GB2203388A

GB2203388A - Liferaft launching system

Info

Publication number: GB2203388A
Application number: GB08708297A
Authority: GB
Inventors: Kenneth George Barber
Original assignee: WELIN LAMBIE Ltd
Current assignee: WELIN LAMBIE Ltd
Priority date: 1987-04-07
Filing date: 1987-04-07
Publication date: 1988-10-19
Anticipated expiration: 2007-04-07
Also published as: GB8708297D0; GB2203388B

Abstract

A launching system for launching liferafts (10) from ships and other vessels, comprises means (12) to store a plurality of liferafts (10) each in a stowed condition, means (11) to move each of the life rafts (10) severally, to a launching position from where the liferafts may each in turn, be launched so that there is no need for the liferafts (10) to be manhandled from the stored position to the launching position. As described, the storage means comprises a carousel 16 and the launching means comprises a davit 11. <IMAGE>

Description

Title: "Liferaft launching system Description of Invention This invention relates to a launching system for launching liferafts from ships and other vessels, oil rigs and the like floating structures (hereinafter all generically called "ships").

Launching systems are known which include a lifting means to lift a liferaft from a launching position e.g. on the deck of a ship adjacent the launching means, into the water. After the liferaft has been launched, a further liferaft is manhandled from a stored position to the launching position for launching. Obviously manhandling a liferaft when a ship may be listing for example, is difficult and hence it is an object of the present invention to provide a new or improved launching system which overcomes or reduces this problem.

According to the invention we provide a launching system for launching liferafts comprising means to store a plurality of liferafts each in a stowed condition, means to move each of the liferafts severally, to a launching position from where the liferafts may each in turn, be launched.

Thus there is no need for the liferafts to be manhandled from the stored position to the launching position but the means which move the liferafts is operated to bring each of the liferafts severally to the launching position.

Conventionally, liferafts are packed into containers which are generally cylindrical in configuration. Preferably the liferafts are stored in a position in which the longitudinal axes of the cylindrical containers are all generally in the same plane and the liferafts are moved only in the plane from the store to the launching position.

Alternatively, the liferafts may be stored in an upright condition, in which case the liferafts are preferably each moved in a plane transverse, preferably generally perpendicular, to the longitudinal axes of the liferaft containers.

Preferably the store comprises a conveyor such as a carousel to which the liferafts are secured at spaced positions whereby the liferafts may be moved sequentially to the launching position.

Where the conveyor is a carousel, the liferafts may each be secured to an arm which extends generally radially from an axis of rotation, the arms each being movable about the axis of rotation to enable the arms and hence the liferafts to be moved to the launching position.

The arms may each comprise a cradle, there being a release means to enable the associated liferaft to be released from the cradle when in the launching position.

For example, each liferaft may be secured to its respective cradle by a strap which may be rapidly released.

The arms may be foldable for stowage when no liferaft is secured thereto, although preferably when the ship is in use, the carousel or other conveyor is fully loaded.

The means which move the liferafts to the launching position may comprise a drive means which may be powered but which is preferably manually operated, for example by means of a winding handle which is connected via a suitable transmission to the carousel or other conveyor, to cause the liferafts to move.

The liferafts may be launched from the launching position using a davit which permits each liferaft to be moved from the launching position outboard of the ship where the liferaft may be inflated so that passengers and/or crew of the ship may board the inflated liferaft prior to the liferaft being lowered into the water by the davit.

When in the launching position, the lines from the liferaft container (bowsing, steering and painters etc) can be secured to the deck so as to allow the cradle to be folded for storage before the raft is launched.

Alternatively, or in addition, the liferaft may be launched directly into the water from the launching position, by releasing a chock or the like which may be provided on the cradle of the carousel, where appropriate. This may allow the cradle to rotate on the arm and the raft to fall free under gravity, over the side. Conventionally, liferafts are packed in their containers so that when the containers come into contact with the water, the liferaft automatically becomes unpacked and inflates. For example, the container may comprise hydrostatic fastenings which release on contact with water.

Thus further alternatively, or in addition, the liferaft may be adapted for automatic launching from the launching position if the ship sinks in the water to a level such that the container is subjected to water, whereby the liferaft may automatically become unpacked and be inflated.

The means which secure the container to a cradle, may also comprise hydrostatic fastenings or another device which, upon contact with water, release the container from the cradle, so that it is not even necessary for the liferaft to be manually released from the cradle to achieve automatic launching in this way.

Where a davit is provided, this may comprise a column which may be mounted adjacent the launching position, the column being pivotal at or adjacent the base thereof to permit the upper end of the column to be moved from an upright position to a position outboard of the ship. At the upper end, the column may include an arm which extends from the column generally parallel to the side of the ship at that position, the arm overbearing the launching position when upright.

The davit conventionally includes a winch means which may be used to lift the liferaft from the launching position, swung outwardly of the ship to the outboard position by pivoting the column, and then to permit the liferaft, preferably in an inflated loaded condition, to be lowered into the water.

The invention will now be described with the aid of the accompanying drawings in which: FIGURE I is a front view of a first embodiment of a liferaft launching system in accordance with the invention.

FIGURE 2 is a side view of the system of Figure 1 showing a liferaft in an inflated condition during launching.

FIGURE 3 is a plan view of the system of Figures I and 2.

FIGURE 4 is a view on arrow A of Figure FIGURE 5 is a side view of a second embodiment of the invention.

Referring to figures I to 4, a launching system for launching liferafts 10 comprises a davit II, and a conveyor 12 which comprises a carousel structure.

The liferafts 10 are each packed in a container comprising a plurality of straps 14 and stays 15 which contain the liferafts 10 each in a generally cylindrical configuration. The straps 14 and stays IS are secured by hydrostatic fastenings, of a proprietory type which are adapted to release automatically when sufficiently wetted. Upon release of the straps 14 and stays 15, an inflating means comprising a cylinder of compressed gas (not shown) is adapted to inflate the liferafts 10. Alternatively, the straps and stays may be arranged so as to break free as the raft inflates inside the container.

The carousel conveyor structure 12 has a centrepost 16 from which extends a plurality, in the present example four, arms 17 each of which carries a liferaft 10. The arms 17 are pivoted to the centrepost 16 at 18 so that when not in use, the arms 17 can be pivoted upwards to an upright stowed position. However when a ship is in use, preferably the arms 17 are in a lowered position and each have a liferaft 10 secured thereto in a stored, but ready to launch stowed condition.

The carousel structure 12 is mounted adjacent a launching position 20 from where the liferafts 10 may be launched, the centrepost 16 and arms 17 being rotatable to bring the liferafts 10 severally to the launching position 20.

To achieve this, the carousel structure 16 has a drive means comprising a worm gear 22 mounted at the upper end of an axle 23, about which the post 16 rotates, in bearings. A shaft 21 of the worm gear 22 extends radially from a bevel gear 21 outwardly beyond the arms 17 and terminates in a squared end 21 a which is adapted to receive a winding handle by which the drive means may be manually operated. When the worm gear shaft 21 is rotated, the worm gear 22 causes the centrepost 16 and hence the arms 17 to rotate about a rotational axis B.

If desired, a power assisted means for driving the carousel structure 12 may be provided, although preferably a manually operated drive means is also provided as a back-up.

The arms 17 each comprise a cradle 24 to which the respective liferafts 10 are lashed, by lashings 25 secured by hydrostatic fasteners, which lashings 25 can be quickly released when the respective liferafts 10 are in the launching position 20 or which are automatically released by virtue of the hydrostatic fastenings if the ships sinks so that the liferofts 10 are subjected to water. In this event the hydrostatic fastenings of the straps 14, stays 15 of the containers 13 will also be released to permit the liferafts 10 to be automatically inflated.

When a liferaft 10 is in the launching position 20 and the lashings 25 are manually released, the liferaft 10 may be lifted from the cradle 24 as hereinafter explained, or can be directly launched by releasing a chock arm (see Figure 4) to permit the cradle 24 to pivot relative to the arm 17 about an axis C so that the liferaft 10 in its container will be launched, under gravity, over a side 17 of the ship into the water below.

When the liferaft 10 reaches the water, the hydrostatic fastenings will release the straps 14 and stays 15, as hereinbefore explained and the liferaft 10 will automatically inflate, although passengers or crew wishing to embark from the ship would need to board the liferaft 10 when it is in the water.

In a preferred arrangement, the davit II is used to enable the liferafts 10 to be inflated and loaded before lowering into the water, although preferably the cradle 24 is provided as hereinebefore described, to permit launching of the liferafts 10 in an emergency if for example there is insufficient time to launch the rafts by the davit II, or if the davit 11 is damaged.

The davit 11 comprises an upright column 31 which, at the upper end thereof, has an outwardly extending arm 32 which overbears the carousel structure 12 and extends generally parallel with the adjacent side 17 of the ship. At the base 33 of the column 31, bearings are provided whereby the column 31 is mounted for pivoting movement about an axis D from the generally upright position shown in full lines in Figure 2, to a position in which the upper end of the column 31 is outboard of the ship, as shown by the line 30 in Figure 2.

The arm 32 carries a sheave 34 which is pivoted to the arm 32 so that as the column 31 is pivoted outwardly, the sheave 34 remains hanging generally vertically.

Fixed to the column 31 in line with the sheave 34, is a further sheave 35, and mounted adjacent the base 33 is a winch mechanism 36 including a winding drum 37. A cable 38 extends from the winding drum 37 up to the fixed sheave 35, through an opening 39 in the column 31, over the swinging sheave 34 and down to a lifting hook (not shown). The winch mechanism 36 is used for lifting the liferafts 10 from the launching position 20.

The winding mechanism 36 includes a braking drum 40 which has a weighted actuator 41, which causes the braking drum 40 normally to frictionally engage with the winding drum 37 to provide a braking action. A secondary brake (not shown) is also provided which, when the braking drum 40 releases the winding drum 37 by operating actuator 41, permits the hook carrying a liferaft i0, to descend to lower the liferaft 10 into the water, at a predetermined rate.

The brake drum 40 has a square ended shaft S to which a winding handle may be attached, for lifting the container 10 from its cradle, the shaft S being connected to the drum'37 by a suitable transmission mechanism.

A further square ended shaft T is provided, with a suitable transmission mechanism to the drum to quickly return the light hook after launch for attachment of the next raft.

Outward pivoting of the davit II is achieved by a luffing screw 42 which can be operated by a winding handle, movement of the handle being transmitted from the luffing screw 42 through an enclosed bevel gear which is anchored at a pivot 43 provided at the upper end of a housing 44 which mounts the winch mechanism 36.

Davit mechanisms are well known and hence further detailed description is not considered necessary.

Operation of the launching system will now be described.

First, the davit II is operated so that the arm 32 of the column 31 extends outboard of the side 17 of the ship for example, in the position shown by line 30 in Figure 2.

The hook on the end of the cable 38 of the winch mechanism 36 will thus hang outboard of the ship and must be drawn in (with a lanyard attached to the hook) and engaged with a lifting ring of a liferaft 10 which is in the launching position 20.

Bowsing lines of the liferaft 10 need to be secured relative to the deck of the ship on which the launching system is mounted and the painter of the liferaft 10 also needs to be secured, for example by a cleat on the deck.

The lashings 25 which secure the liferaft 10 to the cradle 24 must be released, and then, by operating the winch mechanism 36, i.e. attaching a winding handle to the shafts of the brake drum 39, and turning the handle, the liferaft 10 may be lifted clear of its cradle 24 and permitted to swing outboard of the ship.

When the liferaft 10 is outboard of the ship, the liferaft 10 may be inflated. An inflated liferaft 10 in a position outboard of the ship is indicated at 50 in figure 2. The outreach of the column 31 may need to be adjusted to ensure that the liferaft 10 is clear of the side 17 of the ship. If the angle of list of the ship is increasing as the liferaft 10 is launched, the angle of outreach of the column 31 may need to be continually adjusted by operating the luffing screw 42.

The liferaft 10 may in this position 50, be boarded by passengers and/or crew wishing to embark the ship, if necessary a boarding apron being provided between the deck of the ship and the liferaft 10.

When the liferaft 10 is loaded, the bowsing lines and painter of the liferaft 10 would be released from engagement with the ship. The liferaft 10 is then lowered into the water by releasing the brake drum 40 by lifting the weighted actuator 41 to disengage the friction between the brake drum 40 and the winding drum 37. The rate of descent of the liferaft 10 into the water will be governed by the secondary braking mechanism within the winch mechanism 36 hereinbefore described.

The actuator 41 can be operated to release the friction between the winding drum 37 and the brake drum 40, from aboard the liferaft. This is achieved because extending from the brake drum actuator 41, is a cable 45 which is wound about a pulley mechanism 46 and extends upwardly to a cross member 47 of the column 41, an outer end of which, 48 will overlie an entrance to the liferaft 10 where a crewman may position himself. Thus he may pull on the end of cable 45 to operate the actuator 41 of the brake drum 40. If desired, a control may be provided to enable the crewman to control the rate of descent, or the rate of descent may be controlled automatically by the secondary brake.

When a liferaft 10 hos been launched in the manner described, by operating the worm gear 21 of the carousel structure 12, the next liferaft (anticlockwise in figure 3) can be brought to the launching position 20 and the launching procedure repeated.

In the construction shown, the davit II is designed to be useable where the ship is listing at an angle of up to 200 and having an angle of trim of up to 100.

In an emergency the liferafts may be launched from the launching position 20 by releasing the lashings 25 which secure the liferaft 10 to the cradle 24 and then releasing the chock arm 26 (see Figure 4) to permit the liferaft 10 to fall over the side of the ship into the water under gravity.

In each method of launching the liferafts 10, after one liferaft 10 hos been launched, the next may be brought to the launching position 20 by operating the carousel structure 12.

The carousel structure 12 takes up minimum deck space whilst permitting convenient storage of the liferafts 10 and launching of the liferafts 10 severally from the launching position 20.

Referring to Figure 5, a modified arrangement is shown.

In the Figures I to 4 embodiment, the liferafts 10 are stored so that the longitudinal axes of the generally cylindrical packed configuration in which they are contained, each extend generally parallel, in a plane generally parallel with the deck of the ship on which the launching system is mounted.

Thus on moving each of the liferafts 10 from a stored position to the launching position 20, the liferafts 10 are only moved in that plane.

In the Figure 5 embodiment, similar parts to the Figures I to 4 embodiment are labelled with the same reference numerals although with a prime sign added. Only the carousel structure 12' is shown, but it can be seen that in this arrangement, when the liferafts 10' are stored, their axes E lie generally vertically.

When the structure 12' is rotated to bring a liferaft 10' to a launching position 20' (in a similar manner that the liferafts 10 are rotated in the Figures I to 4 embodiment) arms 17' of the carousel structure 12' may be pivoted down about a pivot axis 18' so that the liferaft 10' about to be launched is in a generally horizontal condition similar to a liferaft 10 in the launching position 20 in the Figures I to 4 embodiment. Thus the launching procedure includes the step of pivoting the liferafts 10' from the upright position shown to a generally horizontal position.

This arrangement has the advantage that the liferafts 10' when stored take up even less deck space than the liferafts 10 on the carousel structure 12 of the Figures I to 4 embodiment.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

I. A launching system for launching liferafts comprising means to store a plurality of liferafts each in a stowed condition, means to move each of the liferafts severally, to a launching position from where the liferafts may each in turn, be launched.
2. A system according to claim I wherein the liferafts are packed into containers which are generally cylindrical in configuration.
3. A system accoring to claim 2 wherein the liferafts are stored in a position in which the longitudinal axes of the cylindrical containers are all generally in the same plane.
4. A system according to claim 3 wherein the Iiferafts are moved only in the plane from the store to the launching position.
5. A system according to claim 2 wherein the liferafts are stored in an upright condition, and are each moved in a plane tronsverse, to the longitudinal axes of the liferaft containers.
6. A system according to claim 5 wherein the plane is generally perpendicular to the longitudinal axes of the liferaft containers.
7. A system according to any one of the preceding claims wherein the store comprises a conveyor to which the liferafts are secured at spaced positions to enable the liferofts to be moved sequentially to the launching position.
8. A system according to claim 7 wherein the conveyor is a carousel.
9. A system according to claim 8 wherein the liferafts are each secured to an arm which extends generally radially from an axis of rotation, the arms each being movable about an axis of rotation to enable the arms and hence the liferafts to be moved to the launching position.
10. A system according to claim 9 wherein the arms each comprise a cradle, there being a release means to enable the associated liferaft to be released from the cradle when in the launching position.
II. A system according to claim 10 wherein each liferaft is secured to its respective cradle by a strap which is adapted to be rapidly released.
12. A system according to any one of claims 9 to 11 wherein the arms are foldable for stowage when no liferaft is secured thereto.
13. A system according to any one of the preceding claims wherein the means which move the liferafts to the launching position comprises a drive means.
14. A system according to claim 13 wherein the drive means is manually operated, by means of a winding handle to cause the liferafts to move.
I 5. A system according to any one of the preceding claims wherein the liferafts are launched from the launching position using a davit which permits each liferaft to be moved from the launching position outboard of the ship where the liferaft may be inflated so that passengers and/or crew of the ship may board the inflated liferaft prior to the liferaft being lowered into the water by the davit.
16. A system according to claim 15 wherein the liferaft has lines which are securable to a deck of the ship when the liferaft is in the launching position.
17. A system according to claim 15 or claim 16 wherein the davit comprises a column which is mounted adjacent the launching position, the column being pivotal at or adjacent the base thereof to permit the upper end of the column to be moved from an upright position to a position outboard of the ship.
18. A system according to claim 17 wherein at the upper end, the column includes an arm which extends from the column generally parallel to the side of the ship at that position, the arm overbearing the launching position when upright.
19. A system according to any one of claims 15 to 18 wherein the davit includes a winch means for lifting the liferaft from the launching position, and to permit the liferaft, to be lowered into the water.
20. A system according to any one of claims I to 14 wherein the liferaft is launched directly into the water from the launching position, by releasing a chock and allowing the raft to fall free under gravity, over the side of the ship.
21. A system according to any one of the preceding claims wherein the Iiferafts are packed in containers so that when the containers come into contact with the water, the liferaft automatically becomes unpacked and inflates.
22. A system according to claim 21 wherein the container comprises hydrostatic fastenings which release on contact with water.
23. A system according to claim 22 when appendent to claim 10 wherein the means which secure the container to a cradle, comprises a device which, upon contact with water, release the container from the cradle.
24. A launching system substantially as hereinafter described with reference to and as shown in the accompanying. drawings.
25. Any novel feature or combination of features disclosed herein.