WO1989009723A1

WO1989009723A1 - Device for launching and hoisting up a lifeboat, pick-up boat, etc.

Info

Publication number: WO1989009723A1
Application number: PCT/NO1988/000027
Authority: WO
Inventors: Peer Christensen; Sigurd Per Karlsen
Original assignee: Ships A/S Excelsior
Priority date: 1987-03-18
Filing date: 1988-04-14
Publication date: 1989-10-19
Also published as: NO871103L; NO162184B; NO162184C; EP0414679A1; CA1326614C; NO871103D0

Abstract

A device is disclosed for launching and hoisting a lifeboat, a pick-up boat, etc., and for picking up people and objects which are afloat, comprising two booms from which ropes extend to two elongated buoyancy means, which are connected at a mutual distance, via spreader yokes from which lines extend to said buoyancy means, and bottom members which span the space between buoyancy means and are positioned in the water when said buoyancy means are afloat, said lines running in guides on the buoyancy means and acting as steering means for the buoyancy means when the latter are afloat, said lines being connected with respective adjacent bottom members. Booms (12, 13) are combined to a fork-shaped swing crane-boom unit (11, 12, 13). Booms (12, 13) are telescopic (14, 16; 15, 17), and ropes (19, 21) extend from the stationary boom sections (14, 15) to a spreader yoke (30) for one of the buoyancy means (28), whereas ropes (20, 22) extend from the extendable boom sections (16, 17) to a spreader yoke (31) for the other buoyancy means (29).

Description

A device for launching and hoisting up a lifeboat, pick-u boat, etc.

The invention relates to a device for launching and hoisting up a lifeboat, pick-up boat, etc., and for picking up persons and objects floating in the water, which comprises two booms from which ropes extend to two elongated buoyancy means which are connected at a mutual distance and are connected with the ropes by the aid of spreader yokes, from which lines extend to the buoyancy means, and bottom members spanning the space between said buoyancy means and being in the water when the buoyancy means are afloat, said lines extending in guides on the buoyancy means and acting as guides of the buoyancy means when the latter are afloat, said lines being connected with the respective adjacent bottom members.

From NO-PS 140 530 and 141 929 a device for launching and hoisting up a lifeboat, pick-up boat, etc. is known, which comprises two booms from which ropes extend to elongated buoyancy means which are connected at a mutual distance and are connected with the ropes by spreader yokes from which lines extend to the buoyancy means. The space between buoyancy means is spanned by bottom elements which are in the water when the buoyancy means are afloat. The utilized booms are designed to be independent units, as known from conven¬ tional davit arrangements. To stabilize the dock formed by the buoyancy means in the water a comparatively complicated and expensive arrangement of hydraulic arms extending down into the water from supporting means placed along the ship's side is used.

Furthermore, a weight lowered into the water is known to stabilize a vertically suspended line, and it is also known that said weight may be designed as a bottom member spanning a pick-up dock. Based on this known technology a device as mentioned above is proposed according to the invention, which is characterized by the fact that said two booms are combined into a fork- shaped swingcrane-boom unit, that the booms are telescopic, and that ropes extend from the fixed boom sections to spreader yoke for one buoyancy means, whereas ropes exten from the extendable boom sections to a spreader yoke for th other buoyancy means.

With the present invention the davit-arrangement is, thus, abandoned and the advantages achievable by the aid of swing crane are in stead utilized. Due to the fact that th booms are designed as members of a swing crane the doc formed by buoyancy means may be hoisted up from the water an may, by the aid of the swing crane, be slewed quite distance inwards on deck, e.g. onto the relatively protecte working deck on a supply vessel. Such a possibility o hoisting the dock with its content upward and inward i essential in connection with picking up hyperbaric lifeboats, because necessary equipment and assistance may, thus, reac the lifeboat.

Each spreader yoke is connected with one buoyancy means. Each, spreader yoke is connected with both arms or booms o the two-armed swing crane. Due to the fact that the booms ar telescopic the position of outermost buoyancy means relativ to the swing crane may be adjusted relative to the othe buoyancy means by retraction/extension of the telescopi outer boom sections. This provides for a possibility o achieving an especially advantageous mutual adjustment o the buoyancy means, so that the dock formed by the buoyanc means may be provided with an enlarged lead-in opening b arranging the buoyancy means in a mutually divergen position. This is achieved by extending one telescopic boo more than the other one. By swinging the swing crane th entire dock may, at the same time be positioned in such manner that the lead-in opening faces away from the ship' side or from the side of the installation where the device i placed, so that, e.g. a lifeboat may be steered into the doc at an angle to the ship's side. Experience tells us that t greatest hazard in rescue operations at sea in rough weathe occurs when the object to be rescued gets too close to th ship's- side. Then, the hazard of the object being smashe will be imminent. By being able to steer the device by th aid of the crane, as mentioned, it will be possible t overcome this problem of distance. If the dock formed by th buoyancy means is, e.g. slewed 30° relative to the ship' side, an open fairway will be achieved for a life boat to b safely navigated/picked up in the dock. Combined with th possibility of enlarging the lead-in opening of the dock thi will provide a very safe device.

In an advantageous embodiment of the device said boom uni comprises a rigid fork stem which is slewable about horizontal axis on the slew ring of the crane, said two for members being telescopic. That means that only the outermos portion of the swing crane is fork shaped or two-armed. Thi embodiment is advantageous in that that there is one singl fork stem to be slewed and raised and lowered in stead of tw booms outside the slewing ring.

The fork elements are, advantageously, placed to enclose a obtuse angle with the fork stem. In the normal workin position of the fork stem the fork members will then advantageously, extend horizontally outwards, i.e. fairly i parallel with the water surface. In this manner the fre length of both outer ropes is reduced.

In order to stabilize the device, I.e. the dock formed b buoyancy means, a control line may, advantageously, exten from each end area of the buoyancy means closest to the cran to a suitable winch. By the aid of said control lines It wil be possible to steer the dock in a controlled manner and kee It in a stable position during hoisting/launching or when th crane is slewed to land the dock on deck. To protect th object to be hoisted or launched, the respective spreade yokes are preferably built in the shape of a rigid body bake into a fender material.

A three-armed line-fork may, advantageously, extend from eac rope to the corresponding spreader yoke. Such a design wil provide the necessary stable suspension of spreader yokes an associated buoyancy means.

The elongated buoyancy means may, advantageously, comprise number of sequencially joined floats. Spreader yokes wil provide the necessary stability, at the same time as the doc will show desired flexibility in the water.

The dock may be open at one or both ends, as required. On dock end may be closed by the aid of floats of the same kin as those used for the elongated buoyancy means.

As mentioned, bottom members connect the lines beneat buoyancy means and act as spreader members. An especiall suitable design of the bottom members, which is of Indepen dent inventive value, comprises bottom members in the shap of slings having the same length of spring steel attached t them, which are baked into a flexible material protectin both materials. Such a bottom member would be sufficientl rigid to provide desired spreading and will, at the sam time, at least to some degree, adapt to the shape of th object inside the dock and support said object.

Between bottom members a net may, advantageously, extend in manner known per se, which is of special importance whe relatively small objects, e.g. persons, are picked up fro the water.

The swing crane is preferably provided with a contact face which the dock may be made to contact Said control lines may advantageously be used to this end.

The invention will be described in more detail below with reference to the drawings, where

Figure 1 shows an elevation of the device according to the invention, as seen along a ship's side,

Figure 2 is a plan view of the two-armed swingcrane shown in Figure 1,

Figure 3 shows the device of Figure 1, as seen in a smaller scale towards the ship's side,

Figure 4 is a plan view of the device of Figure 3, Figure 5 shows the device according to the invention with ropes heaved in so that the shown rescue craft is ready to be hoisted on board,

Figure 6 shows the same situation as Figure 5, as seen towards the ship's side, Figure 7 shows the rescue craft shown in Figures 5 and

6, in a hoisted up position and ready to be slewed inwards onto the ship's deck,

Figure 8 Is a plan view like Figure 4, but with the dock formed by buoyancy means in a state with an enlarged lead-in opening,

Figure 9 shows an elevation of the rope and line arrangement at associated bottom members, Figure 10 shows the arrangement of Figure 9 in an end view, Figure 11 is a diagrammatical view of one half of a bottom member, Figure 12 is a sectional view through the bottom member along sectional line XII-XII in

Figure 11 and in larger scale, and

Figure 13 is a view, partly in section, of a spreader yoke. On deck 1 of a vessel 2 a crane foundation 3 is provided in Figure 1. On crane foundation 3 a unit 4 is slewably mounted and comprises a crane tower 5, a cranedriver's cabin 6, and a slewing ring 7. By the aid of slewing ring 7 unit 4 is, thus, in a manner known per se mounted to be slewable about a vertical axis of crane foundation 3.

A fork-shaped boom unit 8 is mounted to be slewable about a horizontal axis 9 in tower 5 and may be slewed up and down ₀ about journal 9 by tbe aid of a hydraulic working cylinder 10.

The fork-shaped design of boom unit 8 will appear clearly from Figure 2, showing the swing crane from above. Boom unit ₅ 8, thus, comprises a rigid fork stem 11 and and a fork which extends at an obtuse angle relative to stem 11 and comprises two telescopic boom sections or fork members 12 and 13. Each fork member is comprised of a firm section 14 and 15, respectively, and a telescopic or extendable boom section 16 o and 17, respectively. The swing crane totally comprises four ropes extending from winches 18. Ropes 19, 20, 21, 22 extend over pulleys to respective vertical pulleys 23, 24, 25, 26, and then the ropes extend down to dock 27.

₅ Dock 27 comprises two elongated buoyancy means 28, 29. Each buoyancy means is connected with a respective spreader yoke

30, 31 by the aid of lines 40 extending from each spreader yoke, down through vertical line guides 41, 42 on the buoyancy means and further down to respective bottom members ₀ 43. As shown in Figure 9, lines 40 extend to spreader yoke

31, and 32, respectively, and are connected with the spreader yoke in a manner not shown in detail. From the spreader yoke lines 40 are collected by the aid of three-armed line-fork 44, 45, shown in Figure 9, from which the respective ropes ₅ 19,22 extend. It will appear, especially from Figure 9, that each buoyanc means is built from a number of sequencially connected float 46. Connection is achieved by simple lugs which are joined b the aid of vertical bolts 47.

In the shown embodiment the dock is closed at one end by th aid of two floats 46, which will appear most clearly fro Figures 4 and 8. The structure of respective bottom member 43 of the embodiment is special and is shown in detail i Figures 11 and 12.

As shown in Figure 11, the bottom member in this cas consists of a polyester strap 48 onto which^* a spring steel member 49 Is fastened at spaced points. Said fastening is achieved by the aid of bows 50, and the assembled members are baked into a suitable material, in the present case PVC, designated by 51. In connection with hoisting bottom member 43 can adapt to the shape of the rescued object and provide good support for the object together with the buoyancy means. This is, e.g. shown in Figures 5 and 7 (compare with Figure 1). The operation of the device will now be explained in more detail with reference to Figures 1-7. In Figure 1 dock 27 is shown in the water. Spreader yokes 30 and 31 rest lowermost adjacent buoyancy means 28,29, and lines 40 extending from spreader yokes pass down into the water with associated bottom members 43. In the actual embodiment bottom members 43 in Figure 1 will be approximately 2.5 m below the bottom of the shown rescue craft which has navigated Into dock 27 formed by the buoyancy means. This depth of 2.5 m will provide safe clearing for use of the rescue craft screw. The situation shown in Figure 1 is also found in Figure 3, where the dock and the rescue craft are viewed towards ship 2. Figure 4 shows a plan view of the situation of Figures 1 and 3.

From inner buoyancy means 28 a respective control line 53, 54 extends to a respective so called tugger winch 55, 56 on slewable crane unit 4. Control lines 53, 54 serve to prevent swing during hoisting/launching operations or when the slewing crane is slewed to land the rescued object 52 on deck 1, and may be used to pull dock 27 towards a contact surface 60 on the swing crane.

In Figure 4, furthermore, a line 57 is shown, which extends forwards to an auxiliary boom 58 cantilevered from vessel 2. Line 57 contributes to stabilize the dock in the water.

In Figures 5 and 6 the device is shown after the ropes 19-22 are hauled in by winches 18. Bottom members 43, as shown, are now positioned just under the bottom of rescue craft 52. As the ropes are hauled further in rescue craft 52 will be lifted from the water, as shown in Figure 7. It is shown i Figure 7 how dock 27 with rescue craft 52 is pulled in to contact with slewable crane unit 4. Now, the crane may be slewed so that dock 27 with rescue craft 52 can be placed at a central location on deck 1, where the dock may be put dow wit the rescue craft. ^"When a hyperbaric lifeboat is rescued, pressured air, oxygen, water, current, etc. may now be supplied by simple connections, so that a diver under pressure will also be safe in case of evacuation.

A net 59 is extended between bottom members 43, as shown i Figures 3 and 6.

Figure 8 shows how the telescopic boom arms and the slewabl crane structure may be utilized to advantage. Crane unit 4 with fork stem 11 and associated fork members 12,13 is slightly slewed as compared witb the position shown in Figur 4, at the same time as one telescopic fork member 13 i extended causing outer buoyancy means 29 to be no longe substantially parallel with inner buoyancy means 28, but t diverge outwards relative to the latter. Dock 27, thus, has wider lead-in opening 60 for rescue craft 52. As soon a rescue craft 52 is navigated into dock 27 hoisting operation ay start, if desired, upon or with simultaneous positionin in parallel of buoyancy means by retracting telescopic for arm 13.

Spreader yokes 30,31 are constructed to be rigid members, a shown in Figure 13, e.g. a steel rod 61 being baked into suitable fender material 62. Lines 40, as shown, exten freely through bows 63 attached to the spreader yoke. Sinc lines 40 are through-going, and are only connected wit spreader yoke 31 to be spread the greater part of the weigh will be absorbed by the lines, and dimensions of the spreade yoke proper may, thus, be reduced.

The new device may advantageously be winterized. All winche 18 and rope drums and pulleys may, thus, advantageously b built inside the crane, and ropes 19-22 may run inside cran booms 12,13. By supplying hot air, either directly from th engine room of the vessel, or from a hot air ventilator (no shown) placed inside the crane proper, the device will b operationally independent of the temperature outside.

Claims

PATENT CLAIMS:

1.

A device for launching and hoisting up a lifeboat, a pick boat, etc. and for picking up people and objects aflo comprising two booms (12,13), from which ropes (19-22) ext to two elongated buoyancy means (28,29) which are connec at a mutual distance and are connected with said ropes, spreader yokes (30,31), from which lines (40) extend to buoyancy means, and bottom members (43) spanning the sp between buoyancy means and being positioned in the wa when the buoyancy means are afloat, lines (40) running guides on buoyancy means (28,29) and acting as steering me for the buoyancy means when the latter are afloat, lines ( being connected with said respective adjacent bottom memb (43), c h a r a c t e r i z e d i n that booms (12,13) mounted to form a fork-shaped swing crane boom unit (11,1 13), that booms (12,13) are telescopic (14,1-6; 15,17), that ropes (19,21) extend from stationary boom secti (14,15) to a spreader yoke (30) for one buoyancy means (2 whereas ropes (20,22) extend from extendable boom secti (16,17) to a spreader yoke (31) for the other buoyancy me (29).

2.

A device as stated in claim 1, c h a r a c t e r i z e i n that the boom unit comprises a rigid fork stem ( wbich is slewable about a horizontal axis (9) in the s ring (4,7) of the crane, and that fork members (12,13) telescopic (14,16; 15,17).

3.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that fork members (12, form an obtuse angle with fork stem (11) in the verti plane.

4.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that a control line (53,54 extends from each end area of buoyancy means (28) bein closest to the crane and to a suitable winch (55,56).

5.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that each spreader yok (30,31) is constructed to be a rigid member baked into fender material.

6.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that a three-armed line form (44,45) extends from each rope (19-22) to an associate line fork (30,31).

7.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that each of the elongated buoyancy means (28,29) is composed of a number of sequenci- ally connected floats (46).

8.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that bottom members (43) are designed as straps (48) with an equal length of spring steel (49) attached to them and baked into a flexible material (51) which protects both components.

9.

A device as stated in claim 8, c h a r a c t e r i z e d i n that bottom members (43) are mutually connected with a net (59) extending between them.

10.

A device as stated in one of the preceding claims, c h a r a c t e r i z e d i n that swing crane (4,7) is provided with a contact surface (60) against which dock (27) may be contacted.