US3543526A

US3543526A - Underwater submersible chamber system

Info

Publication number: US3543526A
Application number: US730552A
Authority: US
Inventors: Wilbur J O'neill; Alan R Krasberg
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1968-05-20
Filing date: 1968-05-20
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01
Also published as: DE1925566A1; GB1203569A; FR2008880A1; NL6907601A

Description

Dec. 1, 1970 J ONEILL ETAL UNDERWATER SUBMERSIBLE CHAMBER SYSTEM 4 Sheets-Sheet 1 Filed May 20, 1968 WITNESSES INVENTORS Wllbur J. O'Neill and Alan R. Krosberg BY ATTORNEY Dec. 1, 1970 w ONElLL ETAL 3,543,526

' UNDERWATER SUBMERSIBLE CHAMBER SYSTEM Filed May 20, 1968 4 Sheets-Sheet 2 E 5 40 L llir l I 52 I I 53 o o 50 H+AH l7 H o o Al I A 6 1; J H x II V A I B Dec. 1, 1970 w. J. O'NEILL ET AL 3,543,526

UNDERWATER SUBMERSIBLE CHAMBER SYSTEM Filed May 20, 1968 4 Sheets-Sheet S Dec. 1, 1970 I w, J. O'NEILL ETAL 3,543,526

UNDERWATER SUBMERSIBLE CHAMBER SYSTEM Filed May 20, 1968 4 Sheets-Sheet 4.

FIGS.

GAS ADMISSION CONTROL\ f 11 III, |H|

United States Patent 3,543,526 UNDERWATER SUBMERSIBLE CHAMBER SYSTEM Wilbur J. ONeill, Severna Park, and Alan R. Krasberg, Annapolis, Md., assignors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed May 20, 1968, Ser. No. 730,552 Int. Cl. B63c 11/00 US. Cl. 61-69 13 Claims ABSTRACT OF THE DISCLOSURE A track in the form of a chain is laid out on the sea bottom in a desired pattern. A submersible chamber which is normally positively buoyant includes a carriage which grips the chain, the action being to exert an upward force on the chain. Drive means on the carriage enables the submersible chamber to propel itself along the track. With an open bottom chamber pressurized to the surrounding sea water pressure, any change in buoyancy is essentially self-compensating by lifting or setting down a short length of the chain according to the changes in buoyant conditions. In another embodiment first and second chain tracks are carried by the submersible work chamber in continuous loop fashion. To further compensate for buoyancy variations water level or pressure sensor means are utilized.

BACKGROUND OF THE INVENTION Field of the invention This invention in general relates to underwater chamber complexes and more particularly to an underwater transportation system.

Description of the prior art For commercial or scientific applications it is often required that divers live for periods of time at pressure in an underseas habitation and work in or from the habitation or other submersible chambers. Many underwater operations require the divers to have horizontal mobility, however the divers are limited to swimming in the immediate vicinity of the habitation. Tethered divers are limited by hose or line length and untethered divers run the risk of losing contact with the sub-sea dwelling.

In order to extend the range of the divers from the dwelling, use may be made of a free ranging underwater vehicle. Such vehicles however become complex, dangerous and expensive and in addition require accurate navigational equipment. It is proposed that some of these vehicles have neutral buoyancy. Neutral buoyancy is hard to achieve and maintain, and its loss leaves the vehicle stranded on the bottom and too much buoyancy sends it to the surface. Where the vehicle includes means for allowing divers in a saturated condition to swim in and out, the loss of neutral buoyancy can be disastrous.

In one type of chamber apparatus, described in US. Pat. 3,299,645 an underwater capsule in conjunction with a winch mechanism allows the capsule to be transported from a support ship on the surface to an underwater dwelling and vice versa thus in eliect acting as an elevator. Such system however is strictly limited to vertical movement.

It is therefore a general object of the present invention to provide a system which allows a diver to safely and dependably have horizontal mobility over the sea bottom.

Another object is to provide such system which is economical to construct and which eliminates the need for complex navigational equipment.

A further object is to provide such system which includes a submersible work chamber adapted to traverse various types of terrain.

SUMMARY OF THE INVENTION In its broad aspects the invention utilizes an underwater vehicle which is normally positively buoyant, as part of the system and is illustrated herein as a submersible chamber system including a submersible work or observation chamber which is normally positively buoyant. A track means, and preferably a flexible track means such as a chain or cable is laid out in any desired pattern on the sea bottom and track engagement means track and exerts an upward force upon it since the chainber is positively buoyant. Drive means are provided for relatively moving the track means past the engagement means. The track engagement and drive means are preferably located below the submersible chamber and are positioned for cooperatively moving the chamber lateral- 1y above the sea bottom.

In other embodiments the chamber carries its own track and places it on the sea bottom. In one method the track may be unrolled from a chamber carried reel. In another method, first and second continuous loop tracks are carried by the chamber which may thereby traverse the sea bottom independently of a predetermined fixed track.

Buoyancy variations may be compensated for with proper choice of track weight per foot and/or automatic buoyancy adjustment means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view of one embodiment of the present invention;

FIGS. 2A and 2B illustrate the chamber response when a diver exists therefrom;

FIGS. 3A and 3B illustrate the chamber response when a piece of heavy equipment is removed therefrom;

FIG. 4 is a side elevational view with part broken away illustrating the internal arrangement of the track engagernent means for the submersible chamber of FIG. 1;

FIG. 5 is a view along the line VV of FIG. 4 and additionally illustrating one form of drive means;

FIGS. 6A and 6B illustrate the chamber response when traversing an inclined terrain;

FIG. 7 is a pictorial representation of another embodiment of the present invention;

FIG. 8 illustrates the embodiment of FIG. 7 during one intended use; and

FIG. 9 illustrates an embodiment of an automatic buoyancy control means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates an in situ embodiment of a submersible chamber system according to the present invention. In a typical operation a sub-sea dwelling 10 is positioned on the sea bottom 11 and is pressurized to be equal to the surrounding ambient water pressure. The dwelling 10 includes a bottom opening vertical trunk 12 for divers to exit and enter the dwelling. Such trunk may remain open at all times since the pressurization within the dwelling 10 prevents any water from entering.

The system includes track means such as individualelongate flexible members in the form of tracks 14 to 18 each extending from a first point P, at which is located hub member 20, to respective second points at which are located anchor means 22 to 24 for tracks 14 to 16 respectively so that the tracks are secured to the sea bottom at spaced apart points. It is seen that the point P is close to to the dwelling 10 and that the tracks extend out in a star pattern. The pattern may be laid out on level or inclined terrain and it is seen that track 18 even traverses a ravine 27. It is of course obvious that various single track patterns may be utilized to form a circular or spiral configuration or any other type of straight line or curved design. For example the track could be deposited alongside or above a pipe line when installed and used thereafter for pipe line inspection, or with proper compensating means a reel of track could be carried by the submersible chamber which would then in effect lay its own track. Various patterns are also obtainable with the use of a plurality of tracks.

The vehicle for transporting personnel and/ or payloads along the sea bottom is a positively buoyant submersible chamber means which includes the submersible chamber 32. Submersible chamber 32 contains a breathable gas mixture at a pressure substantially equal to the ambient water pressure so that

divers

35 and 36 may, with facility, enter and exit the submersible chamber through bottom opening vertical access trunk 40.

Lines

42 and 43 are connected with the inside of submersible chamber 32 and may include a tether, communication lines, hot water for the divers suit, electrical wires for sensing equipment, in addition to a breathable gas mixture which is supplied from the inside of the submersible chamber 32 and which may be provided by means of gas tanks 45 carried externally of the submersible chamber 32. Alternatively, the submersible chamber 32 could be supplied with a breathable gas, hot water, etc. through an umbilical from a re. mote supply point.

The chamber 32 is designed to be positively buoyant for the upright position illustrated. For chambers which have a tendency to be negatively buoyant additional buoyancy or other means may be provided for obtaining a chamber complex having a net upward force in the water. For the environment illustrated in FIG. 1, the submersible chamber 32 may be made of a very light material since it is not necessary to withstand large pressure differentials. In instances where it is desirable that the submersible chamber be transportable to the surface while maintaining bottom pressure, or alternatively to use the submersible work chamber 32 as an observation chamber with an internal pressure of one atmosphere, a bottom closing hatch may be provided and the chamber may be of a material and of a specific design to withstand such pressure differentials as may be encountered.

In one embodiment and as illustrated in FIG. 1, the track means takes the form of a flexible track having a sulficiently high weight per length factor. For purposes of illustration therefore the tracks 14 to 18 take the form of heavy link chain. Associated with the submersible chamber 32 is a track engagement means in the form of carriage 50 into or through which passes the track or chain 17, and which is freely suspended below the submersible chamber by means of

small chains

52 and 53. By virtue of the positive buoyancy of the submersible chamber 32 an upward force is exerted upon the chain 17 and due to the flexibility and slack thereof a short length of the chain is lifted off of the sea bottom 11. The length of chain from point A to A is utilized to maintain a state equivalent to neutral buoyancy, or stable equilibrium. By way of example if the length of chain between points A and A is 20 feet and the chain is pounds per foot, an extra downward force of 200 pounds is exerted upon the submersible chamber 32. During the course of operation more or less chain may be lifted according to the terrain as will be illustrated in FIGS. 6A and 6B, or according to personnel or payload changes within the submersible chamber 32, as illustrated in FIGS. 2A, 2B, 3A and 3B to which reference is now made.

FIG. 2A illustrates an inside view of the submersible chamber 32 and wherein the diver 35 is standing on the floor 56. The diver 35 has a certain volume and he is rigged to be neutrally buoyant. The submersible chamber 32 in FIG. 2A is at an altitude H above the sea bottom 11 and the water extends up the vertical access trunk 40 to level L. In FIG. 2B when the diver 35 exits, the void created, equal to the diver's volume, is filled by an equivalent volume of water entering the vertical access trunk 40 to bring the water level up to L. The extra volume of water, shown shaded, is equal to the weight of the diver so in effect an exiting weight and volume (the diver) is replaced by substantially the same weight and volume (the water from level L to L). Accordingly, there is no effective change in condition and the submersible chamber 32 remains at the same altitude H as in FIG. 2A. In FIG. 3A there is depicted the situation wherein the submersible chamber 32 is carrying a piece of equipment such as a valve 60 having a volume V which is much smaller than the volume of the diver 35 of FIG. 2A. The valve 60 however may Weigh considerably more than the diver. The chamber is at an altitude H above the sea bottom 11 and the chain 17 extends from the sea bottom from point A, through the carriage 50, to point A. When the valve 60 is removed from the submersible chamber 32, as in FIG. 3B, an equivalent volume of water V enters the vertical access trunk to bring the water level up from L to L, and shown shaded. The weight of the shaded volume of water however does not equal the weight of the removed valve and accordingly the submersible chamber 32 tends to rise. The submersible chamber 32 will rise to an altitude H +AH at which point additional chain will have been picked off the sea bottom. Previous to the removal of the valve 60 points A and A just touch the sea bottom whereas after the removal points B and B just touch the sea bottom. The weight of the additional chain pulled up, that is the weight of the chain from point A to B and from point A to B is substantially equal to the weight of the valve 60 minus the weight of the additional water of volume V that entered the hatchway 40.

In a converse situation to that illustrated in 2A and 2B and 3A and 3B if a diver or payload enters the chamber an equivalent volume of water will be displaced from the bottom of the vertical access trunk 40. If the weight of the object entering is greater than the Weight of the displaced water then an amount of chain equal to the difference in weight will be placed back down upon the sea bottom. It is therefore seen that complex equipment needed to maintain a neutral buoyancy under varying conditions need not be provided since the system is essentially self-compensating by using the weight of the chain to maintain a state of equilibrium within a limited vertical range. Coupled with this is the fact that a safety feature is provided, in that the submersible chamber 32 by virtue of its connection and cooperation with the chain 17 cannot pop up to the surface by loss of an equilibrium position, as can happen in other neutral buoyancy systems.

The track engagement means in the form of carriage 50 is shown in somewhat more detail in FIGS. 4 and 5 which additionally show the drive means to provide for lateral movement of the submersible chamber above the sea bottom. In FIG. 4 a view inside the carriage 50 reveals a plurality of wheels over and under which the chain 17 passes. The two

end sprocket wheels

64 and 65 may be idler wheels, or pulleys, while the middle wheel 66 functions as a drive sprocket wheel.

FIG. 5 which is a view along V-V of FIG. 4 illustrates one form of motive power which may be utilized, the motive power taking the form of motor 68 suitably connected to the drive sprocket wheel 66 by coupling means 69. The motor 68 may be supplied with power from a control within the submersible chamber which would also include means for reversing the motor to enable the submersible chamber to move in either direction along the chain. It is apparent that various other forms of track engagement means or drive means may be utilized. In a multitrack arrangement, if its is desired to switch to a new track, there may be provided on the new track a carriage such as that illustrated in FIGS. 4 and 5. The submersible chamber may first be connected to the new carriage and thereafter disconnected from old carriage.

With respect to the drive means, an emergency, or even the primary power source may be the diver, operating the apparatus manually. The track engagement and drive means are positioned and cooperate to move the submersible chamber not only above horizontal terrain but are capable of transporting the submersible chamber over inclined terrains and to this end reference is now made to FIGS. 6A and 6B.

In FIG. 6A there is illustrated the ravine 27 also shown in FIG. 1, being traversed by the track, or chain 18. De pending upon the depth of the ravine, the chain 18 may either hang above the bottom in a catenary shape as shown dotted in FIG. 6, or may lie on the bottom following the contour of the ravine. For comparison purposes the submersible chamber is illustrated in FIG. 6B at a greater depth, nearer the bottom of the ravine. In the first position, FIG. 6A, the water in the vertical access trunk is at the level L and an upward force is exerted upon the chain 18 thus pulling it from its normally laying state, shown in dashed line below the submersible chamber 32. With the drive means actuated and the chain 18 moved relatively past the track engagement means the submersible chamber 32 arrives at its second position, FIG. 6B. The pressure at the second position, due to the increase in depth, is greater than the pressure at the first position and accordingly the water in the hatchway 40 has risen to a new level L. At the second position the additional weight of the water taken in results in less of a net upward force on the chain 18 and accordingly less of the chain is pulled out of its natural position. This may be seen in FIGS. 6A and 6B, by comparing the curvature of the chain through the carriage at the first and second positions. In situations where it is necessary that the submersible chamber 32 descend to a point where the water would rise above the vertical access trunk 40, the diver could manually admit more gas to equalize the pressures.

FIG. 7 illustrates another embodiment of the invention wherein the positively buoyant submersible chamber means includes submersible chamber having a gas supply 77 externally mounted, and having a bottom opening vertical access trunk 79 which may or may not have a closable hatch, such consideration being dependent upon the intended use and constructional features of the submersible chamber 75. The track means are carried entirely by the submersible chamber 75 and includes first and second loop portions contacting the sea bottom. By way of example the loop portions may be separate and independent

flexible tracks

82 and 83 each in the form of a continuous loop chain. A variation in the track means for the embodiment of FIG. 7 includes tractor or tank type tread which would tend to provide more frictional engagement with the sea bottom.

The track engagement means includes idler sprocket wheels 86 and 87 for chain 82 and

idler sprocket wheels

88 and 89 for chain 83. The drive means includes a drive sprocket wheel 92 for chain 82 and drive sprocket wheel 93 for chain 83 each of which drive sprocket wheels may be powered either manually or by motors.

The arrangement of FIG. 7 illustrates the idler sprocket wheels 86 to 89 being carried on framework 95 which may be welded to the submersible chamber 75; obviously other arrangements to track engagement and/ or drive means may be provided.

Operation with respect to stable equilibrium of the embodiment of FIG. 7 is the same as the embodiments previously described in that any change of personnel or payload is compensated for by more of the

chains

82 and 83 being deposited on the sea bottom 11 or conversely more of the chain being removed from the sea bottom to compensate for a resulting increase in net upward force.

The embodiment of FIG. 7 is particularly well adapted for pipe line inspection, as illustrated in FIG. 8 wherein an underwater pipe 97 is straddeled, with the chain 82 on one side and the chain 83 on the other side of the pipe.

With equal energization of the drive means, each of the

chains

82 and 83 will be driven at the same rate and the submersible chamber 75 will travel in a straight line directly over the pipe 97. If the pipe should curve or if it is desired to turn the submersible chamber 75, the drive means may be operated independently at different rates.

In FIGS. 2A and 2B and 3A and 3B, when an object left the submersible chamber an equivalent volume of water entered the vertical access trunk, and in FIG. 6 when the submersible chamber traveled down an inclined terrain the water level in the access trunk rose, due to the increasing pressure. In many instances it is desirable to free the diver from the task of having to admit more gas to the interior of the submersible chamber. In other circumstances the change in water density or gas temperature can cause the level of the water within the vertical trunk to change, that is, the volume of gas within the submersible chamber changes. FIG. 9 illustrates a control for a submersible chamber system which obviates the need for constant diver attention of the gas system.

A portion of a submersible chamber 100 is shown partially in section and includes a vertical access trunk 102 open at the bottom to sea pressure. In order to sense the water level in the access trunk 102 there is provided a water level detection means 105, such water level detection means being well known to those skilled in the art. In FIG. 9 the water level within the access trunk 102 is midway between the top and bottom of the level detector 105. Means are provided for coupling the water level detector 105 with a gas admission control 108, the means for coupling being indicated by the line 111. The means for coupling, by way of example, may be mechanical, electrical or pneumatic, or even a coupling without a physical connection such as by optical or sonic signals.

In order to choose and vary the setting of the water level within the vertical access trunk 102 means such as a track or guide 113 are provided to relatively adjust the vertical position of the water level detector 105. The vertical adjustment feature allows a greater or lesser force to be exerted upon a track or anchor means. For example if the chain or anchor in stuck in the mud on the sea bottom, the water level detector 105 may be placed further down the guide 113 to lower the water level and admit more gas. There is consequently a resulting increased upward force which may be enough to release the chain or anchor from the stuck condition.

In operation, if the water within the vertical access trunk 102 rises from the bottom of the trunk toward the floor or deck 115 of the submersible chamber 100 it will cause activation of the gas admission control 108 when the level reaches a point as is shown in FIG. 9 whereupon additional gas is admitted to equalize the water pressure to prevent further rise in the water level. If an object now enters the submersible chamber 100 it will cause displacement of the water back down the vertical access trunk 102. Similarly if the temperature of the gas within the submersible chamber rises it will cause a gaseous expansion to similarly displace the water. In various situations it is desired that the submersible chamber remain in a fixed altitude position, or within limits, independently of temperature variations causing gaseous volume changes. The apparatus thus far described in FIG. 9 prevents water from rising above the level of the level detector 105 if the gas inside starts to contract. In order to maintain the same volume when the gas expands, means are provided for admitting water to the vertical access trunk when the level of the water starts to drop below a predetermined point. This operation may be accomplished with the provision of a conduit 118 having an open bottom and extending from a first point within the vertical access trunk 102 to a second point above the first point such as in the vicinity of the deck 115 where the opposite end of the conduit 118 may be exposed to ambient water pressure when the valve 122 is open, by virtue of a through-hull connection 120. The open end of the conduit 118 is even with the water level detector 105 and may be attached thereto and since the level detector 105 is movable vertically within the access trunk 102 the conduit 118 may be flexible. With this arrangement, should the water level drop, gas will escape to the surrounding water via a path from the lower open end of conduit 118, through the valve 122 and through the through-hull connection 120. In response to the escape of gas the water level will again rise to the predetermined level. (Water will also rise up the conduit 118.)

What has been described therefore in FIG. 9 is a volume control system for a submersible chamber which is suspended ofi? of the sea bottom, such as shown in FIGS. 1 and 7. The control is also applicable to other chambers suspended off the sea bottom such as by anchor means.

Although the present invention has been described with a certain degree of particularity, it should be understood that the present disclosure has been made by way of example. The use of the term sea herein is meant to include other bodies of water such as rivers, bays, gulfs, oceans, etc. Drive motors may include the electrical, mechanical and hydraulic varieties and power may be either chamber carried, generated or may be supplied from a remote point, underwater or on the surface. In FIG. 1 there is shown one chamber on a track 17. Ohviously two or more chambers may operate along that track. With respect to contructional details it is apparent that modifications and variations of the present invention are made possible in the light of the above teachings.

We claim as our invention:

1. An underwater submersible vehicle system compris- (a) a submersible vehicle means being positively buoyant when submerged;

(b) fiexible track means for contact with the bottom of a body of water;

() track engagement means for said submersible vehicle means for engaging said track means;

((1) the positive buoyancy of said submersible vehicle means being of a magnitude to lift a portion of said track means out of contact with said bottom, when said track means is engaged with said track engagement means;

(e) the weight of said portion of said track means out of contact with said bottom being of a magnitude to maintain said submersible vehicle means within a limited vertical range above said bottom;

(f) drive means for relatively moving said track means past said track engagement means; and

(g) said track engagement and drive means positioned for cooperatively moving said submersible vehicle means laterally above said bottom.

2. A system according to claim 1 wherein:

(a) the vehicle is a submersible chamber.

3. A system according to claim 1 wherein:

(a) the track means includes at least one chain.

4. A system according to claim 1 wherein:

(a) the track means includes an elongate flexible member secured to the sea bottom at spaced apart points.

5. A sytsem according to claim 1 wherein:

(a) the track means includes first and second flexible loop portions each for contacting the sea bottom.

6. A system according to claim 5 wherein:

(a) the loop portions are separate and independent continuous loop tracks.

7. A system according to claim 6 wherein:

(a) the drive means includes first and second independently operable drives, one for each continuous loop track.

8. A system according to claim 2 wherein:

(a) the submersible chamber means includes a vertical access trunk open at the bottom to the ambient water.

9. A system according to claim 2 wherein:

(a) the track engagement means is below the bottom of the submersible chamber means.

10. A system according to claim 9 wherein:

(a) the track engagement means is freely suspended.

11. A control for a submersible chamber including an internal gaseous atmosphere and a vertical access trunk open at the bottom to sea pressure, comprising:

(a) water level detection means for sensing the water level in the access trunk;

(b) gas admission control means;

(c) means coupling said water level detection means with said gas admission control means for admitting additional gas to the submersible chamber when said water level tends to rise above a predetermined point; and

(d) means for admitting additional water into the vertical access trunk when the water level tends to drop below a predetermined point.

12. A control according to claim 11 wherein:

(a) the means of claim 14, clause d, includes an open ended conduit extending from a point within the vertical access trunk to a higher point communicative with the water surrounding the submersible chamber.

13. A control according to claim 12 wherein:

(a) the conduit is a flexible conduit; and

'(b) the open end of the conduit in the vertical access trunk is connected to the water level detection means.

References Cited UNITED STATES PATENTS I. KARL BELL, Primary Examiner US. Cl. X.R. 114-16;115-63