EP0296783B1 - Seabed trenching apparatus - Google Patents
Seabed trenching apparatus Download PDFInfo
- Publication number
- EP0296783B1 EP0296783B1 EP88305613A EP88305613A EP0296783B1 EP 0296783 B1 EP0296783 B1 EP 0296783B1 EP 88305613 A EP88305613 A EP 88305613A EP 88305613 A EP88305613 A EP 88305613A EP 0296783 B1 EP0296783 B1 EP 0296783B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- plough
- trench
- shares
- profile
- seabed
- 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.)
- Expired - Lifetime
Links
Images
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
- E02F5/027—Dredgers or soil-shifting machines for special purposes for digging trenches or ditches with coulters, ploughs, scraper plates, or the like
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
- B67C—CLEANING, FILLING WITH LIQUIDS OR SEMILIQUIDS, OR EMPTYING, OF BOTTLES, JARS, CANS, CASKS, BARRELS, OR SIMILAR CONTAINERS, NOT OTHERWISE PROVIDED FOR; FUNNELS
- B67C3/00—Bottling liquids or semiliquids; Filling jars or cans with liquids or semiliquids using bottling or like apparatus; Filling casks or barrels with liquids or semiliquids
- B67C3/02—Bottling liquids or semiliquids; Filling jars or cans with liquids or semiliquids using bottling or like apparatus
- B67C3/22—Details
- B67C3/26—Filling-heads; Means for engaging filling-heads with bottle necks
- B67C2003/266—Means for centering the container with the filling head
Definitions
- the present invention relates to apparatus for use in the formation of subsea trenches for burial of pipelines and cables.
- apparatus for forming a trench in a seabed comprising a first plough having two fixed plough shares and thereby adapted to form a trench of a fixed profile, and characterised by a second plough having two plough shares, one situated on either side of the first plough, movable relative to the first plough and thereby adapted to produce a trench having a selectively variable profile.
- the second, movable plough means is situated behind the first plough means.
- the second plough means may then be adjusted so that the finished trench profile is determined solely by the first plough means, or alternatively so that the second plough means alters the profile of the trench produced by the first plough means.
- the profile of the trench can be altered according to the type of seabed encountered.
- the second plough is longitudinally displaced from the first plough.
- the second plough means may be adapted to be able to alter the profile of the trench produced by the first plough means over the full depth of the trench, or in the upper portion of the trench only.
- the second plough means comprises two plough shares, one situated on either side of the first plough means.
- the trenching apparatus comprises a forward towing and support portion 10 which is attached to a trenching portion 14.
- the towing and support portion 10 is fitted with a support skid 16, which is pivotally mounted at pivot 18 to enable the skid to pass over uneven surfaces.
- the portion 10 is also provided with a towing cable attachment 20, by means of which a towing cable 22, extending from a surface ship, is attached to the trenching apparatus, whereby the apparatus may be towed along the seabed.
- the trenching portion 14 comprises an upper elongate frame member 24 and two lower elongate frame members 26.
- the upper frame member 24 is rigidly attached to the forward portion 10, and each lower frame member 26 is hingedly attached to the forward portion 10 at a vertical hinge 12.
- a lifting cable attachment 28 is provided on the upper frame member 24, by means of which the trenching apparatus may be lifted from, or lowered onto, the seabed.
- the upper frame member 24 is also provided with other articles such as a hydraulic fluid pressure generator 30, but these other articles are not involved in the understanding of the present invention, and will not be described further.
- the undersurface of the lower frame members 26 is provided with a first plough means in the form of two fixed plough shares 32, one attached to respective frame members 26 and a second plough means in the form of two secondary plough shares 34a, 34b, positioned behind, and situated one either side of, the fixed plough shares 32a, 32b.
- the fixed plough shares 32a, 32b are symmetrical about a central ploughing edge 36, which is inclined rearwardly, such that the material removed by the fixed plough shares 32a, 32b is displaced approximately equally on each side, and so that the plough shares will form a trench whose profile is symmetrical about a vertical plane.
- the secondary plough shares 34a, 34b extend outwardly from respective slots 37a, 37b in the fixed plough shares 32a, 32b and are hingedly attached to the fixed plough shares 32a, 32b by means of hinges 38, situated at the base of the slots 37a, 37b whereby the secondary plough shares 34a, 34b are pivotable about an axis normal to the surface 43 of the fixed shares 32a, 32b.
- the secondary plough shares 34a, 34b are each pivotable by means of a double-acting hydraulic ram 40 extending between, and pivotally connected by means of mountings 42 to a respective secondary plough share and the fixed plough shares 32a, 32b.
- the two secondary plough shares are pivoted upwardly into the position shown in Fig. 2, wherein the edges of the secondary plough shares are aligned with the edge of the fixed plough shares 32a, 32b.
- the secondary plough shares 34a, 34b are pivoted and thereby protrude beyond the edge of the fixed plough shares 32a, 32b.
- the position of the secondary plough shares 34a, 34b at their maximum protrusion is illustrated in Fig. 3.
- the trenching apparatus is lowered onto the seabed with a towing cable 22 attached to the cable attachment 20.
- the trenching apparatus is then towed along the seabed by a towing boat, thereby causing the trenching apparatus to form a trench in the seabed, into which a pipeline or cable may be laid.
- the rams 40 are fully retracted as in Fig. 2, thereby making the profile of the trench solely dependent upon the fixed plough shares 32a, 32b. If, however, the seabed is formed of softer or more granular materials, it is necessary to produce a more shallow-sided trench, otherwise the walls of the trench may collapse and fill in the trench. In this case, the rams 40 are extended, thereby causing the secondary plough shares to change the profile of the trench formed by the fixed plough share, by making the slope of the upper portions of the trench cut by the fixed share more shallow-sloping.
- the apparatus of this particular embodiment produces a base having the profile of its lowermost portions with relatively steep-sided walls, as determined by the fixed plough shares 32a, 32b, and having the profile of the uppermost portions with relatively shallow-sloped walls, as determined by the protrusion of the secondary plough shares 34a, 34b beyond the fixed plough shares 32a, 32b.
- FIG. 4 An alternative embodiment is illustrated schematically in Fig. 4, and is similar to the first embodiment except that the secondary plough shares 34a, 34b are hinged at a hinge 38′ situated at or near the level of the lowermost portion of the fixed plough shares 32a, 32b.
- the result of this is that a trench having walls of constant slope is produced.
- the rams 40 are retracted, causing the profile of the trench to be determined solely by the fixed plough share 32a, whereas in the right-hand side of Fig.
- the one trenching apparatus can be used to form trenches having different profiles, without the need to replace the plough shares or the apparatus itself if the composition of the seabed changes. Also, by virtue of the fact that the fixed ploughshares always forms a trench, when a shallower trench is then formed by projecting the secondary plough shares, much less seabed material has to be displaced by the secondary plough shares, and the towing force required is generally much less than if all the seabed material for a shallow-sided trench is removed by a single plough share.
- the invention is not restricted to the details of the foregoing embodiments.
- the movable plough shares may be positioned in front of the fixed plough share if desired.
Landscapes
- 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)
- Signal Processing For Digital Recording And Reproducing (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Control Of High-Frequency Heating Circuits (AREA)
Description
- The present invention relates to apparatus for use in the formation of subsea trenches for burial of pipelines and cables.
- When laying pipelines and cables on the seabed, it is sometimes necessary to form a trench in which the pipeline or cable can be seated. In a seabed formed of relatively soft and granular materials, a wide, shallow-sided trench is required to achieve the stability necessary for the trench walls to be self- supporting during pipeline or cable installation. In harder materials, such as clay or soft rock, a steeper sided trench is acceptable.
- The formation of such a trench can be achieved using an underwater plough, a component or components of which are known as shares. This term is used to describe both the seabed engaging "share", and the spoil moving "mouldboard". Plough shares can be detachable items, or an integral part of the plough structure. EP-A-0221581 discloses a plough having fixed plough shares which are preceded by two disc cutters mutually inclined to cut slits in the sea bed ahead of the plough in a V relationship. However, if the composition of the seabed changes, it may be necessary either to replace the plough or the plough shares to produce a trench of the correct profile. Not only is this time consuming, but it is also expensive, since it is necessary to have replacement ploughs or plough shares of the correct profile as well as the personnel to carry out such replacements.
- It is an object of the present invention to provide apparatus capable of forming seabed trenches of different profiles, depending on the composition of the seabed.
- In accordance with the present invention, there is provided apparatus for forming a trench in a seabed, comprising a first plough having two fixed plough shares and thereby adapted to form a trench of a fixed profile, and characterised by a second plough having two plough shares, one situated on either side of the first plough, movable relative to the first plough and thereby adapted to produce a trench having a selectively variable profile.
- This reduces the force needed to tow the apparatus. In harder seabed soils it allows the formation of a stable, steep-sided trench with a minimum cross-sectional area, and at the same time provides a facility whereby shares on the second plough means may be adjusted to produce a stable shallow sided trench with increased cross-sectional area in soft cohesive and granular seabed soils. In these areas the plough pulling forces will generally be less than for the equivalent trench profile in harder seabed soils.
- Preferably, the second, movable plough means is situated behind the first plough means. The second plough means may then be adjusted so that the finished trench profile is determined solely by the first plough means, or alternatively so that the second plough means alters the profile of the trench produced by the first plough means.
- In this way, the profile of the trench can be altered according to the type of seabed encountered.
- Preferably, the second plough is longitudinally displaced from the first plough.
- The second plough means may be adapted to be able to alter the profile of the trench produced by the first plough means over the full depth of the trench, or in the upper portion of the trench only.
- Preferably, the second plough means comprises two plough shares, one situated on either side of the first plough means.
- By way of example only, a specific embodiment of the present invention will now be described, with reference to the accompanying drawings, in which:
- Fig. 1 is a aide elevation of an embodiment of seabed trenching apparatus in accordance with the present invention, positioned on the seabed;
- Fig. 2 is a rear elevation of the apparatus shown in Fig. 1, in a first configuration;
- Fig. 3 is a rear elevation of the apparatus shown in Fig. 1, in a second configuration; and
- Fig. 4 is a profile of two trenches which may be formed using a modification of this invention.
- Referring firstly to Figs. 1 to 3, the trenching apparatus comprises a forward towing and
support portion 10 which is attached to a trenching portion 14. The towing andsupport portion 10 is fitted with a support skid 16, which is pivotally mounted atpivot 18 to enable the skid to pass over uneven surfaces. Theportion 10 is also provided with atowing cable attachment 20, by means of which atowing cable 22, extending from a surface ship, is attached to the trenching apparatus, whereby the apparatus may be towed along the seabed. - The trenching portion 14 comprises an upper
elongate frame member 24 and two lowerelongate frame members 26. Theupper frame member 24 is rigidly attached to theforward portion 10, and eachlower frame member 26 is hingedly attached to theforward portion 10 at a vertical hinge 12. A lifting cable attachment 28 is provided on theupper frame member 24, by means of which the trenching apparatus may be lifted from, or lowered onto, the seabed. Theupper frame member 24 is also provided with other articles such as a hydraulicfluid pressure generator 30, but these other articles are not involved in the understanding of the present invention, and will not be described further. - The undersurface of the
lower frame members 26 is provided with a first plough means in the form of two fixed plough shares 32, one attached torespective frame members 26 and a second plough means in the form of twosecondary plough shares fixed plough shares plough shares central ploughing edge 36, which is inclined rearwardly, such that the material removed by the fixedplough shares - The
secondary plough shares respective slots fixed plough shares plough shares hinges 38, situated at the base of theslots secondary plough shares surface 43 of thefixed shares secondary plough shares hydraulic ram 40 extending between, and pivotally connected by means ofmountings 42 to a respective secondary plough share and the fixedplough shares rams 40 fully, the two secondary plough shares are pivoted upwardly into the position shown in Fig. 2, wherein the edges of the secondary plough shares are aligned with the edge of the fixedplough shares rams 40, the secondary plough shares 34a, 34b are pivoted and thereby protrude beyond the edge of the fixedplough shares - In use, the trenching apparatus is lowered onto the seabed with a
towing cable 22 attached to thecable attachment 20. The trenching apparatus is then towed along the seabed by a towing boat, thereby causing the trenching apparatus to form a trench in the seabed, into which a pipeline or cable may be laid. - If the seabed is formed of relatively hard materials, such as clay or soft rock, a relatively steep-sided trench will not collapse. In such a case, the
rams 40 are fully retracted as in Fig. 2, thereby making the profile of the trench solely dependent upon thefixed plough shares rams 40 are extended, thereby causing the secondary plough shares to change the profile of the trench formed by the fixed plough share, by making the slope of the upper portions of the trench cut by the fixed share more shallow-sloping. The degree to which the rams are extended, and the trench profile modified, depends upon the properties of the seabed, but the two extreme positions are shown in Figs. 2 and 3 respectively. As seen in Fig. 3, the apparatus of this particular embodiment produces a base having the profile of its lowermost portions with relatively steep-sided walls, as determined by thefixed plough shares secondary plough shares plough shares - An alternative embodiment is illustrated schematically in Fig. 4, and is similar to the first embodiment except that the
secondary plough shares hinge 38′ situated at or near the level of the lowermost portion of the fixedplough shares rams 40 are retracted, causing the profile of the trench to be determined solely by the fixedplough share 32a, whereas in the right-hand side of Fig. 4, which illustrates one secondary plough share in the other extreme position, the profile of the trench originally formed by thefixed plough share 32b has been modified by thesecondary plough share 34b which now protrudes beyond thefixed plough share 32b by virtue of the extension of therams 40. - In both embodiments, the one trenching apparatus can be used to form trenches having different profiles, without the need to replace the plough shares or the apparatus itself if the composition of the seabed changes. Also, by virtue of the fact that the fixed ploughshares always forms a trench, when a shallower trench is then formed by projecting the secondary plough shares, much less seabed material has to be displaced by the secondary plough shares, and the towing force required is generally much less than if all the seabed material for a shallow-sided trench is removed by a single plough share.
- The invention is not restricted to the details of the foregoing embodiments. For example, the movable plough shares may be positioned in front of the fixed plough share if desired.
Claims (10)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8714515 | 1987-06-20 | ||
GB878714515A GB8714515D0 (en) | 1987-06-20 | 1987-06-20 | Seabed trenching apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0296783A1 EP0296783A1 (en) | 1988-12-28 |
EP0296783B1 true EP0296783B1 (en) | 1991-11-21 |
Family
ID=10619299
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP88305613A Expired - Lifetime EP0296783B1 (en) | 1987-06-20 | 1988-06-20 | Seabed trenching apparatus |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0296783B1 (en) |
GB (1) | GB8714515D0 (en) |
NO (1) | NO882720L (en) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9401351D0 (en) * | 1994-01-25 | 1994-03-23 | Soil Machine Dynamics Ltd | Trenching plough |
GB9618638D0 (en) * | 1996-09-06 | 1996-10-16 | Cable & Wireless Plc | Improvements in underwater ploughing |
US5988948A (en) * | 1997-09-04 | 1999-11-23 | Cable And Wireless Plc | Underwater plough and method for varying ploughing depth |
WO1999013171A1 (en) * | 1997-09-05 | 1999-03-18 | Soil Machine Dynamics Limited | Submarine plough |
US9422690B2 (en) | 2012-11-30 | 2016-08-23 | Michael W. N. Wilson | Method and apparatus for performing burial assessment surveys |
US10323383B2 (en) | 2012-11-30 | 2019-06-18 | Oceaneering International, Inc. | Seabed plow capable of over-the-stern release and retrieval in any of boulder clearing, trenching and backfill configurations |
EP2840187A1 (en) * | 2013-08-22 | 2015-02-25 | Soil Machine Dynamics Limited | Method and apparatus for forming a trench in a sea floor |
CA2929673A1 (en) * | 2013-11-18 | 2015-05-21 | Michael W.N. Wilson | Method and apparatus for performing burial assessment surveys |
EP3677727A1 (en) * | 2016-03-08 | 2020-07-08 | Soil Machine Dynamics Limited | Method and apparatus for forming a trench in a sea floor |
EP3800297A1 (en) | 2019-10-02 | 2021-04-07 | Soil Machine Dynamics Limited | Method and apparatus for inserting an elongate object into a trench in a sea floor |
EP3832026B1 (en) | 2019-12-05 | 2023-07-26 | Soil Machine Dynamics Limited | Apparatus for locating elongate object in a trench in a floor of a body of water |
EP4432495A2 (en) | 2021-06-28 | 2024-09-18 | Soil Machine Dynamics Limited | Apparatus for inserting an elongate object into a trench |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1069961A (en) * | 1965-01-13 | 1967-05-24 | Edward Arthur Yates | Improvements in mole ploughs |
GB1493346A (en) * | 1974-12-03 | 1977-11-30 | Ede A | Soil blade implement |
US4384415A (en) * | 1977-07-12 | 1983-05-24 | R. J. Brown & Associates Ag | Trenching plow |
GB8331892D0 (en) * | 1983-11-30 | 1984-01-04 | Soil Machine Dynamics Ltd | Ploughs |
GB8524410D0 (en) * | 1985-10-03 | 1985-11-06 | Soil Machine Dynamics Ltd | Pipeline/cable plough |
-
1987
- 1987-06-20 GB GB878714515A patent/GB8714515D0/en active Pending
-
1988
- 1988-06-20 EP EP88305613A patent/EP0296783B1/en not_active Expired - Lifetime
- 1988-06-20 NO NO882720A patent/NO882720L/en unknown
Also Published As
Publication number | Publication date |
---|---|
EP0296783A1 (en) | 1988-12-28 |
NO882720D0 (en) | 1988-06-20 |
GB8714515D0 (en) | 1987-07-22 |
NO882720L (en) | 1988-12-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0296783B1 (en) | Seabed trenching apparatus | |
CA1331101C (en) | Cable plough | |
JP7229403B2 (en) | Method and apparatus for forming trenches in seafloor | |
US3462963A (en) | Apparatus for pipelaying and trenching operations in a body of water | |
US4802793A (en) | Pipeline or cable plough | |
US4664553A (en) | Plough assembly | |
EP1009886B1 (en) | Submarine plough | |
GB2285821A (en) | Trenching plough | |
US4655639A (en) | Plough | |
US20160333549A1 (en) | Trench Apparatus with Leveling Means | |
GB2364358A (en) | Plough for laying elongate articles | |
EP0088190B1 (en) | Pipe or cable burying plough | |
WO2020148514A1 (en) | Subsea plough for burying a flexible elongate member | |
US3430366A (en) | Earth-working device | |
US2916835A (en) | Ditcher | |
GB2329201A (en) | Submarine plough | |
GB2027771A (en) | Deep Vertical Trench Plough | |
WO2001075236A1 (en) | Submarine plough | |
CN114243579B (en) | Submarine cable buries plough underground | |
GB2357134A (en) | A cable or pipe laying plough | |
NL2030849B1 (en) | Underwater plough and method of operating an underwater plough | |
US43664A (en) | Improvement in submarine excavators | |
Reece | The cable plough revolution |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): GB NL |
|
17P | Request for examination filed |
Effective date: 19890313 |
|
17Q | First examination report despatched |
Effective date: 19900528 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): GB NL |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19940610 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19940630 Year of fee payment: 7 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19950620 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19960101 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19950620 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 19960101 |