EP0828031A1 - Vorrichtung zum Pflügen unter Wasser - Google Patents

Vorrichtung zum Pflügen unter Wasser Download PDF

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Publication number
EP0828031A1
EP0828031A1 EP97306880A EP97306880A EP0828031A1 EP 0828031 A1 EP0828031 A1 EP 0828031A1 EP 97306880 A EP97306880 A EP 97306880A EP 97306880 A EP97306880 A EP 97306880A EP 0828031 A1 EP0828031 A1 EP 0828031A1
Authority
EP
European Patent Office
Prior art keywords
share
plough
ploughing
depressor
respect
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP97306880A
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English (en)
French (fr)
Other versions
EP0828031B1 (de
Inventor
Jeremy John Richard Featherstone
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Global Marine Systems Ltd
Original Assignee
Cable and Wireless PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cable and Wireless PLC filed Critical Cable and Wireless PLC
Priority to US08/989,398 priority Critical patent/US5988948A/en
Publication of EP0828031A1 publication Critical patent/EP0828031A1/de
Application granted granted Critical
Publication of EP0828031B1 publication Critical patent/EP0828031B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F5/00—Dredgers or soil-shifting machines for special purposes
    • E02F5/02—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches
    • E02F5/10—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with arrangements for reinforcing trenches or ditches; with arrangements for making or assembling conduits or for laying conduits or cables
    • E02F5/104—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with arrangements for reinforcing trenches or ditches; with arrangements for making or assembling conduits or for laying conduits or cables for burying conduits or cables in trenches under water
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F5/00—Dredgers or soil-shifting machines for special purposes
    • E02F5/02—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches
    • E02F5/10—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with arrangements for reinforcing trenches or ditches; with arrangements for making or assembling conduits or for laying conduits or cables
    • E02F5/104—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with arrangements for reinforcing trenches or ditches; with arrangements for making or assembling conduits or for laying conduits or cables for burying conduits or cables in trenches under water
    • E02F5/106—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with arrangements for reinforcing trenches or ditches; with arrangements for making or assembling conduits or for laying conduits or cables for burying conduits or cables in trenches under water using ploughs, coulters, rippers

Definitions

  • the present invention relates to an underwater plough and methods of ploughing an underwater bed, for instance in order to bury an elongate member (such as a cable or pipe) in the underwater bed.
  • an elongate member such as a cable or pipe
  • One approach is to use different size ploughs for different parts of a route, so that a 1m plough may be used for the hard ground and a 3m soft ground plough for those areas expected to have weak soils.
  • this approach has a number of problems. Firstly, recovering the plough to the ship and replacing it with a larger plough inevitably results in higher costs. Secondly, the recovery process inevitably leaves unburied sections of cable which require post lay burial. Thirdly, conventional 3m ploughs have poor hard ground capability, may not handle repeaters and cannot be adjusted to zero burial depth. Fourthly, a conventional 3m plough is much bigger than a 1m plough, which results in handling problems from existing A frames and deck spreads.
  • an underwater plough for ploughing an underwater bed comprising a first share and a second share which is movable with respect to the first share whereby the depth of the ploughing profile presented by the plough can be varied.
  • the second share may present a ploughing profile or surface in all positions, or may have a retracted non-ploughing position in which only the first share ploughs the underwater bed.
  • the first aspect of the present invention provides a particularly elegant solution to the problems presented above.
  • the adjustable second share can be raised and lowered as required in order to vary the depth of the ploughing profile presented by the plough, and hence vary the depth of trench which is cut.
  • the plough has the additional advantage that the second share can be fitted to an existing conventional plough chassis.
  • the first share provides a ploughing profile (and hence minimum ploughing depth) of approximately 1m with the second share retracted, and the second share can be extended to a maximum extension in which the ploughing profile is increased up to a maximum of approximately 3m.
  • the plough is no larger than a conventional 1m burial plough, whilst providing a variable ploughing depth up to approximately 3m.
  • the plough may be used for a number of purposes, but is particularly suited to the burial of an elongate member (such as a cable or pipe).
  • the plough typically comprises means (such as a conduit) for receiving the elongate member which is buried in use by the plough, and/or a depressor for guiding the elongate member by applying a downward force to the elongate member.
  • the depressor is preferably movable with respect to the first share, typically synchronously with the second share.
  • the second share can be designed to minimise these forces.
  • the second share may provide a backwardly raked cutting surface in at least one position. The backwardly raked surface will generate a soil reaction with an upward component to minimise the required heel force.
  • the second share has a cutting portion which provides a cutting action (eg a cutting edge or face) and a heel portion behind the cutting portion (typically comprising a lower surface of the second share) which provides a bearing area for plough heel forces.
  • the second share has an extended position in which a plane extending along the heel portion does not intersect with the depressor. This ensures that the heel portion bears the majority of the heel forces, and thus reduces heel forces on the elongate member.
  • the cutting portion and the heel portion may subtend an angle greater than 90 degrees. This enables the cutting portion to provide a backwardly raked blade whilst the heel portion runs horizontally.
  • the second share may be slidably mounted but preferably is pivotally mounted with respect to the first share.
  • the second share may be mounted separately from the first share, for instance the second share may be mounted behind the first share on a longitudinal plough beam. However preferably the second share is mounted to the first share.
  • the first share preferably comprises a pair of side plates, wherein the second share is mounted between the side plates.
  • the depressor and the elongate member are also at least partially located between the side plates.
  • the second share has a retracted position in which it forms at least part of a plough heel behind the first share with respect to the ploughing direction.
  • the second share does not provide a cutting surface or ploughing profile when in its retracted position but offers a bearing area for plough heel forces.
  • the second share may be moved with respect to the first share by actuating means such as a hydraulic cylinder.
  • the plough may comprise resilient means which biases the second share towards an extended position with respect to the first share.
  • the second share may not be driven, but may simply adopt a particular position in response to the forces presented to it (i.e. the resilient force and the force presented by the ploughed material).
  • the actuating means and resilient means are provided by the same means, such as a hydraulic cylinder which is sprung with a hydraulic accumulator.
  • the plough may be towed from a ship or may be part of a self-motivating sub-sea vehicle.
  • the actuating means is typically controlled from the ship via a data line but alternatively (particularly in shallow water) it may be controlled by divers.
  • the plough is also constructed such that the rear of the plough can pitch back up to greater than 10-15°. This amount of pitch is normally prevented on conventional ploughs by stabilising arms and other rearward structure. By allowing the rear of the plough to pitch back (particularly in soft soil) the depth of the plough profile can be maximised.
  • a method of ploughing an underwater bed comprising ploughing the bed with a plough comprising a first share and a second share which is movable with respect to the first share, and varying the depth of the ploughing profile presented by the plough by moving the second share with respect to the first share.
  • the second share may be moved during ploughing.
  • the ploughing may be temporarily stopped when the second share is adjusted.
  • the method further comprises laying an elongate member in the ploughed underwater bed.
  • the burial depth can be controlled in accordance with burial requirements.
  • the elongate member may be buried more deeply in soft soils or sand where the risk of damage from external influences such as fishing gear is greatest.
  • the elongate member may be laid during ploughing or may be laid in a trench which has been previously ploughed.
  • the method further comprises monitoring a parameter related to the amount by which the buried elongate member is protected from external influences, and varying the depth of the ploughing profile in accordance with the monitored parameter.
  • the method comprises moving the second share when required in order to maintain the parameter substantially constant. This may be achieved by an operator on a surface ship, or by an automated feedback mechanism. By adjusting the second share (and hence the ploughing depth) a constant “burial protection index" can be achieved.
  • the parameter comprises the resistive force presented by the underwater bed to the plough.
  • the parameter typically comprises one of the towing force and towing energy (i.e. force x speed). That is, the second share is adjusted such that a substantially constant towing force (or towing energy) is applied to the plough.
  • a constant towing force or towing energy
  • the burial depth will increase and decrease in accordance with the strength of the ploughed undersea bed, but the burial protection index will remain substantially constant.
  • the monitored parameter may comprise the strength of the material being ploughed.
  • the strength of the material being ploughed may have been previously monitored by carrying out a detailed survey of the stretch of underwater bed in which the cable is to be buried.
  • the method further comprises adjusting a depressor with respect to the first share in accordance with the monitored parameter and/or the position of the second share.
  • a plough 1 has a beam 2 on the front end of which are a pair of skids comprising a left-hand skid 3 and a right-hand skid (hidden).
  • a share assembly 10 is mounted at the rear of the beam 2.
  • skid 3 is pivotally mounted to a skid arm 6 via a skid pivot 7.
  • Skid arm 6 is pivotally mounted to beam 2 via a skid arm upper pivot 5.
  • the left-hand skid 3 is shown in its raised position 8 and lowered position 9. In the lowered position illustrated at 9 the skid arm 6 is omitted for clarity.
  • the skids are driven between their lowered position 9 (no trench cut) and their raised position 8 (maximum depth of trench cut).
  • the plough 1 also has a pair of burial depth limiting skids (shown in Figures 15 and 16 only).
  • the share assembly 10 comprises a first or upper share comprising a knife 13 and point 14.
  • the knife 13 comprises the cutting edge of a pair of tapering plates 100,101 which taper from a maximum width of 180mm at 102,103 to a minimum width at the knife 13.
  • a cable trough 24 with tapered sides 130,131 runs along the top of beam 2, as shown in Figures 2, 3 and 4.
  • Figure 7 shows that the base of point 14 is flat.
  • the point 14 tapers to a horizontal cutting edge 19.
  • the share assembly 10 comprises a pair of side plates 134,135 ( Figure 5) which define a cable slot 20 ( Figure 2) which houses an adjustable second or lower share 21 (shown in Figures 6 and 9 and omitted in Figure 5), a depressor 22 (shown in Figure 14) and a second share adjustment cylinder 23 (shown in Figures 9 and 14).
  • a curved plate between the sideplates 134,135 defines an upper plough bend 25 ( Figures 2 and 9).
  • the second or lower share 21 comprises a pair of sideplates 50,51 which are joined along opposite sides of a plate defining a cutting face 32 and along a curved lower plough bend 28.
  • the second share 21 is pivotally mounted to the share assembly 10 at 29.
  • the hydraulic cylinder 23 drives an actuating piston 52 which is pivotally mounted to the second share 21 at 30.
  • the hydraulic cylinder 23 is pivotally mounted to the share assembly 10 at 31.
  • Figure 9 shows the second share in its raised position at 53 with the actuating piston 52 retracted at 55, and in its lowered position at 54 with the actuating piston 52 extended at 56.
  • the lower share 21 In its raised position 53 the lower share 21 does not present a ploughing profile, and the cutting face 32 of the second share 21 is flush with the ends 132,133 of sideplates 134,135.
  • drive means (not shown) controlled from the surface of the water pressurises the cylinder 23, driving the second share 21 into its lowered position 54.
  • the cutting face 32 of the second share forms a backward raked cutting surface when in the lowered position 54.
  • the second share may also be deployed in any intermediate position between raised position 53 and lowered position 54.
  • the cutting face 32 is a non-tapered flat face. Since the second share is only generally deployed in soft soil which can be easily cut by a blunt edge, it is not necessary for the cutting face 32 to taper to a point in the same manner as knife 13 and point 14 (which are for general use and therefore need to be able to cut through strong soils).
  • the face 32 may be replaced by a pair of tapering plates 60,61 ( Figure 12) which meet at a point 62 in the same way as knife 13.
  • the face 32 may be replaced by a pair of tapering plates 63,64 ( Figure 13) which are joined by a horizontal plate 65. This provides a compromise between the flat face 32 of Figures 10 and 11 which provides a wide surface for the plough bottom when the second share is raised, and the cutting edge 62 which provides a narrower plough heel area but cuts more efficiently.
  • a cable 70 is paid off from the stern of a ship which also tows the plough 1.
  • the cable 70 passes along cable trough 24 and is guided into cable slot 20 and around upper plough bend 25 by depressor upper arm 71.
  • the depressor upper arm 71 is pivotally mounted to a support frame (not shown) at 73.
  • the upper arm 71 is driven from a raised position (not shown) to the lowered position shown in Figure 14 by a hydraulic actuator comprising hydraulic cylinder 74 pivotally mounted to the support frame at 75, and an actuating piston 76 pivotally mounted to the upper arm 71 at 77.
  • the upper arm 71 comprises a cylinder 78 which houses a sliding arm shown in its raised position at 79 and its lowered position at 80.
  • the sliding arm is driven between its raised and lowered positions by a hydraulic actuator comprising a hydraulic cylinder 81 which is mounted to the upper arm 71 at 90 and an actuating piston 82 which is mounted to the sliding arm at 83.
  • Depressor lower arm 84 is mounted on the end of the sliding arm, and defines a cable exit point 85,86 at the bottom of the ploughed trench.
  • the heel surface 113 of the second share 21 behind the cutting surface 32 runs approximately horizontally and bears plough heel forces.
  • a plane 140 along the heel surface 113 passes below and behind the share assembly 10 and the cable exit point 86 and therefore does not intersect with the cable 70 or the depressor lower arm 84.
  • the angle 143 between the cutting surface 32 and the heel surface 113 is greater than 90 degrees (in this example the angle 143 is approximately 135 degrees).
  • Figures 15 and 16 are schematic side views of the plough 1 burying a cable 70.
  • the cable 70 is being buried in hard soil 91 and therefore the second share 21 is in its raised position. In this position the plough operates in a similar fashion to a conventional long beam plough.
  • the plough 1 is towed by a tow wire 92 and the second share 21, depressor 72 and skids 3 are controlled by control signals which are transmitted to the plough from the ship via data line 93.
  • the main forces operating on the plough are a towing force 94, soil force 95, plough weight force 96, skid force 110 and heel force 97.
  • additional upward force may be provided by rear (wheeled) stabilisers or skids which run along the surface and ensure that the plough runs level.
  • the conventional skids are replaced by a pair of fixed skids 170 (only the right-hand skid 70 being shown) which are fixed at an angle (e.g. 10-15°) to the plough beam.
  • the burial depth 98 in hard soils is typically of the order of 1m. The ploughed trench collapses behind the plough to bury the cable 70.
  • the second share 21 can also be deployed in soft soil and the edge 32 provides a backwardly raked cutting blade.
  • the fixed skids 170 limit the pitch of the plough to a required maximum pitch angle (e.g. 10-15°). If a large amount of pitch is required, the skids 170 may be omitted entirely. In this position the surface 113 of lower share 21 is approximately horizontal.
  • the burial depth 98 can increase up to approximately 3m.
  • the second share cutting force 111 may increase so that the plough tends to lift out of the ground. Hence the second share is most usefully deployed in softer ground.
  • the plough runs at 0° pitch. That is, the base 114 of the share assembly 10 (formed by the lower edges 132,133 of sideplates 134,135 and the cutting face 32 of the lower share 21) runs parallel with the seabed 91 and provides a plough heel surface which bears the plough heel force 97.
  • the ploughing profile (given by the height from the lowest point 12 ( Figure 9) of the share assembly 10 to the lower surface 4 of skid 3) is approximately 1 metre.
  • the ploughing profile is increased in two ways, namely:
  • the ploughing profile can increase as a result up to 3 metres.
  • the plough is prevented from sinking too far by the burial depth limiting skids 170 which ensure that the plane 140 ( Figure 14) is horizontal or angled up (looking backwards).
  • the actuator 81 of depressor lower arm 84 is controlled in conjunction with second share actuator 23 to ensure that the depressor is not lowered far enough to add forces to the cable 70.
  • BPI is a parameter relating to the degree of protection provided to the cable from external influences such as fishing gear or anchors.
  • Fig. 17 is a graph illustrating the variation in BPI with burial depth, assuming that the plough is towed at low speed. Fishing gear or anchors will also tend to be towed at low speed, so this is a valid simplification to the analysis. The low speed assumption is also conservative, in that for a given tow force the penetration depth achieved (for instance by a plough or anchor grapnel trawl board) will diminish with increased speed.
  • Four example lines 120-123 are shown in Fig. 17.
  • the burial protection index may vary with depth as indicated at 120.
  • the gradient of the line 120 is so shallow that doubling the burial depth only leads to a small increase in BPI.
  • to achieve that doubling in burial depth may be very expensive (eg requiring a bigger plough, bigger ship required to launch the bigger plough etc.) and this may not be cost effective.
  • burial cannot provide good protection and armour may be the better solution.
  • the likely variation of BPI for a clay with medium cohesiveness is illustrated at 121, and the likely variation for a hard clay is illustrated at 122.
  • the likely variation in BPI for sand is illustrated at 123.
  • a conventional constant burial depth specification is given by a vertical line 124 on the graph of Fig. 17. It is clear from line 124 that a cable buried to 1m in very soft clay will be provided with a much smaller degree of protection than in hard clay. In contrast, a method of burial according to the present invention involving a constant BPI would use a horizontal line 125 on the graph up to the maximum burial depth of the plough. For any given plough there is a maximum BPI capability limited by plough weight.
  • Fig. 18 is a flow diagram illustrating important steps in two alternative burial methods.
  • the first five method steps are common to both methods.
  • a first step 150 the cable is loaded into the plough on the deck of the ship prior to launch. Throughout ploughing operations the cable runs through the plough structure.
  • the plough is launched at 151 from the ship and landed on the seabed with the skids fully down, the depressor down sufficiently to ensure that the cable is trapped between the share side plates, and the second share fully retracted.
  • the plough tow wire is paid out at 152 from the winch on the ship to establish the towing catenary.
  • the skids are raised gradually at 153 to achieve deeper burial.
  • the operator will monitor the cable tension measured at the depressor, and if this is higher than anticipated may lift the depressor fractionally to ensure that the weight of the plough is not bearing on the cable, assuming that the burial depth requirement is being met.
  • Typical variables which are monitored during operation are the plough position, plough speed, burial depth achieved and cable tension.
  • the burial depth may be measured in a number of ways. For example, the burial depth may be given by a combination of the angle of deployment of the skid arms 6 and the angle of deployment of the second share 21.
  • the cable tension is measured at the depressor 72. These variables are transmitted to the ship via data line 93 and recorded for later analysis. If the plough gets stuck or is in hard ground with unacceptably high cable tension or poor progress rate the skids may be lowered to reduce the burial depth.
  • the second share 21 is biassed towards its lowered position by resilient means such as a spring or a hydraulic cylinder sprung with a hydraulic accumulator.
  • the biassing force may be adjustable.
  • the second share 21 is always automatically working to maximum depth for the soil conditions. For example, in hard soil the soil force 97 will force the second share 21 into its raised position against the biasing force. When the strength of the soil decreases, the force 97 will decrease, allowing the plough to pitch back and the second share to lower slightly.
  • the operator merely needs to set the tow force (and optionally the biassing force) at 154, and the position of the second share will adjust automatically to achieve an approximately constant tow force.
  • the second share 21 is actively controlled by an operator on the ship or by suitable software.
  • the operator sets the desired tow force T s (related to the desired BPI) at 155, and the position of the second share is adjusted by a suitable feedback loop to maintain the tow force T at approximately the desired tow force T s . That is, the tow force T is monitored during a cable burial operation, and if the tow force T drops below the required tow force T s at 156, the operator (or the software) lowers the second share at 157 to increase the burial depth. If, alternatively, the tow force T rises above the desired towing force T s at 158, the operator or software raises the second share at 159.
  • the second share is activated by a double acting hydraulic cylinder.
  • the circuitry incorporates a high volume flow pressure relief valve so that if a hard obstacle is struck the second share can move back to clear the obstacle.
  • the second share is lowered and retracted on the move. If the operator observes that lowering the second share is causing the plough to come out of the ground, then the operator will not lower the second share any further.
  • the second share will only increase burial depth where the ground is not hard enough to generate up forces sufficient to lift the plough out. During shallower burial ploughing the operator will be able to develop a good feel for when the second share can be deployed, by monitoring tow force T and plough pitch.
  • the stretch of seabed in which the cable is being buried may have been surveyed previously, and the second share is deployed in accordance with previously measured soil cohesiveness values.
  • the depressor is operated in conjunction with the second share.
  • the depressor has two stage control as previously described, with two independent hydraulic cylinders 74, 81.
  • the first cylinder 74 raises and lowers the depressor down to the maximum required for the fixed part of the plough (i.e. the top one metre of burial).
  • the second cylinder 81 moves the lower depressor arm 84 down within the lowered second share.
  • a software lock prevents the second share being deployed unless the first actuating piston of 76 is fully extended. This ensures that the depressor is always running within the side plates 50,51 of the second share and that there is no opportunity for the cable 70 to escape up the side.
  • the cable diameter needs to be large compared to the gap between the depressor and the share side plates.
  • the plough design previously described is particularly suited to a constant BPI. It has the same capability as a standard plough down to one metre burial depth, and can bury deeper in soft soils. For the one metre to three metre depth range it has variable geometry which can either be actuated from the ship or may be sprung such that the depth achieved is always automatically maximised for a given plough geometry and tow force, within certain limits.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Electric Cable Installation (AREA)
EP19970306880 1996-09-06 1997-09-04 Vorrichtung zum Pflügen unter Wasser Expired - Lifetime EP0828031B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08/989,398 US5988948A (en) 1997-09-04 1997-12-12 Underwater plough and method for varying ploughing depth

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9618638 1996-09-06
GBGB9618638.2A GB9618638D0 (en) 1996-09-06 1996-09-06 Improvements in underwater ploughing

Publications (2)

Publication Number Publication Date
EP0828031A1 true EP0828031A1 (de) 1998-03-11
EP0828031B1 EP0828031B1 (de) 2002-08-14

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Application Number Title Priority Date Filing Date
EP19970306880 Expired - Lifetime EP0828031B1 (de) 1996-09-06 1997-09-04 Vorrichtung zum Pflügen unter Wasser

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EP (1) EP0828031B1 (de)
DE (1) DE69714672D1 (de)
GB (1) GB9618638D0 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999013171A1 (en) * 1997-09-05 1999-03-18 Soil Machine Dynamics Limited Submarine plough
WO2000052268A1 (en) * 1999-03-05 2000-09-08 Soil Machine Dynamics Limited Submarine plough
GB2354886A (en) * 1999-09-28 2001-04-04 Engineering Business Ltd Cable or pipe laying apparatus
WO2003029568A1 (en) * 2001-10-02 2003-04-10 Global Marine Systems Limited Cable of pipe retrieval and burial apparatus and methods
DE102014113831B3 (de) * 2014-09-24 2016-01-21 Frank Föckersperger GmbH Kabelpflug und Verfahren zum Betreiben des Kabelpflugs
JP2022060519A (ja) * 2016-03-08 2022-04-14 ソイル マシン ダイナミクス リミテッド 海底にトレンチを形成する方法及び装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3898852A (en) * 1972-06-07 1975-08-12 Kokusai Cable Ship Co Ltd Ditching machines for submarine cable
US4011727A (en) * 1974-07-26 1977-03-15 Nippon Telegraph And Telephone Public Corporation Movable cable plow for constructing underwater cable
GB1493346A (en) * 1974-12-03 1977-11-30 Ede A Soil blade implement
US4129992A (en) * 1976-05-03 1978-12-19 Telefonaktiebolaget L M Ericsson Laying tool for laying of submarine cables into a sea-bottom
US4664553A (en) * 1983-01-20 1987-05-12 The British Petroleum Company P.L.C. Plough assembly
EP0296783A1 (de) * 1987-06-20 1988-12-28 LAND & MARINE ENGINEERING LIMITED Vorrichtung zum Ausheben von Meeresboden
US5462389A (en) * 1993-01-04 1995-10-31 At&T Ipm Corp. Undersea cable burial plowshare and sled apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3898852A (en) * 1972-06-07 1975-08-12 Kokusai Cable Ship Co Ltd Ditching machines for submarine cable
US4011727A (en) * 1974-07-26 1977-03-15 Nippon Telegraph And Telephone Public Corporation Movable cable plow for constructing underwater cable
GB1493346A (en) * 1974-12-03 1977-11-30 Ede A Soil blade implement
US4129992A (en) * 1976-05-03 1978-12-19 Telefonaktiebolaget L M Ericsson Laying tool for laying of submarine cables into a sea-bottom
US4664553A (en) * 1983-01-20 1987-05-12 The British Petroleum Company P.L.C. Plough assembly
EP0296783A1 (de) * 1987-06-20 1988-12-28 LAND & MARINE ENGINEERING LIMITED Vorrichtung zum Ausheben von Meeresboden
US5462389A (en) * 1993-01-04 1995-10-31 At&T Ipm Corp. Undersea cable burial plowshare and sled apparatus

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999013171A1 (en) * 1997-09-05 1999-03-18 Soil Machine Dynamics Limited Submarine plough
US6435772B1 (en) 1997-09-05 2002-08-20 Soil Machine Dynamics Limited Submarine plough
WO2000052268A1 (en) * 1999-03-05 2000-09-08 Soil Machine Dynamics Limited Submarine plough
GB2354886A (en) * 1999-09-28 2001-04-04 Engineering Business Ltd Cable or pipe laying apparatus
GB2354886B (en) * 1999-09-28 2003-10-15 Engineering Business Ltd Cable or pipe laying macxhines
WO2003029568A1 (en) * 2001-10-02 2003-04-10 Global Marine Systems Limited Cable of pipe retrieval and burial apparatus and methods
US7101116B2 (en) 2001-10-02 2006-09-05 Global Marine Systems Limited Cable or pipe retrieval and burial apparatus and methods
DE102014113831B3 (de) * 2014-09-24 2016-01-21 Frank Föckersperger GmbH Kabelpflug und Verfahren zum Betreiben des Kabelpflugs
JP2022060519A (ja) * 2016-03-08 2022-04-14 ソイル マシン ダイナミクス リミテッド 海底にトレンチを形成する方法及び装置

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Publication number Publication date
EP0828031B1 (de) 2002-08-14
GB9618638D0 (en) 1996-10-16
DE69714672D1 (de) 2002-09-19

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