# US 2014/0150303 A1 · Seabed Plow Capable of Over-the-Stern Release and Retrieval in Any Boulder Clearing, Trenching and Backfill Configurations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150303 A1 - Document ID: US20140150303A1 - Status: Published application - Kind: A1 - Application number: 13/691,076 - Filed: 2012-11-30 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Oceaneering International, Inc. - Inventors: Michael W. N. Wilson - Web page: https://patentgrep.com/patent/US20140150303A1 ## CPC - E02F 5/027: {with coulters, ploughs, scraper plates, or the like (E02F5/102, E02F5/103, E02F5/106 take precedence)} - E02F 5/106: {using ploughs, coulters, rippers} - E02F 5/125: {underwater} - E02F 5/14: Component parts for trench excavators, e.g. indicating devices {travelling gear chassis, supports, skids} - H02G 1/10: in or under water - B63B 2027/165: {Deployment or recovery of underwater vehicles using lifts or hoists} - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) ## Abstract A seabed plow capable of over-the-stern release and retrieval is usable in any of boulder clearing, trench cutting and backfill modes. In its boulder clearing mode, the plow uses its skid in torquing configuration followed by moldboards to push boulders out of the path to be trenched. In the trench cutting mode, the plow uses the skid in the same configuration with its share and moldboards for initial trench depth and the same share and moldboards with moldboard extensions for increasing trench depth in subsequent passes. In the backfill mode, the plow uses its skid in trench-straddling configuration following a blade with a passage designed to discharge fragmented spoil directly onto the pipe being covered. Thus, a single plow can be reconfigured for all modes for release and retrieval to and from a relatively small vessel without use of heavy lifting equipment. ## Claims ### Claim 1 A seabed-plow chassis comprising: an elongated member; one end of said elongated member being adapted for mounting a skid thereon for supporting said one end of said elongated member above the seabed; and another end of said elongated member being adapted for mounting thereon a tool comprising moldboards for clearing boulders pushed by the skid outward of a path traveled by the skid further outward from its path as the skid leads the moldboards along the seabed. ### Claim 2 (depends on 1) A seabed-plow chassis according to claim 1, said elongated member having a first transition surface configured to extend between the skid and the tool, said first transition surface being contoured to pivot about a fulcrum on a stern of a vessel contacting said first transition surface as a plow crosses the fulcrum during release of the plow from the vessel into the sea and during retrieval of the plow from the sea onto the vessel. ### Claim 3 (depends on 2) A seabed-plow chassis according to claim 2, a shape of said first transition surface and a weight of said elongated member being coordinated to resist roll of said chassis about a longitudinal axis of said elongated member. ### Claim 4 (depends on 2) A seabed-plow chassis according to claim 2, vertical longitudinal cross-sections of said first transition surface being concave. ### Claim 5 (depends on 2) A seabed-plow chassis according to claim 2, the fulcrum being a roller and paths defined by continuous symmetrically opposite points of said first transition surface being contoured to maintain contact with the roller as the plow crosses the roller. ### Claim 6 (depends on 1) A seabed-plow chassis according to claim 1, said another end of said elongated member being further adapted for mounting thereon a selected one of (a) said tool comprising moldboards and (b) a tool comprising a plow share and moldboards for sequentially cutting and moving outward and upward, respectively, spoil from the seabed to create a trench as the skid leads the plow share and moldboards along the seabed. ### Claim 7 (depends on 6) A seabed plow chassis according to claim 6, said elongated member further having a second transition surface configured to extend between said skid and said tool comprising a plow share and moldboards, said second transition surface being contoured to pivot about the fulcrum on the stern of the vessel contacting said second transition surface as the plow crosses the fulcrum during release of the plow into the sea from the vessel and during retrieval of the plow from the sea onto the vessel. ### Claim 8 (depends on 7) A seabed-plow chassis according to claim 7 a shape of said second transition surface and said weight of said elongated member being coordinated to resist roll of the plow about a longitudinal axis of said elongated member. ### Claim 9 (depends on 7) A seabed-plow chassis according to claim 7, the fulcrum being a roller and paths defined by continuous symmetrically opposite points of said second transition surface being contoured to maintain contact with the roller as the plow crosses the roller. ### Claim 10 (depends on 1) A seabed-plow chassis according to claim 1, said another end of said elongated member being further adapted for mounting thereon a selected one of (a) said tool comprising moldboards and (b) a tool comprising a blade and moldboards cooperating as the blade and moldboards lead the skid along the seabed to sequentially collect, funnel inward and release downward into the trench spoil lying outside of the trench. ### Claim 11 (depends on 10) A seabed-plow chassis according to claim 10, said elongated member having a first transition surface configured to extend between said skid and any selected one of (a) said tool comprising moldboards and (b) said tool comprising a blade and moldboards, said first transition surface being contoured to pivot about the fulcrum on the stern of the vessel contacting said first transition surface as the plow crosses the fulcrum during release of the plow from the vessel into the sea and during retrieval of the plow from the sea onto the vessel. ### Claim 12 (depends on 11) A seabed-plow chassis according to claim 11, a shape of said first transition surface and a weight of said elongated member being coordinated to resist roll of the plow about a longitudinal axis of said elongated member. ### Claim 13 (depends on 11) A seabed-plow chassis according to claim 11, longitudinal vertical cross-sections of said first transition surface being concave. ### Claim 14 (depends on 11) A seabed-plow chassis according to claim 11, the fulcrum being a roller and paths defined by continuous symmetrically opposite points of said first transition surface being contoured to maintain contact with the roller as the plow crosses the roller. ### Claim 15 (depends on 1) A-seabed plow chassis according to claim 1, said another end of said elongated member being further adapted for mounting thereon a selected one of (a) said tool comprising moldboards, (b) a tool comprising a blade and moldboards cooperating as the blade and moldboards lead the skid along the seabed to sequentially collect, funnel inward and release downward into the trench spoil lying outside of the trench and (c) a tool comprising a plow share and moldboards for sequentially cutting and moving outward and upward, respectively, spoil from the seabed to create a trench as the skid leads the plow share and moldboards along the seabed. ### Claim 16 (depends on 15) A seabed-plow chassis according to claim 15, said elongated member having a first transition surface configured to extend between said skid and any selected one of (a) said tool comprising moldboards and (b) said tool comprising a blade and moldboards and a second transition surface configured to extend between said skid and said tool comprising a plow share and moldboards, said first and second transition surfaces being contoured to pivot about a fulcrum on a stern of a vessel contacting one of said first and second transition surfaces as the plow crosses the fulcrum during release of the plow from the vessel into the sea and during retrieval of the plow from the sea onto the vessel. ### Claim 17 (depends on 16) A seabed-plow chassis according to claim 16, said shapes of each of said first and second transition surfaces and said weight of said elongated member being coordinated to resist roll of the plow about a longitudinal axis of said elongated member. ### Claim 18 (depends on 16) A seabed-plow chassis according to claim 16, longitudinal vertical cross-sections of each of said first and second transition surfaces being concave. ### Claim 19 (depends on 16) A seabed-plow chassis according to claim 16, the fulcrum being a roller and paths defined by continuous symmetrically opposite points of each of said first and second transition surfaces being contoured to maintain contact with the roller as the plow crosses the roller. ### Claim 20 For clearing boulders from a seabed, a plow comprising: a chassis; a skid mounted on and supporting one end of said chassis above the seabed; and moldboards mounted on and oriented in relation to another end of said chassis to clear boulders pushed by said skid outward of a path traveled by said skid further outward from the path traveled by said skid as said skid leads said moldboards along the seabed. ### Claim 21 (depends on 20) A plow according to claim 20, further comprising a head mounted on a leading end of said skid, said head having leading faces angled rearward from a vertical, longitudinal center plane of said skid and tapered rearward from bottom edges thereof. ### Claim 22 (depends on 20) A plow according to claim 20, said chassis having a surface between said skid and said moldboards contoured to pivot about a fulcrum on a stern of a vessel contacting said surface as the plow crosses the fulcrum during release of the plow to the sea from the vessel and during retrieval of the plow from the sea to the vessel. ### Claim 23 (depends on 22) A plow according to claim 22, said chassis, said moldboards and said skid being in weight and in contact surfaces with the fulcrum coordinated to resist roll of the plow about its transition axis. ### Claim 24 (depends on 23) A plow according to claim 23, the fulcrum being a roller and the plow further comprising pulling points for connection of a pulling line to the plow, said points being symmetrically arranged in relation to a longitudinal axis of said chassis and being displaced from a bottom of the plow by a height less than a radius of the roller. ### Claim 25 (depends on 23) A plow according to claim 23 further comprising keel plates, each said moldboard having at least one said keel plate extending thereunder. ### Claim 26 (depends on 25) A plow according to claim 25, the fulcrum being a roller and the plow further comprising pulling points for connection of a pulling line to the plow, said points being symmetrically arranged in relation to said longitudinal axis of said chassis and being displaced from a bottom of the plow by a height less than a radius of the roller. ### Claim 27 A method of clearing boulders from a path on a seabed comprising the steps of: positioning a plow bow-forward in a direction of an initial seabed path; and propelling the plow along the initial seabed path to clear boulders from the initial seabed path to the port and starboard sides of the plow. ### Claim 28 (depends on 27) A method according to claim 27 further comprising the steps of: repositioning the plow bow-forward in a direction opposite the initial seabed path direction and on a second seabed path along one of the port and starboard sides of the initial seabed path; and propelling the plow along the second seabed path to clear boulders from the second seabed path further to one of the starboard and port sides of the plow, respectively. ### Claim 29 (depends on 28) A method according to claim 28 further comprising the steps of: repositioning the plow bow-forward in the direction of the initial seabed path and on a third seabed path along another of the starboard and port sides of the initial seabed path; and propelling the plow along the third seabed path to clear boulders from the third seabed path further to the other of the starboard and port sides of the plow, respectively. ### Claim 30 (depends on 28, 29) A method according to claim 29 further comprising repeating the steps of claims 28 and 29 along a path resulting from a contiguity of the initial, second and third paths. ### Claim 31 (depends on 30) A method according to claim 30 further comprising repeating the steps of claim 30 for successively contiguous paths until a single path of desired width has been cleared along the seabed. ### Claim 32 (depends on 27) A method according to claim 27 preceded by the steps of: propelling the plow on the deck of a vessel toward and across a fulcrum on a stern of the vessel; allowing the plow to rotate about the fulcrum as the plow crosses the fulcrum and is released from the fulcrum into the sea; and lowering the released plow at tow-line end toward the seabed. ### Claim 33 (depends on 27) A method according to claim 27 followed by the steps of: raising the released plow at tow-line end toward a fulcrum on a stern of a vessel at another end of the tow line; and pulling the plow across the fulcrum onto a deck of the vessel. ### Claim 34 For backfilling spoil into a seabed trench, a plow comprising: a chassis; a skid supporting an aft end of said chassis above the seabed; moldboards mounted on said chassis forward of said skid, said moldboards being sized and oriented to span the trench and funnel spoil disposed on the seabed laterally of the trench toward the center of the trench as the plow travels forward on the seabed; and a blade mounted on and spanning bottom edges of said moldboards to collect the spoil in its path as the plow travels forward on the seabed, said blade having a passage at a rear apex thereof configured to dispense spoil collected by said blade and funneled by said moldboards to said passage on top of a pipe disposed in the trench below said passage. ### Claim 35 (depends on 34) A plow according to claim 34 further comprising a flapper board aft of said passage fragmenting spoil discharged through said passage. ### Claim 36 (depends on 35) A plow according to claim 35, said flapper board comprising: a plate swinging below a horizontal shaft; and a weight biasing said plate toward a vertical orientation. ### Claim 37 (depends on 34) A plow according to claim 34, said skid being configured to straddle the trench. ### Claim 38 (depends on 37) A plow according to claim 37, said skid comprising: a crossbar mounted on a rear end of said chassis; a pair of skid posts, one on each end of said crossbar; and a pair of skis, one on a bottom of each said post. ### Claim 39 (depends on 38) A plow according to claim 38, said crossbar having a front surface adapted to level spoil discharged into the trench. ### Claim 40 (depends on 34) A plow according to claim 34, at least one of said chassis, said moldboards, said blade and said skid having a surface contoured to pivot about a fulcrum on a stern of a vessel contacting said surface as the plow crosses the fulcrum during release of the plow to the sea from the vessel and during retrieval of the plow from the sea to the vessel. ### Claim 41 (depends on 40) A plow according to claim 40, longitudinal vertical cross-sections of said surface being concave. ### Claim 42 (depends on 41) A plow according to claim 41, said chassis, said moldboards, said blade and said skid being in weight and in contact surfaces with the fulcrum coordinated to resist roll of the plow about its transition axis. ### Claim 43 (depends on 42) A plow according to claim 42, the fulcrum being a roller and the plow further comprising towing points for connection of a towing line to the plow, said points being symmetrically arranged in relation to a longitudinal axis of said chassis and being displaced from a bottom of the plow by a height less than a radius of the roller. ### Claim 44 (depends on 42) A plow according to claim 42 further comprising keel plates, said blade having at least two said keel plates spaced apart and extending thereunder. ### Claim 45 (depends on 44) A plow according to claim 44, the fulcrum being a roller and the plow further comprising towing points for connection of a towing line to the plow, said points being symmetrically arranged in relation to a longitudinal axis of said chassis and being displaced from a bottom of the plow by a height less than a radius of the roller. ### Claim 46 A method of backfilling spoil into a seabed trench comprising the steps of: propelling a blade to travel forward on the seabed and collect spoil along the sides of the trench; funneling the collected spoil toward a rear apex of the blade; and allowing the funneled spoil to be discharged through an opening in the blade apex and onto a top surface of a pipe disposed in the trench. ### Claim 47 (depends on 46) A method according to claim 46 further comprising the step of leveling the spoil discharged into the trench. ### Claim 48 (depends on 46) A method according to claim 46 further comprising the step of fragmenting the discharged spoil before the discharged spoil reaches the pipe. ### Claim 49 (depends on 48) A method according to claim 48 further comprising the step of leveling the spoil discharged into the trench. ### Claim 50 A method of backfilling spoil into a seabed trench comprising the steps of: propelling a backfill plow on the deck of a vessel toward and across a fulcrum on a stern of the vessel; allowing the plow to rotate about the fulcrum as the plow crosses the fulcrum and is released from the fulcrum into the sea; and lowering the released plow at towing line end to the seabed. ### Claim 51 (depends on 50) A method according to claim 50 followed by the step of towing the plow to backfill the trench. ### Claim 52 (depends on 51) A method according to claim 51 followed by the steps of: raising the plow at towing line end toward the fulcrum on the stern of the vessel; and pulling the plow across the fulcrum onto the deck of the vessel.