APPARATUS AND METHOD FOR DEEP SEA DREDGING

• US 3,638,338 A
• Filed: 11/04/1969
• Issued: 02/01/1972
• Est. Priority Date: 11/04/1969
• Status: Expired due to Term

• Current Assignee: Arthur J. Nelson
• Original Assignee: Arthur J. Nelson
• Inventors: Nelson, Arthur J.
• Primary Examiner(s): Pulfrey, Robert E.
• Assistant Examiner(s): Crowder, Clifford D.
• Application Number:
  US04/873,985
• Time in Patent Office: 819 Days
• Field of Search: 175/7 114/144 37/58,72,DIG.8,64-67 61/46,46.5
• US Class Current: 37/308
• CPC Class Codes: E02F 3/907 Measuring or control devices, e.g. control units, detection means or sensors E02F3/902 takes precedence
• CPC Class Codes: E02F 3/9231 Suction wheels with axis of rotation parallel to longitudinal axis of the suction pipe
• CPC Class Codes: E02F 3/9293 Component parts of suction heads, e.g. edges, strainers for preventing the entry of stones or the like

Abstract

A pair of cutters and a dredge pump mounted to a lowermost pontoon is immersed to penetrate the floor of a body of water employing an indicator to limit the depth of cut for the pendulous traverse over a selected floor area. Anchors are selectively embedded into the floor remote to the dredged area to which wires are connected extending from powered winches mounted on the lowermost pontoon. The extended anchored wires are intermediately supported by a buoyed pendant so as to elevate those wires off the floor to avoid prolonged dragging and contaminating effect to them. Consequential with the catenary curve resulting from that elevation, a tension is developed creating an artificial demand of a slacked wire paid off one of a pair of identical winches at a greater rate than the opposite wire hauled-in to effect the pendulous swing established by a wire fixed to an anchor axially central with but remote to the selected area. Each pendulous swing is at a radius shortened by a winch oriented in mounting with the two identical winches so that all wires lead from the winch as tangent lines direct to the anchor. The anchors are relocated by towing on a surfaced conduit pendant extending to a lower buoy of adjustable support capacity secured by a cable pendant to the anchor whereby the buoy lift capacity is increased to free the embedded anchor off the floor. An articulative conduit in fluid communication between the pump and a delivery terminal on a surfaced service station is supported as a suspended tensioned array stabilized by immersed pontoons of selected and automatically adjusted support capacity responsive to changes encountered. An arrangement of hoists, structural provisions and utilization of pontoons common with the array facilitate the transfer of objects to and from the service station and the array to modify the dredging apparatus.

Claims

1. In an elongated array of objects stably disposed to selected elevations respective the floor of a body of water and contiguous with a buoyant service station subject to vagrancies of the surface of said water, an improved dredging apparatus comprising:

a. dredging means powered to yield material procured stratawise from penetration of said floor;

b. conduit means in fluid communication between said dredging means and a delivery terminal means adjustably mounted to said service station;

c. a plurality of immersed buoyant chambers sectionally disposed to said array and adapted for each chamber to contribute partial support to only the dependent portion of said array in cooperation with supplementary support consequential from said floor establishing vertical stability of said array;

d. an equalized tensioned wire system transmits to the uppermost of said chambers a deliberate deficiency of support by each lower chamber to avoid columnar compressive stress in said conduit;

e. monitoring and control means to retain said stability responsive to changes in environment, assumed loads, surface elevation and floor elevation encountered by said array;

f. maneuvering means adapted to effect the traverse of said dredging means over a selected area of said floor by an arrangement of winches and anchored wires, said arrangement entirely immersed in said water; and

, g. the elongated array pivotally suspends at the upper end to and in fixed elevation with a substation formed to and above the uppermost of chambers having adjustable buoyant support controlled by an indicator selectively established to monitor said penetration.

2. shoes pivotally mounted to the ends of said tilt beam are counterbalanced and expose broad bearing surfaces to diminish their self embedment upon contact with said floor;

3. a clamp means to selectively support the assembly portion of said array with said dredging means disposed off said floor by a stabilizing means monitoring increased freeboard of the platform above water surface through volume control of said adjustable buoyant chamber to supplant said floor support;

4. a cooperative utility station of adjustable buoyant support with clamp means alternately with the substation supports and positions said assembled portion to adjusted elevation relative the substation when modifying the length of the inoperated array;

and,

5. said oppositely disposed winches are fitted with magnetic switches to monitor controls to reverse rotate the winches upon interception of a vane closing switch means mounted to said wire for termination of traverse and to activate return swing;

6. A vertical dredging apparatus assembled as a tensioned nonadjustable elongated array of objects stably disposed to selected elevations respective the floor of a body of water and contiguous with a buoyant service station restrictively subject to the vagrant water surface, the improvement comprises:

a. a dredging means integral with a lowermost pontoon confining an adjustable volume buoyant chamber monitored and controlled to effect a deliberate insufficient support to the resultant aggregate weight of the dredging means supported in part by allowable floor reaction to penetration by the dredging means, comprises;

7. A vertical dredging apparatus assembled as a tensioned elongated array of objects stably disposed to selected elevations respective the floor of a body of water and contiguous with a buoyant service station restrictively subject to the vagrant water surface, the improvement comprises:

a. a dredging means integral with a lowermost pontoon confining an adjustable volume buoyant chamber monitored and controlled to effect a deliberate insufficient support to the resultant aggregate weight of the dredging means supported in part by allowable floor reaction to penetration by the dredging means with pEnetration regulated by an indicator means having;

8. said detector buoy is attended by auxiliary gas charging and venting means effecting said adjustable capacity to free said anchor from embedment in the floor and suspend same while in transit between positions for embedment.

9. A vertical dredging apparatus to be assembled as a tensioned elongated array of objects stably disposed to selected elevations respective the floor of a body of water and contiguous with a buoyant service station restrictively subject to the vagrant water surface, having:

a. a dredging means integral with a lowermost pontoon confining an adjustable volume buoyant chamber monitored and controlled to effect a deliberate insufficient support to the resultant aggregate weight of the dredging means supported in part by allowable floor reaction to penetration by the dredging means;

b. an articulative conduit means in fluid communication between said dredging means and a delivery terminal means adjustably mounted to said service station comprises a vertical constituent with the dredging means to define said elongated array and a trussed pivotal constituent with guide means accommodating the flexible connection of contiguous ends of the two constituents in contention with displacement of said movable service station relative the stable array;

c. a substation having a platform mounted to and towering above an immersed uppermost pontoon confining an adjustable volume buoyant chamber monitored and controlled to effect a support capacity to maintain said tensioned array suspended from said platform in accommodation with penetration of the floor;

d. an equalized selectively adjusted wire system connected between pontoons tensioned by part of the consequential net unsupported said weight of the dredging means to minimize tension in the vertical constituent of the suspended array;

e. monitoring and control means responsive to changes in environmental conditions, assumed loads, water surface and floor elevations encountered, maintains said stable array relation with the service station; and

, wherein the improvement comprises;

10. An elongated dredging apparatus vertically disposed as a tensioned array of objects in a body of water, mainly supported by buoyant means, extends from a selected penetration of the water floor to an articulative portion of the apparatus contiguous with a water surfaced buoyant service station monitored and implemented to retain spaced relationship with said array stabilized consequential with said penetration and by monitoring and control means responding to changes in environment, loading and obstructions encountered during traverse of the dredging apparatus over a selected area of said floor, said traverse implemented by a method comprising:

a. embedding anchors in the floor oriented with and remote to said area for direct connection of wires deformed solely when wound to drums of powered submerged winches affixed to dredging means disposed lowermost in said array;

b. controlling the array elevation by a floor penetration detector integral with the dredging means supporting floor cutter means and pump from a lowermost pontoon having an adjustable buoyant chamber and said penetration detector monitors in immersed uppermost adjustable chamber in buoyant support of a substation from which the elongated apparatus suspends;

c. effecting a port and starboard said traverse by alternately reversing rotation of identical winches oppositely disposed to dredge with a pendulous swing from a wire repetitiously shortened from each advance in the area by a bow winch;

d. suspending the extended wires by a buoyed wire pendant intermediately connected between anchor and winch to generate catenary curves of the slacked wire paidoff a powered winch at a greater rate than the rate of haul-in wire establishing traverse; and

, e. tensioning of the slacked wires consequential with catenary curves provides an artificial demand consistent with supply of wire paidoff to preserve undisturbed the remaining stored wire to be unreeled from the winch powered to revolve.

11. In a dredging apparatus according to claim 10 additional equipment included to implement modifications to the array and shift anchors, employs a method comprising:

a. arranging the array off said floor by a surfaced stabilizing means influenced by periodic immersion to control the support capacity of said buoyant means;

b. transferring said objects between the stable array and movable service station by altering both location of support of the array and the support means, and exchanging objects by coordinating a plurality of hoist means disposed with accommodating passageways;

c. imparting a lifting force to free the embedded anchor by means of a buoyant pendant extended to the water surface for towing to new location.