US3543527A - Underwater mining method - Google Patents

Description

Dec. 1, 1970 M. w. SMITH ETAL 3,543,527

I UNDERWATER MINING METHOD Filed May 31, 1968 5 Sheets-Sheet 1 FIG.I

WITNESSES INVENTORS M 9 9W Melvin W. Smith 8 Charles S.Klu1h Dec. 1, 1970 M. w. SMITH ETAL 3,543,527

UNDERWATER MINING METHOD Filed May 31, 1968 5 Sheets-Sheet 2 FIG. 8

Dec. 1, 1970 M. w. SMITH ETAL 3,543,527

UNDERWATER MINING METHOD Filed May 31, 1968 5 Sheets-Sheet 5 Dc. 1,1970 M. W.SMI I'H ETAL 3,543,527

UNDERWATER MINING METHOD Filed May 31, 1968 5 Sheets-Sheet 4.

Dec. 1,1970 M. w. SMITH ETAL 3,543,527

. UNDERWATER MINING METHOD Filed May 31, 1968 5 Sheets-Sheet 5 3,543,527 UNDERWATER MINING METHOD Melvin W. Smith, Edgewater, and Charles S. Kluth, Baltimore, Md., assignors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed May 31, 1968, Ser. No. 733,532 Int. Cl. Flol 1/00 US. Cl. 6172.3 3 Claims ABSTRACT OF THE DISCLOSURE A surface vessel travels through the water while conmeeting and paying out conduit sections, to which is connected an underwater mining collector. A gimbal arrangement on the vessel allows the conduit to assume a certain angle with respect to vertical as the vessel travels through the water. A derrick on the vessel is tilted at the same angle that the conduit makes with the vertical and includes means for gripping a conduit section to be added onto the already payed out conduit. The tilted derrick serves to receive a new conduit section, lower the section down to the gimbal arrangement for joining onto the payed out conduit, and repeat the process until the desired length of conduit is payed out. Thereafter, the surface vessel trailing the conduit and collector slows down to a predetermined speed for placing the collector on the sea bottom to commence mining operations.

BACKGROUND OF THE INVENTION Field of the invention The invention in general relates to underwater mining systems and in particular to apparatus and a method for joining and paying out conduit sections used in the mining operations.

Description of the prior art For various mining operations, at depths of many thousands of feet there have been described systems utilizing a bottom collector which rides on, or is dragged along, the sea bottom and in so doing picks up desired aggregates, such as manganese nodules. The collector is connected to a surface vessel by means of joined conduit sections forming a conduit several miles long. A lift system such as an air lift or pump is connected to the conduit for raising the collected aggregates from the colleetor to the surface vessel.

At the start of mining operations, the collector may be connected to a flexible conduit and lowered through a working well located at the center of the vessel. While the vessel is dead in the water additional sections, in the form of metallic conduit sections are brought to a vertical position above the already payed out conduit hanging from, and held by, a holding and joining station. The new conduit section is connected to the held conduit section and thereafter lowered to a point where it then becomes the held conduit section. The process is continued until sufiicient conduit is payed out whereby the collector is placed on the sea bottom. Swivel or ball joints in conjunction with enough slack in the flexible conduit aid in allowing the collector to remain on the bottom when the vessel commences its travel through the Water over the mining area.

With the surface vessel dead in the water, and the collector just above the sea bottom, surface conditions may arise 'wherein the vessel would be subjected to heave, that is, a vertical movement of the vessel due to wave action. It is possible therefore that even with flexible 3,543,527 Patented Dec. 1, 1970 conduit connected to the collector extensive damage could be incurred by the collector since the vertical movement of the ship could cause the collector to be smashed against the sea bottom.

It is therefore one object of the present invention to provide conduit payout apparatus which eliminates the danger to the collector due to vessel heave, when the collector is placed on the sea bottom.

For mining depths of for example 16,000 feet, the paying out of conduit and the placement of the collector on the sea bottom may take one or more days. With the vessel dead in the Water it is subject to various unfavorable sea conditions which would necessitate either a halt in the paying out operation, or a complex positioning system for maintaining a favorable heading with respect to the sea (wave) direction.

It is therefore another object to provide a conduit payout system which eliminates the need for complex and expensive vessel positioning systems.

Where a mining area includes various depths to the sea bottom, it is necessary to halt mining operations, bring the vessel to a standstill, and add on more conduit sections. In addition to being a time consuming operation, the vessel is again subject to unfavorable seas.

It is therefore another object to provide a conduit payout system which is readily adaptable to various depths of sea bottom.

SUMMARY OF THE INVENTION A surface vessel is provided for traveling through the water and includes a conduit holding and joining station for holding a conduit section at an angle greater than zero degrees with respect to vertical. While the vessel is underway the conduit depends from the vessel at a certain angle 6. Structural means are provided for the vessel for holding and positioning a conduit section at that angle 0 for joining to a held conduit section, in the holding and joining station.

When a predetermined length of conduit has been payed out the vessel may be slowed down to a predetermined speed whereby a collector at the end of the conduit will settle on and thereafter be pulled along the sea bottom, for mining operation.

BRIEF DESQRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic representation illustrating the surface vessel, conduit and collector of a mining system;

FIGS. 2 to 5 are side elevational views, of the vessel of FIG. 1, with portions cut away, illustrating various stages in the paying out of conduit;

FIG. 6 is a plan view of gimbal arrangement which may be utilized herein;

FIG. 7 is a view along line VIIVII of FIG. 6; and

FIG. 8 illustrates various angular relationships.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a surface vessel 10 moving through the water astern in the direction of the arrow. Depending angularly from the surface vessel 10 is a conduit 12, made up of a plurality of conduit sections, and at the end of which is connected a collector 14 traveling over the sea bottom 15 for collecting desired aggregates. One example of a collector which may be utilized is described and claimed in co-pending application Ser. No. 729,728 filed May 16, 1968 and assigned to the assignee of the present invention.

To accommodate for variation in sea bottom altitude, the lower section 17 of conduit 12 may be comprised of flexible conduit connected to metallic conduit by means of a ball joint 18.

It is seen that the vessel It} includes a tilted or slanted derrick means 20 which is instrumental in the paying out of conduit 12, and typical joining and paying out of conduit sections is illustrated in FIGS. 2 to 5, to which reference is now made.

In FIGS. 2 to 5 the central portion of the vessel It] is illustrated in side elevational view with a portion broken away to show the central working well 24 through which collector, conduit, and other apparatus is lowered to the sea bottom. Center Well vessels are commonly used in drilling and mining operations and are well known to those skilled in the art.

Located at the level of the main deck 26, and right above the working well 24, is a conduit holding and joining station 28 which includes means to hold a conduit section at various angles, such means by way of example taking the form of a gimbal 30 shown in more detail in FIGS. 6 and 7 to which reference should now be made.

FIG. 6 is a plan view of a typical gimbal which includes an outer frame member 32 which is rotatable about axis XX by means of bearings 33 and 34, also shown in section in FIG. 7. Connected to the frame member 32 are two bearings 36 and 37 connected to an inner frame j member 39 which is accordingly, rotatable about axis YY. The central aperture 41 of the inner frame member 39 includes a sloped wall portion 42, also shown in FIG. 7.

FIG. 7 illustrates the central aperture of the gimbal accommodating a conduit section 45 held in place by means of removable wedges such as 47 and 48 each having a sloping outer edge mating with the sloped wall porq tion 42 and a toothed or ridged inner edge for gripping the conduit 45. Such gimbal arrangements with the conduit holding feature are commonly used on mining ships to accommodate for pitch and roll movements of the vessel to thereby reduce stresses on the conduit as the collector is moved along the bottom during mining operations.

In the present invention the gimbal arrangement is utilized not only to accommodate for pitch and roll movements of the ship while conducting mining operations, but is additionally used to maintain the conduit, or a conduit section at a predetermined angle with respect to vertical while the conduit sections are being joined and the conduit payed out from the vessel.

Referring back to FIG. 2, the vessel 10 includes a structural means for holding and positioning a conduit section at an angle 6 greater than with respect to vertical for joining a new conduit section to a conduit section held by the gimbal 30. This structural means is illustrated in FIGS. 2 to as a derrick means 20 generally extending along a central line C disposed at said angle 0. Angular relationships are illustrated in FIG. 8 which shows a line C at an angle 0 with respect to the vertical V. C is the angle of the derrick means 20 and is the same line C as shown in FIGS. 2 to 5. Line C in FIG. 8 is also at an angle 0 with respect to the vertical V and is representative of a conduit section after the vessel has attained a certain predetermined speed at which metallic conduit section joining operations are commenced. Referring again to FIG. 2, the derrick means includes an upper fixed pulley arrangement 50 and a lower traveling pulley arrangement 52 connected to the upper pulleys 50 by means of cables 53 and operable to travel substantially along the line C via track means 54. The traveling pulley 52 includes conduit gripping means 65 depending therefrom. Movement of the pulleys is accomplished by suitably provided draw works (not shown).

The vessel includes conduit storage facilities (not shown) and each conduit section may be delivered to the derrick means by way of a conveyor 57 shown located at a level above the main deck 26. In FIG. 2, there is depicted the situation wherein the vessel It] is dead in the water and a collector 14 connected to flexible conduit 17 has been lowered through the central well 24, with the upper part of the flexible conduit 17 being held by the ll gimbal 30 at the conduit holding and joining station 28.

Due to the flexible nature of the conduit 17 the portion below the gimbal 30 hangs vertically while the portion above the gimbal 36 connected to the gripping means 65 has imparted thereto a slight curvature. For operations where it is desired that no curvature be imparted to the conduit, the derrick means may have provisions for assuming a vertical position whereby the line C is vertical and passes through the center of gimbal 3t This may be accomplished by the provision of a hinged foot pad 67 pivotally connected to the rear derrick leg 69. The other rear derrick leg, not shown, would also be pivotally mounted. The lower segment 7 0 of the front derrick leg '71, connected to foot pad 73, may be made collapsible or removable so that when the derrick means 20 is brought to a vertical position point A of leg 71 engages and is connected to foot pad 74. The other front derrick leg, not shown, would have a similar arrangement.

Located within the structure of the derrick means 20 is a working platform 77 and a snubber 80 movable in the directions as indicated by the double ended arrow. The purpose and operation of the snubber 80 will be brought out in the subsequent figures.

The major portion of the derrick means 20 is located between a bridge structure 83 and the stern of the vessel 10. The bridge structure 83 is provided with viewing facilities whereby the joining and paying out of conduit may be supervised.

Better control of the vessel can be established once the vessel is underway. The vessel may be headed into the most favorable sea direction to minimize or eliminate unwanted vessel movements due to unfavorable sea conditions. The arrangement of the present invention allows the conduit to be joined and payed out while the vessel is underway whereas in prior art methods the vessel is dead in the water and subject to these sea conditions.

After the collector 14 has been lowered through the well, the vessel 10 is accelerated astern. The propelling of the vessel backwards is commonly done to obtain better vessel control when conduit is being towed. The vessel travels backwards until a certain speed is attained whereby the conduit held by the gimbal 30 substantially becomes an extension of the line C, that is, the conduit assumes the angle 0 With respect to vertical. This situation is depicted in FIG. 3.

In FIG. 3 by proper choice of vessel speed the conduit 12 has assumed the same angle as the derrick means 20, it being understood that the conduit 12 could also be the flexible conduit 17. It is seen that the conveyor 57 has just delivered a conduit section 86 to the derrick means 20 and a workman on the platform 77 has connected the gripping means 65 of the traveling pulley 52 to the upper end of the conduit section 86.

The traveling pulley 52 is then raised to a position illustrated in FIG. 4 and the snubber 80 is moved to a position to engage the lower end of conduit section 86 as it comes off the conveyor 57. After engagement with the lower end of conduit 86 the snubber 8G is moved back to a position whereby the conduit section 86 lies substantially along the line C and assumes the angle 0. The traveling pulley 52 is then lowered somewhat so that the conduit section 86 may be joined to the conduit held by the gimbal 30, as depicted in FIG. 5. After joining, the wedges 47 and 48 (FIG. 7) are removed and the traveling pulley 52 is lowered to the position shown dotted and during the course of travel of which the snubber 80 is moved out of position. When the traveling pulley 52 is lowered to the position shown dotted, the conduit section 86 is wedged into and depends from the gimbal 30 at the angle 6 with respect to vertical. With the ship underway, the process illustrated in FIGS. 3 to 5 is repeated until a predetermined length of conduit has been payed out, at which time a suitable pump or lift system is connected to the conduit for raising collected aggregates and the vessel slowed down so that the collector may be placed, in effect, landed, on the sea bottom.

If a number of extra conduit sections are required for mining in deeper water the vessel need not come to a complete halt but may speed up to lift the collector off the sea bottom and to bring the conduit angle again into agreement with the derrick angle 0. The extra conduit section may be added on as previously described and the vessel thereafter slowed down to again commence mining operations.

Accordingly, there has been described a method and apparatus whereby a conduit having a mining collector at the lower end thereof and made up of a plurality of conduit sections may be payed out by joining the conduit sections while the vessel is underway. The traveling of the vessel through the water at a predetermined speed coupled with the gimbal arrangement places the conduit at a predetermined angle which may be maintained in rough sea states since the vessel may choose its heading.

In prior art type of paying out operations the vessel remains dead in the water and for certain sea states joining operations must be halted, or alternatively, complex maneuvering systems must be provided for the vessel. In those same sea states, the apparatus and method described herein allows continuous and uninterrupted joining operations.

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 and 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 mining method for joining and paying out conduit sections, comprising the steps of:

(a) lowering a mining collector with at least a first conduit section connected, from a vessel adapted to move through the water;

(b) accelerating said vessel until said mining collector is being towed, at a predetermined vessel speed of a magnitude to position said conduit section at a predetermined angle with respect to vertical;

(0) joining successive conduit sections while said vessel is traveling through the water at said predetermined speed.

2. An underwater mining method for joining and paying out conduit sections, comprising the steps of:

(a) lowering a mining collector with conduit connected, from a surface vessel adapted to move through the water;

(b) accelerating said vessel until said conduit assumes a predetermined angle with respect to vertical;

(0) substantially maintaining said predetermined angle by vessel control;

(d) placing a conduct section at said predetermined angle;

(e) joining the conduit section of clause (d) with the conduit of clause (b);

(f) paying out the joined conduit section and conduit of clause (e); and

(g) joining and paying out successive conduit sections while said vessel is underway.

3. An underwater mining method according to claim 2 which additionally includes the step of;

(a) slowing down the vessel after a predetermined length of conduit has been payed out, for allowing the mining collector to engage the sea bottom.

References Cited UNITED STATES PATENTS 3,373,807 3/1968 Fischer et al. 61-72.3 3,389,563 6/1968 Postlewaite et al. 6172.3 3,429,062 2/1969 Nelson 37-72 X JACOB SHAP'IRO, Primary Examiner U.S. Cl. X.R. 3750

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