US2281233A - Marine lifesaving equipment - Google Patents

Description

April 1942- R. s. CHIPCHASE 2,281,233

. MARINE LIFE SAVING EQUIPMENT Filed March 8, 1941 Patented Apr. 28, 1942 srsrss this Robert Stanley Chipchase, South Shields, England Application March 8, 1941, Serial No. 38.23% In Great Britain January 25, 19%

5 Claims.

This invention relates to marine life saving equipment, and has for its object to enable buoyant units, such as rafts, to be discharged into the water from a vessel in distress in the shortest possible time and with a minimum of trouble or risk of injury to life and limb, or to be released and floated without human intervention in the event of excessive heeling over or rapid sinking of the vessel.

With this object in view. the invention consists in providing means for launching a raft or the like over a ships side, comprising a slip-way structure adapted to be mounted on a ship in an inclined position with its lower end flush with or extendi outwardly of the ships hull, and manually releasable means for retaining the raft or the like poised in a launching position relatively to said slip-way.

The slip-way structure is preferably so mounted that its lower end rests upon the top of the gunwale or the top rail of th ships upper works, since in this case there is no encroachment on deck space either in stowing the equipment or in actual launching.

According to a further feature of the inv ntion the length and pitch of the slip-way are so determined, having regard for the weight of the raft that when the raft is released for launching, its impetus will carry it clear of the ships hull irrespective of the position of the ship in the Water at the moment of release.

The invention also compri es the provision of in the form for instance of fences and hooped guard members, for preventing the raft from shifting relatively to the slip-way when in the poised position, owing to normal movement of the ship in a sea way, and from running off the slip-way during launching.

The manually releasable retaining means may comprise Chocks operable by quick releasing mechanism, or a flexible suspension element attached to the raft, taken over a transverse member of the slip-way structure and made fast to a fixed point on the ship in such a manner as to be rapidly and easily detachable, for instance with the aid of a slip-hock of conventional design, or in other ways that will occur readily to those skilled in the art to which the invention pertains.

Although the means set forth above enable rafts or the like to be launched clear of a ship in a very short time and with a minimum of "effort, and require no skill for their manipulation, emergencies in seafaring are apt to arise, particularly in war-time, in which it is difficult or impossible to ensure the manual operation or the releasing means, to launch the rafts in the time available, particularly in the case of large vessels carrying a considerable number of units of the described life saving-equipment.

It is also the purpose of the present invention, therefore, as already mentioned, to arrange for the raft or the like to be releasable, for launching or floating off, independently of manual operation, in response to abnormal movement or submersion of the ships hull, that is to say in the event of the ship heeling over at an abnormal angle or actually sinking in so short a time that the releasing means cannot be reached and operated manually. 7

According to the invention, therefore, in marine life saving equipment of the kind comprising a slip-way structure adapted to be mounted in an inclined position with its lower end flush with or projecting beyond the outer surface of a ships hull and readily releasable means for retaining a raft or the like poised in a launching position on said structure, the weight of the raft or the like in the poised position is carried by a removable support which opposes movement of the raft in a downward sense, while the raft is retained in the poised position relatively to the slip-way structure by means capable of disengagement by, or of yielding to, a force tending to move the raft bodily upwards and/or outwards.

According to a further feature of this aspect of the invention, the said removable support is releasably arrested in the supporting position and adapted, when released, to move in the direction of travel of the launched raft.

An embodiment of the invention is shown, by way of example, in the accompanying drawing, in which Figure l is a more or less diagrammatic'side elevation of a unit of life saving equipment according to the invention with the buoyant member (raft) in the poised position ready for launching. V

Figure 2 is a similar front elevational view of the same unit.

Figures 3 to 6 show structural details, each on an enlarged scale.

Figures 7 and 8 are a side elevation and-a'front elevation respectively of the upper portion of the raft showing a modified form of retaining means therefor.

Referring to Figures 1 and 2, the deck of "a ship to which a. unit of the life saving equipment according to the invention is 'fittedjis de.

noted by I, while 2 denotes the gunwale or upper works at one side of the hull, 3 the top rail thereof, 4 a mast, and 5, 5 two shrouds pertaining to the standing rigging of the ship and tautened between a point on the mast 4 and the upper works 2 by means of Warwick screws 6, 6.

A slip-way structure for carrying a buoyant life saving unit (in the present instance a life raft 1) is built up of longitudinal wooden battens 8 and similar transverse battens 9 and is adapted to be secured at the lower end to the top of the rail 3 at the required slope, and at the upper end by means of stirrups ID, ID, to the shrouds 5, 5. Alternatively, the upper end of the slip-way structure may be suspended from a mast or spar with the aid of suitable tackle.

In this embodiment, the raft is supported in the poised position, in which it is shown in Figures 1 and 2, by a flap or drop piece I I (Figures 5 and 6) pivoted at I2 0n the slip-way structure and adapted to bear, in the operative position, against the lower end face of the raft substantially at right angles to the main plane of the slip-way structure, and to be releasably retained in this position by a rip-cord I3, attached to one i tached and to the other end of which there is pivotally connected the one arm of an angular or elbowed latch member I9 the other arm of which is adapted to bear against one side of the link I8 and to be releasably retained in this position by means of a sliding keeper 2!] adapted to embrace both this arm of the angular latch member and the side limb of the link I8. Looped loosely around the other arm of the latch member I9, between its elbow and fulcrum, is a cord 2I pertaining to the means by which the slip release device is anchored to a fixed point on the ship. The device is preferably arranged to be assembled in the position in which it is shown in Figure 3, and it will be clear that if the keeper 2!] is displaced upwards, for instance by a blow delivered with any convenient implement or object, the latch member I9 will be swung outwards and downwards by the tension of the retaining gear and pulled through the loop of the cord 2 I, with 1 the result that the slip device is released from its anchorage, thereby allowing the drop piece I I to pivot and releasing the raft for launching down the slip-way.

For reasons of strength and rigidity, the drop piece I I is provided on the underside with an angle section stiffening element 22.

Various expedients may be adopted for the purpose of retaining the raft in position relatively of the slip-way structure and preventing it from jawing or coming adrift owing to the movement of the ship at sea, while at the same time enabling the raft to be thrown or floated clear when the ship heels over to an abnormal extent or becomes submerged without the raft having been launched by operation of the described releasing means. In the present embodiment, the foot end of the raft is confined between fences 23, 23 provided at the lower end of the slip-way structure on either side thereof, while in the end wall of the raft forming the base when the raft is in the poised position, or in an element thereof, there is provided a socket 24 suitably positioned and dimensioned for the reception of a registering stud 25 secured, for instance by welding, to the upper surface of the drop piece II. The socket 24 is preferably flared. This arrangement serves to retain the foot of the raft in position on the slip-way structure during all normal movements of the ship while allowing it to come clear in response to an upwardly and/or outwardly acting force, as for instance when the ship heels over abnormally or sinks before the raft launching means have been operated.

Various expedients may likewise be adopted to hold the upper end of the raft in position in a similar manner. In the present example a through bolt 26 is passed through holes in the side battens 8 of the slip-way structure and positioned so as to extend across this structure with clearance both from the supporting plane of the structure and the plane of the upper end surface of the life raft when in the poised position thereon, in order to allow for warping and swelling of the wooden elements of these structures. These clearances are indicated in Figure 4 in which they are denoted by :c and y respectively. I have found that a clearance of /2 inch at a: and of 3 inches at 1/ Will be satisfactory in practice. Attached to the upper end of the raft I are two angle lugs 21, 21 for instance of 5 inches x 3 inches right angle section, so that one limb (preferably the longer) thereof is flush with the hearing surface of the raft and extends beneath and beyond the through bolt 26 when the raft is in the poised position. By virtue of this arrangement, the upper end of the raft is prevented from being thrown or jolted clear of the slip-way structure by normal and transient movements of the ship or shocks imparted thereto while allowing the raft to come clear in response to abnormal movement or a persistent force acting with an upward component. The clearance y being greater than the engaging length of the stud 25, it will be understood that, as soon as the foot end of the raft is disengaged by such abnormal movement or force, the lugs 27 on the upper end of the raft can become disengaged from the bolt 26 by a downward movement or a pivotal upward movement of the raft, according to circumstances.

Alternatively, as shown in Figures '7 and 8, the upper end of the raft may be retained in position by means of a cage consisting of one or more stirrup or hoop members 28 embracing the upper portion of the raft and pivoted as at 29 on the slip-way structure, the pivot axis being above, and preferably a considerable distance above, the top of the raft when in the poised position. This cage is thus effective to prevent the raft from jumping out of the slip-way structure, for instance owing to rolling motion of the ship, as long as the angle of inclination of the slip-way structure remains within certain limits and the weight of the raft bears against the removable support, while allowing of movement of the raft bodily upwards and/or outwards in response to a persistent force, such as the force of gravity if the ship heels over beyond a certain angle, or the buoyancy of the raft if the ship is submerged.

A painter 30 is attached to one end of the raft in conventional manner, preferably with the aid of a manilla bridle 3|, and may conveniently be utilised for hoisting the raft into the launching position. For this purpose. the painter 30 is passed over a pulley block 32 suspended from the rigging and the slack is gathered in a suitable receptacle such as a tub 33, on deck, so as to be ready for instant and free withdrawal.

In order to prevent cross-jamming of the raft between the side cheeks of the slip-away structure I prefer to make these cheeks of relatively small depth, and as a further expedient for this purpose, the invention provides for rounding the sides of the raft after the manner of the bulge of a ships hull. The raft will then be thrown or floated clear of the slip-way structure with certainty even if the moving force acts unevenly thereon.

The described equipment may be provided in any desired numbers on a ship, and has the advantages of extreme simplicity and reliability, as well as of being always ready for instantaneous use and of requiring no particular skill to handle. The equipment is also inexpensive to construct and install, and has the further advantage of not taking up any deck space or occupying an outboard position in which it might foul in bringing the ship alongside a quay or tips or mooring alongside other vessels.

The equipment may be so distributed throughout a ship that in the event of serious damage it will always be possible to launch at least some of the rafts. This circumstance, coupled with the ease and speed of launching has an encouraging effect on the morale of the ships personnel.

It will be understood that the life saving equipment according to the invention may be built and supplied in self-contained units including rafts, ready for erection, or that alternatively the slipway structures may be built to suit existing rafts. The rafts used may be of any known type, such as those recommended by the ministry of shipping.

It will be understood that the conditions governing the determination of the length and pitch of the slip-way structure, in conformity with the principle set forth in the statement of invention, will vary, for instance according to the size of the ship and the nature and mass of the raft or other buoyant member used. It is therefore impossible to lay down rules of universal application for the determination of these factors and the values deducible from the accompanying drawing are i1- lustrative only and not intended to be in any way restrictive. In practice, the optimum values will be determined empirically and tabulated for different sizes and classes of vessels and different kinds and weights of rafts or the like, such data may then be referred to for guidance in installing the equipment.

It is desirable, particularly when the buoyant units are constructed of wood, to keep the bearing surfaces of the slip-way or of both slip-way and raft, well greased to reduce friction. The relatively moving parts of the slip-link device I l should also be kept well greased, to ensure proper functioning of this device after a period of immobility in the closed condition.

What I claim and desire to secure by Letters Patent is:

1. Marine life-saving equipment for installation on a ship, comprising in combination with a buoyant unit, a slip-way structure adapted to be mounted in a downwardly and outwardly inclined position on a ship with the foot end of said structure extending at least flush with the outside of the ships hull, a first releasable retaining means carried by said structure and adapted to engage the lower end of said unit to arrest said unit in an elevated position bearing against said structure, said retaining means being adapted to oppose movement of said unit in a downward sense relatively to said structure, while permitting movement of said unit away from said structure in a direction other than downwards, and a second retaining means on said structure engageable with the upper part of said unit inoperative to prevent release of said unit by release of said first retaining means and releasable by movement of the lower end of said unit away from said structure in a direction other than downwards.

2. Marine life-saving equipment as claimed in claim 1, in which said second retaining means comprises a fixed member on the upper part of said structure and a lug attached to the unit engaging with clearance beneath said fixed member.

3. Marine life-saving equipment as claimed in claim 1, in which said first retaining means comprises interengaging means on the lower end of the unit and a contacting portion of said structure, said interengaging means being adapted to become disengaged by a relative lifting movement of the raft through a certain distance, and said second retaining means comprises a fixed member on the upper part of said structure, said fixed member being spaced from the upper end of said unit by an amount greater than said distance, and a lug attached to the upper end of the unit engaging with clearance beneath said fixed member.

4. Marine life-saving equipment as claimed in claim 1, in which said first retaining means comprises interengaging means on the lower end of the unit and a contacting portion of said structure, said interengaging means being adapted to become disengaged by a relative lifting movement of the raft through a certain distance, and said second retaining means comprises a fixed member on the upper part of said structure, said fixed member being spaced from the upper end of said unit by an amount greater than said distance, and a lug attached to the upper end of the unit engaging with clearance beneath said fixed member, said interengaging means comprising a registering stud and socket on contacting portions of said first retaining means and the lower end of said unit.

5. Marine life-saving equipment as claimed in claim 1, wherein said second engaging means comprises a hoop member pivoted on said structure about an axis located above the upper end of said unit, and adapted to embrace and overlie a portion of said unit.

ROBERT STANLEY CHIPCHASE.

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