Description LIFEBOAT
[1] The present invention relates to a lifeboat, which is intended to be used in vessels or other constructions used at sea and which comprises a hull part and a cover part fixedly attached thereto and being movable with respect to the hull part to a first position for the storage of the lifeboat and to a second position for the utilisation of the lifeboat, whereby the height of the lifeboat, when the cover part is in said first position, is substantially smaller than the height thereof, when the cover part is in said second position.
[2] The structure of prior art lifeboats is that of a boat. If the aim is to make them hold larger amounts of people and at the same time meet the safety requirements, their size will, consequently, increase and due to their height, in particular, they will take a lot of space. A solution in accordance with the preamble of claim 1 is disclosed in EP 1135290 Bl. These prior arrangements provided for moving and supporting the cover part are in practice applicable only for rather small lifeboats.
[3] An object of the invention is to eliminate the above-mentioned disadvantages and provide a lifeboat having a low structure, which is reliable and simple to manufacture and which complies with the requirements included in the prevailing orders of the au¬ thorities. This object is achieved mainly according to what is disclosed in the char¬ acterising part of claim 1.
[4] The basic idea of the invention is to form the interior spaces of the lifeboat so that they, when used, are sufficiently spacious and stable as regards usability and safety, and that the lifeboat is easy and convenient to handle in storage position. This is ac¬ complished by making the assembly of the lifeboat's cover part such that it is collapsible with respect to the hull part of the lifeboat to a first position for storage and it may be lifted up to a second position, i.e. to service height, when the lifeboat is being used. In this manner a lifeboat is provided, which in the storage position takes as little space as possible, and which in service meets the requirements set for a lifeboat. More precisely, a lifeboat should be a partially covered lifeboat complying with the SOLAS regulations of IMO (International Maritime Organisation) and preferably be di¬ mensioned for about 150 people at the most.
[5] The collapsible or foldable cover part is kept in service height by using support members, which are supported by the hull part and cover part of the lifeboat. With respect to the space utilisation it is preferable that the support members can be inserted at least partially inside the hull part for the storage position of the cover part and that they are arranged on both sides of the lifeboat and at both ends thereof.
[6] For lifting the cover part to its service height, power cylinders, for instance gas
springs, which act on turnable lifting arm mechanisms, which are supported by the hull part and the cover part, may be used advantageously. Also the lifting arm mechanisms and power cylinders are arranged on both sides of the lifeboat and at both ends thereof, and they may partly be supported by the support menbers.
[7] The hull part and/or the cover part is/are preferably provided with guiding means, for instance guide rails, for guiding the ends of the arms of the lifting mechanisms and for synchronising the motions of the mechanisms.
[8] For providing necessary stiffness and stability for the cover part, the cover part is, at least partially, formed of stiff elements in the longitudinal direction of the lifeboat, which elements make a foldable structure, for instance an accordion structure, which may preferably be supported by the support members in the service position of the lifeboat.
[9] Preferably, the cover part comprises a stiff roof in the longitudinal direction of the lifeboat and two separate accordion structures or the like attached to the roof and hull part and arranged at both ends of the lifeboat, which structures are provided with support members of their own. An intermediate part, which is foldable or made of flexible material, is preferably arranged between the accordion structures in the lon¬ gitudinal direction of the lifeboat, which intermediate part acts as an access passage to the lifeboat. In this fashion the entrance to and exit from the lifeboat are facilitated and the total weight of lifeboat is decreased, but nevertheless sufficient stiffness and stability of the cover part according to the IMO-SOLAS regulations are ensured.
[10] The hull part of the lifeboat is preferably formed as a trimaran type of structure, whereby the resistance to motion may be reduced due to the bottom's narrow hull parts, which come into contact with water. To this contributes also the fact that the angles of the floating lines of the bottom's side hull parts in a trimaran structure can be kept small. Seaworthiness is improved, since the surfaces subjected to so-called slamming, i.e. water impacts, remain small. The arch parts located between the bottom's hull parts in a trimaran structure and providing dimensional stiffness improve the longitudinal stiffness. In addition, the bottom's hull parts in a trimaran structure may be used as a footwell for the occupants of the lifeboat.
[11] Alternatively, the hull part of the lifeboat may be formed as a single-hull structure, whereby the general arrangement on the lifeboat remains free and the floor may be kept flat. Additionally, good transverse stiffness is provided, as well as low resistance to motion, due to the small wet surface area.
[12] A lifeboat according to the invention is preferably used on passenger ships or on so-called cruisers, as the lifeboat according to the invention is relatively low in comparison with conventional lifeboats. If the lifeboats are placed on the vessel's side, underneath a deck, the distance between the vessel's decks may be made shorter, and
the lifeboats may be stored e.g. in a space corresponding only to two deck heights. Then the vessel's centre of gravity is lowered, stability improved and weight decreased. In this case the lifeboat is provided with suspending means or the like so that it may be suspended from a telescopic or similar type of davit.
[13] If the lifeboat is placed on the vessel's side in an open space, i.e. on top of a deck, its low height makes it possible to build more of so-called balcony cabins on the ship, as there are less visual obstructions. In this case the lifeboat is preferably adapted so that it may be suspended from a conventional davit, for instance from a so-called 'roller track' davit.
[14] In the latter cases the effect is substantial considering the fact that current larger passenger ships or cruisers, for instance, may be provided with 20 - 24 lifeboats on the average, whereby it is assumed, in accordance with the IMO-SOLAS regulations, that the capacity of one lifeboat is 150 persons and the lifeboat capacity covers about 75 % of the total number of people onboard. The basic concept of the invention is not as such, however, limited to the number of persons determined by the prevailing IMO- SOLAS regulations on the filing date of the application, but it may also, if required, be applied on lifeboats intended for much larger volumes of people.
[15] The lifeboat is preferably provided with a propulsion device of its own. Then it is also advisable to provide it with a steering device, which may be located in the middle of the lifeboat, which is an advantageous arrangement with regard to space utilisation, stability and visibility.
[16] In the following the invention is described by way of example with reference to the attached schematic drawings, in which
[17] Figures Ia, Ib and 1 c show a side view of the lifeboat according to the invention with various positions of the cover part;
[18] Figures 2a, 2b and 2c show a front view of the lifeboat according to figures Ia - Ic, respectively;
[19] Figures 3a, 3b and 3c show a side view, partly in section, of the lifeboat according to figures Ia - Ic with various positions of the cover part so that the lifting mechanisms and support members of the cover part are visible;
[20] Figures 4a, 4b and 4c show a front view of the lifeboat according to figures 3, re¬ spectively;
[21] Figure 5 shows an end view, partly in section, of the lifeboat according to another embodiment with the cover part in lifted position;
[22] Figure 6 shows the lifeboat on a conventional davit; and
[23] Figure 7 shows the lifeboat on a telescopic davit;
[24] Figure 8 shows a top view of the lifeboat; and
[25] Figure 9 shows a top view of the lifeboat in an enlarged scale with the cover part
removed.
[26] Figures Ia - Ic and 2a - 2c show side and front views, respectively, of a lifeboat 1 according to the invention comprising a hull part 2 and a cover part 3. The hull part 2 is of stiff material so as to provide safe accommodation for the passengers. The cover part 3 is with respect to the hull part 2 lifted to a second position, i.e. to service height, which is applied when the lifeboat is being used. The cover part comprises a stiff roof 3a (see Fig. 8) and two construction parts 4 made of substantially stiff material and an intermediate part 5 of substantially flexible material formed between them. The stiff construction parts 4 are formed as accordion structures and they comprise elements extending in the longitudinal direction of the boat and being attached to and foldable with respect to one another, the fabrication material of which elements may be e.g. reinforced plastic or carbon fibre. The intermediate part may consist for instance of a protective cover or the like, which may, if required, be stiffened by means of horizontal or vertical elements so that it will form a door-like passage to the lifeboat. The stiff construction parts are arranged at both ends of the lifeboat, i.e. at the forebody and rear, and preferably their respective lengths correspond to at least about 20 % of the total length of the lifeboat in accordance with the IMO-SOLAS regulations.
[27] In conjunction with both ends of the stiff construction parts 4 there are support members 6 (Figures 3a - 4c), which are adapted to support the cover part 3, when it is in its service position, i.e. in the upper position. The support members 6 are also arranged so that they can be locked into their service position. When the cover part 3 is moved to its lower, i.e. storage, position against the hull part 2 in the manner shown in figures Ic and 2c, the support members 6 are also in a lower position at least partly inside the hull part 2. The support members 6 at the ends of the lifeboat are of such type that they may e.g. telescopically be partially compressed for space saving purposes. The support members 6 may be manufactured e.g. of profiled tube comprising aluminium alloy.
[28] For moving the cover part 3 from the storage position to its service position the lifeboat is provided with lifting arm mechanisms 16 and 17, which are turned by power cylinders 7, which mechanisms are placed on both sides of the lifeboat and at both ends thereof and supported by the hull part 2 and cover part 3, as is shown in figures 3a - 3c and 4a - 4c. In principle, the moving may also be performed manually, but naturally it is more advantageous to do it by power cylinders 7, which may be gas springs. The lifeboat is also provided with guiding means 18, e.g. guide grooves or rails, by which the ends of the lifting arms can be guided and the mutual motions of the mechanisms synchronised. Also the lifting arm mechanisms 16 and 17 and the power cylinders 7 that drive them may be locked in their extreme positions, whereby they also contribute to keeping the cover part 3 in place. As obvious from figures 3a-3c and
4a-4c the lifting arm mechanisms 16 and 17 may be partly supported by the support members 6.
[29] The cover part 3 is equipped with necessary manholes 22 and other similar structures for control and maintenance (cf. figure 8). Furthermore, the lifeboat is preferably provided with a propulsion device 20 of its own and a cabin part 19. The practical dimensions, stiffness and supporting methods of the accordion structure may be chosen as desired, as long as the requirements included in the IMO-SOLAS regulations are fulfilled.
[30] Both ends of the hull part 2 of the lifeboat 1 are equipped with suspending means, i.e. boat hooks 8, for instance for suspending the lifeboat from a davit, which is explained in more detail in conjunction with the description of figures 6 and 7.
[31] Figures 2a - 2c show how the hull part 2 may be formed as a trimaran structure.
Thus, there are two side hull parts 9 and a centre hull part 10 as well as arch parts 11 in between at the bottom of the hull part 2. The trimaran structure has specific nav¬ igational advantages, which are described in the foregoing. Moreover, the side hull parts 9 and the centre hull part 10 may act as a footwell for the occupants of the lifeboat 1, which reduces the total height of the lifeboat and makes the utilisation of the spaces of the lifeboat more efficient.
[32] Figure 5 illustrates how, for instance, the hull part 2 of the lifeboat 1 may optionally be formed as a single-hull structure, whereby the floor of the lifeboat may be kept flat for facilitating e.g. the general arrangements on the lifeboat.
[33] Figure 6 shows a lifeboat 1 that is suspended, e.g. from a conventional, so-called
'roller track' davit 14 of a passenger ship 12. The lifeboat is shown in two positions: a first position, i.e. storage position, where the cover part 3 is collapsed according to figures Ic and 3c, and a second position, i.e. for a situation when the lifeboat is in use, where the cover part 3 is lifted up to service height according to figures Ia and 3a. This kind of arrangement is suitable, when the lifeboat is placed on the ship's 12 side in an open space above a deck.
[34] Figure 7 shows a lifeboat 1 that is suspended from a telescopic davit 15, for instance, arranged in a recess formed e.g. at two deck heights 13 on the side of a passenger ship 12, underneath a deck. The lifeboat is shown in two positions: a first position, i.e. storage position, where the cover part 3 is collapsed according to figures Ic and 3c, and a second position, i.e. for a situation when the lifeboat is in use, where the cover part 3 is lifted up to service height according to figures Ia and 3a.
[35] Figures 8 and 9 show a top view of the lifeboat 1 according to figures Ia - 4c.
Figure 8 illustrates the cover part's 2 stiff uniform roof 3a, to which the flexible in¬ termediate part 5 may be attached from its upper end. Requirements set for the cover part are, among other things, an advantageous material with respect to fire safety, a
specific density and capability to resist changes of weather as well as a specific heat insulating ability. The figures also show a preferable alternative for locating the cabin part 19 in the middle of the lifeboat. In practice, the cabin part is placed above normal person seats 21, as is shown in figure 3a. The aim in the location of the person seats 21 was to utilise the possibilities provided by the trimaran structure, but the practical locating alternatives are dependent e.g. on the current position of the support members 6.
[36] The hull structure may, naturally, differ from the two above-described concepts, as the hull structures may be selected on the basis of the current purpose of use.
[37] The above description and the associated figures are intended only for illustrating the invention. The details, such as the structure and support of the cover part, the structure and form of the hull part, the storage applications of the lifeboat etc. may vary within the scope of the appended claims.