US2413226A - Life raft - Google Patents

Description

Dec. 24, 1946.

Filed April 7, 1944 M. HALLWARD LIFE RAFT 4 Sheets-Sheet 1 Dec. 24, 1946. v' M, HALLWARD 2,413,226

LIFE RAFT Filed April 7. 1944 4 Sheets-Sheet 2 M. HALLWARD Dec. 24, 1946.

LIFE RAFT 4 Sheets-Sheet 3 Filed April '7, 1944 Patented Dec. 24, 1946 UNITED STATES PATENT OFFICE LIFE RAFT Michael Hauwara, swampscott, Mass.

Application April 7, 1944,-Serial No. 4529,976

4 Claims.

circumstances, the standard lifeboat has proved to be of little value, since it must be lowered away carefully to avoid capsizing or smashing upon impact with the water or by being thrown by the seas against the side of the vessel, and

requires that the passengers take their places prior to lowering.

Because of these disadvantages, attempts have been directed to the provision of lifesaving devices in the form of rafts, which may be quickly released from the sinking vessel into the water and thereafter boarded by the personnel who have left the vessel by jumping or by climbing down ropes or nets. Generally, -such rafts are so constructed as to perform their intended function regardless of Whether, after reaching the Water, they are in normal or inverted position, due to the impossibility of turning over a raft once it has been launched.

In order that the ship may be abandoned with all possible speed, the life rafts, together with their launching cradles, are supported in steeply inclined position on framework provided for the purpose adjacent the rail of the Vessel. In the event of an emergency, the raft and cradle are freed by cutting lashings or by other rapidly operated release mechanism. Since the rafts are frequently high above the water upon release, in many cases thirty or forty feet, the raft is subjected to severe stresses upon striking the water, in many cases shattering the structure and destroying its usefulness. The release of the launching cradle along with the raft adds to the possibility of damage to the raft.

While the majority of life -rafts so far employed have relied on tanks or other pneumatic means to provide buoyancy, experience has indicated that such arrangements are not satis factory. Not only may the buoyancy be lost by damage to the tanks during launching, but the tanks themselves may be punctured or broken subsequently, as by gunfire in the event the loss of the vessel is due to enemy action during war. In the case of the larger rafts, with which the present invention is particularly concerned, it has been found extremely dilicult to provide a structure employing metal air tanks for buoyancy, which is capable of withstanding the shock of impact upon emergency launching or of being thrown against the sides of the vessel by the waves after launching. It has been established that a raft, to be satisfactory for the intended purpose, must be capable of being dropped from a height of 'at least forty-five feet and striking the water in any attitude without incurring structural damage.

Assuming that the ship has been abandoned successfully and that the personnel has climbed aboard the raft, the raft must now perform many of the functions of the vessel left behind. In addition to be sufficiently seaworthy to carry perhaps twenty men through rough seas, it is necessary lto provide shelter against sun, rain, wind and breaking -waves if the men are not to perish from exposure. ,If the vessel has been lost far from land, as may happen during wartime, many days may pass before the men are picked up. Accordingly, it is desirable to provide means for propelling and directing the raft, as even slow progress may enable the craft to reach land and will in any event be preferable to drifting aimlessly.

One of the objects of the present invention is therefore to provide a life raft of very great structural strength, so as to be capable of withstanding the shock of striking the water from any height at which it may be released from the ship, yet light enough in relation to its displacement to alford ample buoyancy while loaded.

It is likewise an object of the invention to provide a life raft which is not dependent for its buoyancy on air tanks or on watertight compartments and bulkheads.

The invention has as a further object the provision of a, life raft for emergency use on vessels at sea, the raft being so constructed and arranged as to obviate the need for a launching cradle or other special gear, and instead to be capable of being launched directly from the sup- A porting framework on the vessel.

members I8 extending transversely of the raft between the tiers of fore and aft members. The last mentioned members have their edges notched slightly at each intersection with the transverse members I8 and at the points where said members pass through the slots in the main transverse members I2 at each end of the well. These slots are of suicient size to permit; sliding the fore and aft supplementary members I6 into place, after which, by driving wedges y2li into the slots, the lwhole structure of main and supplementary members may be caused to interlock as The several features of the invention are illustrated in the accompanying drawings, in which-I Fig. 1 is a view of the raft in side elevation, the

protective enclosure being partly broken away;'

Fig. 2 is a top plan view of the raft, partly broken away and partly in section; Fig. 3 is a view in sectional elevation, taken along the line 3'3 of Fig. 2; and Fig. 41s an oblique view of a corner portion of the raft, illustrating certain structural features thereof at partial'assembly.

The raft is of generally rectangular contour, with oblique corners and with sloping sides which flare outwardly to a chine 8 which extends around the raft at the mid-height. As a result, in any edgewise attitude in which the raft may strike the water, a V section is presented which substantially eases the entrance.

The raft is provided with a centrally disposed shallow well or cockpit, the oor level of which is normally above water level. In order that the raft may be fully effective regardless `of which side iioats up after launching, cockpits are provided on each side of the raft, and in substantially every other respect, the raft is symmetrical about a plane through the mid-height, as represented by the level of chine 8. Accordingly,while in certain instances the terms top and bottom may be employed in the description, it will be understood that their signicance is limited, because either side serves equally well as and may be the top or bottom, respectively, of the raft.

The structure of the raft is characterized by the fact that the principal structural elements are disposed around the well or cockpit, rather than at the outer margins of the raft. As shown in Figs; 2 and 4, the raft structure -is based upon main fore and aft members I0 and main'transverse members I2 which are assembled in interlocking relation by means of complementary notches at the intersections. These members are substantially the full depth of the raft, and are preferably of laminated construction for maximum strength without excessive weight.

Outwardly of these principal members, the raft is divided into a plurality of bays by means of a series of bulkheads I4, likewise preferably of laminatedwood construction. The margins of these bulkheads are shaped to carry out the contour provided by the ends of the main members'projecting beyond their respective intersections at the corners of the well.

The bulkheads are supported, at least in part, and the whole structure integrated into a rigid whole of great strength relative to its weight, by means of a plurality of fore and aft members I6 and'transverse members I8 which extend across the well of the raft and project through slots in the principal members to embrace the bulkheads. The members are employed in pairs spaced a distance equal to the thickness of the bulkheads, vand are arranged in tiers, with two tiers of pairs of members It running fore andaft at eachrbulkhead at the ends 'of the raft, and one tier of paired a result of engagement with the notches. Cheek 'pieces 22 reenfcrce the numerous intersections of supplementary members, main members, and bulkheads. Glued joints, supplemented by screw fastenings where required, permit the full strength of the materials to be realized.

The bulkheads are interconnected by numerous structural members which distribute the loads and likewise serve as supporting members for the covering or sheathing 30 of laminated wood or plywood which encloses the bays. Such members include the chine 8, rails 24, cap pieces 26, and intermediate strips 28, the'bulkheads being appropriately notched to receive these members as shown in Fig. 4. As a result, the sheathing is rigidly supported at closely spaced points to withstand the shock of impact with the water consequent upon launching the raft.

I t is thus apparent that a thoroughly integrated structure has been provided which is characterized by the use of principal frame members dis posed around and defining a well or cockpit, with a plurality of individual bays outwardly of the main frame. Through the use of numerous supplementary members which bridge the well to provide support for the floor boards 32 and which extend through the main frame members to embrace the bulkheads,l any strains to which one portion of the raft may be subjected are distributed throughout the entire structure.

To render the raft buoyant without dependence on watertight compartments or tanks, the bays of the structure are filled with a buoyant material 34 such as cork or a cellular plastic substance. As a result, the bays need not necessarily be capable of excluding water in themselves, but are required to withstand shocks and impacts so that sudden violent pressure changes are not transmitted to'the cellular material within, with consequent damage to the material. The shock of impact of the raft with the water on launching is so great that without the protection which the rigid construction of the bays affords to the buoyant material within, the cork or other cellular substance would in many instances have its cellular structure destroyed, with consequent loss of its' Ybuoyant properties. VBy employing buoyant material inconjunction with suitable protective structure, the raft is rendered unsinkable, without depending on Vwatertight compartments or tanks. Even though the bays be damaged or punctured, as by bullet holes, the buoyancy will be `substantially unimpaired.

-In"order that the raft after launching may perform effectively its intended function of saving personnnebnumerous features of construction and arrangement are provided for the safety and protection of survivors. A handrail 40 extending around the chine 8 Vand grab ropes 42 at the railsl 24Ypermit the survivors to'climb 'aboard theraf't from thefsea'. Undernormal' conditions,.it is contemplated 'that the men will sit on the sloping Slat-type seats 44 provided around the decking of the bays. To protect the backs of the men from splashing of the waves, a back rest is provided in the form of a fabric strip 4S supported on struts 48 hinged at their lower end to permit folding to horizontal position. 'Ihe rails 24 are notched to receive the struts when in erect position, to aiford additional support. Pockets B in the fabric strip receive the ends of the struts to provide attachment thereto. Further protection is afforded by a complete enclosure which may be set up after launching. Corner posts 52 fit into sockets 54 to support a waterproof fabric cover 56 having sides which may be raised or lowered as needed. When lowered, the sides may be fastened to the top of the fabric seat back 46 to provide a full enclosure. The center of the top is supported by a line 58 from a mast 6B with which the raft is provided. If the cover be lowered from its normally raised position to the approximate position indicated by the dotted line 62 (Fig. l), rain water may be collected in the cover and withdrawn through a drain tube. When the cover is not needed, a sail (not illustrated) may be carried by the mast, at which time the raft may be directed by the rudder 64. The sloping sides and oblique corners of the raft permit fair progress to be made under favorable conditions of wind and sea.

The type of construction of the raft permits stoWage lockers 65 to be provided for necessary supplies. These lockers, which may be of watertight construction, are disposed in certain of the bays, with openings 68 accessible from either.

cockpit.

As has already been pointed out, the larger types of life rafts are generally supported in steeply inclined position above the deck of the vessel near the rail, so that they may be launched either by operating release gear which permits the rafts to slide by action of gravity into the water, or to be automatically floated from their supporting framework in case the vessel sinks before the raft can be launched in normal fashion. In most instances a cradle is provided for the raft, the cradle and raft being launched together by sliding the cradle down the supporting and guiding members of the framework.

To eliminate the need for a separate cradle, the raft of the present invention is so constructed that the longitudinal rails Z of the raft may serve as the cradle or skids for launching. For this purpose the rails are formed with a relatively deep section (see Fig. 3) and are cut away at intervals to leave raised sections lll of relatively limited area in order to minimize sliding friction with the guide members of the supporting and launching framework. These raised areas may conveniently be disposed in the way of the struts for the seat backs, as shown. The cutouts in the rail likewise minimize the shock of striking the water during launching, in case the raft strikes in flatwise position, by permitting the escape of air that would otherwise be trapped or pocketed between the rail 24 and the cap piece 26 below the decking.

To avoid the effects of trapped air in the cockthat at least some of the floor boards 32 of both cockpits be left off and secured to the sides of the cockpit in order to provide an opening through the center of the raft for the escape of air. After launching, the floor boards may be placed in position. Since the raft, even when loaded, oats with its floor above the level of the water, the cockpit may be made self-bailing, either by using scuppers (not illustrated) or by employing a non-watertight construction for the floor boards to permit drainage.

The invention thus comprises a life raft char. acterized by a type of construction which permits it to withstand the shock of launching by dropping into the water from a considerable height, yet is not so heavy as to be ineffective for its intended function of supporting a relatively large number of passengers safely and with comparative comfort.

I claim as my invention:

1. A life raft comprising main fore and aft and transverse members defining a cockpit, supplementary fore and aft and transverse members spanning the cockpit and extending through the main transverse and fore and aft members, respectively, means including bulkheads carried by said supplementary members outwardly of the main members to form a plurality of enclosed bays disposed around the cockpit, and buoyant solid material within said bays.

2. A life raft comprising a pair of spaced deep fore and aft members, a pair of spaced deep transverse members, said members being arranged in intersecting edgewise relation, a plurality of shallow supplementary fore and aft and transverse members arranged in overlying relation intermediate the deep members and projecting therethrough, a plurality of bulkheads disposed outside the deep members and engaged by the projecting portions of the supplementary members, rigid covering means cooperating with the principal members and the bulkheads to form a plurality of individual bays around the outside of the principal members, and buoyant solid material within and filling said bays.

3. A life raft comprising a pair of main fore and aft members and a pair of main transverse members arranged in intersecting edgewise relation to define a central well, supplementary fore and aft and transverse members spanning the well in edgewise overlying relation intermediate the main members and projecting through slots in said main members, said supplementary members being notched at points of intersection to provide interlocking engagement, bulkheads disposed outside the main members and engaged Aby the projecting portionsVv of the supplementary members, rail and chine members carried by and spanning the bulkheads, rigid covering means carried by the bulkheads and rail and chine members to provide a-plurality of enclosed bays outwardly of the central well, and buoyant solid material within and lling said bays.

4. A life raft having a centrally disposed cockpit and buoyant raised structure outwardly thereof adapted to provide seats, foldable seat backs comprising hinged struts and eXible fabric material f prising a mast projecting upwardly above the roof and a line from the mast to the central portion of the roof.

MICHAEL HALLWARD.

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