US2622552A - Ship salvage device - Google Patents

Description

Dec. 23, 1952 'r. K. JAMISON SHIP SALVAGE DEVICE 7 Sheets-Sheet 1 Filed June 21, 1948 INVENTOR. TRUMAN K. JAM/SON ATTORNEYS Dec. 23,v 1952 'r. K. JAMISON SHIP SALVAGE DEVICE 7 Sheets-Sheet 2 Filed June 21, 1948 ATTORNEYS m M w m TRUMAN K JAMlsoN Dec. 23, 1952 T. K. JAMISON SHIP SALVAGE DEVICE 7 Sheets-Sheet 3 Filed June 21, 1948 JNVENTOR. TRUMAN K JAM/so/v ATTORNEYS Dec. 23; 1952 1'. K. JAMISON SHIP SALVAGE DEVICE '7 Sheets-Sheet 4 Filed June 21, 1948 m w H H 3 0 md M M um H./% l um J m n. u 2 W I m M hm j H P ,7.

ATTORNEYS Dec. 23, 1952 a: K. JAMISON 2,622,552

SHIP SALVAGE DEVICE Filed June 31, 19 48 7 Sheets-Sheet 5 INVENTOR. TRUMAN K. JAM/SON BY J- z ATTORNEYS Dec. 23, 1 952 T. K. JAMISON SHIP SALVAGE DEVICE Filed June 21, 1948 7 Sheets-Sheet 6 fNVENTOR. TRUMAN JAM/SON ATTORNEYS Patented Dec. 23,1952

UNITED STATES PATENT OFFICE SHIP SALVAGE DEVICE Truman K. Jamison, Seattle, Wash.

Application June 21, 1948, Serial No. 34,272

This invention relates to ship salvage vessels, and particularly to the hoisting mechanism used in connection therewith to raise sunken ships for salvage or repair purposes.

The hoisting mechanism of my present invention is used preferably in connection with the general type of salvage vessel which may be termed a pontoon dock, and is so described illustratively herein.

One of the primary purposes of my present invention is to provide hoisting means more readily and rapidly operated, and housed more nearly in its entirety within the confines of the pontoon dock. Accordingly, only the necessary lift cables, cable guides and thelike, which project into the sheltered encirclement of the dock, extend laterally beyond the pontoon fioats of my device. For certain types of salvaging operations the excellent mobility of the vessel when devoid of exterior lateral projections, and the convenience of all its operating equipment being located inboard,

is decidedly advantageous. Also, all the actuating mechanism for driving the lift cables is contained in the pontoon structure.

Raising sunken ships under any conditions presents a complex engineering problem with many aspects. Ships are likely to be found lying at almost any attitude upon the ocean bottoms. Consequently, as a first step it is necessary to right them before or during raising operations and to maintain them level as they are raised into the harbor of the pontoon dock for salvage and repair operations. Multiple independently controllable cable hoisting units, connected to the sunken vessel at different locations along opposite sides of its hull line, are therefore a practical necessity in carrying out the initial phases of the raising operations. Moreover, after the sunken vessel has been righted by controlled operation of the individual hoisting units and is ready for lifting bodily to the surface, it is desirable to coordinate operation of the individual hoisting units, as an integrated system to continue holding the vessel on an even keel as it rises. If allowed to tilt longitudinally or to heel over appreciably cargoes may shift, and strains on the hoisting units will become unbalanced.

Perhaps the most difficult aspect of the problem is the provision of powerful hoisting equipment which requires only comparatively simple and low powered operating equipment, and which is sufiiciently compact to be housed in the hull of the salvage vessel. A particular object of my present invention is to devise hoisting mechanism based generally upon the counterweight princi- 9 Claims. (Cl. 114-51) ple, in which the several member-hoisting units may be conditioned for hoisting action by expenditure of even smaller amounts of power than before, yet such concerted hoisting action produces the desired tremendous lifting force required to raise the vessel.

Such an object is attained generally by means of counterweight fluid tanks providing the lifting power of the individual hoisting units. The tanks are raised into elevated position While lightened by relieving them of their water load; are refilled with water, or perhaps other fluids; when all tanks are elevated and filled, are released together for descending in unison to hoist the vessel a prescribed incremental distance. In descended position the tanks are again drained to lighten them for subsequent elevating. During the periods between intermittent hoisting operations, occupied by draining, elevating and refilling the tanks, the sunken vessel is held in its successive incrementally raised positions by lift holding mechanism cooperating with the hoist. Although all of the counterweight hoisting tanks operate in concert for hoisting, they may be elevated and refilled in smaller groups independently, one or more at a time, thereby further minimizing the power and power equipment utilized for these purposes.

A further and related object of my present invention is to devise hoisting mechanism of the counterweight type, the cooperating units of which have coordinated check points at equal lifting intervals of each hoisting unit, and in the operation of raising a vessel, all of the units will reach a particular check point before any of the units lifts to its next succeeding check point. By this means the raised vessel is brought to a level position at the end of each incremental hoisting interval and cannot get far out of level at any time even if other controls over lifting do not coordinate properly through some contingency or failure. The intermittently acting hoisting tanks achieve this object, as will be described.

Further objects of the invention are attained in control mechanism, primarily hydraulic, operable to initiate descent of the tanks together, to retard their downward movement to prevent excessive accelerations, and generally to coordinate the downward movement of such tanks.

Such coordinating means comprises a plurality of hydraulic cylinder and piston units which check the descent of individual hoisting tanks by controlled evacuation of hydraulic fluid from the cylinders.

Since it is this source of restraint on downward movement of the tanks which primarily determines rate of descent of the tanks, any circumstantial difierences in loading of the individual hoisting units by the sunken vessel, tending to cause one tank to descend more rapidly than another, will be largely overcome. Further coordination results from evacuating the tanks against a common pressure head, as described.

Further features of the invention, in the coordinating and control mechanism, reside in the means for implementing the method of refilling the hydraulic cylinders in connection with levating the hoisting tanks, in closing off the refilled cylinders of individual groups of tanks until the tanks of combined groups have all been filled and readied for hoisting operation, and thereupon transferring cylinder closing control to means operable to effect opening of th cylinders of the combined groups simultaneously.

These and other features, objects, and advantages of the invention will be further apparent from the following description based upon the accompanying drawing.

Figure l is a diagrammatic plan view of a preferred type of pontoon dock to incorporate the present hoisting mechanism.

Figure 2 is a simplified transverse sectional view of the dock, showing a sunken vessel raised by the hoisting mechanism into working position within its harbor.

Figure 3 is a fragmentary isometric view of the upper hull side and adjoining deck plate of the sunken vessel showing preferred means forming a connection to the lift cable of a hoisting unit.

Figure 4 is a sectional elevation view illustrating major elements of a hoisting unit, showing a hoisting tank, hydraulic cylinder and piston means coacting with the tank structure, and a drainage tank arranged beneath the hoisting tank to receive water emptied from the hoisting tank in its descended position.

Figure 5 is a diagrammatic elevation view of a group of hoisting tanks and cooperable drainage tanks, showing a pumping system for refilling the hoisting tanks.

Figure 6 is a diagrammatic isometric view of a representative section or fractional part of the composite system of control valves and piping for the hydraulic mechanism coordinating and controlling descent of the hoisting tanks, the View showing the separately controlled groups of primary or holding valves and the coordinately controlled groups of secondary or final release valves associated with two hoisting units.

Figur '7 is a plan view of typical control mechanism for the group of primary valves closing the hydraulic control cylinders of a single hoisting unit; and Figure 8 is an elevation view of one of these valves so controlled.

Figure 9 is an end elevation view of one of the final release valves for the respective hydraulic cylinders.

Figure 10 is a simplified side view of the pr ferred type of master actuating control for the conjointly operated final release valves, shown in simplified form connected operatively to one of such valves.

Figure 11 is an isometric view, with parts broken away, of one of the counterweight or hoisting tanks.

Figure 12 is a plan view of a hoisting or liftholding mechanism for one of the lift cables, showing drum drive pulleys rotated by cabl con.

lustrating the ratchet mechanism operable to hold the cable drum in successive incrementally rotated positions following each incremental hoisting operation.

Figure 15 is a fragmentary plan view of one side or section of the illustrative parallel-section pontoon dock, supporting and housing on of the hoisting units, illustrating the preferred arrangement for guiding the lift cable and winding it upon the drum.

As diagrammed in Figure 1 the illustrated pontoon dock 20 has two spaced generally parallel sides or pontoon sections 22, corresponding ends of which are permanently bridged across by a prow section 24, and the opposite ends of which are interconnected by a removable stern section 26, defining an nclosed haroor 23. The sunken vessel 3t will then be raised by hoisting means mounted on the pontoon dock into the harbor 23 for salvage or repair operations. In order to accomplish the raising operation, each of the pontoon sections 22 incorporates a plurality of hoisting units 32 arranged at intervals along its length. Parallel dotted lines as in the figure, leading from the units 32 to the respective sides of the vessel 39, represent the lift cables.

In accordanc with this invention as herein described, the individual hoisting units, capable of coordinated vessel hoisting action, are housed within the pontoon sections, can be operated by power mechanism of comparatively small capacity and are rugged in construction and dependable and positive in operation. Moreover, by virtue of their intermittent incremental, or check-point, action these hoisting units keep the sunken vessel under control at all times and lessen danger of mishaps.

In the cross-section shown in Figure 2, a counterweight hoisting tank 35 appears in its relation to the surrounding structure in each of the opposite pontoon sections 22, wherein such tanks are guided for elevation and descent in effecting the described hoisting action drawing in lift cables 34. In this figure the sunken vessel 3?] is shown in fully raised position, its deck slightly above the waters surface 38, and ready to be worked upon within the shelter of the docks harbor 28.

In the illustrated construction of the pontoon clock, the two opposite pontoon sections 22 are braced and rigidly held apart laterally by the crossed diagonal braces 49, anchored at their respective ends to the opposite sections, as shown, leaving ample working space beneath the braces 40 to work on the raised vessel. The pontoon sections are of the typical watertight compartmented construction. Bilge compartments 42 are formed at the bottom and successive tiers of watertight compartments 44 up the inboard sides of the docks pontoon sections adjacent to the harbon 28, as shown. The remaining general space 46 within the pontoon sections, between the inner vertical walls of the compartment tiers 44 and the outboard walls of the pontoon sections, is reserved generally for the hoisting tank and associated apparatus to be described. For all practical purposes the two pontoon sections may be substantially identical in their general construction.

In Figure 3 I have illustrated a convenient and reliable method of connecting the lift cables 34 to the sunken vessel. This is accomplished by burning spaced holes 21 through the deck plate 29, spaced fore and aft, near the side of the vessel 30, and corresponding holes 3| in the sides of the vessel. Through the holes 3| will be inserted the apertured couplers 33 attached to the ends of short connector cables 35, and through each of the coupler apertures is passed a crossbar 31 which bears against the inside of the vessels hull to prevent withdrawal of the couplers 33 by tension on the connector cables 35. All of the cables 35 are then connected to a ring 3'! carried at the lower end of a lift cable 34. Such a connection distributes the lifting force exerted on the vessel 30 more safely and reliably, over a wider area than if a single point of connection were used.

Lift cables 34 of each hoisting unit carrying the raised vessel 30 enwrap the drum of the respective hoisting or lift-holding mechanisms 48 mounted near the top of the general pontoon compartments 46. These cables extend from the lift-holding mechanism 48 to the ship 30 through the inwardly and downwardly curved cable races 50 opening into the harbor 28, to the stand-off guide sheaves 52. brackets 54 projected a distance into the harbor space 28 to support the raised vessel 36 with its hull sides spaced a working distance away from the inboard sides of the pontoon sections. In

this same connection the sheaves 52 should not be excessively high above the water line of the dock or the point of connection of the lift cables 34 to the vessel 30, because an excessive unguided length of lift cable may give rise to a tendency for the vessel 30 to swing too far laterally for safety or convenience when the dock rolls in heavy swells.

As illustrated, the curved cable races comprise a series of guide sheaves 56 journaled at interval locations between curved support members 58 extending between the outside and inside walls of a pontoon section. The hoisting or liftholding mechanism 48 is likewise carried by the support members 58, at a location 66 appropriate to the position of the respective hoisting tanks 36 in the hold space 46. As seen best in Figures 2 and 15, each cable race is located in a passageway 62, with a flight of steps 64 at either or both sides of the race to allow access for installation, inspection and repairs of the mechanism, and for convenient access to the harbor through the pontoon sections.

In cases where it is desired to relieve the lift cables 34 of their load after having raised the vessel to an appropriate position within the harbar 26, the load may be transferred to auxiliary hold cables 66 operating out of appropriate auxiliary winch mechanism 68 (Figure 2) within the pontoon sections. The hold cables 66 may be guided over grooves in the guide sheaves 52 parallel to the lift cables 34, or by other sets of similar guide sheaves at locations intermediate to the sheaves 52.

The lift-holding mechanisms 48 operate as mechanical advantage elements in the hoisting system, in a manner to be described subsequently. These mechanisms are preferably of the ratchet type, operable to haul in the lift cables 34 by rotation of the drum drive sheaves l0 and to hold the drums against paying out the lift cables un- The sheaves 52 are carried by less deliberately released for that purpose, at times between raising ships. The drive sheaves 10 are enwrapped by drive cables '12 suspending the respective counterweight hoisting tanks 36. Descent of the tanks 36 guided between the sets of vertical guides 14, from their raised position shown in Figure 2 to a predetermined lower descended position, causes a corresponding hauling in of lift cables 34 to raise the sunken vessel by an incremental amount, as determined by the dropping distance of the hoisting tanks and the drive ratio of the lift-holding mechanism. At the end of the down stroke of the hoisting tanks 36 the ratchet mechanisms in the lift-holding mechanisms 43 cooperate to hold the incrementally raised vessel 30 until such time as the hoisting tanks can again be raised to elevated position for a succeeding incremental hoisting operation.

Before raising a hoisting tank into elevated position it is preferably first lightened by draining its water load from it, as by means of a pipe 15 and control valve 78, into a lower receiving compartment or tank 80. Elevating of the individual tanks is effected conveniently by winches 82 mounted above the hoisting or lift-holding mechanisms 48, as indicated (Figure 2). Alternatively, the drive sheaves l6 themselves could be rotated reversely, if decoupled from the lift cable drums 39, to elevate the respective tanks 36.

Within the range of working loads on a salvage dock constructed according to the invention, moderate variations in height of the dock water line for different weights raised should not alter the functioning of the hoisting mechanism nor the convenience or economy of operating the auxiliary equipment. Reference is made, in particular, to the possibility in some instances that the water line may actually come above the level of the bottoms of the hoisting tanks 36 in descended position, and since the tanks are drained more conveniently by gravity flow than by pumping, this difference in levels might be objectionable were it not for the use of separate drainage tanks within the pontoon structure proper. Drainage of the hoisting tanks 35 into the storage tanks 33 instead of into the sea removes all dependency of the gravity-flow draining operation upon water level outside the pontoon hull, as desired. Then, too, by draining into the tanks 66, and reusing from these tanks, the total weight of the salvage vessel is kept more or less constant during hoisting operations so that its draft is correspondingly constant.

It will be understood that the valves 18 draining the tanks 36 may be operated either manually or by automatic control means, either separately or conjointly, since no special problem of coordination of this particular operation between the various tanks is necessary. Similarly, the ele vating winches 82 may be operated individually or in groups.

Figure 5 illustrates diagrammatically in side elevation a system for draining and refilling a group of five hoisting units, this number being selected arbitrarily for illustration. The diagram shows the drain pipes 16 carried by the counterweight tanks 36, the drainage tanks 80 beneath the latter, and a pump 84 for returning water from the drainage tanks 36, through the collecting pipe 86, the return pipe 88, and the distribution pipes finally back into the indi vidual hoisting tanks 36 of the group. Other small groups of hoisting tanks in the pontoon dock may be connected in a similar water circulation system, each of which requires comparatively low power pumps. Any suitable type of controls for the draining and refilling operations may be employed.

The preferred type of hoisting or lift-holding mechanism and related mechanism is illustrated in detail in Figures 12, 13 and 14. A plan view of the lift-holding mechanism 48 to a smaller scale appears in Figure 15, wherein the general plan of a single hoisting unit is illustrated. As shown in Figure 13, the lift cable 34 carries a hook 90 at its free end by which the cable, wrapped around the drum 29, is secured to the drum by engaging the hook in one of several drum apertures 92. As seen in Figure 15, the apertures 92 are formed in the drum at circumferential intervals staggered-offset from one another to provide a selection of spaced connecting points, one of which will correspond very closely to the desired position of hook 90 as the lift cable is initially secured to the drum. This multiple aperture arrangement will usually be more convenient for securing the cable to the drum at a selected point around its periphery than by attempting to hoist with a drum having but a single aperture, to align such aperture with the hook 90. The drum 89 is indented or recessed next to each aperture at M to receive in depressed position the cable-connecting eye of the hook 913 so that the cable will wind on the drum more uniformly.

The end flanges of the drum as are bolted to the sides of concentric gears constituting power transmission elements in a double-ended drive for the drum. The drum and gear assembly rotate freely upon a main shaft 93, journaled at points intermediate their ends in side supporting plates 58, constituting inner branches of the curved supports 58 which carry the mechanism 48 and the cable race sheaves E5, as shown in Figures 2 and 15. The ends of the mounting shaft 98 are journaled in the outer branches 58" of the same supporting members 58, leaving intervening spaces for the drive sheaves I53 and other mechanism to be described.

A countershaft IGE! journaled in the plates 5- parallel to the main shaft 98, drives the idler gears I02 which it carries, meshing with the drum gears 96, as shown. On the outer sides of the plates 58 the projecting countershaft ends carry the respective idler gears I34, likewise connected to the countershaft V38. Registering with the gears IN, a further set of gears I06 is carried by the main shaft 93, driven by the two coacting drive sheaves It. Through this pair of corresponding gear trains rotation of the drive sheaves it caused by unwrapping drive action of drive cables 12 is converted into driven rotation of the drum 89 and hauling in of the lift cable 34. The mechanical advantage derived from use of the hoisting or lift-holding mechanism 48 depends upon the respective diameters of the drive sheaves, the gears and the drum.

It will frequently be necessary to wind up rapidly the lift cables on the drum without load. For this purpose, one end of the main shaft 98 carries a clutch plate I88 engageable by a cooperable clutch plate I46 driven by an auxiliary power transmission system. The clutch plate I I0, mounted for free rotation on the shaft 38 and for endwise movement thereon effected by swinging of the clutch actuating lever H2, is driven through an appropriate chain and sprocket drive H4 from a geared electric motor II-6 mounted on the adjacent support 58", as shown. Hence, slack in the lift cables 34 may be taken up rapidly by clutch-engaging movement of the clutch lever II2.

The coacting drive cables I2, suspending a tank 36, wrap around the respective winch drive sheaves 16 through the required angle to permit full descent of the tank without complete paying out of these cables. Each cable I2 has a connecting hook IE8 engageable with an apertured lug I26 of a plurality projecting inwardly from the opposite sheave rims I22 at short intervals around the peripheries of the sheaves. The series of lugs I29 at the opposite rims of a sheave are offset to provide an even closer circumferential spacing of the cable-connecting points. By such means, taking up the slack in the drive cable I2, which is hauled in by a winch and line or by way of various well known devices, and connecting it to its drive sheave each time a tank 36 is elevated from lowered position may be done simply, without special mechanism to disconnect the drive sheaves and drum of lift-holding mechanisms 43. While there may be slight discrepancies in the degree of tautnessof the drive cables of different hoisting units at the time when all units are poised for an incremental hoisting operation, these can never be appreciable because of the close spacing of the lugs IZEl around the periphery of the drive sheaves. Obviously, other arrangements could be made to tauten the drive cables under these conditions, either manually or by mechanical means.

Suitable ratchet mechanism operable to hold the drum 89 against rotation under load in one direction and to permit its free rotation in the opposite direction is illustrated particularly in Figure 14, complemented by the showing in Figure 12. Any mechanism employed for this purpose must be of the releasable type, which can be readily actuated to free the drum for paying out the lift cable as necessary. As shown best in Figure 14, the mechanism includes the arcuately arranged series of pawls i2 5 pivotally carried by the supporting plates 58 at the opposite ends of the drum 89 generally above the shaft 98. These ratchet pawls engage a circularly arranged series of ratchet lugs I26 projecting endwise of the drums end gears 96. The tendency of the pawls IE is to rock resiliently or by force of gravity into ratchet lug-engaging position of their arms i2 3, thereby preventing rotation of the drum in cable-releasing direction. The pivoted paw-ls are swung freely upward by the lugs the drum is rotated in reverse direction, taree on each side being provided.

Pawl release cams l'il, free t0 rock on shaft have lobes I 29 which engage the arms 53% of the respective sets of pawls lZ l. These arms are offset from the lug-engaging arms 28 axially of the pawl to clear the lugs when rotated. Rocking the release cams I29 in one direction forces the pawls out of holding en agement with the ratchet lugs I25 to permit free rotation of the drum lift-holding mechanism as desired. The cams are thus rocked by pulling on the draw links I32 connected respectively by pins Its to the cams, as shown in Figure l-i. Returning the cam to initial position locates the cam lobes offset from the pawl arms E32 in lowered position to permit reestablishing holding engagement of the ratchet lugs. Normally the release cams are not to be used, the lift-holding mechanism 43 locking automatically after succesive hoisting intervalsin progressive rotated positions of the drum, until the job of raising the sunken vessel is completed.

Turning now in the discussion from the hoisting or lift-holding mechanism 48 to the counterweight hoisting tank apparatus driving the winches, reference is made to Figures 4 and 11 in particular, which illustrate a preferred type of tank construction; The tanks are cubical in form and may be bolted, riveted or welded in construction. A pair of spaced lifting eyes I40 mounted at the top wall of the tank, shown best in Figure 11, provide anchor holds for the hooks I42 of the cooperable pair of drive cables 12, or corresponding cable hooks for the auxiliary, tankelevating winches 82, as shown in Figure 2. The flanges of lifting eyes I40 are welded or otherwise secured to the upper ends of tie rods I43 bolted at their lower ends to the bottom of the tank, both to support the tank bottom and to hold the lifting eyes fast to the tank top. The tie rods diverge downward from the lifting eyes I40 to distribute the reinforcing support over the tank bottom in the desired manner.

A manhole opening I44 permits access to the tank for initial construction and repair work within it, and affords a convenient opening through which to refill the tank with water at the times described. As shown in Figure 4, the four corners of the tank slidably engage in the right-angle corners of the angle iron guides 14 to guide the tanks for vertical reciprocation. Suitable lubricant or bearing antifriction means may be employed between these guides and the tank outer walls to lessen friction.

In addition to the tie rods I43, further reinforcing of the tank bottoms and tops is derived from the end-opening vertical tube I46 interconnecting them, as shown in Figures 4 and 11. Five of these tubes are shown in the illustrated case, four near the respective corners of the tank and one at the center. Through these tubes are passed the piston rods I48 of hydraulic cylinder and piston units which cooperate to retard the descent of the tanks in the manner described.

As shown in Figure 4, each of the piston rods its projects upwardly through a tube I 46 for connection at the top of the tank to the flanges I50, locking pins I52 being passed through flanges and rods to prevent displacement of the tank axially of the piston rods I43. These rods project vertically downward out of the encircling tubes W and through the bottom of the tank 35 into hydraulic cylinders I54 for connection to the coacting hydraulic pistons I516. The five cylinders I54 have flanges at top and bottom which are bolted to the top and bottom plates of the drain age tank 80 of a hoisting unit. This reinforces the drainage tank and at the same time maintains the hydraulic cylindersin vertical, pistonguiding position. The hydraulic cylinders are filled and evacuated from their lower .ends through pipes I 60. As shown in Figure 2, the pipes I60 lead to a hydraulic pumping unit I62 and associated fluid supply reservoir I64.

By filling the hydraulic cylinders of one hoisting unit at a time, instead of filling the cylinders of all such units simultaneously, a single lowpower pump unit I 62 may be used instead of one large pump or a number of smaller ones, thereby effecting further power savings. To minimize the possibility of airlocks in the hydraulic cylinders during the process of elevating the hoisting tank of that unit by a winch 82, the pump will normally be turned on to keep the expanding cylinder spaces constantly filled with fluid. In addition to serving as retarding devices, the cylinder and piston units could operate as hydraulic jacks to elevate the hoisting tanks as desired. In that event, the hydraulic fluid pump I62 selected would be of suihcient capacity to provide the requisite force hydraulically through the piston and cylinder units to elevate the hoisting tanks without the aid of auxiliary winches 32.

According to the preferred system of controlling the harnessed descents of the tanks, I provide two sets of control valves, one of each type, in the individual fluid cylinder supply pipes I60. These valves are used to close off such cylinders at selected times and to regulate evacuation of the cylinders at other times. As shown in Figure 6, the primary or holding valves I65 in the respective cylinder supply and evacuation pipes I60 of a hoisting unit are interconnected by valve actuating mechanism in the form of a chain I68 and valve-operating sprockets I10 (Figure 7). These valves, I66, may be of the globe type, in which the valve stem is rotated to open and close the valve ports.

As shown in Figure 6, the valve actuating chain is deflected serpentine fashion by the idler sprockets I12 which maintain engagement of the chain with the valve actuating sprockets I10. The chain is rotated or moved by a drive sprocket I18 turned by a control handle I30, which may be either mechanically or manually operated. After the'hoisting tank of a particular unit has been elevated and the hydraulic cylinders refilled with hydraulic fluid, the handle I will be turned until the globe valves I66 are closed, thereby preventing hydraulic fluid from draining from the cylinders.

As previously explained, time may be saved by conditioning thehoisting units in time-overlapping sequence, thereby making most efficient use of the hydraulic pump and other power equipment used in filling the tanks 36 and the hydraulic cylinders. In some cases it may be preferred to handle the elevating of two or more hoisting tanks together, and simultaneously refilling their hydraulic cylinders, in which event it will be evident that the valve control mechanism, including the chain I68 and drive sprocket I18, may be extended to control the associated primary valves I66 of such tanks.

After all of the hoisting units of one pontoon section have been prepared for hoisting operations, their respective hydraulic control valves I66 may be opened to transfer the control to the secondary or quick-release valve I82 likewise located in pipes I60. At this time the entire weight of the hoisting tanks, freed of the auxiliary winch connections, is preferably carried by the hydraulic cylinder and piston units, and thereby the quickrelease valves I82. All of these valves of a pontoon section are interconnected for conjoint operation by single control means, such as a control cable. I 84 extending along the series of valves I82 in the difierent pipes I60 for connection to the valve-actuating levers I86. As illustrated the valve levers are pivoted between their ends on fixed supporting arms I38 (Figure 9). A cableconnector sleeve I90 has a set screw I92 which provides the necessary adjustable drive connection between the cable and the lever I to cause a valve to operate with the others. The end portion of the lever or. the side of its pivot away from the cable is slotted to receive a pin I94 projecting laterally from the valve stem I96, the valve being actuated rapidly by endwise reciprocation of the valve stem in well-known manner. A

holding spring I98 holds the valve I82 normally closed.

The control cable I34 is guided for travel on a guide sheave 266. In the illustrated case of Figure 6, the valve levers are connected to the upperstretch of the cable, which extends between the guide sheave 260 and cable actuating mechanism 262 (Figure The end of the upper stretch of cable is connected to a steam-operated cylinder and piston unit 264, operable to draw the upper stretch of cable I84 to open the valves I82. A similar steam-operated unit 206 operable to draw the lower stretch of cable I84 applies a valve closing force to levers I86 to aid the springs I96 in maintaining closure of the quick-acting valves I82 against the tremendous hydraulic force acting upon them with the hoisting tanks poised for descent. A steam supply pipe 268, input valves 2m and exhaust valves 2I2 control selective operation' of the units 264 and 265 respectively. Each pontoon section has a similar valve control arrangement.

Actuation of the corresponding units 204 opens the valves I82 of all of the hydraulic units in one pontoon section conjointly, initiating descent of the hoisting tanks simultaneously. Coordination of the hoisting units in the two pontoon sections may be obtained readily either manually, with the use of clocks for timing operations in the opposite pontoon sections, or by simple electric controls or other synchronizing means operating the corresponding actuating units 204. In this way, both sides of the sunken vessel 36 may be raised together during each hoisting increment.

A catch mechanism 2I4, shown in Figure 10,

with inwardly directed spring-actuated latch fingers 2| 6 engaged by the enlarged head 2I8 of the cable-connected piston rod of unit 204, holds such rod, and thereby holds open the quickacting valves I82, until the fingers 2I6 are withdrawn manually or otherwise from holding engagement with the rods end. At the same time that the units 264 are actuated to open the valves I82, steam pressure operating the units 206 will be turned off to release the valves for such operation. The normal position of the valves I82 is open, since these are used primarily in carrying the load of the hoisting tanks hydraulically during the last interval before final release of the tanks in each hoisting operation.

As the hoisting tanks descend, hydraulic fluid is forced back into the respective reservoirs I64 common to the diiierent groups of tanks, thereby providing a common pressure head against which the hydraulic pistons work in unison in expelling fluid from the hydraulic cylinders through the then open valves I66 and I82. The opening of the valves I66 may be adjusted to regulate the rate of discharge of hydraulic fluid from the individual hoisting unit cylinders through the pipes I66, and thereby the rate of descent of any or all of the hoisting tanks. This adjustment may be made in accordance with the weight of the particular sunken vessel being raised at any time, or, if desired, to effectively equalize tank descent rates if unbalanced as a result of excessive unbalance in loads.

After all of the tanks in the pontoon sections have descended fully, all hydraulic control valves will again be reopened to condition the hoisting units for a succeeding lifting cycle of operation.

The sequence of operations involved in carrying out a complete lifting cycle of the mechanism is as follows. Initially the hoisting tanks 36, filled with water, are held poised in elevated position (Figure 2) by the hydraulic piston rods I48 (Figure 4), valves I66 and I82 being closed to prevent evacuation of cylinders I56. The individual hoisting cables 34 wound on the ratchetlocked drums of the respective lift-holding mechanisms 48 (Figure 12) are under tension created by the weight of the sunken vessel 30 assumed to be partly raised from the ocean bottom. The primary valves I66 (Figure 6) are now opened, followed at the desired instant by opening of all of the quick-release valves I82, which is effected by the control mechanism (Figures 8 and 9) including the control cable I84. This permits evacuation of hydraulic cylinders I54 through pipes I60 under pressure created by pistons I56, and allows the hoisting tanks 36 to descend in their guides. The drive cables 12 are thereby drawn from the drive sheaves III to rotate the lift-holding mechanism drums 89 and wind in a predetermined incremental length of hoist cables 34, which raises the sunken vessel 30 by a corresponding increment. When the hoisting tanks 36 reach the bottom of their descent they are emptied of water through pipes I6 and, thus lightened, are re-elevated by winches 82 (Figure 2) either independently or as aided by pumps I62 simultaneously operated to fill hydraulic cylinders I54. In the meantime the vessel 30 is held in its incrementally raised position by drum ratchets I24 (Figure 14). When the hoisting tanks are re-elevatecl, the valves I66 and I82 are again closed and the tanks refilled with water by pumps 84 preparatory to a succeeding incremental hoisting operation, which is repeated as many times as necessary to raise the vessel 30 the full distance to the waters surface.

I claim as my invention:

1. Lift-holding means for drawing in by increments a lift cable, and raising a load carried thereby, said means comprising a lift cable drum, a drive sheave, reduction gearing interconnecting said lift cable drum and said drive sheave to effect driving rotation of said drum by rotation of said sheave, at a mechanical advantage, a drive cable, said drive sheave having a peripheral groove therein to receive said drive cable wrapped therearound, and further having at least one cable-end securement means at a selected point on its periphery, and ratchet means normally operable to stop rotation of said lift cable drum in an unwinding direction, but releasable at will to pay out lift cable from such drum, weight means comprising a liquid container, which can be drained and refilled, for securement to the free end of said drive cable wrapped around said drive sheave, whereby unwinding of such drive cable by descent of said weight means rotates said sheave and thereby effects incremental enwrapment of the lift cable upon said drum to raise said load thereby, and hoisting means operable to elevate said weight means independent of rotation of said lift cable drum for a succeeding incremental lifting operation by repeated unwinding of the drive cable from said drive sheave.

2. A ship salvage device comprising a pontoon dock, and hoisting means operable to raise sunken vessels to said dock, said hoisting means comprising a plurality of lift cables for securement to a sunken vessel, individual lift cable haul-in mechanisms cooperating individually with the respective lift cables and located at spaced intervals along a side of said dock, said mechanisms having releasable holding devices normally operable to hold the lift cables against 13 paying out but permitting operation of said mechanisms to haul in such cables, and means 'for driving said haul-in mechanisms to raise the sunken vessel connected to the lift cables, said drive means comprising a plurality of counterweight liquid tanks each associated with a different haul-in mechanism, means guiding said tanks individually for direct elevation and descent movement between lowered and elevated positions in said pontoon dock, said tanks being adapted for filling with liquid to increase their weight when in elevated position, and for draining when in lowered position, and means forming a drive connection between individual hoisting tanks and the respective haul-in mechanisms for driving operation of the latter during descent of said liquid tanks, thereby to raise the sunken vessel by an increment, means operable to hold said tanks in elevated position, means actuating said means holding the liquid tanks in elevated position, to release the same and permit simultaneous descent of said tanks by gravity to effect said incremental hoisting operation, and means operable to elevate said tanks for a succeeding incremental hoisting operation.

3. The ship salvage device defined in claim 2, wherein the pontoon dock has laterally spaced pontoon side sections defining a harbor therebetween for receiving raised sunken vessels, a bow pontoon section interconnecting the forward ends of said side pontoon sections and closing the forward end of said harbor, and a removable stern pontoon section interconnecting the aft ends of said side pontoon sections and closing the aft end of said harbor, the cooperating re spective lift cables, haul-in mechanisms and associated drive means being arranged at intervals along opposite sides of the pontoon dock for paying out lift cable into and downward through said harbor along opposite inner sides thereof.

4. The ship salvage device defined in claim 3, and liquid storage means within the pontoon dock for supplying weight liquid to the counterweight liquid tanks and for receiving such liquid drained from said tanks, thereby to maintain substantially constant floating level of said dock during filling and draining of the counterweight liquid tanks preparatory to descent and elevational movements, respectively, thereof, and means operable to fill and drain said counterweight tanks from and into said storage means, in elevated and descended position of the tanks, respectively.

5. A ship salvage device comprising a pontoon dock having opposite side sections spaced apart to define a harbor therebetween, a counterweight liquid tank in each side section, means in each side section guiding the corresponding liquid tank for elevation and descent therein, lift cables for connection to a sunken vessel or other object to be raised to the dock, means for connecting said lift cables to the respective counterweight liquid tanks in elevated position of said tanks, liquid storage means in said dock for storing liquid for filling said counterweight tanks in elevated position thereof, pump means operable to transfer liquid from said storage means to said counterweight tanks to increase the weight of said tanks for hauling in the lift cables by descent of said tanks, means for draining said tanks into said storage means when said tanks are in descended position, and means operable to elevate said counterweight tanks thus drained 14 of weight liquid for a succeeding incremental hoisting operation.

6. The ship salvage device defined in claim 5, wherein the means interconnecting the lift cable and the counterweight liquid tank comprises a lift cable drum for reeling in lift cable by driven rotation of said drum, a drive sheave rotatively connected to said drum, a drive cable connected at one end to the counterweight liquid tank and at its opposite end to a point on the periphery of the drive sheave, the portion of said drive cable adjoining said latter end thereof wrapping around the drive sheave to take up slack in such drive cable, descent of the counterweight tank causing rotation of the drive sheave by unwrapping of the drive cable thereon, hence driving rotation of the lift cable drum to raise the sunken vessel by an incremental amount, and holding means operable to prevent counterrotation of the lift cable drum after each incremental hoisting operation eifected by descent of the counterweight tank.

7. A ship salvage device comprising a pontoon dock, and hoisting means operable to raise sunken vessels to said dock, said hoisting means comprising a plurality of lift cables for securement to a sunken vessel, individual lift cable haul-in mechanisms cooperating individually with the respective lift cables and located at spaced intervals along a side of said dock, said mechanisms having releasable holding devices normally operable to hold the lift cables against paying out but permitting operation of said mechanisms to haul in such cables, and means for driving said haul-in mechanisms to raise the sunken vessel connected to the lift cables, said drive means comprising a plurality of counterweights each associated with a different haul-in mechanism, means guiding said counterweights individually for direct elevation and descent movement in said pontoon dock, and means forming a drive connection between individual counterweights and the respective haul-in mechanisms for driving operation of the latter upon descent of said counterweights thereby to raise the sunken vessel by an increment, means operable to hold said counterweights in elevated position therein, means actuating said means holding the counterweights in elevated position, to release the same for simultaneous descent thereof by gravity to effect such incremental hoisting operation, and means operable to elevate said counterweights for a succeeding incremental hoisting operation.

8. The ship salvage device defined in claim 2,

wherein the means operable to hold the tanks in elevated position comprise a plurality of tank supporting hydraulic units associated with the respective tanks, each such unit comprising piston and cooperating cylinder elements, one such element being fixed to the dock and the cooperating element being supportingly connected to the associated tank for displacing hydraulic liquid from the cylinder accompanying descent movement of such tank, and further wherein the actuating means comprise a plurality of normally closed cylinder control valves preventing discharge of hydraulic liquid from the respective cylinders, and means operable to open said control valves for all the tank hydraulic units simultaneously.

9. The ship salvage device defined in claim 8, and means to contain hydraulic liquid and conduit means interconnecting said container means and the discharge sides of a plurality of 15 the control valves to permit free flow of hydraufic Number liquid therebetween. 409,257 TRUMAN K. JAMISON. 438,215 1,318,467 REFERENCES CITED 5 1,622,866 The following references are of record in the 1310,1013 file of this patent: UNITED STATES PATEN'lS 2,272,785 Number Name Date 10 72,343 Week Dec. 17, 1367 99,307 Garlington Feb. 1, 1870 Number 163,548 Tiffany May 13, 1875 00,260

Name Date Wanner Aug. 20, 1889 Young Oct. 14, 1890 Travell Oct. 14, 1919 Gardner Mar. 29, 1927 Nelson Apr. 23, 1929 Sonntag Feb. 11, 1930 Anderson Aug. 30, 1932 Z011 Feb. 10, 1942 FOREIGN PATENTS Country Date Great Britain Apr. 20, 1916

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