US3572273A - Apparatus for breaking a layer of ice on a body of water by repetitive combustive explosions - Google Patents

Abstract

AN APPARATUS TO BREAK THE ICE ON BODIES OF WATER TO ALLOW PASSAGE OF VESSELS BY PROVIDING A MOVABLE BUOYANT BODY HAVING A FACE FOR CONTACT WITH THE ICE AND A PLURALITY OF EXHAUST OPENINGS IN THE FACE AND POSITIONED BELOW THE WATERLINE OF THE BODY WITH EACH EXHAUST OPENING CONNECTED TO A COMBUSTION CHAMBER FOR APPLYING THE COMBUSTION ENERGY FROM A HYDROCARBON FUEL DIRCTLY TO THE ICE FOR BREAKING AND MELTING THE ICE. PLURALITY OF EXHAUST OPNINGS IN THE HULL OF AN ICE BREAKER ADJACENT THE BOW WITH A NORMALLY CLOSED COMBUSTION CHAMBER CONNECTED TO EACH OPENING. A BUOYANT PONTOON NON-RIGIDLY ATTACHED TO THE BOW OF A SHIP AND HAVING A FRONT FACE EXTENDING DOWNWARDLY ADN OUTWARDLY TO SLIDE UNDER LAYERS OF ICE WITH A PLURALITY OF EXHAUST OPENINGS FOR PORVIDING A COMBUSTIVE EXPOSION DIRECTED AGAINST THE ICE AND HAVING VALVE MEANS NORMALLY CLOSING THE COMBUSTION CHAMBER FOR PREVENTING WATER ENTERING THEREIN BUT OPENING ON A PREDETERMINED PRESSURE BUILDUP IN THE CHAMBER.

Description

. March 23, 1971 c. 0. W000 3,572,273 APPARATUS FOR BREAKING A LAYER OF ICE ON A BODY OF WATER BY REPE'I'ITIVE COMBUSTIVE EXPLOSIONS 2 Sheets-Sheet 1 Filed Aug. 6, 1969 Mal-ch23, 1971 WOOD 3,572,213

C. D. APPARATUS FOR BREAKING A LAYER OE ICE ON A BODY OF WATER vBY REPETITIVE COMBUSTIVE EXPLOSIONS 2 Sheets-Sheet 2 Filed Aug. 6, 1969 Char/ea 17. Wood ATTO/P/VEVJ United States Patent O APPARATUS FOR BREAKING A LAYER OF ICE ON A BODY OF WATER BY REPETITIVE COM- BUSTIVE EXPLOSIONS Charles D. Wood, San Antonio, Tex., assignor to Southwest Research Institute, San Antonio, Tex. Filed Aug. 6, 1969, Ser. No. 847,904 Int. Cl. B63b 35/08 US. Cl. 114-40 13 Claims ABSTRACT OF THE DISCLOSURE An apparatus to break the ice on bodies of water to allow passage of vessels by providing a movable buoyant body having a face for contact with the ice and a plurality of exhaust openings in the face and positioned below the waterline of the body with each exhaust opening connected to a combustion chamber for applying the combustion energy from a hydrocarbon fuel directly to the ice for breaking and melting the ice. A plurality of exhaust openings in the hull of an ice-breaker adjacent the bow with a normally closed combustion chamber connected to each opening. A buoyant pontoon non-rigidly attached to the bow of a ship and having a front face extending downwardly and outwardly to slide under layers of ice with a plurality of exhaust openings for providing a combustive explosion directed against the ice and having valve means normally closing the combustion chamber for preventing water entering therein but opening on a predetermined pressure buildup in the chamber.

BACKGROUND OF THE INVENTION Generally, the discovery of natural resources in the Arctic Sea has created a problem of increasing transportation through the sea even when it is frozen over. However, the only practical way to break up the ice has been by icebreakers. The present invention provides an apparatus which can assist an icebreaker or can be utilized with other types of vessels as an icebreaker.

SUMMARY The present invention is directed to applying the principle of displacing materials by applying the combustion energy from a hydrocarbon fuel as disclosed in copending patent application Ser. No. 514,057, dated Dec. 15, 1965, now Pat. No. 3,461,577 and entitled Method of and Apparatus for Displacing Materials, and applying this concept to breaking ice from bodies of water by using the explosive force and heat energy of the combustion of hydrocarbon fuel and air as a source of energy.

The present invention is directed to providing a movable buoyant body adapted to float in the water and having a face on the front for contact with the ice with a plurality of exhaust openings in the front face positioned below the waterline of the body for being positioned against the ice with each exhaust opening attached to a combustion chamber having a supply of hydrocarbon fuel and air connected thereto with igniting means for repetitively providing an explosive force against the ice.

In one embodiment the exhaust openings from the combustion chamber are connected directly to the hull of an icebreaker hull adjacent the bow and directed downwardly below the waterline whereby the icebreaker may ride upon thick layers of ice for breaking and exploding an opening through the ice.

In another embodiment a buoyant pontoon is attached, preferably non-rigidly to the bow of a suitable ship, and is moved through the water with a face extending forwardly and downwardly to slide under a layer of ice with exhaust openings in the face of the pontoon for positioning adjacent the ice whereupon the exhaust gas produces an impact load upon the ice and causes melting of the ice which provides a layer of water between the ice and pontoon that is effective as a lubricant.

Other features and advantages will be apparent from the following description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view illustrating the use of the invention in connection with the pontoon adapted to be connected to and moved b a ship,

FIG. 2 is a cross-sectional view of the pontoon of FIG. 1,

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 2 and includes a schematic control of the valves,

FIG. 4 is a fragmentary elevational view, partly in cross section, illustrating another embodiment of the present invention connected directly to the bow of an icebreaker, and

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and particularly to FIGS. 1, 2 and 3, the reference numeral 10 generally indicates a buoyant pontoon having a rear side 12 including a surface 14 contoured to coact with a bow of any suitable ship such as a tanker 16 so that the pontoon 10 may be moved through the water. Preferably, the front face of the pontoon includes a leading edge 18 and faces 20 and 22 directed downwardly and outwardly but behind edge 18 so as to, as best seen in FIG. 3, slide under an ice layer 24 and apply an upward force on the ice 24 due to the buoyancy of the pontoon 10. While the pontoon 10 could be rigidly connected to the ship 16, it is desirable to allow the pontoon 10 to contact and follow the contours of the lower surface of the ice sheet 24 and tend to be pushed downwardly into the water by such contact. In the preferred embodiment of the present invention, it is desirable that the pontoon 20 be connected to the ship 16 by connecting means which allow relative movement between the ship 16 and pontoon 10. For example, the pontoon may be connected to the ship 16 by steel cables 26 and relative movement may thus be provided between the pontoon 10 and the ship 16 by trimming or easing the cables 26 with suitable winches. A third cable 28 may be attached to the center line of the pontoon and lead over a boom 30 to a winch 32 and can be used to help control the pitch of the pontoon and by means of a slipping brake on the winch can also absorb some of the recoil force which will be described hereinafter.

A plurality of exhaust openings 32 are provided in the front faces 20 and 22 of the pontoon directed upwardly and outwardly from the pontoon so that the combustive forces from the openings 32 are directed toward the lower surface of the ice layer 24 when the face of the pontoon is in contact with the ice. A combustion chamber, and preferably a separate combustion chamber 34 for each opening 32, which are positioned inside of the pontoon, are connected to each of the exhaust openings 32 through an exhaust duct 36. The combustion chambers 34 are charged with a suitable combustion mixture for creating an explosion therein, and preferably the chambers 34 are charged with an air/fuel mixture, the air being provided by any suitable and conventional means as described in the above mentioned patent application such as a compressor (not shown) through an air inlet 38 and the fuel is provided by any suitable and conventional fuel supply means such as a fuel injection nozzle 40 to provide an air/fuel mixture at the desired pressure and air/ fuel mixture ratio. Combustion may be initiated in the mixture by any suitable ignition means such as an ignition source 42 preferably extending to the center of the combustion chamber. Chamber 34 may also be of a spherical shape to provide the shortest possible flame travel and thus the maximum rate of pressure rise in the combustion chamber. While it is preferable that the combustion chambers 34 be located in the pontoon 10, the fuel lines 40, air lines 38 and ignition source 42 lines are preferably bundled together through a flexible hose 44 leading to the ship 16 for connection thereto to a suitable air supply, fuel supply and ignition control means. Any suitable man ually operated or automatic control and timing means may be utilized to suitably control the admission of fuel, air and timing of the explosions in the chamber 34.

The combustion chambers 34 are preferably closed While they are being charged with fuel and air to the desired initial pressure prior to ignition. One type of structure that may be provided to close the chambers 34 and also prevent water in the ducts 36 from entering the combustion chambers 34 is to provide suitable valve means such as poppet valve 50 (FIG. 3) having a valve seat 52 and a valve stem 54 which is acted upon by a spring 56 against a stop 58 tending to close the valve 50. A piston 55 is connected to valve stem 54 and has a first side 57 directly exposed to pressure in the combustion chamber 34. The cross-sectional area of the piston side 54 is larger than the cross-sectional area 51 of the valve 50 that is exposed to pressure in the combustion chamber 34. Gas may reach or leave the second side 59 of the piston 55 through a line 70 and through actuating valve 72 which has two positions. When position 74, as shown, is placed in the line 70, the gas pressure on the side 59 of the piston is vented to atmosphere. Thus when the valve 72 is in position 74 and pressure is increased in the combustion chamber 34, the poppet valve 50' is held in the closed position since the area of side 57 of the piston 55 exceeds the area of side 51 of valve 50'. Therefore, the chamber 34 can be charged and fired and the valve 50 will remain closed. However, when the control valve 72 is actuated to move position 76 into line 70, the pressure in the chamber 34 will be in communication with side 59 of the piston through line 70. Thus the pressure forces from chamber 34 are acting on both sides 57 and 59 of pistons 55 and are balanced and the force acting on side 51 of valve 50 opens valve 50 releasing the combustive forces into the ducts 36. The spring 56 is sized so that after combustion it closes valve 50 while the pressure in the combustion chamber 34 exceeds the outside water pressure by a small amount thus preventing water flow into the combustion chamber 34.

The actuating valve 72 may be controlled by any suitable means such as a pressure actuated switch 78 which is responsive to the pressure in the combustion chamber 34 through line 80. Switch 78 is connected to a battery 82 and switch contact 84 energizes solenoid 84 connected to valve 72. Thus when the pressure in chamber 34 reaches a preset level, switch 78 moves to contact 84 energizing solenoid 84 moving valve 72 into position 76 to open valve 50. Of course, other types of valve means such as disclosed in the above mentioned co-pending patent application may be used.

The terminal combustion pressures and temperature can also be varied as desired. For example, with an air/ fuel mixture of 12.5/ 1, an initial air pressure charge of 200 p.s.i. will result in combustion that produces a peak pressure of approximately 1000 p.s.i. and a temperature of approximately 4660 F. By increasing the initial air pressure charge to 425 p.s.i., the resulting combustion from the explosive mixture would produce a pressure of approximately 1625 p.s.i. and a temperature of approximately 4790 F. The resulting high pressures and high temperature gases are exhausted through the rapidly opening exhaust valve 50 to provide an explosive release of energy which acting against the ice sheet 24 and combined with the buoyant force of the pontoon 10 produces an impact load on the ice sheet 24 which causes failure of the ice. In addition, the hot exhaust gases passing up the forward face of the pontoon 10 between the broken ice and pontoon cause melting of the ice which provides a layer of .water between the ice and the metal pontoon that is effective as a lubricant, thus reducing the frictional resistance to the forward motion of the pontoon 10. When the valves 50 are open the chamber pressure in the combustion chambers 34 greatly exceeds the water pressure in the exhaust ducts 36 so that the gas flows from the chamber pushing the water ahead of the gas. When the chamber pressure begins to approach the surrounding water pressure but while it still exceeds the surrounding water pressure, the valves 50 are closed by the springs 58 and prevent the water re-entering the ducts 36 from reaching the combustion chambers 34.

And as previously mentioned, the third cable 28 can be used to help control the pitch of the pontoon and absorb some of the recoil forces as the buoyant pontoon 10 may be pushed downwardly by the recoil force of the explosions.

Thus, the pontoon allows any vessel which is not normally equipped for ice breaking duties, such as an oil tanker, to act as an icebreaker by attaching the ice breaking pontoon 10 to the bow of the vessel and the pontoon will absorb the recoil of the explosion by the downward motion of the pontoon without transmission of undesirable recoil forces into the ship 16. Additionally, the pontoon 10 will follow the bottom ice contour through the freedom of its leading edge 18 to move upwardly and downwardly.

However, the pontoon 10 has its limitations. For instance, for very heavy ice sheets 24, the skin of the pontoon 10 must be made thicker to withstand the ice impact forces and thus the buoyancy of the pontoon for creating an upward force on the bottom of the ice may become marginal. And in areas where the ice sheets 24 are extremely thick with the bottom of the sheets extending to great depths in the water, it is not feasible to make the pontoon with a sufiicient draft to extend under the ice. Under such conditions, the embodiment illustrated in FIGS. 4 and 5 can be provided to assist in breaking up the ice to provide passage for a vessel. For convenience of reference, the sufiix a is applied to parts corresponding to those in FIGS. 1-3. Thus a conventional icebreaker hull 60 is provided with a plurality of exhaust openings 32a in its hull and positioned adjacent the bow 62 and directed downwardly and outwardly from the hull below the Waterline 64. Preferably, some of the openings are positioned on one side of keel 66 and other openings being on the second side of the keel 66. A combustion chamber 34a, air supply 38a, fuel supply 40a and ignition means 42a similar to that previously described in connection with the embodiments of FIGS. 1-3 are connected, preferably to each exhaust opening 32a and operate in a similar manner. The ice breaking hull 60 differs in that it will ride upon an ice layer as is conventional and when one or more of the combustion chamber 34a are fired, the exhaust gas will be directed through the openings 32a against the ice. The resulting force of the weight of the ship 60 plus the pressure and heat forces of the exhaust gases, provide impact blows as well as a constant pressure on the ice. By means of the repetitive combustion explosions the icebreaker is able to break heavier ice than is possible without the combustion devices.

In operation, the pontoon 10 of the embodiment of FIGS. l-3 or the icebreaker 60 of the embodiment of FIGS. 4 and 5 is conventionally moved through the water to place the exhaust openings 32 or 32a against the ice so that the high impact pressures and temperatures may be positioned as close as possible to the ice. High pressure air is supplied to the combustion chamber, fuel is injected into the combustion chamber through fuel injection means 40, and conventional ignition means may be used to ignite the mixture. As the flame propagates through the air/fuel mixture charge, pressure is rapidly developed within the combustion chambers 34 and 34a and builds up causing predetermined release pressure to be reached thus causing the valve 50 to open and the force of the explosion is expelled through the ducts 36 and openings 32. After the combustion gases have exhausted down to a predetermined level, the valve 50 is closed to reseal the chamber and prevent water from entering therein and the exhaust openings 32 are again moved into proximity of the unbroken ice to repeat the cycle.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein.

What is claimed is:

1. An apparatus for breaking a layer of ice on a body of water by repetitive combustive explosions comprising,

a buoyant body adapted to float on the water,

means for moving the body in the water and against the ice,

said body having a face on the front for contact with the ice,

at least one combustion chamber in the body,

a plurality of exhaust openings in the front face and positioned below the waterline of the body for being positioned adjacent the ice, each opening being connected to a combustion chamber,

means connected to the chamber for admitting air under pressure into the chamber,

means connected to the chamber for admitting fuel under pressure in the chamber thus forming a pressurized mixture of air and fuel,

igniting means in said chamber for igniting said pressurized mixture of air and fuel,

control means for repetitively controlling the admission of fuel, air and ignition of the mixture, and

valve means normally closing said combustion chamber for allowing buildup of pressure in the chamber and preventing entrance of water thereto, but opening upon combustion of the mixture upon a predetermined pressure buildup in said chamber.

2. In combination with an icebreaker hull, an apparatus for breaking ice by repetitive combustive explosions comprising,

at least one combustion chamber connected to said hull,

a plurality of exhaust openings in the hull adjacent the bow and directed downwardly and outwardly below the waterline, each opening being connected to a combustion chamber,

means connected to the chamber for admitting hydrocarbon fuel under pressure into the chamber,

means connected to the chamber for admitting air under pressure into the chamber,

igniting means in said chamber for igniting said pressurized mixture of air and fuel, and

valve means normally closing said combustion chamber for containing the pressurized mixture in the chamber prior to ignition and preventing the entrance of water therein, but opening upon combustion of the mixture and upon a predetermined pressure buildup in said chamber.

3. In combination with an icebreaker hull, an apparatus for breaking ice by repetitive combustive explosions comprising,

a plurality of combustion chambers connected to said hull,

a plurality of exhaust openings in the hull, each of which is connected to a combustion chamber and positioned adjacent the bow and directed downwardly and outwardly from the hull below the waterline, at least one opening being on one side of the keel and at least another opening being on the second side of the keel,

means connected to the chamber for admitting hydrocarbon fuel under pressure into the chamber,

means connected to the chamber for admitting air under pressure into the chamber,

igniting means in said chamber for igniting said pressurized mixture of air and fuel, and

valve means normally closing said combustion chamber, but opening upon combustion of the mixture upon a predetermined pressure buildup in said chamber.

4. The apparatus of claim 3 wherein a separate combustion chamber is connected to each exhaust opening.

5. The apparatus of claim 4 wherein the combustion chambers are spherical.

6. Apparatus for breaking a layer of ice on a body of water comprising,

a buoyant pontoon, the rear of the pontoon being contoured to coact with a ships bow so that the pontoon may be moved in the water,

the buoyant pontoon having a front face extending downwardly and outwardly for allowing the face to slide under a layer of ice,

connecting means attached to the pontoon adapted to be connected to a ship,

at least one combustion chamber carried by the pontoon,

a plurality of exhaust openings in the front face of the pontoon, each of which is connected to a combustion chamber,

means connected to the chamber for admitting hydrocarbon fuel under pressure into the chamber,

means connected to the chamber for admitting air under pressure into the chamber,

igniting means in said chamber for igniting said pressurized mixture of air and fuel, and

valve means normally closing said combustion chamber, but opening upon combustion of the mixture upon a predetermined pressure buildup in said chamber.

7. The apparatus of claim 6 wherein a separate combustion chamber is connected to each exhaust opening.

8. The apparatus of claim 7 wherein the combustion chambers are spherical.

9. The apparatus of claim 6 wherein the connecting means is a non-rigid connection allowing vertical movement between the pontoon and the ship.

10. The apparatus of claim 6 wherein the connecting means includes cables and winches for lengthening or shortening the connection between the ship and the pontoon as the pontoon follows the contour of the lower surface of the ice.

11. The apparatus of claim 6 wherein the exhaust openings are below the waterline of the pontoon and are directed forwardly and upwardly.

12. The apparatus of claim 6 wherein,

the front face of the pontoon includes a leading edge extending downwardly and outwardly for sliding under a layer of ice, and

a face on either side leading downwardly and outwardly behind the leading edge.

13. The apparatus of claim 12 wherein the connecting means includes cables and winches for lengthening or shortening the connection between the ship and the pontoon including cables controlling the vertical movement leading edge of the pontoon.

References Cited UNITED STATES PATENTS 2,885,988 5/1959 Myers 114-235X FOREIGN PATENTS 56,416 4/1936 Norway 1l440 TRYGVE M. BLIX, Primary Examiner

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