US3453980A - Submersible barge - Google Patents

Description

y 1969 DARCY A. SHOCK ,4

SUBMERS I BLE BARGE Filed April :1, 1968 Sheet of 2 l3 IO PH/Of? ART F/GKI INVENTOR.

D'ARCY A. SHOCK ATTORNEY y 1969 DARCY A. SHOCK 3,453,980

SUBMERSIBLE BARGE Filed April 1, 1968 Sheet 2 of 2 FIG. 8

INVENTOR.

054m) A. SHOCK ATTORNEY United States Patent ()fiiice 3,453,980 Patented July 8, 1969 3,453,980 SUBMERSIBLE BARGE DArcy A. Shock, Ponca City, Okla., assignor to Continental Oil Company, Ponco City, Okla., a corporation of Delaware Filed Apr. 1, 1968, Ser. No. 718,316 Int. Cl. B63!) 21/56 US. Cl. 114235 12 Claims ABSTRACT OF THE DISCLOSURE A submersible towed barge is maintained at a constant depth in the water by attaching to the bow and/or stern of the submersible barge a rod or stinger aligned with the longitudinal axis of the barge. A paravane is attached to the rod such that the paravane is free to rotate about the rod and prevented from moving longitudinally along the rod. The paravane contains all of the depth control sensing apparatus and vanes necessary to maintain the barge at the predetermined depth. The paravane can also be attached to the tow rope or other locations on the barge.

Description of the prior art The submersible barge has always been an extremely attractive method for movement of products, particularly liquid products, economically from one point to another. Many patents have been issued relating to the submersible barge, e.g., Patents Nos. 3,208,423; 3,368,512; 3,352,271; 3,368,515; 3,369,515. All of these fairly recent patents suggest feasible submersible barges and methods of filling and operating the barges in order to make them commercially useable. The barge described in these patents, however, is the type wherein the depth is controlled by lengthening or shortening the tow rope in a manner to decrease or increase respectively the vertical lift on the barge. Since the barge contains a built-in downward force created by the fins, the depth could be maintained constant by balancing the upward and downward forces. This barge is quite feasible when the density of the water is constant. However, if the barge must operate in areas where the specific gravity varies by any appreciable extent over a fairly short distance (a change in specific gravity of .001 causes the barge to change its depth by as much as feet), then the tow rope must be reeled and unreeled by an extent exceeding the ability of most deck winches. Since it is extremely important that the barge be maintained at a constant depth, an extensive amount of work was done in an attempt to determine and maintain the depth of the barge. In the controllable barge field, the approach has been to either control the depth of the barge fro-m the ship by remotely sensing the depth of the barge and transmitting a signal to the barge, causing built-in apparatus to shift the depth, or build into the barge automatic depth sensing equipment which can control apparatus which is built into the barge for maintaining the depth relatively constant. This type of barge unfortunately approached the cost of a submarine and since the barge contained in a permanent nature all of the expensive equipment necessary to maintain the depth constant, the cost of the barge became prohibitive. Further, in many instances, it is necessary to leave the barge as a storage facility for an extended period of time. The initial investment in the barge made the storage charges prohibitive for this type use.

Summary of the invention The present invention contemplates retaining the economy of the barge depth controlled by varying the length of the tow rope and yet having the versatility of the barge depth controlled by having built-in depth control equipment. In Patent No. 3,375,800, a paravane is disclosed which maintains a neutral body at a consant depth by proper mounting of the paravane on the neutral body. The paravane is mounted such that it is free to rotate about the neutral body but is also prevented from moving longitudinally along the neutral body. Contained within the paravane is depth sensing means and apparatus necessary to maintain the paravane and the neutral body at a constant depth. It was discovered by the inventors that a submersible barge under proper buoyancy conditions could be considered a neutral body. Therefore, if a means were available for mounting such a paravane on the submersible barge, then it would be possible to maintain the submersible barge at a constant depth. The paravanes would also have the advantage of being removable such that if the barge were to be used for storage, the paravane could be removed from the barge, thereby permitting it to be used for towing other barges, thus eliminating the storage costs for the control means during the time the barge is idle. It has further advantages in that complex gear is not necessary aboard the tow ship in order to maintain the barge at a constant depth, such as special winches or depth control sensing apparatus and the like.

Therefore, it is an object of this invention to provide a depth sensing means for a barge which is external to the barge hull.

It is a further object of this invention to provide a depth sensing means for a submersible barge which is removable.

It is a still further object of this invention to provide a depth sensing means for a barge that eliminates the necessity for complex towing gear aboard the tow vessel.

It is a further object of this invention to provide a submersible barge which has a replaceable towing mechanism that, if damaged or faulty, can be quickly replaced by inexperienced personnel without the necessity for drydocking the barge.

Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate the invention.

Brief description 'of the figures FIG. 1 is the top view of a paravane used for maintaining the barge at constant depth.

FIG. 2 is a side view of the barge showing the paravane axially mounted on the front of the barge and the tow connection at a point separate from the paravane location.

FIG. 3 is a side view of the barge wherein the tow point is on the paravane mount.

FIG. 4 is a partial side view of the barge showing the paravane attached to the tow cable.

FIG. 5 illustrates a method for towing more than one barge.

FIGURES 6 and 7 show the front view of the barge with various methods for mounting the paravane, and FIG. 8 shows a submersible barge having a paravane mounted in both the front and the rear of the barge. Referring to all of the figures (similar numbers will be used for similar elements throughout this application) but in particular to FIG. 1, a paravane 10 is shown having a body 11, a pair of control vanes 12 and a plurality of end fins 13. Particular details of the paravane, its construction and mode of operation are clearly described in Patent No. 3,375,800, but the construction and operation can be briefly described as comprising body 11 which has contained therein a pressure reference chamber mechanically linked to control vanes 12. The reference chamber is filled with air pressure such that when the proper depth of the paravane is reached, the forces externally and internally on the reference chamber will be balanced, causing the control vanes 12 to be parallel to the movement of the paravane through the water. Any change in the depth of the paravane will cause an unbalancing of forces on the reference chamber which will be reflected in a position change of vanes 12. The paravane, in addition to the depth sensing apparatus, contains a bearing at the nose 14 of paravane 10 which permits the paravane to freely rotate about cable 15. The bearing also prevents longitudinal movement of the paravane along cable 15.

FIG. 2 shows a submersible barge hull having a tow rope 21 attached to hull 20 by anchor means 22. A plurality of fins 23 are mounted on the stern end of hull 20. A rod or stinger is mounted axially to hull 20 by a socket 26. Attached to stinger 25 is paravane 10.

FIG. 3 varies from FIG. 2 only in that the tow rope 21 is attached to the end of stinger 25 by means of a swivel connection 30.

In FIG. 4 paravane 10 is mounted on the tow rope 21 and clamped to the tow rope in a manner similar to that described in reference to the apparatus of FIG. 1. Tow rope 21 is attached to barge hull 20 by anchor means 22A.

FIG. 8 shows a modified version of FIG. 2, wherein an additional stinger 31 is added axially to the stern of barge 20 and having a second paravane 10A attached thereto.

FIGURES 6 and 7, which show the front view of the barge, illustrate various positions for mounting paravanes. One of the problems that has been experienced in towing a barge through the water in port is that the barge will tend to dive with the slightest forward movement since the vanes of the paravane are in the full dive position. The vanes must of necessity be in the full dive position since the reference cell pressure will have no water pressure counteracting or equalizing the forces on the reference chamber. The mounting location of the paravane 10 in FIG. 6 eliminates the above problem. In FIG. 6, paravane 10 is mounted so that when the ballast of the barge is removed, the paravane will be just above the water line 50. The ballast referred to above is the liquid ballast carried in the tanks which is placed there in sufiicient quantities so that the barge will retain a certain calculated buoyancy when fully loaded. The ballast serves two purposes. The first purpose is to insure the proper buoyancy of the barge, e.g., in the case of a 5,000 dwt. barge, the reserve buoyancy should be 50 tons. If the cargo is not suflicient to reach this reserve buoyancy, then additional ballast must be added so that the barge will be within the operating limits of reserve buoyancy. The second purpose of the ballast is to raise (when the ballast is pumped out) the barge sufficiently out of the water so that it can be handled in the port of destination. Thus, referring to FIG. 6, when the barge is in port, the water line will be at 50 and when the barge is filled to its proper reserve buoyancy, the water line will be at the line shown in 50'. The difference between 50 and 50 is made up by filling the ballast tanks with sea Water. The difference in water line 50 and 50' affords a convenient place for mounting paravane 10. Thus, when the ballast is blown or pumped out, moving the water line from 50' to 50, paravane 10 will be lifted out of the water. Since the vanes 12 cannot contact the surface of the water, the barge can be easily towed on the surface of the water. Since most harbors are fairly shallow, it is important that the barge does not attempt or succeed in diving to any depth while being towed.

FIG. 7 shows a means for mounting more than one paravane so that more force can be brought on the barge hull 20 for diving purposes. Two paravanes, as illustrated, however, present certain problems since both paravanes must be very closely matched in performance or else a rotational force will be generated about center axis 40 of barge hull 20.

Operation Referring to all of the figures, but in particular to FIG. 2, when the barge is on the surface, vane 12 will be in the position shown. As the barge acquires forward movement, the water flowing over vane 12 will cause a downward force on the bow of hull 20. Pins 23 tend to stabilize the barge about roll axis or center 40. Fins 23 can also have a downward force which tends to aid in diving the barge and maintaining it at a constant depth. Since stinger 25 'is rigidly attached through socket 26 to hull 20 and since stinger 25 is itself rigid, the forces generated by vane 12 will be immediately applied to barge hull 20. Once the barge attains the desired depth, which will be controlled principally by the reference chamber within paravane 10, vane 12 will tend to rotate until it is parallel with the axis 40 of barge 20. Since there will be an upward component of force generated by cable 21, some downward force must of necessity be continuously generated by fin 12. It is of course obvious that the longer the rope 21, the less counteracting force will need to be generated by vane 12.

The preferred embodiment is shown in FIG. 2, as above described; however, a modified version of FIG. 2 is shown in FIG. 8, wherein both the bow and stern of barge hull 20 contain paravanes 10 and 10A. The two paravanes will tend to maintain more control over the barge at all times. Also, the barge will submerge faster with two paravanes than with one since a larger total downward force is being applied when the tow is initially begun. The over-all control of the barge will be better since both the bow and the stern will have controllable fins. The dual control will also tend to eliminate any tendency to dive, caused by paravane 10 when the tow ship begins to slow down. The two paravanes as shown in FIG. 8, would also lend the system to a multiple tow, as shown in FIG. 5. Since more than one barge can still be considered an elongated neutral body, additional paravanes will maintain barges following the initial barge, e.g., barge 28, at a predetermined depth. One of the basic problems heretofore with multiple towing of barges has been the porpoise effect, caused by the effect of one barge on the barges being towed behind. For example, if barge 20, for some reason, began to lift, the stern of barge 20 would cause a vertical component on the bow of barge 28, causing barge 28 to lift. The lift would be transmitted through barge 28 to any subsequent barges following. Likewise, any lift on any of the middle barges would cause lift forces to be transmitted to all of the other nearby barges. The chain effect would cause an oscillation in the barges being towed, creating an unstable condition. Control of the tow could be lost very quickly under some conditions. However, with a system as shown in FIG. 5, wherein each barge has its own individual depth control, any forces transmitted from barge 20, for example, to barge 28, would immediately be counteracted by paravane 10A. The counteracting force would tend to dampen out the transmission of these forces to subsequent barges. Therefore, the instability of one barge would never cause the tow to reach an uncontrollable state.

When barge 20 has reached port, the control portion 10 or 10A could easily be removed. For example, paravane 10 can be separated into two pieces, an upper and lower portion, and removed from around the stinger 25. The bearing can be left on the stinger and reused at a later date. The expensive paravane, however, can then be used on the next tow, which will probably already have a mounting bearing on its stinger, thereby simply requiring that the paravane be clamped around the new stinger and bearing. It is obviously under these conditions that the high cost of the control mechanism must not be figured into the storage cost of the barge. Further an added advantage is that the barge owner can control the use of the barge since without the control mechanism, the barge cannot be towed except on the surface of the water. The paravanes also provide several other features. One of the most important is that in case a paravane becomes defective, it can simply be removed and a replacement substituted. Paravane 10 can be removed by any unskilled crewman aboard the tow ship. The removal and replacement can be done while the barge is in the water, eliminating the requirement for dry-dock facilities and downtime which for every day the barge is inoperative, costs the owner docking fees and depreciation expenses. It is obvious that many configurations of the barge paravane and tow cable are conceivable. FIG. 4 illustrates a method of mounting the paravane directly on the cable. This operational method does have one disadvantage in that when the tension on cable 21 is released, e.g., when slowing down, the natural tendency of the paravane is to maintain the depth constant. This upward force on a slack cable will tend to raise the paravane and the cable up, causing momentary loss of control of the barge. Using the configuration of FIG. 4 then, it is obvious that some tension must be maintained on the cable at all times.

Example A model constructed in accordance with the teachings of FIG. 3 was built and tested. The model was approximately one ton dwt. and 18 feet long. Ballast was added to the barge having a total weight of 691 pounds. The stringer 25 was made of tubing 40 feet long and 2 /8 inches outside diameter. The controller 10 mounted to the stinger is a standard CONDEP cable depth control used in a seismic exploration for maintaining seismic cables at a constant depth. The controller was set to maintain a 20' depth. The tests were run in water having a depth of approximately 70 on a 2.1 nautical mile course in Boston harbor. During run number 1, the average speed was 7.3 knots. After the ship reached 7.3 knots, the barge maintained a depth of 18.5i' and maintained this depth throughout the run. Run number 2the average speed was 8.9 knots. During this run the barge maintained its depth within i2. The third run was made at 9.2 knots and after the ship reached full speed, the barge attained a depth of 16'11.

An additional modification is shown in FIG. wherein two paravanes and 100 are attached to a single stinger 25 to the bow of hull 20. The additional paravane or paravanes will only become necessary if more diving force is needed, or if large variations are experienced in water density, for example. It is, of course, within the scope of this invention that any number of paravanes can be attached to the bow or the stem or intermediate the bow and the stern of the submersible hull 20.

All of the drawings have shown a substantially cylindrical hull 20. It is obvious that other shapes could be used. The cylindrical hull is preferred since it offers the least resistance and hence the highest efiiciency for a submersible barge. However, if the situation calls for a barge that must be towed in fairly shallow water, a flattened form of barge hull could be used.

Changes may be made in the combination and arrangement of elements as heretofore set forth in this specification and shown in the drawings; it being understood that changes maybe made in the embodiments disclosed without departing from the spirit and scope of the invention.

What is claimed is:

1. A submersible tow comprising (a) an elongated cargo carrying hull having a bow and stern and having a longitudinal axis;

(b) a cylindrical shaft having a longitudinal axis;

(0) means for attaching said shaft to said hull such that said shaft axis is substantially parallel to said hulls longitudinal axis;

(d) a paravane, containing depth sensing apparatus and means responsive to said depth sensing apparatus for maintaining said paravane at a constant control depth when said paravane is moved through the water;

(e) bearing means for rotatably mounting said paravane to said shaft.

2. A device as described in claim 1 wherein the longitudinal axis of said shaft is common with said hull axis.

3. A device as described in claim 1 wherein said shaft is rigidly attached to said hull.

4. A device as described in claim 1 wherein said shaft axis is parallel with said hull axis and at a point on the bow of said hull falling in a vertical plane through said hull axis.

5. A device as described in claim 1 additionally including a second shaft, means for attaching said second shaft to the stern of said hull such that the axis of said second shaft is parallel with the axis of said hull, and a second paravane means rotatably mounted on. said second shaft.

6. In a submersible tow having a cargo carrying hull including means for towing said hull through the water, an improvement comprising paravane means, bearing means for rotatably attaching said paravane to said hull, said paravane means including depth sensing means, and, means for causing said paravane to seek a predetermined depth in the water connected to said depth sensing means.

7. A device as described in claim 6 wherein said paravane means comprise a plurality of paravanes.

8. A device as described in claim 7 wherein said plurality of paravanes includes at least a paravane attached to the bow and a paravane attached to the stern of said submersible tow.

9. A device as described in claim 6 wherein said plurality of paravane means comprises at least two paravanes, means for attaching said two paravanes so that the longitudinal axis of said paravanes coincides with the longitudinal axis of said submersible tow and wherein at least one paravane is attached to the bow of said barge and a second paravane is attached to the stern of said barge.

10. A device as described in claim 6 wherein said plurality of paravane means comprise at least two paravanes and wherein each of said paravanes is mounted in the bow of said submersible barge such that the longitudinal axis of each of said paravanes is parallel to the longitudinal axis of said submersible barge.

11. A submersible barge train comprising a plurality of submersible barges each having an elongated hull; means for attaching a tow rope to said ifirst submersible barge; means for attaching the bow of second barge to the stern of said first barge; means for attaching the bow of each succeeding barge to the stern of the barge in front of said succeeding barge; paravane means; and bearing means for rotatably attaching said paravane means to the bow of each of said barges.

12. A train as described in claim lll wherein each of said paravanes is mounted on said connecting means between said barges so that paravane means is free to rotate about said connecting means but prevented from moving longitudinally along said connecting means and means for attaching a paravane to the bow of said first submersible barge.

3/ 1968 Baker. 4/1968 Cole et al.

TRYGVE M. BLIX, Primary Examiner.

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