US3859944A

US3859944A - Tanker integrity system

Info

Publication number: US3859944A
Application number: US299870A
Authority: US
Inventors: Gifford D Warner
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-24
Filing date: 1972-10-24
Publication date: 1975-01-14
Anticipated expiration: 1992-01-14

Abstract

A tanker integrity system for minimizing any cargo loss and preventing any ship loss due to collision, etc. and providing for closing and pressurizing the tanker holds and for selectively transferring cargo between holds and offloading cargo from the ship notwithstanding loss of the ship power plant and/or damage to the ship resulting in the ship breaking in two.

Description

United States Patent 1191 Warner Jan. 14, 1975 [54] TANKER INTEGRITY SYSTEM 3,162,168 12/1964 Ferris et al ll4/72 3,307,512 3/1967 Fell 114/74 R [76] Inventorg z g'gg 1 Map6 Ave-1 3,704,678 12/1972 Kelly 114/74 R 7 ssex, onn.

[22] Filed: Oct. 24, 1972 Primary ExaminerTrygve M. Blix Assistant Examiner-Stuart M. Goldstein [21] Appl' 299870 Attorney, Agent, or FirmCooper, Dunham, Clark,

Griffin & Moran [52] US. Cl. 114/74 R, 114/72 [51] Int. Cl B631) 25/08 57] ABSTRACT [58] Field of Search 114/72, 74 R, 74 T, 211,

114/212, 73, 16 D; 137/512, 636-640; A tanker integr ty system for m1mm1z1ng any cargo 126 I28 5 B 286 loss and preventmg any sh1p loss due to coll1s1on, etc. 1 and providing for closing and pressurizing the tanker [56] References Cited holds and for selectwely transferring cargo between holds and offloadmg cargo from the ship notw1th- UNITED STATES PATENTS standing loss of the ship power plant and/or damage to 2 the ship resulting in the ship breaking in two. ar son 2,599,925 6/1952 Lamb 114/211 11 Claims, 4 Drawing Figures PMEHIED JAN 1 41975 SHEET 1 BF 2 IIIII PATENTEB JAN I 41975 SHEET 2 BF 2 TANKER INTEGRITY SYSTEM BRIEF SUMMARY OF THE INVENTION The present invention relates generally to tanker integrity systems for minimizing cargo and ship loss due to collision, etc. and more particularly to a tanker integrity system having notable utility in preventing cargo loss from the separate sections of a ship which has broken in two.

It is a primary aim of the present invention to provide a new and improved tanker integrity system for closing the holds of any tanker section in response to severance of that section from the bridge of the ship. In accordance with the present invention the holds of any such section are also automatically pressurized to a preestablished pressure upon such section being severed from the bridge.

It is another aim of the present invention to provide a tanker integrity system of minimizing cargo loss resulting from puncture of the ship hull and/or breakage of the ship in two.

It is a further aim of the present invention to provide a new and improved tanker integrity system for pressurizing any punctured tanker holds for minimizing flooding.

It is another aim of the present invention to provide a new and improved liner for a tankerhold for protecting the hold against rupture.

It is a still further aim of the presentinvention:toprovide a new and improved auxiliary cargo handling system for a tanker for transferring cargo between holds and/or offloading cargo from the ship.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

A betterunderstanding of the invention will be obtained from the following detailed description andthe accompanying drawings of an illustrative application of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a generally diagramatic side elevation view, partly broken away and partly in section, ofa tanker incorporating an embodiment of the tanker integrity system of the present invention;

FIG. 2 is an enlarged generally diagramatic partial top plan view, partly broken away, showing a forward section of the tanker;

FIG. 3 is an enlarged partial side elevation view, partly broken away and partly in section, of a vent stack of the tanker showing a valve mechanism thereof; and

FIG. 4 is an enlarged partial front elevation view, partly broken away and partly in section, of the tanker showing a hold liner thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, wherein. like numerals areused to designate like parts, a tanker incorporating an embodiment of an integrity system of the present invention is shown having a conventional hull 12 with transverse and longitudinally extending bulkheads 14, 16, (FIG. 2) respectively and a main deck 18 which together form a plurality of separate substantially airtight holds or tanks 20 for storing crude oil or other liquid cargo being transported by the tanker. In particular, the transverse bulkheads 14 divide the ship into a plurality of longitudinally spaced cargo storage sections, and a pair of parallel longitudinally extending bulkheads l6 divide each such storage section into three separate cargo holds 20. In a conventional manner access is provided to each hold 20 by a suitable removable ullage cover 22.

The tanker is shown having a superstructure 24 with a bridge 26 located generally amidships. The tanker is also shown with a separate vent stack or funnel 30 for each cargo storage section and with each stack 30 connected by separate vent conduits 31-33 for venting the holds 20 of the respective cargo storage section.

Referring to FIG. 3, a butterfly closure valve 36 is provided in each vent stack 30 and a valve operating mechanism 38 (hereinafter described) is provided for each butterfly valve 36 for pivoting the butterfly valve from its vertical or fully open position to its closed posi' tion to completely close the respective holds 20. Also a manually operable valve 40 is providedin eachof the vent conduits 31-33 as a backup valve to the stack butterfly valve 36 and for selectively individually closing the holds 20. A suitable pressure regulator 44 having a pressure gauge 46 is provided for each of the holds 20 for registering the pressure within the hold and for setting the maximum pressure and relieving any pressure in excess of the set maximum.

In a conventional manner the tanker has an above deck primary steam smothering conduit 50 extending substantially thefull length of the ship and connected to each of the holds by transversely extending steam conduits 51-53 and to a suitable steam source (not shown) for selectively conveying steam from the steam source to the holds 20. Suitable one-wsy check valves 54 are provided in the transverse conduits 51-53 for preventing backflow from the holds to the primary steam conduit 50 and in the steam conduit (not shown) from the steam source for preventing backflow to the steam source. Also suitable manually operable valves 60 are provided in the primary steam conduit 50 adjacent the transverse bulkheads 14 (with the valves 60 preferably located slightly forward of the transverse bulkheads 14 at the forward end of the ship and slightly aft of the bulkheads 14 at the aft end of the ship) for assisting in isolating that portion of the steam conduit system in use from the remainder of the system. Also suitable flow responsive shut off valves62 are provided in the primary steam conduit 50 for closing the primary conduit 50 when there is excess flow due to any adjacent rupture of the primary conduit 50. The flow responsive valves 62 and the manually operable valves 60 are therefore useful in preventing flow through the steam conduit 50 to atmosphere where for example the ship has broken in two and the primary steam conduit 50has thereby been broken.

In accordance with the present invention a completely separate and independently operable compressed air source or system 68 is provided at both the stem and stern of the ship. Each compressed air system 68 comprises a suitable air compressor 70 which is connected to supply compressed airto the primary steam conduit 50 via a suitable one-way check valve 72 (to prevent reverse flow of steam to the compressor), a diesel engine 74 connected for driving the compressor 70 and a suitable engine control system 76 for activating the compressed air system for delivering compressed air. Each compressed air system 68 is therefore useful for supplying compressed air via the primary steam conduit 50 and the transverse conduits 51-53 for pressurizing the holds 20. i

The tanker has a suitable primary cargo handling system (not shown) for transferring cargo between tanks and for loading and off-loading cargo. Conventionally, a primary cargo handling system incorporates a central primary suction conduit (not shown) located just above the keel of the tanker for withdrawing cargo from the holds 20. In accordance with the present invention; the tanker also incorporates an auxiliary cargo handling system having an above deck auxiliary discharge conduit 82 and an above deck auxiliary suction conduit 84 extending substantially the full length of the ship between forward and rear pump rooms 86, 88, respectively. A suitable pump 90 in each of the pump rooms is connected to each of the auxiliary discharge and suction conduits for withdrawing fluid from the holds 20 and transferring cargo to another hold or for offloading cargo. For this purpose the auxiliary discharge and suction conduits 82, 84 are connected via transverse conduits 91-93 and 94-96, respectively to each of the holds 20 and manually operable valves 97 are provided in the auxiliary discharge and suction conduits 82, 84 and in the transverse conduits for selectively connecting the forward pump fortransferring cargo from a selected hold to another selected hold and similarly for connecting the aft pump for transferring cargo from a selected hold to another selected hold. Also forward and aft off-loading conduits 98 (also having valves 97) are connected to the auxiliary discharge conduit 82 at'the forward and aft ends of theship for off-loading cargo from the ship with the auxiliary cargo handling system. As shown in FIG. 2, all the valves 97 are located above deck and are operable from that location. Thus should the tankerbreak into two sections, the auxiliary cargo handling subsystems at the forward and aft sections of the ship could be used for transferring cargo between the holds of the respective section and if desired for off-loading cargo from the ship section. For this reason the forward and aft pumps are operable independently of the main power plant of the ship and may, for example, be driven by the air compressor engines 74 or be connected to be operated by compressed air from the air compressors 70.

A suction hose 99 is provided in each of the holds 20 and a suitable hose winch 100 manually operable from the deck is provided for selectively positioning the intake end of the hose for withdrawing cargo at a given level within the hold and therefore for permitting withdrawing cargo even where the hold has been punctured and partially flooded. The manual winch 100 is preferably operable from the deck without removing the access cover 22 and so as to maintain the airtight integrity of the hold and prevent any additional inflow of water into a ruptured hold. The air pressure regulator 44 for any hold from which cargo is being withdrawn or into which cargo isbeing discharged should be readjusted as the cargo is withdrawn or discharged into the hold in accordance with the changing cargo level and such that the optimum air pressure is maintained in accordance with the cargo level.

To protect against rupture of the holds 20 each hold is provided at its lower end with a liner 101 suitably formed to fit snugly but loosely within the lower hold cavity and having its upper periphery suitably secured to the sides of the hold. The liner 101 comprises a suitable heavy gauge flexible and resilient imperforate inner liner 102 of neoprene or 'the like and an outer heavy gauge wire or chain mesh 103 that provides a protective outer casing for the inner liner 102. Thus, if the hull is punctured the outer steel mesh would protect the inner liner against the torn hull and the liner would merely be deflected inwardly without the puncturing of the inner liner 102.

The vent system, air compressor system and auxiliary cargo handling systemtogether provide a versatile ship integrity system for eliminating or at least minimizing cargo loss, minimizing flooding, and preventing any ship loss if the ship hull is ruptured and/or severed in two due to collision, running aground or other cause.

For example if the hull ispunctured to permit the entry of water into one or more of the holds 20, the butterfly valves 36 for the respective vent stacks 30 are closed to prevent the loss of air from the ruptured holds and to thereby reduce the inflow of water into the holds. Also one or both of the compressors are activated to supply compressed air to the holds to pressurize the holds and thereby assist further in preventing inflow of water into a punctured hold. The pressure regulators 44 for the holds are preadjusted in accordance with the level of the cargo in the holds relative to the waterline and the density of the cargo so asto establish an optimum pressure for each hold and to prevent excessive pressure from discharging cargo through any punctured opening in the hold.

The vent butterfly valves 36 and the air compressors 70 are operated upon the occurrence of any collision, etc. in which the ship may be damaged. The holds should be maintained in substantially airtight condition, excepting for the hold vents during the normal operation of the ship so that closure of the vents will make the holds airtight above the cargo level in the hold. in the event the ship breaks in two, the vents of that portion of the ship severed from the bridge and which is therefore not normally manned are closed and the holds are pressurized. More particularly the butterfly valves 36 are connected to be operated from the bridge by forward and aft longitudinally extending cables 110, 111 mounted on suitable pulleys 112 and such that the cables 110, 111 provide for operating the butterfly valves 36 to close the stack vents of any part of the ship which is severed from the bridge. Also the cables 110, 111 can be individually manually pulled from the bridge to close the vents 30 forward of the bridge with the cable and close the vents 30 aft of the-bridge with the cable 111. Also the cables 110, 111 may be pulled from the deck to operate the butterfly valves. Each butterfly valve 36 is biased to a closed position by a tension spring 113 and is latched in the open position by a latch 114. Also the butterfly valves 36 are mounted off-center such that any pressure within the respective holds assists in holding a valve closed. A loop fixed to the respective cable 110, 111 is mounted over the upper end of the latch 114 such that by pulling the cable the latch is withdrawn to release the butterfly valve 36 for being closed by its tension spring 113. Thus in the event a section of the ship is severed from the bridge, the vent butterfly valves 36,of that section are closed as a result of the pull on the cable due to the separation of the two sections of the ship. Also a suitable electromagnet is connected to the latch 114 for withdrawing the latch 114 with a tension spring 121 when the electromagnet is de-energized. The electromagnets 120 are suitably electrically connected to the bridge (not shown) preferably for manually operating the closure valves either individually or collectively as desired from the bridge. Also the electromagnets are suitably connected so that the electromagnets of any section of the ship severed from the bridge are deenergized to release the closure valves. The latches 114 may also be manually operated to release the closure valves.

The engine controls 76 may, for example, be operated by the cables 110, 111 through similar latches (not shown) such that each engine control latch is tripped to activate the compressor when the cable is pulled and therefore for activating the compressor of any section of the ship severed from the bridge. Thus the forward cable 110 is connected to the forward engine control 76for activating the forward compressed air system for supplying compressed air via the primary steam conduit 50 to the holds of any forward section of the ship severed from the bridge, in which event the flow responsive shut-off valves would prevent loss of com-,

pressed air to atmosphere through the opening in the severed steam conduit 50. In this regard,'it is contemplated that the diesel engine 74 maybe pre-rigged to start as described above or the engine may be maintained in an idling condition during any portion of a voyage wheretrouble might occur and the engine control provide for governing the engine speed at a sufficiently high RPM for supplying adequate compressed air to the holds. Also the longitudinally extending conduits 50, 82 and 84arepreferablyforineifor example, with telescoping sections, so that if the ship is severed in two the conduit sections of the two sections of the ship separate relatively easily and theconduits are still useful in maintaining the integrity of the ship.

As will beapparentto persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can bemade without departing from the teachings of the present invention.

I claim:

1. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced, transversely extending bulkheads separating thehull into a plurality of longitudinally spaced cargo sections, and an overlying deck together providing a plurality of separate substantially fluid tight holds; and a plurality of vent conduits connectedto the-holds 'for venting gases therefrom; a tanker integrity system comprising:

a. vent conduit closure valves mounted in the vent conduits and operable for closing the vent conduits for closing the holds connected thereto, and valve operator means including control means connecting each valve with the bridge, and means effective upon severance of the control means to close the valve leading to the holds of any section of the ship severed from the bridge;

b. a forward air compressor system at the stem of the tanker connected for supplying compressed air at least to the forward'holds of the tanker;

c. further control means connecting the bridge with the forward air compressor system; and

d. means responsive to severance of the stem of the tanker fromthe bridge to actuate the forward air compressor system to supply compressed air to the holds of the severed forward section of thetanker.

2. A tanker integrity system according to claim 1 wherein the bridge is located generally amidships and further comprising an aft air compressor system at the stern of the tanker connected for supplying compressed 'air at least to the aft holds of the tanker, and aft control means connecting the bridge with the aft air compressor system, and means responsive to severance of the stern of the tanker from the bridge to actuate the aft air compressor system to supply compressed air to the holds of the severed aft section of the tanker.

3. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced, transversely extending bulkheads separating the hull into a plurality of longitudinally spaced cargo sections, and an overlying deck together providing a plurality of separate substantially fluid tight holds; and a plurality of vent conduits connected to the holds for venting gases therefrom; a tanker integrity system comprising:

a. vent conduit closure valves mounted in the vent conduits and operable forclosing the vent conduits for closing the holds connected thereto, and valve operator means including control means connecting each valve with the bridge, and means effective upon severance of the control means to close the valves leading to the holds of any section of the ship severed from the bridge;

b. an auxiliary cargo handling system for transferring cargo between holds, the auxiliary cargo handling systemcomprising:

1. a pair of cargo pumps, one at each end of the tanker;

2. longitudinally extending pump inlet and outlet conduits located above deck and connected to each of the pumps;

3. branchconduits connecting the pump inlet and outlet conduits respectively to the holds;

4. valvemeans in the inlet and outlet conduits and operable from above deck for selectively isolating forward and aft auxiliary cargohandling subsystems of the auxiliary cargo handling system; and

5. valvemeans in the branch conduits and operable from above deck for withdrawing cargo from and discharging cargo into selected holds with the pump.

4. In an elongated tanker having aplurality of separate substantially fluid tightholds, and a plurality of vent stacks extending upwardly from the deck connected to the holds for venting gases therefrom, a

tanker integrity system comprising valve means in each vent stack operable for closing the stack for preventing the escape of gases from the holds connected thereto, valve operator means for selectively operating the valve means for closing the vent stacks, and a hold pressurizing system comprising alpair of independently operable air compressor systems, one at each end of the tanker, a primary conduit connected to the pair of air compressor systems for receiving compressed air therefrom, secondary conduits connecting the primary conduit to the holds for supplying compressed air from the primary conduit to the holds, control means for independently operating the air compressor systems for supplying compressed air to the holds via the primary and secondary conduits and valve means in the primary conduit for isolating forward and aft subsystems of the pressurizing system.

5. A tanker integrity system according to claim 4, wherein the control means includes a common control station remote from both air compressor systems and means connecting the common control station to each of the air compressor systems; and each air compressor system includes means effective upon severance of the connecting means between the control station and the air compressor system to initiate operation of the air compressor system to supply compressed air to the hold of any severed end section of the ship upon severence of such end section from the rest of the ship.

6. A tanker integrity system according to claim 4, including a plurality of flow responsive valves in the primary conduit, each operable to close the primary conduit when the fluid flow therethrough exceeds a predetermined value.

7. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced transversely extending bulkheads, and an overlying deck together providing a plurality of substantially fluid tight holds; a plurality of vent stacks extending upwardly from the deck and connected to the holds for venting gases therefrom; a tanker integrity system comprising valve means in each vent stack operable for selectively closing the stack for preventing the escape of gases from the holds connected thereto, valve operator means for selectively operating the valve means for closing the, vent stacks; a hold pressurizing systemcomprising an air compressor system at each end of the tanker, an above deck primary conduit connected for receiving compressed air from each of the air compressor systems, secondary conduits connecting the primary conduit to each of the holds for supplying compressed air from the compressor systems via the primary and secondary conduits to the holds, a plurality of spaced valve means along the primary conduit and operable from above deck for selectively isolating forward and aft subsystems of the hold pressurizing system, and control means for selectively operating each air compressor system for supplying compressed air to the primary conduit; and an auxiliary cargo handling system for transferring cargo between holds, the auxiliary cargo handling system comprising a pump at each end of the tanker and longitudinally extending inlet and outlet cargo conduits located above deck and connected to each of the pumps, branch conduits connecting the pump inlet and outlet conduits respectively to the holds, valve means in the inlet and outlet conduits and operable from above deck for selectively isolating forward and aft auxiliary cargo handling subsystems of the auxiliary cargo handling system, and valve means in the branch conduits and operable from above deck for withdrawing cargo from and discharging cargo into selected holds with the pumps.

8. A tanker integrity system according to claim 7 wherein the branch inlet conduits comprise an inlet hose in each hold for withdrawing cargo from the hold and means for selectively raising and lowering the inlet hose to withdraw cargo at a selected level within the hold.

9. A tanker, including:

a. a hull, including a plurality of fluid tight holds;

b. an overlying deck on the hull;

c. a pair of independently operable air compressor systems, one at each end of the tanker;

d. a primary conduit connecting the pair of air compressor systems for receiving compressed air therefrom;

e. branch conduits connecting the primary conduit to the respective holds for supplying compressed air thereto;

f. a common control station for said air compressor systems;

g. means connecting the two air compressor systems to the common control station;

h. means effective upon disconnection of either air compressor system from the common control stationto initiate operation of the air compressor system to supply compressed air to the primary conduit; and

i. valve means in the primary conduit closable to isolate a break in the primary conduit from either compressor.

10. A tanker, including:

a. a hull, including a plurality of fluid tight holds;

b. an overlying deck on the hull; and

c. an auxiliary cargo handling system for transferring cargo between holds, comprising:

1. a pair of pumps, one adjacent each end of the tanker;

2. a pump inlet conduit connected to both pumps and extending above said deck;

3. an outlet conduit connected to both pumps and extending above said deck;

4. branch inlet and outlet conduits connecting the primary inlet and outlet conduits respectively to the several holds;

5. valve means in the primary inlet and outlet conduits and accessible from above the deck for isolating forward and aft sections of said conduit; and

6. valve means in the secondary inlet and outlet conduits and accessible. from abovethe deck for selectively withdrawing cargo from and discharging cargo into the holds by means of the pumps.

11. A tanker, including:

a. a hull, including a plurality of fluid tight holds;

b. an overlying deck on the hull;

c. a plurality of vent stacks and a plurality of vent conduit means, each connected to one of the holds and extending up through the deck to one of the vent stacks above the deck;

d. a vent valve in each vent stack biased toward closed position;

e. a common control station;

f. valve operating means, including means connecting the common control station to the vent valves, for opening them against their bias;

g. means effective upon disconnection of any vent valve from the common control station to release the valve for closure by its bias, so that upon separation of a hold from the common control station by severance of the ship, its associated valve is closed;

h. a pair of independently operable air compressor systems, one at each end of the tanker;

i. a primary conduit connecting the pair of air compressor systems for receiving compressed air therefrom;

j. branch conduits connecting the primary conduits to the respective holds for supplying compressed air thereto;

9 10 k. means connecting the two air compressor systems full horizontaldistance between the pumps;

to the common control station; 3. an outlet conduit connected to both pumps and 1. means effective upon disconnection of either an t di b v id de k substantially th full compressor system from the common control stahorizontal distance between the pumps; to operatlon of h comPressor 4. branch inlet and outlet conduits connecting the tern to supply compressed air to the primary conprimary inlet and outlet conduits respectively to the several holds; 5. valve means in the primary inlet and outlet conduits and accessible from above the deck for isolatduit; m. valve means in the primary conduit closable to isolate a break in the primary conduit from either compressor; and

11. an auxiliary cargo handling system for transferring mg forward a aft sewons condunt and cargo between holds, comprising; 6. valve means in the secondary inlet and outlet con- 1 a i f pumps, one adjacent each end f the duits and accessible from above the deck for select k tively withdrawing cargo from and discharging 2. a pump inlet conduit connected to both pumps 5 cargo into the holds by means of the pumps.

and extending above said deck substantially the

Claims

1. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced, transversely extending bulkheads separating the hull into a plurality of longitudinally spaced cargo sections, and an overlying deck together providing a plurality of separate substantially fluid tight holds; and a plurality of vent conduits connected to the holds for venting gases therefrom; a tanker integrity system comprising: a. vent conduit closure valves mounted in the vent conduits and operable for closing the vent conduits for closing the holds connected thereto, and valve operator means including control means connecting each valve with the bridge, and means effective upon severance of the control means to close the valve leading to the holds of any section of the ship severed from the bridge; b. a forward air compressor system at the stem of the tanker connected for supplying compressed air at least to the forward holds of the tanker; c. further control means connecting the bridge with the forward air compressor system; and d. means responsive to severance of the stem of the tanker from the bridge to actuate the forward air compressor system to supply compressed air to the holds of the severed forward section of the tanker.

2. a pump inlet conduit connected to both pumps and extending above said deck substantially the full horizontal distance between thE pumps;

2. a pump inlet conduit connected to both pumps and extending above said deck;

2. A tanker integrity system according to claim 1 wherein the bridge is located generally amidships and further comprising an aft air compressor system at the stern of the tanker connected for supplying compressed air at least to the aft holds of the tanker, and aft control means connecting the bridge with the aft air compressor system, and means responsive to severance of the stern of the tanker from the bridge to actuate the aft air compressor system to supply compressed air to the holds of the severed aft section of the tanker.

3. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced, transversely extending bulkheads separating the hull into a plurality of longitudinally spaced cargo sections, and an overlying deck together providing a plurality of separate substantially fluid tight holds; and a plurality of vent conduits connected to the holds for venting gases therefrom; a tanker integrity system comprising: a. vent conduit closure valves mounted in the vent conduits and operable for closing the vent conduits for closing the holds connected thereto, and valve operator means including control means connecting each valve with the bridge, and means effective upon severance of the control means to close the valves leading to the holds of any section of the ship severed from the bridge; b. an auxiliary cargo handling system for transferring cargo between holds, the auxiliary cargo handling system comprising:

3. branch conduits connecting the pump inlet and outlet conduits respectively to the holds;

3. an outlet conduit connected to both pumps and extending above said deck;

3. an outlet conduit connected to both pumps and extending above said deck substantially the full horizontal distance between the pumps;

4. valve means in the inlet and outlet conduits and operable from above deck for selectively isolating forward and aft auxiliary cargo handling subsystems of the auxiliary cargo handling system; and

4. In an elongated tanker having a plurality of separate substantially fluid tight holds, and a plurality of vent stacks extending upwardly from the deck connected to the holds for venting gases therefrom, a tanker integrity system comprising valve means in each vent stack operable for closing the stack for preventing the escape of gases from the holds connected thereto, valve operator means for selectively operating the valve means for closing the vent stacks, and a hold pressurizing system comprising a pair of independently operable air compressor systems, one at each end of the tanker, a primary conduit connected to the pair of air compressor systems for receiving compressed air therefrom, secondary conduits connecting the primary conduit to the holds for supplying compressed air from the primary conduit to the holds, control means for independently operating the air compressor systems for supplying compressed air to the holds via the primary and secondary conduits and valve means in the primary conduit for isolating forward and aft subsystems of the pressurizing system.

5. valve means in the branch conduits and operaBle from above deck for withdrawing cargo from and discharging cargo into selected holds with the pump.

6. valve means in the secondary inlet and outlet conduits and accessible from above the deck for selectively withdrawing cargo from and discharging cargo into the holds by means of the pumps.

7. In an elongated tanker having a hull with a bridge; a plurality of bulkheads, including a plurality of longitudinally spaced transversely extending bulkheads, and an overlying deck together providing a plurality of substantially fluid tight holds; a plurality of vent stacks extending upwardly from the deck and connected to the holds for venting gases therefrom; a tanker integrity system comprising valve means in each vent stack operable for selectively closing the stack for preventing the escape of gases from the holds connected thereto, valve operator means for selectively operating the valve means for closing the vent stacks; a hold pressurizing system comprising an air compressor system at each end of the tanker, an above deck primary conduit connected for receiving compressed air from each of the air compressor systems, secondary conduits connecting the primary conduit to each of the holds for supplying compressed air from the compressor systems via the primary and secondary conduits to the holds, a plurality of spaced valve means along the primary conduit and operable from above deck for selectively isolating forward and aft subsystems of the hold pressurizing system, and control means for selectively operating each air compressor system for supplying compressed air to the primary conduit; and an auxiliary cargo handling system for transferring cargo between holds, the auxiliary cargo handling system comprising a pump at each end of the tanker and longitudinally extending inlet and outlet cargo conduits located above deck and connected to each of the pumps, branch conduits connecting the pump inlet and outlet conduits respectively to the holds, valve means in the inlet and outlet conduits and operable from above deck for selectively isolating forward and aft auxiliary cargo handling subsystems of the auxiliary cargo handling system, and valve means in the branch conduits and operable from above deck for withdrawing cargo from and discharging cargo into selected holds with the pumps.

9. A tanker, including: a. a hull, including a plurality of fluid tight holds; b. an overlying deck on the hull; c. a pair of independently operable air compressor systems, one at each end of the tanker; d. a primary conduit connecting the pair of air compressor systems for receiving compressed air therefrom; e. branch conduits connecting the primary conduit to the respective holds for supplying compressed air thereto; f. a common control station for said air compressor systems; g. means connecting the two air compressor systems to the common control station; h. means effective upon disconnection of either air compressor system from the common control station to initiate operation of the air compressor system to supply compressed air to the primary conduit; and i. valve means in the primary conduit closable to isolate a break in the primary conduit from either compressor.

10. A tanker, including: a. a hull, including a plurality of fluid tight holds; b. an overlying deck on the hull; and c. an auxiliary cargo handling system for transferring cargo between holds, comprising:

11. A tanker, including: a. a hull, including a plurality of fluid tight holds; b. an overlying deck on the hull; c. a plurality of vent stacks and a plurality of vent conduit means, each connected to one of the holds and extending up through the deck to one of the vent stacks above the deck; d. a vent valve in each vent stack biased toward closed position; e. a common control station; f. valve operating means, including means connecting the common control station to the vent valves, for opening them against their bias; g. means effective upon disconnection of any vent valve from the common control station to release the valve for closure by its bias, so that upon separation of a hold from the common control station by severance of the ship, its associated valve is closed; h. a pair of independently operable air compressor systems, one at each end of the tanker; i. a primary conduit connecting the pair of air compressor systems for receiving compressed air therefrom; j. branch conduits connecting the primary conduits to the respective holds for supplying compressed air thereto; k. means connecting the two air compressor systems to the common control station; l. means effective upon disconnection of either air compressor system from the common control station to initiate operation of the air compressor system to supply compressed air to the primary conduit; m. valve means in the primary conduit closable to isolate a break in the primary conduit from either compressor; and n. an auxiliary cargo handling system for transferring cargo between holds, comprising: