US3892287A

US3892287A - Vacuum ice anchor

Info

Publication number: US3892287A
Application number: US399239A
Authority: US
Inventors: John Bennett
Original assignee: Sun Oil Co
Current assignee: Sunoco Inc
Priority date: 1973-09-20
Filing date: 1973-09-20
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: CA1004552A

Abstract

A portable anchor for use in ice covered areas is used for towing vehicles over or through ice and includes a structure with a large lateral area having a flexible material around its periphery. A vacuum is formed on the underside of the structure by conventional means, such as a pump. One embodiment of the structure includes a self-propelled surface effect vehicle having reversible fans for hovering or for providing the vacuum.

Description

United States Patent 1191 Bennett July 11 1975 [541 VACUUM ICE ANCHOR 3,458,007 7/1969 Todd 180/124 3,512,603 /1970 Crewe et a1.... 180/124 [75] Inventor: John Bennett, Denton, Tex. 3,717,115 2/1973 Abendroth I h I H H4/42 [73] Assigneez Sun on Company, Dallas, 3,730,300 5/1973 Scherenberg r 188/5 [22] Filed: Sept 1973 Primary Examiner-Duane A. Reger [21] Appl. No: 399,239 Assistant ExaminerGalen L. Barefoot Attorney, Agent, or Firm-George L. Church; Donald 52 us. c1 130/115; 52/155; 114/206 R Johnson; John Hdder [51] lnt. Cl Bb 39/00 58 Field of Search 114/206 R, 67 A; 52/155, ABSTRACT [56] References Cited UNITED STATES PATENTS 2,379,991 7/1945 Riboud 188/5 2,895,301 7/1959 Casagrande et a1. 61/465 3,051,117 8/1962 Hunter 114/206 R 3,116,897 1/1964 Theed /115 3,246,711 4/1966 Snoeyenbos 180/115 3,348,517 10/1967 Johnson et a1 .1 114/206 R A portable anchor for use in ice covered areas is used for towing vehicles over or through ice and includes a structure with a large lateral area having a flexible material around its periphery. A vacuum is formed on the underside of the structure by conventional means, such as a pump. One embodiment of the structure includes a self-propelled surface effect vehicle having reversible fans for hovering or for providing the vacuum.

8 Claims, 3 Drawing Figures PATEHTEMUU MMWM H K W/ MIM HJW H VACUUM ICE ANCHOR BACKGROUND OF THE INVENTION This invention relates to movement of vehicles or structures across ice covered terrain.

There currently is an extensive mineral exploration effort being made in the Canadian Arctic, particularly for oil and gas. Several wells have been drilled on land areas in the high Arctic, and plans are now being made to drill offshore. Since ice and snow cover both onshore and offshore areas, many logistic problems are created. In certain onshore areas, equipment cannot easily be transported overland by conventional wheeled vehicles and must instead be transported by air. This initially entails the dropping of equipment to clear a runway and drill site. These clearing operations often require the expenditure of considerable time and expense due to the conditions of the Arctic terrain. For example, the equipment often gets stuck in areas where a thin layer of ice lies over deep snow. Other vehicles must be used to free them, and they often meet with the same fate. However, once these difficulties are overcome and a landing field is finished, supplies can be bought in by air and fairly conventional drilling can be commenced, modified only to compensate for the extreme cold.

In offshore areas, however, conventional drilling practices cannot be readily utilized except during the short summer months when drilling can be accomplished by drill ships. Logistics in such cases must be prepared long in advance in order to bring the majority of supplies in by ship. Other supplies that are needed on a short term basis must be provided by an auxiliary system, which would ordinarily include an air strip located nearby on land to allow air transport to that point and barges to transfer the supplies from the air strip to the drill ship. In the summer, therefore, exploratory drilling in the offshore Canadian Arctic is little more difficult than in most other remote offshore areas.

After the short summer drilling season has ended, conventional transportation and drilling techniques cannot be used due to the severe conditions created by the Arctic winter. Transportation by water is curtailed except for icebreakers by ice sheets that cover most areas. These sheets can be six to ten feet thick, and in some areas where rafted ice and pressure ridges are present the ice thickness can exceed thirty feet. Rafted ice describes the condition when one portion of an ice sheet slides over another portion. Pressure ridges are caused when adjacent sections of ice crush together and form a pile of broken ice sections above and below the ice sheet. Surface transportation is also curtailed by the irregularity of terrain caused by these phenomena, which necessitates the clearing of roads. In addition there is the problem of the ices breaking away from the shore, creating impassible gulfs.

Other problems are also presented by the Arctic winter to drilling operations. Conventional drillin platforms cannot be utilized due to the tremendous forces generated by the moving ice. Such a rigid structure would be qui-rkl; -stroyed. Some sort of ice removal would l!.3f0rc ue necessary to prevent ice from infringing on the platform. There is also the problem of moving the platform from one location to another, which will be impeded by the transportation problems outlined above whether the platform is floated by water or skidded overland to a new location. Free floating drill ships and semi-submersibles encounter similar problems because of the ice movement. Since these floaters are not rigidly attached to the bottom, they will not be crushed", however, they will be displaced by the moving ice. This of course would prevent them from remaining over the drill site unless the floaters have an ice removal to prevent displacement. Movement of a floater to a new location would require the use of an ice breaker to cut a path through which it can be towed.

Because of these immense problems and the accompanying high cost of utilizing conventional systems, various alternatives have been proposed. Artificially built islands capable of withstanding the moving ice have been considered, but these would be extremely expensive in other than shallow water. Drilling beneath the ice has also been considered, but it is likewise too expensive to merit serious consideration.

One system that holds promise for drilling in the offshore Arctic areas is a surface effect vehicle capable of carrying the drilling equipment needed for exploratory drilling. Such a vehicle would travel in its hover mode on a cushion of air over ice bound areas to the drill site. Once on location, the vehicle would be removed from the hover mode and would be floated in the water as a barge. When the drilling has been completed at one location, the surface effect vehicle would travel to a new location in the hover mode.

Although most surface effect vehicles are selfpropelled, one large enough to carry drilling equipment would have to be towed to the drill site. Large tracked vehicles among other means have been suggested to tow it. Tracked vehicles, however, cannot be used to negotiate open leads, narrow bands of open water created when ice sheets break apart.

It would thus be desirable to have a system for propelling a surface effect vehicle or towing other vehicles or structures that can negotiate narrow bands of open water.

It is therefore an object of the present invention to provide an apparatus for moving arctic vehicles and structures.

A further object of the invention is to anchor a vehicle to ice.

SUMMARY OF THE INVENTION With this an other objects in view, the present invention contemplates an ice anchor comprising a structure, capable of covering a large area, having a flexible sealing material around its periphery and means for creating a partial vacuum beneath the structure. In addition, spikes can be utilized to aid the anchoring effect of the vacuum anchor. One embodiment of the anchor includes a surface effect vehicle having reversible fans to provide hover capability and upon a fan reversal provide a partial vacuum beneath the vehicle.

BRIEF DESCRIPTION OlF THE DRAWINGS lFIG II is a cross-sectional elevational view of a vacuum ice anchor;

IFIG. 2 is a cross-sectional elevational view of a surface effect vehicle which has been adapted for use as an ice anchor;

FIG. 2A is a cross sectional elevational view of the surface effect vehicle vacuum anchor described in FIG. 2 in position to act as an anchor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1 of the drawings, an ice anchor is shown having a semi-rigid structure or planar member which'has downturned edges. The structure 10 may be made of a plastic or rubberized material, and can be constructed in various configurations, such as circular or square. Attached to the down-tumed periphery of the structure 10 is a flexible rubberized material 12 selected to retain its flexibility in extremely cold environments. In the structure 10 there is an opening 14 which is fitted on the topside with a hollow pipe member 16 having a right angle turn so that it lies in a horizontal direction. Spikes 22 attached to the underside of structure 10 are shown embedded in ice 24. Arrow 26, pointed'to vacuum, indicates the direction of air movement when a vacuum created by a conventional air pump is applied to the hollow pipe 16. An attachment eye 18 is attached to the upper structure 10 and has a ring through which a cable 20 can be attached.

In operation the vacuum anchor is located ahead of the vehicle or structure that needs to be moved in the direction that movement is desired. A cable 20 connects the vacuum anchor with the structure or vehicle to be moved. The end of the cable 20 that is attached to the structure or vehicle is connected by means of a winch capable of pulling the vehicle. The structure 10 is set on the ice surface 24 with the spikes 22 positioned so that they will penetrate in the direction of the towed vehicle any snow that may cover the ice 24. The flexible rubberized material 12 provides a seal between the structure 10 and the ice 24. A vacuum producing means which may be located atop the structure 10 or at a more remote location is applied to the interior of the hollow pipe 16 to extract air from beneath the structure 10 and remove it in the direction indicated by arrow 25. As the air is removed from beneath the structure 10, the spikes 22 are driven into the ice 24. The

anchor is thus secured in place both by the vacuum seal provided by the skirts 12 and by the spikes 22. The spikes 22 may be equipped with a heating mechanism to facilitate removal from the ice when the anchor is moved to its next location. As an alternative to the spikes 22, the underside of deck 39 can be constructed with an irregular surface with protrusions sufficiently low to extend down through any snow cover that may overlay the ice 24. Once the vacuum has been pulled on the anchor, the winch located on the structure or vehicle to be moved is placed in operation and the vehicle is drawn toward the anchor. When the vehicleor structure reaches the vacuum ice anchor, the vacuum is released, and the anchor is moved further in the direction of proposed travel. Once placed in a new position, a vacuum is again pulled on the underside of the structure 10 to provide a fixed anchor point against which to pull the vehicle or structure further along the proposed route.

This vacuum ice anchor can be made in any size with a greater anchoring effect being realized by the greater surface area which the structure covers. If small vehicles are to be moved a fairly small easily deployed anchor can be used. If, however, a large surface effect vehicle or other large structure needs to be moved, a much larger ice anchor would be necessary.

Referring next to FIG. 2, there is shown a surface effect vehicle that has been modified to act as an ice anchor resting on' ice 24. The surface effect vehicle 28 has a deck 30 that is usually some form of metal plate. Located around the periphery of the deck '30 is an inflatable, toroidal-shaped skirt 32 made of a reinforced rubberized material. This skirt 32 is kept inflated by a skirt fan 58, which is powered by skirt fan motor 54. This skirt fan motor 54 can be a conventional gasoline powered engine or similar means. The fan 58 is supported by a housing attached to the deck 30. When the skirt fan 58 is operating, air will move as shown by arrows 62.

The propulsion'system for the surface effect vacuum anchor consists of a prop 40 which rotates on a shaft 38 connected with a motor 34. The motor 34 can be of any conventional design. The motor 34 is attached to the upper side of the deck 30 by a mounting 36.

Located on the underside of the deck 30 are spikes 22 of sufficient length to penetrate thin snow layers when a vacuum is applied. These may be attached by conventional means such as welding or bolting. The vacuum is supplied by fan 48 which is housed in an opening through the deck 30. The fan 48 is connected by a shaft 46 to a fan motor 44, which may be of any conventional design. Both the fan 48 and motor 44 are supported by mounting 50 which is attached to the upperside of the deck 30. The mounting 50 has valves 64 to control the communication of air between the atmosphere and the underside of the air cushion vehicle. The fan 48 is reversible to achieve a hover mode when air is pulled into the vehicle in a direction shown by the arrows 52. Located on the upper side of the deck 30 is attachment ring 42.

In the operation of the surface effect vacuum anchor, the skirt 32 is inflated by skirt fan 58, which forces air into the skirt. Although only one skirt section and skirt fan is shown the skirt 32 may be made in several sections, and a multiplicity of skirt fans utilized to supply the several skirt sections. Such use of several skirt sections 32 will allow the surface effect vehicle to bypass uneven and jagged terrain. When the skirt 32 is inflated, the fan 48 is activated to pull air from above the deck 30; and the vehicle will rise into the hover mode due to the air pressure beneath the deck 30. Once airborne the vehicle is propelled to its location by the prop 40. When the vehicle reaches the desired location, the fan 48 is slowed to settle the vehicle to the surface. The fan 48 is then reversed to withdraw air from beneath the deck 30.

Reference is now made to FIG. 2A which shows the surface effect vehicle after the air has been evacuated from beneath the deck 30. In thisposition the fan 48 rotates such that it forces air from beneath the plate 30 in a direction shown by arrows 52. The spikes 22 are thus embedded in the ice 24 to provide additional surface gripping capability If further resistance is needed to tow extra heavy structures, the propeller 40 can be activated to push toward the towed structure. After the vacuum condition has been attained, the fan 48 may be stopped after valves 64 have been closed to seal the vacuum. Fan 58, continuesin operation to maintain an air pressure in skirt 32, which maintains a seal between the deck 30 and the ice surface 24. If an air pressure is not retained in the skirt 32, it will be pulled toward the fan 48, thereby breaking the seal. A cable 20 is connected to attachment ring 42 and is also connected with the vehicle or structure desired to be moved.

This particular configuration of ice anchor provides a large degree of versatility. Not only does it provide a convenient means of anchoring on an icy surface, whether the surface is smooth or as is more likely the case uneven, but it also supplies its own means of locomotion and can traverse the rough terrain of the Arctic regions. in addition to its function as an anchor, it can also be used to transport personnel and equipment.

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. The aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of this invention.

What is claimed is:

1. Ice anchor for providing horizontal restraint, comprising a planar member having a large surface area; means extending downwardly from the periphery of the planar member for sealing said periphery to the ice and for providing an enclosed area under the planar member; means for evacuating air from the enclosed area to hold said anchor against the ice; and a multiplicity of downwardly-directed, rigid elongated spikes attached to the underside of the planar member and slanted at an angle thereto, said spikes being uniformly spaced across said planar member and of such length as to penetrate the ice.

2. The apparatus of claim 1 wherein the sealing means around the periphery of the planar member is an enclosed, flexible air bag which acts as a skirt.

3. The apparatus of claim 2 including fans for inflating the flexible airbags.

4'. An ice anchor movable on a cushion of air comprising: a platform having an opening; reversible fan means mounted on the platform over the opening for providing said cushion of air and for evacuating the air under said platform to hold said anchor against the ice; skirt means comprising an enclosed flexible bag around the periphery of the platform forming a seal with the ice; and a multiplicity of downwardly directed, rigid elongated spikes attached to the underside of the platform, slanted at an angle to said platform and uniformly spaced thereover and of such length to penetrate the ice when the air is evacuated.

5. The apparatus of claim 4 including means for attaching structures for towing attached to the deck of the barge.

6. In a surface effect vehicle comprising a platform and a fan for providing an air cushion to support the vehicle, apparatus for anchoring the vehicle to an ice surface comprising: an enclosed flexible air bag around the periphery of the platform to conform to the ice surface; means for inflating the air bag; means for reversing the fan, whereby the air may be drawn from be neath the platform to create a vacuum thereunder; and a multiplicity of downwardly directed, rigid elongated spikes attached to the underside of the deck, slanted at an angle to said deck and uniformly spaced thereon and of such length to penetrate the ice when said vacuum is created.

7. The apparatus of claim 6 wherein the means for inflating the air bag is a fan.

8. The apparatus of claim 6 which includes valve means for preventing the flow of air into the area under the deck after a vacuum has been attained.

* l 2': k =l

Claims

3. The apparatus of claim 2 including fans for inflating the flexible airbags.

4. An ice anchor movable on a cushion of air comprising: a platform having an opening; reversible fan means mounted on the platform over the opening for providing said cushion of air and for evacuating the air under said platform to hold said anchor against the ice; skirt means comprising an enclosed flexible bag around the periphery of the platform forming a seal with the ice; and a multiplicity of downwardly directed, rigid elongated spikes attached to the underside of the platform, slanted at an angle to said platform and uniformly spaced thereover and of such length to penetrate the ice when the air is evacuated.

6. In a surface effect vehicle comprising a platform and a fan for providing an air cushion to support the vehicle, apparatus for anchoring the vehicle to an ice surface comprising: an enclosed flexible air bag around the periphery of the platform to conform to the ice surface; means for inflating the air bag; means for reversing the fan, whereby the air may be drawn from beneath the platform to create a vacuum thereunder; and a multiplicity of downwardly directed, rigid elongated spikes attached to the underside of the deck, slanted at an angle to said deck and uniformly spaced thereon and of such length to penetrate the ice when said vacuum is created.