US3358884A - Hydraulic salvage jack - Google Patents

Description

Dec. 19, 1967 E. A. LINK 3,358,884

HYDRAULIC SALVAGE JACK Filed Oct. 4, 1965 5 Sheets-Sheet 1 INVENTOR EDWIN A.LINK

' A'rroRNEY Dec. 19, 1967 E. A. LINK HYDRAULIC SALVAGE JACK 5 Sheets-Sheet 2 Filed 001;. 4, 1965 FIG. 3b

FIG. 30.

INVENTOR. ED WIN A. L INK ATTORNEY Dec. 19, 1967 E. A. LINK 3,358,884

HYDRAULIC SALVAGE JACK Filed Oct. 4, 1965 5 Sheets-Sheet :5

INVENTOR. EDW/A/AL I/VK BY ATTORNEY Dec. 19, 1967 E, A, UNK 3,358,884

HYDRAULIC SALVAGE JACK Filed Oct. 4, 1965 5 Sheets-Sheet 4 INVENTOR. ED WIN/1. L INK ATTORNEY E. A. LINK Dec. 19, 1967 HYDRAULIC SALVAGE JACK 5 Sheets-Sheet 5 Filed Oct. 4, 1965 INVENTOR. EDW/IVAL INK %M(AW v ATTORNEY United States Patent 3,358,884 HYDRAULIC SALVAGE JACK Edwin A. Link, Binghampton, N.Y., assignor to Ocean Systems, Inc., a corporation of New York Filed Oct. 4, 1965, Ser. No. 492,715 1 Claim. (Cl. 22294) This invention relates to ships and to the field of marine salvage. More particularly, it relates to novel apparatus for freeing a beached or grounded ship, particularly a novel hydraulic jack.

Ships are frequently driven aground at high tide or in a storm; and, as a result of wave action, are frequently destroyed. If the ship is making headway when grounded, its momentum may carry it up on a reef and make its re-fioating, even at high tide, impossible. There have been numerous prior-art attempts to provide means for increasing the buoyancy of ships. One general idea is to inflate bags with air after they are placed under or alongside the hull. Abraham Lincoln received a patent on a bellows mechanism directed to this end.

Generally, it has been impractical to use such bags or pontoons in a surf, possibly because the wave action causes bouncing of the ship and working of the fastenings with damage to both. Another difiiculty with gas bags comes from the instability of their lifting force. As a bag rises, its volum-n expands and its lift increases.

In common with these prior-art systems and apparatus, the present invention contemplates the use of expansible, flexible, bag-like, hydraulic cushions, connected together to provide a mattress to be placed under the hull. In contrast with the prior art, the bags are fixed to the ground, not to the ship; and they are filled with water, not air.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.

It is an object of the present invention to provide means for stabilizing a grounded ship in a surf and for subsequently raising and freeing it which may be handled and installed with a minimum of special equipment. 'It is a further object to provide means for the above object which may be employed under a wide variety of ground and hull configurations. A further object of the invention is to provide apparatus for ship salvage which is air-transportable in an emergency. A still further object is to provide a novel expansible cushion adapted to serve as a hydraulic jack.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is an illustration of a grounded ship with lifting cushions installed in accordance with the invention,

FIG. 2 is a plan view showing interconnections of the cushions and arrangement of ground tackle in FIG. '1,

FIG. 3 is a sketch of a hydraulic-jack cushion in expanded form,

FIGS. 30 and 3b are sections taken as shown in FIG. 3,

FIG. 4 shows the cushion of FIG. 3 in flattened condition,

FIG. 5 is a sketch showing a grease dispensing modification of the top of a cushion,

FIG. 6 is a sketch of an improvised form of lifting cushion for the practice of the invention, and

FIG. 7 is a sketch of an alternative improvised lifting cushion.

FIG. 1 shows a ship 10 on a reef -12, the bow 14 is raised by pressure from the reef on the bottom 16. Under fiexure poses no problems.

the ship and extending between the bottom of the ship and the ground, or ocean floor, are a plurality of accordian-like expansible hydraulic cushions 20-29. These cushions are fastened together and to cables -54, which with other cables, not shown, secure the assembly to the reef 12 and the ocean floor 18. As will be more fully de veloped below, as the cushions 20-2-9 are pumped full of water and press against the bottom 16, they apply a distributed pressure in excess of the normal hydrostatic pressure to an extended area of the ships bottom, thereby raising the ship and freeing it from contact with the reef. The ship is then held only by friction between the bottom 16 and the tops of the cushions. This friction, unlike the engagement with the reef can be managed and controlled as set forth below.

If, as show-n, the bottom '16 of the ship is tilted, the pressure from the cushions (which is normal to the surface) has a horizontal component in addition to a vertical component resisted by gravity. The ship will tend to move responsive to the horizontal component and the cushions to topple. To prevent this, ground tackle is arranged as shown in FIG. 2.

Assuming the ship is stuck forward on the centerline and port side, the cushions may be arranged amidships wherever the proximity of the bottom to the ground permits and cushions 28 and 29 may be extended forward where clearance over the reef 12 permits.

As shown in the schematic plan view, FIG. 2, and in FIG. 3 the cells are partially contained by inner cable hoops 69 and outer hoops 70 to which connecting rings 72 are fastened, four to each hoop. By hooking these rings 72 together with short lengths of chain, a mattresslike array of the cushions 20-3-9 is formed. Cables 51, 52 and 53 are stretched across the cells and terminate in anchors 8188. The anchors are set before the cushions are expanded. In this way, the expansion of the cushions keeps the cables tight and may even require that they be loosened somewhat. These cables prevent any toppling of the cushions to the side. Other cables 54, 5 5 and 56 strung fore and aft and anchored forward, prevent the cushions from being carried with the hull and tipped as the ship is released from the reef.

The cushions may be of various sizes and shapes. For a ship of about 3,000 tons, displacement cushions as illustrated in FIGS. 3, 4 and 5 are preferred. As an example, a U.S. Navy Allen M. Sumner class destroyer, displacing 3,300 tons fully loaded is 376 /2 feet long, 40% feet wide and draws 19 feet, maximum. Over most of its length the bottom is substantially fiat to a width of 30 feet. Thus three such cushions each 10 feet in diameter may be placed abeam. They may be extended to ten feet more or less in height.

At the operating depth of 18 feet the bottom plates of the ship lying quietly in the water distribute to the frames a pressure of about eight pounds per square inch. While Weight is kept to a minimum, and for that reason, destroyers have been dubbed tin cans, nevertheless the hull must be designed to withstand several times this static pressure to stand up under wave action, the shock of depth charges, etc. Thus one may reasonably use 20 pounds per square inch as a design figure for the overpressure to be exerted by the cushions, and, therefore also, the pressure which must be contained by the skin of the cushions.

For a cylinder ten feet in diameter under an internal pressure of twenty pounds per square inch, the hoop stress is 1,200 pounds per lineal inch. Com-paring this with the 50,000 pounds per square inch strength of nylon fiber indicates that a two-ply bag of the order of onequarter inch thick will sustain the pressure. This is so thin in comparison to the dime sions of the bag that It is preferred that cushions have a maximum expansibility upward, while resisting outward expansion and shear. These objectives are met with an aceordian-pleted bag 301 as shown in FIG. 3 and sections 3a and 3b. The bag is molded in half-extended condition over a similarlyshaped form bag. Reinforcing plies 311, 312 may be applied over a liner 314 by cutting and cementing flat fabric pieces, by stretching knitted tubes, or by filament windmg.

Cable hoops in two sets 69, 70 are applied over the plies. Hoops 69 in the first set are of lesser diameter and are placed one in each of the valleys 320 of the accordion pleats. Hoops 70 from the second set are placed one at each pleat crest 330, held in place by fabric strips 340. These hoops contribute importantly to maintaining the pressure against lateral expansion without adding either stiffness, or resistance to vertical extension. The hoops also provide strong points to which connections may be made. For this purpose, interconnecting rings 72 are fastened to the outer hoops 70, by straps 352.

The accordion-pleated cylinder together with rounded end shoulders 360, 361 is molded to its outer covering 365 and heat cured in the manner of an automobile tire while still supported on its inflatable form bag. This form is then removed and each end piece 370 is applied. The ends 370, which may be exposed to sharp and abrasive coral and to irregularities on the ship bottom which slide over the top, may be stiffer, multiplied and more thickly covered than the accordion-pleated cylinder. Accordingly the ends inflate to a rounded, but not hemispherical condition, and readily conform to flat areas of the bottom.

It will be apparent that the cushions may be molded with any of a number of rubber-like elastomers and rubbers, such as neoprene. Natural rubber would probably not be used because of potential contact with fuel oil. A bronze ring 380 is fastened into the wall as shown in FIG. 3 and contains a port 382 threaded with pipe threads, thereby providing a point of connection through which fluids may be injected to expand the bag. Pressure may also be applied in this way to mold the ends to the pleated cylinder.

For placing the cushions under the ship, groups of cushions connected together may be keel hauled by cables carried under the hull. For placement, the cushions are in their flattened condition, containing a minimum of liquid and no air. An excess of exterior pressure over interior tends then to compress the bag to minimum length as shown in FIG. 4. Lines 401-403 between connecting rings 72 may be used to maintain the cushion in compact condition for handling. A cushion extensible to 10 feet long may typically be so shortened to less than 2 /2 feet in thickness.

When the ship is raised, there remains the job of pulling it over the tops of the cushions into deeper water. To provide a means for lubricating the tops of the cushions, the variation shown in FIG. 5 may be used. The end closure 501 of the cushion comprises an attachment ring 503 which is moulded to the bag shoulder 360. It is also moulded to the mouth of a fluid-tight pouch 505, which extends into the cushion. The mouth of the pouch 505 is closed by a heavy netting 507 of nylon cordage, or such, which has many holes through it, but these holes are sufficiently small that the internal pressure of the cushion will be sustained by the netting backed up by the material of the pouch 505. The pouch 505 may be filled with heavy grease soap, or other lubricant which is effectively retained by the netting until the internal pressure exceeds the external, pressing the pouch toward the netting, and extruding the grease.

To retain the grease until the ship begins to move over the cushions, the grease is preferably contained in a number of plastic bags, '509. Empty, these bags are passed through the netting into the pouch 505, leaving the necks 511 of these bags outside of the netting. To prepare the cushions for use, the plastic bags 509 are injected with grease, and their necks tied off and left protruding from the netting. When the ship starts to move these necks 511 are pinched off, releasing the grease.

Alternatively a separate quilt or wafiie-like mat containing a number of small lubricant pouches may be fastended to the cushion at the rings 72, and be arranged so that the pouches release the lubricant wherever the top presses against the hull.

A cushion as just described is the preferred embodiment for a hydraulic jack to be used in this new method of salvage. It will be recognized that similar bag-like articles are already in use for other purposes. Fabric-reinforced elastomeric bags are now commonly used for the shipment of liquids by dry cargo methods. They are used for the storage of fluids on land and are particularly attractive for the storing of petroleum under water.

As shown in FIG. 6 similar hydraulic jacks may be improvised by piling up a number of these bags 601 which are of a generally oblate spheroidal shape. These bags may be securely fastened together by webbing 603 which may, for convenience be cemented to the bag. These cushions 606, 607 may be interconnected by linkage 608 to form mattresses as above described.

- Each of the bags 601 of such a cushion must be separately injected, by hoses 609 but otherwise the cushion is used substantially as the preferred cushion may be used.

Also available in the trade are elongate fluid storage bags which may be laid up in the form of cribbing as shown in FIG. 7. The bags 701 are put down in layers, criss-cross, and are held together with webbing 703 and injected by hoses 704. In this way, the mattress under the ship may be interlocked into a single structure, but injection of groups of bags must be under separate control as explained below.

As indicated above, pressures of up to about 20 p.s.i. (pounds per square inch) may be exerted against a destroyer hull by cushions of the kind described operating as hydraulic jacks; and at most locations on the hull such forces may be applied. Thirty of the pleated cushions as described above, placed amidships could raise the destroyer used as an example clear out of the water, but the hogging stresses might break her back. It follows, therefore that some attention must be given to the place ment, of the cushions, and to the pressures which individual cushions or groups of cushions apply.

By adjusting the pressures in groups of cushions, the trim of the ship is controlled as it is eased off the reef. Ordinarily, the ship would be pulled free, while sliding along the length of the mattress. Pressure in selected cushions may be varied to steer the motion of the ship so that it remains stably supported. Controlled fluctuation of the pressure of groups of cushions in cyclic order may be employed to control a step-by-step sliding of the ship over the mattress. The need for these functions to have separate control of the pressure on individual cushions or groups of cushions sets a functional limit on the maximum diameter of individual cushions. The required extended length of cushions in turn largely determine the minimum practical diameter.

Ordinarily, the grounding force on a ship at high tide is only a small fraction of her displacement. Three hundred-fifty tons for a 3,300 ton destroyer is typical. Thirty bags under such a ship can relieve it with only about four p.s.i. pressure in the bags. A lighter construction of the bag may be contemplated in such a case.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. Since certain changes may be made in the construction set forth without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claim is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

A hydraulic cushion comprising an expansible accordion-pleated bag of elastomeric material; a pouch for containing a lubricant positioned Within the upper portion of said cushion, said pouch having its outlet communicating with the top surface of said cushion through a plurality of small openings therein, whereby the lubricant will be retained in said pouch until the internal pressure in said cushion is increased.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 8/ 1939 Great Britain.

ANDR'EW H. FARRELL, Primary Examiner. MILTON B UCHLER, Examiner.

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