowering to the sea surface.

With increasing size of ships with an increasing number of passengers relative to the total length of the lifeboat decks, another problem statement is to provide enough space for a sufficient number of lifeboat units along the ship's side.

Another problem which we would like to solve is to gather the entire lifeboat system under the producers' control up to the final assembly of the system comprising a lifeboat, a set of davits and possibly a power accumulator in one assembled and rationally transportable unit comprising each single lifeboat. It is also desirable to reduce the total weight of the system compared to the known lifeboats and davits.

Definition of the invention.

The invention relates to a lifeboat system for a ship, comprising a covered lifeboat, davits and lines for lowering the lifeboat to the sea surface, the novel and characterizing primarily comprising of: a) a low lifeboat hull with a collapsible superstructure ; b) a lifeboat storage room arranged on the ship, immediately below a lifeboat deck, arranged to receive the lifeboat's hull preferrably in horizontal position, and with an opening in the essentially entire length lifeboat storage room,- c) extendable davits arranged for placement in a stored and prepared position in the lifeboat storage room, arranged for:

- to lead the lifeboat out from the lifeboat storage room, and

- to keep the lifeboat in an evacuation / boarding position just below and by the mentioned lifeboat deck or by the underlying lifeboat deck, and outside of the ship's side. The invention further comprises also two alternative preferred solutions, with the first alternative solution being characterized in that the opening where the lifeboat is led out of the lifeboat storage room is arranged in the ship's side and that the davits are telescoping or in other ways extendable, arranged to be displaced through the ship's side opening, and thereby to keep the lifeboat in an evacuation / boarding position just below and near said lifeboat deck.

The other alternative solution is characterized by an opening in the lifeboat storage room residing on the underside of the lifeboat storage room, towards an underlying lifeboat deck, and that the davits are arranged to be lowered or rotated down through this opening towards the underlying lifeboat deck. The davits are telescopically extendable or in other ways displaceable with respect to the ship's side, and thus arranged to keep the lifeboat in an evacuation/boarding position by the underlying lifeboat deck.

Further features of the invention are found in the further dependent patent claims .

Advantages of the preferred embodiments. In the preferred embodiments the invention has advantages among others in that a replaceable cassette may contain the entire lifeboat system. The lifeboat system is, as described above, space-saving and gives more design freedom for the ship. The lifeboat system according to the invention gives room for more passengers in the lifeboat, and gives space available for more passengers on the mother vessel. The lifeboat used according to the invention is easy to board. The lifeboat system according to the invention is efficient, energy conserving and gives simpler and safer transport from the lifeboat manufacturer to the outfitting yard and more rapid, safer and simpler mounting in the mother vessel. The lifeboat system according to the invention is feasible to evacuate back to the mother vessel if the critical situation is changed or cancelled. The lifeboat system according to the invention may be arranged as a closed unit which may be sealed by means of a film and thus reduces the influence of water, salt, sand, and dust and dirt. The lifeboat in the lifeboat system will in its ready state storage in the lifeboat storing room be inaccessible without being released. This reduces the possibility of vandalism and theft of regulation required drugs (morphine) and necessary equipment from the lifeboats without being discovered. The lifeboat system according to the invention gives better view conditions and overview of the lifeboat deck. Fewer, clean surfaces simplifies cleaning and maintenance of the lifeboat deck. The present system is compact and simple, and thus more lifeboats may be arranged in the same volum than by known art, and thus gives improved evacuation safety for more passengers.

Figure captions.

Together with this description drawings are enclosed, drawings which shall illustrate features of the invention, but which shall not be construed as limiting of the scope of the invention.

Fig. 1 illustrates a much simplified section in starboard/port direction through a mother vessel with lifeboat system according to the invention comprising a covered lifeboat with a low lifeboat hull with collapsible superstructure arranged in a lifeboat storage room just below a lifeboat deck where the lifeboat hull is placed. Fig. 2 shows in the same section as Fig. 1 a first alternative of the invention, with the opening arranged to lead the lifeboat out is arranged in the vessels ship side and telescopic davits arranged to be displaced out through the ship's side and to keep the lifeboat in an evacuation / boarding position just below and by said lifeboat deck.

Fig. 3 illustrates the lifeboat with raised superstructure with the lifeboat being in a boarding situation.

Fig. 4 shows the lifeboat lowered to the sea surface.

Fig. 5 illustrates a situation with a negative heel of the actual ship side of the mother vessel. An alternative embodiment of the invention is illustrated, where the lifeboat can be taken out through an opening in the bottom of the lifeboat storage room towards an underlying lifeboat deck.

Fig. 6 shows, in the same section as Fig. 5, the alternatively preferred embodiment of the invention in that an opening in the lifeboat storage room is directed towards, or more correctly, constitutes the underside of the lifeboat storage room, towards an underlying lifeboat deck, and that the davits are lowerable or rotatable about an axis, down through the opening towards the underlying lifeboat deck.

Fig. 7 illustrates an imagined situation on the lifeboat deck in a situation with the vessel having a positive heel α, e.g. between 5 and 8 degrees toards the illustrated ships side.

Fig. 8 show the davits in a fully retracted storage position in a cassette format or in an illustrated lifeboat storage room. Fig. 9 illustrates the telescoping outer davit beams which are arranged to glide from an entirely retracted position to a maximally allowed extended position in tracks in the inner davit beams .

Fig. 10 illustrates, in a perspective seen from slightly above the horizontal plane, among other things a telescopic sliding hoisting block on a hoisting block rail arranged on the telescoping outer davit beam.

Fig. 11 illustrates, in a perspective seen from slightly below the horizontal plane, rollers on the inner davit beam's outer end arranged to supporting, by means of rollers, the outer davit beam's running movement out of and into the main frame.

Fig. 12 shows a wire sheave / tackle system in the sliding elevator block. Fig. 13 shows an elevator device comprising these components which are used to lower the main frame by rotating down the two inner fixed telescope parts, as explained above in connection with the figures 5 and 6.

Fig. 14 illustrates the lifeboat 1 with entirely folded superstructure.

Fig. 15 illustrates a lifeboat according to the invention, with entirely raised superstructure.

Fig. 16 illustrates a bow or loop device arranged to raise and keep up the roof and the walls of the superstructure.

Detailed description.

The lifeboat system.

Fig. 1 illustrates a part of a simplified cross-section of a vessel, e.g. a passenger vessel with, according to a preferred embodiment of the invention, at least one lifeboat deck 112 which may be covered by a roof or not. A lifeboat system according to one of the preferred embodiments of the invention arranged in a lifeboat storage room 20 arranged immediately below the lifeboat deck 112, directed towards an opening 21, 21' through the ship's side 114. The lifeboat system comprises a covered lifeboat 1, davits 4,6, and lines 8 for lowering of the lifeboat 1 to the sea surface. The characterizing features of the invention comprise roughly subdivided the following: a) a low lifeboat hull 10 with collapsible superstructure 12, b) a lifeboat storage room 20 arranged in the vessel, immediately below a lifeboat deck 112, arranged to receive and contain the lifeboat's 1 hull 10 preferrably in horizontal position, and with an opening 21, 21' extending essentially in the entire length of the lifeboat storage room 20 , c) davits 4 , 6 in stored and prepared position arranged in the lifeboat storage room 20, arranged for

- leading the lifeboat 1 out from the lifeboat storage room 20 and

- to keep the lifeboat 1 in an evacuation / boarding position just below and by said lifeboat deck 112 or by the underlying lifeboat deck 112', and outside the ship's side 114.

The lifeboat deck is provided with a foldable railing near the outer edge. To illustrate the dimensions, two passengers are illustrated on the lifeboat deck. The lifeboat system here is illustrated with the mother ship in a normal situation.

Fig. 2 illustrates the opening 21 i the vessel's ship side 114 and the davits 4,6 being telescopic or in other way extractable, arranged to be displaced out through the ship's side opening 21, and thus to hold the lifeboat 1 in an evacuation / boarding position just under and near the mentioned lifeboat deck 112. A railing 111 is here illustrated as laid down onto the lifeboat deck. In other embodiments of the invention the railing 111 may be dumped in the sea or pushed aside. The railing 111 constitutes no part of the invention, but must be arranged so that under no circumstance it may obstruct the lifeboat system and the opening 21, 21'. A hatch 22 in the opening 21 in the ship's side 114 constitutes the outer wall of the lifeboat storage room 20. The hatch 22 is here illustrated turned down about a hinge in its lower edge. It is also possible to arrange thehatch 22 so that it falls into the sea on release of the lifeboat, butthis is considered inappropriate, particularly due to an unnecessary loss of material in connection with lifeboat exercises.

In one possible embodiment of the invention, a functional cooperation between the opening 21 and the the design of the lifeboat 1 can be arranged so that the outwards facing side of the hull of the lifeboat 1 in its stored position fills the function of the hatch 22, or rather closes the opening 21.

Fig. 3 illustrates a rigid roof 14 on the collapsible superstructure 12, here with the superstructure in raised position, and with the lifeboat 1 hanging in its upper position in the davits 4, 6. We have indicated a situation where boarding of the lifeboat from the lifeboat deck has started. In a preferred embodiment of the lifeboat (see Fig. 15) in the lifeboat system there will be arranged a closed foldable fabric 16 or wall 16 ' between the railing 18 of the lifeboat and the roof 14 along the entire railing 18 and the circumference of the roof 14, which in the roof's 14 raised position constitutes the closed outer wall of the superstructure 12.

In Fig. 4 is illustrated that the lifeboat 1 is lowered of the davits 4, 6 via the lines 8 to the sea surface. The lifeboat will normally be provided with propulsion means as motor and propeller and steering means in the form of rudder, or propulion means and steering means combined in other form, e.g. as a water-jet or similar. The propulsion means does not constitute part of the invention. To arrange needed release devices (not illustrated) being arranged to release the lines 8 when and only when the lifeboat 1 has come to the sea surface, is a task for the skilled person. Fig. 5 illustrates a situation with negative heel of the relevant ship's side of the mother vessel. The present sea regulations say that the lifeboats shall be possible to launch from a vessel vith heel to starboard or port up to 20 degrees. In such a situation as illustrated, with negative heel, there may be two obstacles to launching of the lifeboat. 1) the lifeboat 1 and the davits 4, 6 must be displaced "uphill" to get out of the lifeboat storage room 20. 2) the lifeboat runs a risk of hooking to the underlying deck 112 ' so it either may not pass this deck or it comes into an unstable attitude during lowering. This is according to an alternatively preferred embodiment of the invention compensated for in that the opening 21' in the lifeboat storage room 20 is facing towards or, more correctly expressed, constitutes the lower side of the lifeboat storage room 20, i.e. towards an underlying lifeboat deck 112', and in that the davits 4, 6 are arranged to be lowered or pivotable around an axis 41 down through the opening 21' towards the underlying lifeboat deck 112 ' , as illustrated in Fig. 6. The davits 4, 6 is, as explained above, telescopically or in other ways displaceable out relative to the ship's side 114, and thus arranged to hold the lifeboat 1 in an evacuation- or boarding position by the underlying lifeboat deck 112', either in that the davits 4, 6 are turned entirely down to the underlying deck 112 ' or in that the lines 8 are released sufficiently for the lifeboat railing to end up by the lifeboat deck 112 ' . Arranged in this manner it is uncomplicated to board the lifeboat 1 from the lifeboat deck 112 ' . In addition to the needed lowering angle for the davits 4, 6 of e.g. 20 degrees for compensating negative heel, it is desirable to be able to lower and or turn the davits 4, 6 an additional angle of 5 to 10 degrees in order to be able to let the davits 4, 6 slide out only by means of the gravity force before the lifeboat 1 becomes lowered in the lines 8. Thus it is necessary to be able to turn the davits 4, 6 down between 25 and 30 degrees about the axis 41. Devices for compensating the heel of the lifeboat via the lines 8 will be explained below.

Fig. 7 illustrates the lifeboat deck 112' in a situation with the vessel having a positive heel α, e.g. between 5 and 8 degrees towards the ilustrated ship's side 114. In this heel position the davits and the lifeboat may be telescopingly released directly out through the hatch 22 in the ship's side 114 under the lifeboat deck 112 without the use of any other energy but the gravity. From this position the the lifeboat may thereafter be boarded from two different decks: either from the lifeboat deck 112 or that the lifeboat 1 is lowered until it is in level with the underlying lifeboat deck 112 ' .

The davits in the lifeboat system. Fig. 8 illustrates the davits 4, 6 in a fully contracted storage position in a cassette format, as illustrated in section in Fig. 1. In this figure the hatch 22 and the lifeboat deck 112 has been removed and the ship's side 114 is only indicated. A preferrably fork- or U-shaped main frame or a cassette 3 surrounds the lifeboat 10 with collapsed superstructure 12, the davits 4, 6 with lines 8 and control- and release devices 9 for davits 4, 6 and lifeboat 1, and possible power devices 9', arranged for insretion or arrangement of the lifeboat system as an entire unit in an above mentioned lifeboat storage room 20 in a vessel, preferrably via an opening 20, 21'. According to a preferred embodiment of the present invention, the lifeboat in a prepared boarding position has a considerably larger volume than the lifeboat storage room of which it was taken out from. The main frame or cassette 3 is in a preferred embodiment arranged to be pushed nearly like a drawer, horizontally into the lifeboat storage room via the opening 21 in the ship's side 114. On utilizing a rectangular basic outline for the main frame 3 and the lifeboat storage room, an optimum use of space is achieved. The heitght of the entire lifeboat system surrounded by the main frame 3 constitutes typically 1,0 metres. The main frame 3 comprises a preferreably standing horizontal main beam 30 in the (entirely inner) back edge with one horizontal and fixed extending inner fixed telescope part 40, 60 constituting the inner part of each davit 4 , 6 in each end of the main beam 30. The displaceable part of each davit 4, 6 may inthe preferred embodiment comprise a U-shaped frame 5 constituted by an inner longitudinally directed (with respect to the mother vessel) beam 5' connecting the inner ends of the telescoping outer davit beams 41, 61 being arranged to glide from an entirely contracted positon to a maximally allowable extended position along tracks in the inner davit beams 40, 60 as illustrated in Fig. 9. In the completely contracted position the beam 5' resides near the main beam 50. In a preferred embodiment control- and release devices 9 for davits 4, 6, and lifeboat 1, and possible power devices 9' with stored power in a "stored-power" -unit with power accumulators as electric accumulator batteries or hydraulic accumulators, and winches arranged on the main beam 50 farthest inside the lifeboat storage room 20. In a preferred embodiment the winch for lowering of the lifeboat 1 will be arranged at the beam 5 in order to achieve a more simple wire guiding of the lines 8. This will be explained in further detail below. Needed reinforcements in the inner corners against the beams 30 and 5 ' is a task for the skilled person and only indicated in Fig. 8.

Fig. 10 illustrates among other things a "telescopic" sliding hoisting block 43 (63) on a hoisting block rail 45 (65) arranged on the telescoping outer davit beam 41 (61) . The sliding hoisting block 43 (63) kan be moved along the hoisting block rail 45 (65) in several ways, but in a preferred embodiment of the invention the displacement of the sliding hoisting block 43 (63) takes place by means of a wire 80 about a sheave 48 (68) arranged at the outer edge of the telescoping outer davit beam 41 (61) . In an alternative embodiment of the invention the displacement of the sliding hoisting block 43 (63) takes place by means of a forced toothed rack- and cogged wheel device 82 arranged between the sliding hoisting blosk 43 (63) and the telescoping outer davit beam 41 (61) . The sliding hoisting block 43 (63) may in a preferred embodiment be given a displacement movement which can be guided in and out along the outer davit beam's 41 (61) independent of the davit beam's movement. In an alternative preferred embodiment of the invention the displacement of the sliding hoisting block 43 (63) may be forced, e.g. linearly dependent of the telescoping outer davit beam's 41 (61) movement. This forced movement may be provided by means of a the toothed rack- and cogged wheel device 82 arranged on a toothed rack 82a on the sliding hoisting block, a toothed rack 82b arranged on the inner davit beam 40 (60) , and with a cogged wheel 82c arranged inbetween the toothed racks, and with its axis attached near the inner end of the telescoping outer davit beam 41 (61) near the inner end. Fig. 11 illustrates rolls 47 (67) on the inner davit beam's 40 (60) outer end arranged for roll-bearingly supporting the outer davit beam's 41 (61) running displacement out and in from the main frame 3. Correspondingly there is arranged wheels 47' (67') on the outer davit beam's 41 (61) inner end. The wheel 47' (67') is arranged to roll along the upper, respectively lower inner surface of a trench 44 in the inner davit beam 40 (60) . The wheel 47' holds against the lifeboat's 1 and the telescoping davit beams 41, 61 weight moment in outer position or a partially extended position, and is arranged to carry the lifeboat's 1 and the telescoping davit beam's 41, 61 weight while they are situated in the contracted position. In a preferred embodiment of the invention the outer telescoping beam 41 (61) is arranged to be drawn out by means of an endless wire (49' fixed in the inner end or rear edge of the beam 41 (61) and with the wire running over a sheave 49 arranged by the outer end of the inner davit beam 40 (60) .

Fig. 12 illustrates the wire sheave / tackle system in the sliding hoisting block 43 (63) . In a preferred embodiment of the invention there is two lines 8 in the form of wires 8a, 8b fixed in each telescoping davit beam's 41, 61 outer end. The lines 8a runs separately via a tackle (with two sheaves) 81a in each sliding hoisting block 43, 63, and via a sheave 81d in a point in the lifeboat 1, e.g. at another boss in the railing, some distance to the opposite side of the lifeboat's centerline with respect to the sheave 81c. In this way it becomes feasible to correct the lifeboat's heel by operating the two wire lines 8a and 8b independently. This is achieved according to a preferred embodiment of the invention by fixing the wire lines 8a and 8b oneach their winch drum 82a, 82b arranged on the beam 5' connecting the two telescoping beams 41 and 61. In a preferred embodiment of the invention the winch drum 82a, 82b shall be able to winch up the wire 8a, 8b. But if the poser supply to the winch drum 82a, 82b should fail, it is arranged to be operated as a speed regulated brake with the lowering taking place only by means of braking the gravity force sufficiently. The speed regulated brake implies that the lifeboat will become lowered with a speed being essentially independent of the number of passengers in the lifeboat . Details of the winch drum and the braking devices is not concerned in this patent application.

Fig. 13 illustrates a hoisting appliance 70 which comprises those components used for lowering the main frame

3 by rotating the main beam 30 and the two inner fixed telescope parts 40 and 60 down, as explained above in connection with the figures 5 and 6. The hoisting appliance 70 comprises sheaves 78' cooperating with lines 78, preferrably wire lines, running to a winch 75. Each line 78 runs via a tackle 78" near the outer end of each its end near the intersection line between the ship's side 114 and the deck. The main frame 3 is in this embodiment rotatable around two axles 76a, 76b arranged along the main beam's 30 longitudinal direction and in the lower edge of the inner telescoping beams 40, 60. Arranged in this way, the main frame, with the davits 4, 6 in their fully contracted position and with the lifeboat 1 in upper position, can be rotated downwards through the opening 21', whereafter the telescopeparts 41, 61 and the sliding blocks 43, 64 with the lifeboat 1 can be released outwards by means of the gravity force as explained above .

The lifeboat . The lifeboat according to a preferred embodiment of the invention is illustrated in Fig. 14. The lifeboat has, according to the invention, a low lifeboat hull 10 with collapsible superstructure 12, and in a preferred embodiment a rigid roof 14 of the collapsible superstructure 12, with a closed folding fabric or wall 16 ' arranged between the railing 18 and the roof 14 along the entire circumference of the lifeboat's railing 18 and the roof 14, which in the raised position of the roof 14 constitutes a closed outer wall of the superstructure 12. Fig. 14 illustrates the lifeboat 1 with entirely collapsed superstructure 12. In the preferred embodiment of the invention, the lifeboat hull 10 has a flat bottom with mainly rectangular vertical projection in order to have maximum capacith in each lifeboat given the lifeboat deck's 112, 112' breadth and length. The lifboat must be slightly rounded in the bow and the stern in order to be maneouverable . Providing the lifeboat with propulsion means and steering means is known to the skilled person, an will not be discussed here. Essential here is an initiator mechanism 121 in one or more raising devices 120 arranged to raise the superstructure 12 from a collapsed to a raised position. In a preferred embodiment of the invention the initiator mechanism 121 comprises a profiled profiled protrusion arranged to receive a preferrably separate crank axle 121'.

Figure 15 illustrates the lifeboat 1 having entirely raised superstructure 12. The folding fabric 16 may comprise transparent parts constituting windows. Hatches 90, 90' arranged for boarding and possibly evacuation is arranged in openings in the rigid roof 14 and in the closed folding fabric 16 or wall 16' constituting the collapsible superstructure's 12 closed outer wall. The crank axle 121' cooperates with a worm gear 123 driving a long winch drum 125 having preferrably at least four wires 129a,b,c,d. The wires 129a, b run over sheaves 129a', b' to the same side of the lifeboat 1 to corresponding bow arrangements 127 for raising and keeping the rigid roof 14 entirely up. The wires 129c, d run from the winch drum 125 to the opposite side of the boat via sheaves 129 b',c' to the opposite ends of bow arrangements 127. In a preferred embodiment the mechanism for raising the bow arrangements 127 a main bow 127' and two stays 127" to the hull 10 and forms the foot in a λ-shape joining the main bow 127' in its half-height level. The main bow's foot is attached to a bow slide 128 on a slide rail 126, preferrably arranged along the lifeboats' railing 18 and inside the wall 16,16'. The wire 129a is fixed to the bow slide 128. On tensioning the wire 129a (being tensioned simultaneously with the wires 129b, c,d) the bow slide 128 becomes displaced towards the stay's 127" foot point and the bow 127' is forced up so that the roof is raised. A spring- or weight loaded locking dog 128' on the bow slide 128 is arranged to glide and fall into notch by notch or hole 126' in the slide rail 126'. By means of the locking dog 128' the bow slide cannot return without the locking dog 128' becoming manually released. This ensures the roof 10 to be kept up. A pretensioned help spring (not illustrated) can be arranged to give the bow 127' a start force upwards from stored position. Fig. 16 [corr. : Fig. 15] illustrates the bow arrangement 127 in entirely collapsed and entirely raised position, respectively. The bow arrangement is essentially identically designed at both sides and in mirror image embodiment in opposite ends of the lifeboat 1. In other embodiments, due to force distribution considerations, there may be arranged more sets of bow arrangements 127 than what is illustrated in the drawings.

Claims

C l a i m s

1. A lifeboat system for a surface vessel, comprising davits (4,6), control/release devices (9) and possible power devices (9') for the davits (4,6) and lines (8) for lowering a lifeboat (1) to the sea surface, c h a r a c t e r i z e d i n that it comprises the following features : a preferrably U-shaped main frame/cassette (3) comprising a horisontal main beam (30) in the inner rear edge with one horisontally extending inner fixed telescope part (40,60) of the davits (4,6) arranged in eiter end of the main beam (30) , with the main frame/cassette (3) being arranged for, in the lifeboat's (1) stored, prepared position, to enclose essentially the bow, stern and one side of lifeboat (10) ; telescoping outer davit beams (41,61) arranged for running between a fully retracted position and an extended position on the inner fixed telescope parts (40,60) so that the lifeboat (1) is lead out through an opening (21,21') to an evacuation/boarding position outside a ships' side (114); and with the main frame/cassette being arranged for placement of the complete lifeboat system in a lifeboat storage room (20) in a vessel, preferrably via an opening (21,21') in the ship's side (114).

2. Lifeboat system according to claim 1, c h a r a c t e r i z e d i n that the lifeboat storage room (20) is arranged immediately below a lifeboat deck (112) and with the opening (20) of the lifeboat storage room (20) facing out through the ship's side (114) .

3. Lifeboat system according to claim 1, c h a r a c t e r i z e d i n an opening (21') in the lifeboat storage room (20) in the lower side of the lifeboat storage room (20) facing towards an underlying lifeboat deck (112'); and that the davits (4,6) are arranged to be lowered or turned down through the opening (21') towards the underlying lifeboat deck (112') and to be displaced outwards through the opening (21'), so that the lifeboat (1) can be held in an evacuation/boarding position near an underlying lifeboat deck (112 ' ) .

4. Lifeboat system according to one of claim 1-3, c h a r a c t e r i z e d i n that the telescoping outer davit beams (41,61) comprise a U- shaped frame (5) having an inner horizontal beam (5') in the longship direction, connecting the inner ends of the telescoping outer davit beams (41,61).

5. Lifeboat system according to claim 3, c h a r a c t e r i z e d i n that the main frame or cassette (3) has an outer rectangular prism shape arranged to be pushed horizontally into the lifeboat storage room (20) through the opening (21) in the ship's side (114) and with the main frame (3) and the lifeboat storage room comprising cooperating locking devices for releasable fastened arrangement in the lifeboat storage room (20) , and with the main beam (30) being arranged for placement in the extreme inner part of the lifeboat storage room (20), and with the davits (4,6) being arranged along the forward and rearward walls (24,26) of the lifeboat storage room, respectively.

6. Lifeboat system according to claim 1, c h a r a c t e r i z e d i n that the lifeboat (1) comprises a lifeboat hull (10) with a collapsible/raisable superstructure (12) with a preferrably rigid roof (14) , the superstructure (12) being arranged collapsible with the roof (14) to a level with the lifeboat's (1) railing (18) in the lifeboat's (1) retracted prepared position.

7. Lifeboat system according to claim 6, c h a r a c t e r i z e d i n a closed folding fabric (16) or wall (16') arranged along and between essentially the entire railing (18) and collapsible roof (14) of the lifeboat (1) , with the folding fabric or wall (16, 16') in the roof's (14) raised position constituting the closed wall of the superstructure (12) .

8. Lifeboat system according to claim 1, 6 or 7, c h a r a c t e r i z e d i n that the lifeboat hull (10) is flat-bottomed with approximately rectangular vertical projection.

9. Lifeboat for use in a lifeboat system according to claim

6, c h a r a c t e r i z e d i n hatches (90) in the roof (14) of the collapsible superstructure (12) .

10. Lifeboat for use in a lifeboat system according to claim

7, c h a r a c t e r i z e d i n hatches or closable openings (90) in the closed folding fabric (16) or wall (16') constituting the collapsible superstructure's (12) closed outer wall.

11. Lifeboat system according to claim 1, c h a r a c t e r i z e d i n that the lifeboat storage room (20) is horizontally arranged with its longest axis along the long direction of the vessel.

12. Lifeboat system according to one of the preceeding claims, c h a r a c t e r i z e d i n that the lifeboat (1) has a breadth less than or equal to the breadth of the prism shaped lifeboat storage room (20)

13. Lifeboat system according to one of the preceeding claims, c h a r a c t e r i z e d i n a hatch (22) in the opening (21) in the ship's side (114), constituting the outer wall of the lifeboat storage room (20) .

14. Lifeboat system according to claim 13, c h a r a c t e r i z e d i n that the outward facing hull's side of the lifeboat (1) in its stored position constitutes the hatch (22) .

15. Lifeboat system according to claim 1 or 3 , c h a r a c t e r i z e d i n a hatch (22') under the lifeboat storage room (20) facing the underlying lifeboat deck (112').