US3380420A - Salvaging apparatus - Google Patents

Description

United States Patent 3,380,420 SALVAGING APPARATUS George T. Frederick Divine, 3337 NE. 132ml Ave., Portland, Oreg. 97230 Filed Feb. 8, 1966, Ser. No. 525,965 7 Claims. (Cl. 114-50) ABSTRACT OF THE DISCLOSURE Salvaging apparatus for a submerged container, with means for controlling the pressure of air admitted to the container relative to the pressure of water outside of the container in the form of a passage in the container through which air may escape, valve-closure means adapted to open and close such passage, and remotely controlled biasing means for exerting a biasing force on such closure means, such biasing means comprising a fluid-operated ram which tends to extend by the introduction of fluid at different pressures to opposite sides of a piston in the ram.

This invention relates to salvaging apparatus, and more particularly to apparatus of this description which relies upon the introduction of air into the hull of a submerged vessel producing water displacement from the hull permitting it to rise.

It has been customary in salvaging operations to raise a submerged vessel through the expedient of pumping air into the hull to form an air bubble therein, with the displacement of water from the hull. A general object of this invention is to provide novel means for controlling the pressure of air in such an air bubble, whereby the desired buoyancy in the hull is achieved, and at the same time any excessive difference in pressures existing on the outside and on the inside of the hull is prevented. Such a pressure difference is disadvantageous as it tends to cause cracking and other damage in the hull, and even may result in loss of buoyancy if of the type as to permit a significant amount of air to escape from within the hull.

Further explaining, when displacing water from a hull by the production of an air bubble inside the hull, an initial air pressure is selected which is suthcient to produce the size of bubble necessary to produce flotation at the particular depth at which the vessel rests. Any material excess of pressure above that required is avoided, as such pressure excess increases the chance of the hull bursting or cracking, with air then possibly escaping from the vessel. As the hull rises in the water, water pressure on the outside of the hull of course decreases, which means that the pressure of air required to produce flotation similarly decreases.

Various procedures have been suggested for maintaining during raising of a vessel a substantially constant difference in pressure between the inside of the vessel hull and the outside. Thus, the amount of water which must be displaced from the vessel to produce flotation may be calculated from dimensions of the hull, and after such a calculation has been made apertures may be cut in the sides of the hull at the appropriate level, whereby air automatically escapes through such apertures upon the size of the air bubble inside the hull exceeding a certain maximum. Such a procedure however requires that the hull be stable durings its rise from the bottom, i.e. that listing and such movement be controlled. Further, the system is characterized by little flexibility. Alternatively, some sort of relief valve might be incorporated with the salvaging apparatus permitting the bleeding of air from the vessel as the vessel rises. However, difficulties are introduced here since it is preferable that any such valve be readily adjusted, so that for any particular salvage oper- "ice ation it is possible to set the valve to provide for pressure relief at exactly the desired pressure condition. Furthermore, the valve must be sensitive, not to any specific pressure within the hull, but to the difference in pressure existing between the inside and the outside of the hull. Additionally, any valve used for relief purposes preferably should be remotely adjustable, to permit suitable changes in setting to be made from a floating salvage ship with the valve itself submerged and at the location of the sunken hull.

Thus, another object of the invention is to provide, in salvaging apparatus for raising a submerged hull, a novel form of a valve for controlling the pressure of air utilized in displacing water from the vessel.

More specifically, an object is to provide an improved valve for salvaging apparatus which is readily adjusted to provide pressure relief at different pressure levels.

A still further object is to provide such a valve which can be adjusted at a point remotely located from where the valve is situated.

Another object is to provide, in a valve controlling the pressure of air within a submerged hull, improved fluid pressure-operated biasing means which yieldably closes an opening in the valve leading to the inside of the hull, such biasing means producing a biasing force which remains unchanged with change in hull depth.

These and other objects are attained by the invention, and the same is described hereinbelow in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic drawing illustrating salvaging apparatus as contemplated by thi invention, and showing how such may be employed to raise a hull submerged in water;

FIG. 2 is a view, partially in section, illustrating valve mechanism in the apparatus provided for the purpose of regulating the pressure of air within the hull, the drawing being on a substantially larger scale than FIG. 1; and

FIG. 3 is a top plan view of the valve mechanism showing FIG. 1.

Referring now to the drawings, and first of all more particularly to FIG. 1, the cross-section of the hull of a sunken vessel is indicated generally at 10. The hull includes sides 12 and a deck 14, and is shown resting on a bottom 16. At 18 is indicated the level of the body of water in which the hull is submerged. The hull constitutes a substantially closed submerged container in a system where it is intended to displace water from such container.

As generally described above, salvaging of the Vessel hull is performed by displacing a certain amount of the water therein with air. Enough water is displaced to render the hull, together with any remaining water, buoyant. The pressure of the air required to produce such buoyancy must necessarily exceed the pressure of the water which surrounds the vessel, in order that water will be forced to the outside of the hull. Since the density of water varies but little at different depths, the size of any air space or bubble produced in the hull to provide buoyancy need not change as the hull rises from the bottom to various depths during the progress of the salvage operation, and in fact, the size of such air space preferably is maintained substantially constant. Since the pressure of the water outside the hull will change markedly as the hull rises to different depths, it is necessary that air be allowed to escape from the hull as it rises. The escape of air from the hull is controlled by a pop-0E valve mechanism, shown generally at 20.

Considering in more detail the construction of this valve mechanism, and referring now also to FIGS. 2 and 3, the base of the valve mechanism is formed by a cylindrical skirt designated at 22. Joined to top and bottom ends of this skirt are annular flanges 24 and 26. Flange '3 24 provides support for spider or anchor bracket 28 disposed above the cylindrical skirt. Flange 26 is employed in fastening the valve mechanism to the deck of the submerged hull. Extending between flanges 24 and 26, and distributed circumferentially about the skirt, are strengtheners 30.

Skirt 22 is bounded around its upper end by a circumferential edge 22a. This edge defines a valve-opening in the valve mechanism, and provides a seat for a valveclosure means, more specifically a valve plate 32, disposed above skirt. In the embodiment illustrated a sealing element 34 is shown mounted on the underside of the valve plate which element actually contacts edge 22a with the plate resting on the skirt to produce an air tight seal.

Valve plate 32 is joined to an elongated rod 36 extending through the center of the plate. A sleeve 38 slidably supports lower extremities of rod 36. Supporting this sleeve in a centered position within skirt 22 are radial support arms 46 joined at radially inner ends to the sleeve and radially outer ends to the skirt.

Spider bracket 28 includes a hub portion 42, and legs 44 joined to this hub portion which extend radially outwardly from the hub portion and thence downwardly to, feet 46 which rest on flange 24. Securing the spider bracket to the annular flange are multiple fasteners 48.

Hub portion 42 provides a mounting for a pressure fluid operated ram assembly 56 which is utilized in biasing plate 32 to a position closing off the opening defined by edge 22a. The ram assembly includes a cylinder 52 fastened as by nut and bolt assemblies 54 to hub portion 42, and a piston 56 mounted for reciprocation within the cylinder. The upper extremity of rod 36 described in connection with the valve plate also functions as a pistonrod for the ram assembly. Thus, it will be noted that this upper extremity extends upwardly through the bottom wall of the cylinder, thence through the piston, and out through the top wall of the cylinder. The usual seals are provided around this rod where the same passes through the end walls of the cylinder. Summarizing the construction, the ram constitutes a fluid-operated device with one end (its cylinder end) anchored in the assembly, and an opposite, extensible end (the lower part of rod 36), joined to the valve-closure means or plate 32.

Piston 56 divides the inside of cylinder 52 into two chambers defined by the cylinder on opposite sides of the piston, shown at 52a and 52b in FIG. 2. Communicating with chamber 52b adjacent the base of the cylinder is the interior of a conduit 58 provided for supplying fluid under pressure, more specifically air, to this bottom chamber. Communicating with chamber 52a adjacent the top of the cylinder is the interior of a conduit 60 provided for supplying air under pressure to the top of the cylinder. Ordinarily, fluid at a somewhat higher pressure is supplied chamber 52a than that supplied chamber 521). As a consequence, and since the opposite faces of piston 56 have similar areas, a constant biasing force is exerted downwardly on the valve plate by the ram assembly.

In using the apparatus described for the purpose of raising a submerged vessel, a supply of air under pressure is necessary for the purpose of displacing water from the hull of the vessel. Further, a source of air at constant pressure is needed for supplying air to bottom chamber 52b, and still another source of air at a somewhat higher pressure is needed for supplying air to chamber 52a. In FIG. 1, a salvaging vessel 62 is illustrated schematically, carrying both a compressor 64 for supplying the air under pressure required for water displacement purposes, and air pressure sources 66, 68 which together comprise a supply means for the supply of air at constant pressures to chamber 52a, 5212 described.

Describing now how the apparatus may be employed to raise a submerged vessel, a diver may first of all proceed to the submerged hull and mount the pop-oil valve mechanism on the deck of the hull, over a suitably prepared aperture in this deck. Thus, in FIGS. 1 and 2, aperture 70 is illustrated, such as may be prepared by the diver, and valve mechanism 20 is mounted over this aperture, with the interior of skirt 22 communicating with the aperture, by fastening flange 2 against the top of the deck. To seal properly the flange to the deck a gasket 74 may be included.

The hull of the vessel is further prepared for raising by mounting a pipe in the hull, such as the one shown at 76, which may extend through the deck, and the one which provides a path through which water flows on being forced out from the hull. Sources 66, 68 are connected to conduits 60, 58 supplying the two chambers in the ram assembly. A conduit 78 is extended from the cornpressor to the hull, by which air may be introduced into the hull, and if desired a gauge line 82 connected to a gauge 80 may be inst-alled'to enable the operator of the salvaging apparatus to note exactly the pressure conditions within the hull.

With the apparatus installed, air under pressure is forced under the deck through conduit 78, with such air then displacing water to produce what is referred to herein as a bubble, shown at 84. A bubble of sufficient size is produced as to render the hull, together with any residual water within the hull, slightly buoyant. The pressure of air required to produce such a bubble size of course will depend upon the depth at which the vessel resides. Since one foot of water is approximately equivalent to 0.433 pound per square inch pressure, after the appropriate air bubble has formed and at the start of the salvaging operation, adjacent the top of the deck the difference in pressure between the air inside the vessel and the water outside, in pounds per square inch, will be 0.433 times the height in feet of the air bubble produced. As the vessel rises, this difference in pressure should be iaintained to assure the proper buoyancy and to prevent an excessive pressure difference from developing. With a continual decrease in the water pressure surrounding the vessel occurring as the vessel rises, there is a continual decrease in the pressure of the air required to produce such a pressure differential. Pop-off valve mechanism 20 functions to maintain the pressure differential at a substantially constant level.

Considering further the pop-off valve mechanism, initially the pressure of air in chamber 521) at the base of the cylinder is adjusted so as to be somewhat greater than the water perssure surrounding the valve mechanism. This is to inhibit leakage of water into the cylinder past the piston rod and bottom end wall of the cylinder. The pressure of air within upper chamber 52a is adjusted to be greater than the pressure of air within chamber 52b, and the extent to which the pressure in the upper chamber is greater than the pressure in the lower chamber depends on the pressure differential desired between the inside and outside of the hull. Adjustment of the pressure within chambers 52a, 52b is done by suitable adjustment of adjustable air pressure regulators or means shown diagrammatically in FIG. 1 at 67 and 69. Once pressure adjustments have been made, the difference in the pressure of air within chambers 52a and 52b may remain constant throughout the salvage operation. The pressure difference is not affected by a change in the depth of the vessel, and as a consequence, a substantially constant biasing force is exerted downwardly on the valve plate throughout the salvaging operation. With such a constant biasing force, the pressure differential between the inside and the outside of the hull remains essentially the same and the desired buoyancy without excessive pressure build-up within the hull is achieved.

It will be noted that the pop-off valve mechanism is readily installed on a sunken vessel. Relatively little installation work must be done by a diver.

Sources 66, 68 and regulators 67, 69 in effect constitute means remote from the biasing means or rams 50 for energizing this ram, whereby it is made operable to exert a biasing force on closure means or plate 32. The biasing force exerted by the ram in the valve mechanism is readily adjusted, and is controllable remotely, if need be, by suitable adjustment of regulators 67, 69.

While an embodiment of the invention has been described in detail, it is obvious that various changes and modifications are possible without departing from the invention. It is intended to cover all variations of the invention as would be apparent to one skilled in the art, and which come within the scope of the appended claims.

:It is claimed and desired to secure by Letters Patent:

1. In apparatus for raising a substantially closed container submerged in water including means for introducing air under pressure into the container, means for controlling the pressure of such air relative to the pressure of the water outside of said container comprising a passage adjacent the top of said container through which air in said container may escape into the water,

valve-closure means adapted to open and close off said passage,

biasing means operatively connected to said valveclosure means for exerting a biasing force operable to urge the closure means to a posit-ion closing off said passage, and

means remote from said biasing means for energizing said biasing means whereby it is made operable to exert a biasing force on said valve-closure means,

said biasing means comprising a fluid-operated device with opposite ends that are displaced relative to each other on fluid under pressure being admitted thereto, said device having one end anchored to the container and an opposite end operatively connected to the valve-closure means, and conduit means connected to said device for introducing fluid under pressure thereto.

2. The apparatus of claim ,1, wherein said fluid-operated device comprises a fluid-operated ram including a piston and means defining a pair of fluid chambers on opposite sides of said piston, and said conduit means comprising a conduit for each chamber operatively connected to .the chamber for introducing fluid under pressure thereinto, and said ram is operable to exert a biasing force on said valve-closure means when the pressure of fluid introduced into one of said chambers is greater than the pressure of fluid introduced into the other of said chambers.

3. The apparatus of claim 2, wherein the conduit for each chamber connects the chamber to a source of fluid under pressure, and the two sources for said pair of chambers supply fluid at different pressures.

4. The apparatus of claim 1, wherein the biasing means comprises a doubleacting ram including a cylinder, a piston inside the cylinder, and a piston rod connected to said piston, the valve-closure means is connected to the piston through said piston rod, and said piston rod extends out through opposite ends of the cylinder.

5. The apparatus of claim 1, wherein said valveclosure means comprises a member having one face eX- posed to air under pressure in said container and another opposite face exposed to the water outside of said container, and which further comprises an anchor bracket secured to the container, said fluid-operated device being interposed between said anchor bracket and said opposite face of said valve-closure means.

6. The apparatus of claim 2, wherein said means for energizing said biasing means comprises supply means for supplying fluid under pressure to said conduits, said supply means including adjustable means associated with each conduit for adjusting the pressure of fluid in such conduit and the chamber to which the conduit connects.

7. The apparatus of claim 1, wherein said biasing means comprises a ram including a cylinder, a piston mounted within the cylinder, and a piston rod connected to the piston, said piston rod is connected to said va1veclosure means in such manner that extension of the ram operates to urge the closure means to a position closing oif said passage, and which further comprises a bracket joined to the container fastened to the cylinder of said ram and anchoring it in a stationary position.

References Cited UNITED STATES PATENTS 2,3 63,488 11/1944 Bartlett 114-50 2,635,574 4/ 1953 S tu'rtevant 11-4-54 3,339,5'13 9/1967 Cloutier 114-50 ANDREW H. FARR'ELL, Primary Examiner.

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