US3688721A

US3688721A - Subsea towing vessel

Info

Publication number: US3688721A
Application number: US77482A
Authority: US
Inventors: John D Bennett
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-02
Filing date: 1970-10-02
Publication date: 1972-09-05
Anticipated expiration: 1989-09-05

Abstract

A subsea vessel towing submerged tankers for transporting oil under ice covered areas, is constructed so that passages are located at the front end of the vessel and extend to each side with a propeller therein to pull water through the passages for propulsion. Vanes are used to control direction and depth, and whiskers are used to sense contact with the ice or ocean bottom. Navigation aids are placed on the ocean floor along a preselected route. A telescoping escape tower with hot water jets and/or drills are used for cutting through the ice in an emergency. Jets are used near the stern of the vessel to line up the stern for connecting the tankers.

Description

United States Patent Bennett Sept. 5, 1972 [54] SUBSEA TOWING VESSEL FOREIGN PATENTS OR APPLICATIONS [72] Inventor: John D. Bennett, 503 N. Central Ex- 994,261 l0/ 1951 France ..1 15/16 pressway, Richardson, Tex. 75080 Primary Examiner--Trygve M. Blix [22] Flled 1970 Attorney-George L. Church, Donald R. Johnson, 2 App], 77,4 2 Wilmer E. McCorquodale, Jr. and John E. Holder 11 6R 14 40 12 R [57] TRACT [52] us. Cl- 4/1 l l A subsea vessel towing submerged tankers for transporting oil under ice covered areas, is constructed so [51] Int. Cl. ..B63g 8/00, B63h 11/00 that passages are located at the from end ofthe vessel Fleld 0f R, and extend to each i a p p l therein to 4/16 144 R, 144 B; 5/12, pull water through the passages for propulsion. Vanes are used to control direction and depth, and whiskers [56] References Cited are used to sense contact with the ice or ocean bottom. Navigation aids are placed on the ocean floor UNITED STATES PATENTS along a pre-selected route. A telescoping escape tower 3,145,683 8/1964 Kolb et al ..114/144 B with hot W J'F and/0r drills are used for cutting 3,572,273 3/1971 Wood ..114/40 gj ifi z z f xii 3,301,132 l/l967 Lehmann et al. ..114/16 R in the tankers P 3,461,831 8/1969 Lewis ..115/12 g 2,727,485 12/1955 Combs ..114/16 R 12 Claims, 3 Drawing Figures PATENT'EDSEP 51972 'INVENTOR JOHN 0. BENNETT SUBSEA TOWING VESSEL BACKGROUND OF THE INVENTION This invention deals with the problem of transporting substances in areas where it is difficult to use surface vessels because of ice floes or turbulent seas.

Currently, there are extensive plans to locate and develop natural resources in areas where ice covers the waterways during at least a substantial portion of the year. Such an area currently being explored is the North Slope of Alaska where massive hydrocarbon reserves have been found. Since the market for the reserves is located outside the North Slope area, the reserves must be transported long distances through very hostile weather environments.

Two basic transportation methods have been proposed for moving the reserves to market, i.e., tankers equipped to penetrate ice floes and insulated pipelines. A proposed pipeline has encountered opposition because of concern for disruption of the ecology through pollution of the environment. Because of the extreme cold the Arctic area does not recover from damage done to the surface for a very long time. It is argued that construction damage by heavy machinery used to build the pipeline would scar the surface for years because of severe erosion resulting from the killing of growth protecting the permafrost. Additionally, once the pipeline is constructed, other well known pollution hazards exist. An additional problem is that the pipeline traverses areas covered by permafrost and because of the need to maintain low viscosity of the oil for easier flow through the pipeline, such a pipeline would need to be heated because of the low environmental air temperature. Such heating runs the hazard of melting the permafrost and allowing the pipeline to sink in the quagmire remaining. Thus, it can be seen that one of the proposed methods of transporting hydrocarbons from the Arctic region is fraught with problems.

Another proposed method of transporting the hydrocarbons to refinery and marketing areas is by use of specially adapted tankers such as the SS Manhattan. The SS Manhattan recently made a feasibility voyage to the Arctic area to determine if a seagoing vessel could overcome the ice floes located in the Arctic Ocean with a specially reinforced hull. The main ice form encountered in the Arctic Ocean is 6 to 10 feet thick ice sheets, commonly measuring thousands of feet in diameter. Rafted ice, pressure ridges, and icebergs are also encountered, although infrequently, and can be over 100 feet thick. The SS Manhattan encountered pressure ridges it was unable to penetrate, and an alternate route was chosen because the proposed route was obstructed by a large field of pressure ridges. It is thus apparent that a surface vessel used for transporting hydrocarbons or other materials is limited as to where it can travel in the Arctic region. It is conceivable that more efficient ice breaker-type tankers can be designed; however, there would still be areas that could not be reached because of economics or physical incapability. Thus there is a need for an improved transportation system that does not have the inconveniences and limitations of the systems previously proposed. It is therefore an object of the present invention to provide an improved transportation system for use in ice covered ocean areas.

SUMMARY OF THE INVENTION With these and other objects in view, the present invention contemplates a subsea vessel for moving subsea tankers. The vessel is similar in construction to a submarine and has passageways extending from the bow of the vessel to a point along each side. A propeller is positioned in the passageways and is arranged to pull water therethrough for propulsion. Vertical and directional control is obtained by adjustable vanes located near the exit of the passageways. Jets emitting a fluid are located at the stern of the vessel for alignment with the tankers. Navigation aids are located on the ocean floor in a predetermined route thereby facilitating automatic navigation of the vessel. A telescoping tower is used for crew removal and incorporates ice cutters such as hot water jets.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a subsea vessel and tanker;

FIG. 2 is a plan sectional view of the subsea vessel and tanker of FIG. 1 taken along the lines 2-2 of FIG. 1; and

FIGS. 3A and 3B depict elevational views of a vane member in an open and closed position.

7 DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1 there is seen a subsea vessel 7 12 having an inlet 20 located at the front of the vessel and an outlet 28 located on each side of the vessel. A passageway 46 extends between the inlet 20 and the outlet 28 and is shown by hidden lines. lnterposed in the passageway 46 is propeller 18, also shown in hidden lines. Suitable means (not shown) are provided for powering the propeller. The propeller 18 is positioned so that it is shrouded by the passageway 46. Located near the exit 28 of the passageway 46 is horizontal vane member 16 which is shown by both solid and hidden lines and vertical vane member 22, having upstanding portion 50. In the operation of the subsea vessel 12, wateris pulled in through inlet 20 by the shrouded propeller l8 and forced through outlet 28. Horizontal direction, depth control, and braking is provided by

vane members

16 and 22. Alternative braking is provided by deflector 52. When the vane member 16 is pivoted clockwise, the vessel 12 will be forced upward by reaction to the water which is being directed downward by the vane member 16. If the vane member 16 is pivoted counter-clockwise, the vessel 12 will then be forced downward. For turning the vessel 12, one vertical vane member 22 is rotated to direct the water exiting outlet 28 further away from the side of vessel 12. The dissipates the rearward force of the fluid exiting outlet 28 and the reactant forward thrust of the vessel 12. Since the opposite vertical vane member 22 allows water exiting the other outlet 28 to flow substantially straight back, the vessel 12 will turn in the direction of the rotated vertical vane member 22 because that side is being forced forward at a slower rate than the other side. If both vertical vane members 22 are rotated so that water flowing from exits 28 is not directed rearwardly, the vessel 12 will slow down and stop.

Alternatively, deflector 52 may be used for turning or stopping the vessel 12. The deflector 52 is shown in FIG. 2 and will be explained further in the discussion of that figure. Vane

members

16 and 22 and deflector 52 are controlled by vane member linkages (not shown) which are operated by a control means 40. Control means 40 may be manually or automatically operated. For manual operation, levers are manipulated to activate hydraulic cylinders connected to such levers by hydraulic lines. The hydraulic cylinders operate to pivot horizontal vane members 16 or rotate the position of the upstanding portion 50 of the vertical vane member 22. In automatic operation of the vane members l6 and 22, the manual levers are bypassed by circuitry connected with a computer which is continuously fed information as to depth, nearness of obstructions, buoyancy, etc. Such information is blended with a preset course and programmed instructions. The computer through electrical circuitry activates mechanical elements equivalent to the function of the lever for operating the hydraulic cylinders for corrections of vessel position and depth. Control systems suited for use to control the submarine are described in texts such as Chestnut and Mayer, Servomechanisms and Regulating System Design (New York: John Wiley & Sons, Inc., 1951) or BuAer Report AE-6l-4 Methods of Analysis and Synthesis of Piloted Aircraft Flight Control Systems" (Vol. 1, Oct., 1952 Published by the direction of the Chief of the Bureau of Aeronautics). I

Also connected to control means 40 are whiskers 33 which physically contact nearby surfaces. Upon whisker contactwith a surface, the pressure generated by such contact operates to close a circuit to activate a signalling device if manual operation is desired. If automatic operation is being used, the closed circuit provides information to the computer which would then activate controls for evasive action, or the closed circuitry caused by pressure on the feelers would act to energize the control means 40 for operation of the hydraulic cylinders to reposition the vane members 16. Similar whiskers could be positioned on the sides of the vessel 12, and would operate in the same manner to position the vertical vane members 22 or deflectors 52 (FIG. 2). Thus, if an impending collision is sensed by the whiskers 33, a signal is transmitted by control means 40 to change the position of vane member 16 to maneuver the subsea tug 12 away from the sensed surface.

Also located on the subsea tug 12 is telescoping escape tower 24. The telescoping escape tower 24 is normally in a retracted position within the subsea vessel 12. In the event of a breakdown of the vessel 12 beneath an ice flow the escape tower 24 is equipped with escape jets 34 capable of emitting a heated fluid. These escape jets 34 are located around the periphery of the telescoping escape tower 24 and are directed upwardly. In operation, the vessel 12 is located adjacent the lower surface of the ice floe by controlling the amount of ballast in the ballast means 14 (FIG. 2). The escape tower is then in position next to the ice floe and heated fluids from the vessel propulsion system are forced against the bottom surface of the ice floe to effect melting of the ice. Once the ice is melted through, the crew may then escape to the surface of the ice floe. The telescoping escape tower 24 can be raised and lowered by hydraulic or other conventional system.

This escape system should be powered by an energy system independent of the vessel propulsion system, since breakdown of the vessel 12 would ordinarily be caused by failure of the propulsion system.

The subsea vessel 12 is adapted to pull a subsea tanker 30. Connector member 26 secures the subsea tanker 30 to the subsea vessel 12 and can be of any conventional design. For alignment of the subsea vessel 12 with the tanker 30, jets 32 are located near the stern of the vessel 12. The stem jets 32 emit high pressure liquids or gas and are located on each side of the vessel so that the stern of the vessel can be aligned with the tanker 30 for easier connection. As shown here, the vessel 12 and tanker 30 are positioned above an ocean floor 38. Navigation aids 36 are located along a predetermined route on the ocean floor 38 so that sensors located in the vessel 12 could operate controls to keep the vessel on such a predetermined route. These navigation aids 36 may be battery powered and continuously transmit a signal which can be picked up by equipment on the vessel 12 capable of determining the direction from which a signal is initiated. The signal direction equipment can be connected to control means 40 for adjusting vertical vane members 22 to keep the vessel 12 on the predetermined route. Operation of the control means 40 may be in the same manner as previously discussed. It is conceived that such a vessel with the navigation aids 36 could be entirely automated, thereby eliminating the need for a crew for operations. Navigation aids adaptable for use to guide a subsea tanker are made available by various companies such as Thompson-CSF of Versailles, France, or AMF Electrical Products Development Division, Alexandria, Virginia.

Referring next to FIG. 2, there is seen a plan sectional view of the vessel and tanker shown in FIG. 1

taken along the lines 2--2. Here again, propeller l8 pulls water in inlet 20 and forces it through outlets 28. The vane members 16, positioned and manipulated by control means 40, determines vertical positioning together with ballast means 14. The-ballast means 14 includes a pump and ports for admitting and discharging water. The pump and ports are not shown in the drawings, and may be of any conventional design. Operation of the pumps related to the ballast means 14 is accomplished by manual controls or the previously discussed control means 40. If control means 40 is used, information as to depth is fed to the computer which compares the data to-the depth at which the vessel should be, and if a variance occurs, a signal issues from the computer to operate controls which activate the pump for admitting or discharging ballast. This operation may be arranged to occur only after failure of manipulation of the horizontal vane member 16 to stabilize the depth of the vessel. By closing a portion or all of one of the exits 28, the vessel can be turned in one direction or the other. The vane members 16 can be pivoted near its middle so that a single element vane member could be utilized. However, for greater stability and control the vane members shown in FIGS. 3A and 3B are preferred. Vertical vane member 22 having an upstanding portion 50 is positioned adjacent the exit 28. As depicted, the upstanding portion 50 deflects the fluid leaving exit 28 away from the side of the vessel 12 to prevent friction of the water exiting the passageways 46 with the skin of the subsea vessel 12. It also eliminates a great deal of turbulence by allowing the water adjacent the skin of the subsea vessel12 to follow the path shown by arrows 44. When the upstanding portion 50 is rotated away from the. side of the vessel 12, the reactant forward force is diminished. Thus by rotating one or the other upstanding portions 50, the vessel can be made to turn.

Connected to the vessel 12 is tanker 30 which has ballast system 42 therein which is controlled by control means 40 in the same manner as are ballast means 14. Connector means 26 contains an electrical conductor for activating the ballast pump related to system 42. Shown in an outward position on the port side and in a retracted position on the starboard side of the vessel are deflectors 52. These deflectors 52 are rigid, concave members and are rotated by hydraulic cylinders or other conventional manner in the same manner as the

vane members

16 and 22, and are used for turning or stopping the vessel 12. When in an outward position, the fluid exiting passageway 46 strikes the deflector 52 and is directed toward the prow of the vessel. This direction of flow creates a force pushing the vessel 12 backwards. If both deflectors 52 are in an outward position, the forward movement of the vessel will be stopped. If only one is in an outward position, the vessel will be abruptly turned because one side of the vessel 12 will be forced forward and the other side will be forced rearward.

FIGS. 3A and 38 describe two positions of the vane member 16 shown in FIGS. 1 and 2. FIG. 3A shows the vane member 16 in a position which is used to control both direction and braking, by restricting or closing off one of the exits 28. By opening the vane member 16 to close off one of the exits 28, water will exit only the opposing exit 28. Thus, if the vane member 16 of FIG. 2 located on the starboard side of the tug 12 is closed, the tug will turn in a clockwise direction. If both the vane members 16 are opened in the position illustrated in FIG. 3A, the vessel will slow down and stop because both exits 28 are closed. For vertical positioning of the tug 12, the vane member 16 is in a closed position as shown in FIG. 3B. This allows the water exiting the conduit 40 to be directed in an upward or downward direction by slanting the vane member 16, thereby forcing the tug downward or upward by the reactive force.

There are several advantages obtained from the location of the vessel propulsion system and the type of controls utilized therein. Because the propeller l8 and outlets 28 are located in the forward portion of the vessel 12, the vessel responds more quickly to a change in direction. The stern of the vessel does not have to swing around before effecting a change in course. With the combination of the forwardly located outlets 28 and stem jets 32, the vessel 12 can be moved in and out of extremely tight locations. Also with the outlets 28 located on the sides of vessel 12, the tanker 30 is not positioned adjacent a propeller or fluid exhaust, which would have adverse effects due to a substantial reduction of propulsion efliciency. This reduction of efficiency would be caused by forcing water against the tanker 30 and thereby exerting a force in a direction opposite to the vessels forward direction. The

vane members

16 and 22 and deflectors 52 afiord very quick direction and speed changes as well as quick surfacing and diving ability. Additionally, the telescoping-of the escape tower 24 allows for a streamlined vessel for easier passage through the water.

It is contemplated that other configurations of the vane members may be used as well as alternatives to the propeller 18. Therefore, while particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. In a subsea vessel the improvement comprising: conduit means having an entrance in the leading edge of, the prow of the vessel, and having an exit on each side of the vessel in the forward portion of the vessel which communicate with the vessel environment; propeller means located in the conduit means; means located at each exit of the conduit means for controlling the direction of water exiting the conduit means; and jets directed outwardly at right angles to thelongitudinal axis of the vessel and located on the side and at the rear of the vessel for controlling movement of the rear of the vessel.

2. The vessel of claim 1 wherein the conduit means exits have longitudinal axes directed toward the rear of the vessel 3. The vessel of claim 1 including means for connecting a subsea tanker located at the rear of the vessel.

4. An undersea transport system comprising: a cylindrical housing having an inlet at the leading edge of the housing and an outlet on each side of the forward portion of the housing, with conduit means therebetween; water directing means located in the conduit means ad- 40 jacent each outlet; propeller means located in the conduit means adjacent the inlet; storage means removably attached at the rear of the housing; and directional jets located in each side wall of the housing at the rear of the housing and directed at approximately right angles to the longitudinal axis of the housing.

5. The system of claim 4 including a first ballast means located in said housing comprising ballast chambers and ballast control means.

6. The system of claim 5 wherein the storage means comprises a plurality of removably connected chambers having second ballast means for controlling vertically positioning of the storage means which is actuated by the first ballast control means.

7. The system of claim 4 including means located at each outlet on the sides of the housing for directing fluids exiting the conduit means and wherein the conduit means comprises two conduits angled from the sides of the housing which meet to form a single conduit toward the front end of the housing.

8. The system of claim 7 including automatic control means and ballast means wherein said control means controls movement of the fluid directing means and operation of the first ballast means.

9. The system of claim 4 including means for guiding the undersea propulsion means which comprises signal transmitting navigation aids located on the ocean floor along the desired transportation route and means for sel to eachside of the forward portion of the vessel; means for propelling water through the conduit means; means for controlling the direction of water exiting the conduit means; and jetting means located on each side of the rear of the vessel for controlling lateral movement of the rear of the vessel.

Claims

1. In a subsea vessel the improvement comprising: conduit means having an entrance in the leading edge of the prow of the vessel, and having an exit on each side of the vessel in the forward portion of the vessel which communicate with the vessel environment; propeller means located in the conduit means; means located at each exit of the conduit means for controlling the direction of water exiting the conduit means; and jets directed outwardly at right angles to the longitudinal axis of the vessel and located on the side and at the rear of the vessel for controlling movement of the rear of the vessel.

2. The vessel of claim 1 wherein the conduit means exits have longitudinal axes directed toward the rear of the vessel

3. The vessel of claim 1 including means for connecting a subsea tanker located at the rear of the vessel.

4. An undersea transport system comprising: a cylindrical housing having an inlet at the leading edge of the housing and an outlet on each side of the forward portion of the housing, with conduit means thErebetween; water directing means located in the conduit means adjacent each outlet; propeller means located in the conduit means adjacent the inlet; storage means removably attached at the rear of the housing; and directional jets located in each side wall of the housing at the rear of the housing and directed at approximately right angles to the longitudinal axis of the housing.

9. The system of claim 4 including means for guiding the undersea propulsion means which comprises signal transmitting navigation aids located on the ocean floor along the desired transportation route and means for receiving such signals and directing movement of the propulsion means.

10. The system of claim 4 including means located in the housing for penetrating through the ice.

11. The system of claim 10 wherein the ice penetrating means comprises hot fluid jets.

12. In a subsea vessel, a propulsion system comprising: conduit means extending from the prow of the vessel to each side of the forward portion of the vessel; means for propelling water through the conduit means; means for controlling the direction of water exiting the conduit means; and jetting means located on each side of the rear of the vessel for controlling lateral movement of the rear of the vessel.