US3504651A - Ship stabilizing system - Google Patents

Description

' 2 Sheets-Sheet 1 Filed June 4. 1968 Hqrsf Jurgen BY W flffO/"n April 7, 1970 HALDEN ET AL SHIP STABILIZING SYSTEM 2 Sheets-Sheet 2 Filed June 4. 1968 Fig.3a

. h v J Q Q Q w a b 3 a G F x f 5 0 3 I ,iL L 3 a h 0 n t e n 0% w F E H w 4m M m HJ United States Patent O 3,504,651 SHIP STABILIZING SYSTEM Horst Halden, Hamburg, and Jiirgen Fehlauer, Wolfsburg,

Germany, assignors to Licentia Patent-Verwaltuugs- G.m.b.H., Frankfurt am Main, Germany Filed June 4, 1968, Ser. No. 734,410 Int. Cl. B63b 43/06 U.S. Cl. 114-125 8 Claims ABSTRACT OF THE DISCLOSURE A system for stabilizing ships of the type having a liquid storage tank with first and second portions, in fluid com munication with each other, located on opposite sides of a ship. The level of the liquid in the tank can be changed quickly, this being done with means which communicate with the tank for introducing a pressure medium into the tank at a point below the surface of the liquid in the tank and with two separately closable outlet means communicating with the respective tank portions for allowing the liquid and/or the air in one or the other or both the tank portions to escape.

BACKGROUND OF THE INVENTION The present invention relates to apparatus for quickly changing the level of liquid in the liquid tank or tanks of a ship stabilizing system.

When a ship having a liquid tank-type stabilizing system has been damaged at sea, the danger to the ship can be additionally increased by the freely oscillating or rolling masses of liquid in the tank system. It is necessary that these oscillations be braked and that the liquid be distri'buted uniformly throughout the ships tanks in the shortest possible time (e.g., 20 seconds) or that the tank system be quickly emptied,

With air pressure-activated tank-type stabilizing systems it is known in the art to change the characteristics frequency of the liquid in the anti-rolling tanks by inserting an air compressor in the air line interconnecting the side tanks. Such an air compression is slow to operate, however, and is not effective in emptying the tanks.

SUMMARY OF THE INVENTION An object of the present invention, therefore, is to provide apparatus for suppressing, when necessary, the oscillations of the liquid in-or for emptying the liquid fromthe tank system of a tank-type ship stabilizing system, in the shortest possible time. The term tank system, as used here, is intended to include a tank having first and second portions located on opposite sides of the ship and in fluid communication with each other.

This, as well as other objects which will become apparent in the discussion that follows, is achieved, according to the present invention, by providing means communicating with the tank system, means for introducing a pres sure medium below the surface of a liquid stored in the tank system and separately closable first and second outlets communicating with the first and second tank portions, respectively. By introducing the pressure medium into the tank system it is possible to cause the liquid in at least one of the tank portions to be under pressure. This pressure can then be relieved by allowing the liquid and/ or air in one or the other or both tank portions to escape.

A gas is used as a pressure medium, according to the present invention. This gas may either be introduced into the tank system under pressure or passed through the tank inlet openings in the liquid state and allowed to boil.

It would be conceivable to construct the means communicating with the tank system so that it introduces the Patented Apr. 7, 1970 pressure mediume.g., a gas under pressureat a point above the level of the liquid. However, the cooling which results from the expansion of the gas in the tank space would make it diflicult to introduce the necessary quantity of gas in the prescribed time. Unless a costly preheating apparatus were provided, at least part of the pressure medium would freeze.

The cooling of the gas to this undesirable degree will be avoided by introducing the gas directly into the tank liquid. The flow of the gas through the liquid will then result in a heat exchange that will be sufiicient to insure that the gas will not freeze.

If the ship stabiilzing system is of the type having side tanks with at least one liquid equalizing channel and at least one closable air equalizing channel interconnecting the tanks, a preferred embodiment of the present inven tion provides that the inlet openings for the gas under pressure are arranged either in the lower half of the side tanks or at the ends of the liquid equalizing channels. The separately closable outlets which permit compressed air to escape from the tanks are likewise arranged in the upper half of the tanks or at the ends of the air equalizing channels. If the liquid located in the side tanks of this stabilizing system is then caused to flow into one of the side tanks, it can be forced back again into the other side tank by closing the air equalizing channel in an air tight manner and opening the separately closable outlet of the tank to be filled so that the air, which is displaced by the liquid, is allowed to escape.

If the ship is damaged at sea it can be of advantage if the liquid in the tanks of the ship stabilizing system can be jettisoned in the shortest possible time. Thus, ac cording to a further embodiment of the present invention, each side tank is provided, near its bottom, with an outlet opening for the liquid. The gas is then introduced under pressure, with the air equalizing channel open and the outlet openings located in the upper half of the side tanks closed, and the liquid is displaced by the gas.

With a. ship stabilizing system having a tank constructed to operate according to the fiume principle it is again desirable that the liquid be jettisoned from the tank when the ship has been damaged. With a system of this type in which the tank liquid oscillates back and forth in a direction transverse to the forward motion of the ship in a tank consisting of a number of containers of various cross sections, it is not possible, by introducing a gas under pressure, to dampen the oscillations or change the respective levels of the fiuid since the pressure of the gas will uniformly act upon the entire surface of the tank liquid.

The apparatus according to the present invention for controlling the liquid level or to jettison the liquid in the tank of a ship stabilizing system may also be used for other known types of ship stabilizing systems. For example, it may be used in active ship stabilizing systems.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a schematic diagram of the section of a ship having a stabilizing system with a U-shaped tank, according to a preferred embodiment of the present invention.

FIGURE 2 is a schematic diagram of a section of a ship having a stabilizing system with a U-shaped tank, according to another preferred embodiment of the present invention.

FIGURE 3a is a schematic diagram of a section of a ship having a stabilizing system, according to still another preferred embodiment of the present invention, which system has a tank arranged to operate according to the flume principle.

FIGURE 3b is a schematic diagram, in top view, of the ship stabilizing system of FIGURE 3a.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIGURE 1 illustrates schematically a passive ship stabilizing system having two side tanks and 11 which are joined together by an interconnecting channel 12 and a pressure equalizing air line 13. A flap or butterfly valve which is driven by a position adjusting device 14 is arranged in the air line 13.

This valve 15 may be closed to completely seal the air passageway between the side tanks 10 and 11.

A container 16 which holds under pressure a pressure medium either in the gaseous or liquid state is connected to the side tanks 10 and 11 through the lines 17 and the throttle valves 18 and 19. Arranged in the air line 13 on both sides of the flap 15 are openings 22 and 23 which may be independently closed by valves and 21, respectively. High pressure release valves 24 and 25 are also connected to the air line. Float apparatus 26 and 27 is provided in each side tank 10 and 11, respectively, for measuring the level of the liquid in the tanks.

It is particularly practical if the gas which is to be inserted in the side tanks 10 and 11 is stored in the container 16 and introduced into the tanks in the liquid state.

It is possible, for the purposes of the present invention, to use any gas which is not explosive, corrosive, or poisonous. If the gas is to be stored in the liquid state, however, it is preferable to choose a gas that has a boiling point only slightly below room temperature. This permits the gas to be stored without the requirement of costly cooling apparatus.

According to a preferred embodiment of the present invention a fiuorinated hydrocarbon gas is stored and introduced into the side tanks in its liquid state. Dichlorodifluoromethane has proven especially advantageous in this regard. Its boiling point lies approximately at C. It is not poisonous, corrosive or explosive and it exhibits but a limited solubility in water.

If the ship having a stabilizing system of the type shown in FIGURE 1 is damaged and continually lists toward one side, most of the tank liquid will flow into the tank on the lower side of the ship and cause the ship to list still further. If it is assumed, for purposes of example, that the ship is listing toward the right, the valve 19 will open, after an alarm signal is sounded, and allow the liquid dichlorodifiuoromethane which is stored under pressure in the container 16 to escape into the tank liquid of the side tank 11. The flap 15 in the pressure equalizing air channel 13 will simultaneously close. The liquid gas will then expand and press down from above on the column of liquid in the side tank 11. This will force a portion of this liquid back into the other side tank 10 and thus raise the level of liquid in this left tank. The air in the side tank 10 which is displaced by the incoming liquid can be allowed to escape by opening the valve 20 while all the other valves are held closed. The amount of gas which is permitted to flow into the side tank 11 may be chosen so that the liquid in both tanks 10 and 11 will reach a desired level.

Since the gas is introduced into the tank liquid in the liquid state a heat exchange will occur between the incoming expanding gas and the tank liquid. The heat which is given to the gas by the liquid is sufficient to prevent the gas from freezing even during the strong expansion which is necessary here to introduce the desired quantity of gas into the tank. If the gas were introduced into the side tank 11 above the level of the liquid, the danger of freezing would make diflicult the introduction of the necessary quantity of gas in a short time.

' In order to eliminate the disadvantages of a tank-type ship stabilizing system when the ship is damaged at sea, it may also be desirable to quickly jettison the stabilizing liquid from the tanks. This can also be accomplished with the aid of the apparatus according to the present invention by introducing the gas into the tank space below the level .4 of the liquid and allowing the liquid to escape through side openings in the tank.

The apparatus necessary to jettison the liquid in the tanks is schematically shown in FIGURE 2. This figure illustrates a passive stabilizing system of the type shown in FIGURE 1 which also includes side tanks 10 and 11, an interconnecting channel 12 and an air line 13. The means for introducing the gas into the tanks 10 and 11 includes, again, the container 16, the lines 17 and the throttle valves 18 and 19. The lines 17 and the valves 18 and 19 are arranged to introduce the gas at a point in the tanks which is lower than the point at which the gas was introduced by the corresponding lines and valves of FIGURE 1. The tanks 10 and 11 are provided with flap openings 28 and 29, respectively, through which the liquid may be expelled. As the gas from the container 16 is introduced into the tanks 10 and 11, it rises to the air space I above the level of the liquid and forces the liquid out.

FIGURES 3a and 3b illustrate another embodiment of the present invention as applied to a ship stabilizing system 30 which operates according to the flume" principle. The purpose of this embodiment is to jettison the liquid stored in the system 30 as quickly as possible. It is not possible, with a system of this type, to change the relative levels of the liquid at various points of the system.

The gas is again stored, under pressure, in a container 31 in either the liquid or the gaseous state. This gas is passed through lines 32 and 33 and through valves 34 and 35 into the tank space at points below the level of the liquid. When introduced, this gas will rise to the top of the tank space and press the liquid out through flaps 36 and 37.

It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations.

We claim:

1. A ship stablizing system comprising, in combination:

(a) tank means having first and second portions located on opposite sides of the ship, respectively, said portions being in fluid communication with each other for passing fluid therebetween;

(b) means communicating with said tank means for introducing a liquid pressure medium which is a gas at room temperature and atmospheric pressure below the surface of a liquid in said tank means and thereby causing the liquid in at least one of said portions to be under pressure;

(c) separately olosable first and second outlet means communicating with said first and second tank portions, respectively.

2. The system defined in claim 1, wherein said first and second outlet means communicate with the bottoms of said first and second tank portions.

3. The system defined in claim 1 wherein said pressure medium is a fi-uorinated hydrocarbon gas.

4. The system defined in claim 3, wherein said pressure medium is dichlorodifluoromethane.

5. A ship stabilizing system comprising in combination:

(a) tank means having first and second portions located on opposite sides of the ship, respectively, said portions being in fluid communication with each other for passing fluid therebetween;

(b) means communicating with said tank means for introducing a pressure medium below the surface of a liquid in said tank means and thereby causing the liquid in at least one of said portions to be under pressure.

(c) separately closable first and second outlet means communicating with said and second tank portions, respectively, and

(d) said first and outlet means communicating with the tops of said first and second tank portions, and

(c) said tank means including at least one liquid equalizing channel interconnecting said first and said second portions below the level of said liquid, at least one air equalizing channel interconnecting said first and said second portions above the level of said liquid and means for closing said at least one air equalizing channel.

6. The system defined in claim 5, wherein said introducing means introduces said pressure medium into said tank means at the ends of said at least one liquid equalizing channel.

7. The system defined in claim 5, wherein said first and second outlet means are arranged at the ends of said at least one air equalizing channel.

8. The system as defined in claim 1 including storage means for holding said liquid pressure medium under pressure in the liquid condition, and a pressure medium stored in said storage means which is a gas at room temperature and atmospheric pressure and a liquid at the pressure maintained in the storage means.

References Cited UNITED STATES PATENTS 1,888,667 11/1932 Hort l14125 FOREIGN PATENTS 645,660 6/1937 Germany.

OTHER REFERENCES Ser. No. 132,695, Hort (A.P.C.), published May 11, 1943.

TRYGVE M. BLIX, Primary Examiner

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