Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
397 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; primary fluid jet cutting means connected to said frame and directed toward the free end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched, said primary fluid jet cutting means including, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of a vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with said pair of tubular conduits having a plurality of apertures therein for directing a plurality of fluid jets generally toward the fore end of said frame and into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched; alternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched, said alternate fluid jet cutting means including, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with each of said tubular conduits having at least one but less than the total number of apertures in a corresponding conduit of said primary fluid jet cutting means for directing one or more fluid jets generally toward the fore end of said frame and said pair of tubular conduits being operable to direct fluid jets into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched; and means connected to said primary and said alternate cutting means for selectively actuating one or the other of said priMary or said alternate cutting means.
Claim 2
Independent Claim
397 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; primary fluid jet cutting means connected to said frame and directed toward the free end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched, said primary fluid jet cutting means including, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of a vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with said pair of tubular conduits having a plurality of apertures therein for directing a plurality of fluid jets generally toward the fore end of said frame and into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched; alternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched, said alternate fluid jet cutting means including, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with each of said tubular conduits having at least one but less than the total number of apertures in a corresponding conduit of said primary fluid jet cutting means for directing one or more fluid jets generally toward the fore end of said frame and said pair of tubular conduits being operable to direct fluid jets into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched; and means connected to said primary and said alternate cutting means for selectively actuating one or the other of said priMary or said alternate cutting means.
Claim 3
Dependent Claim
55 words
An apparatus for entrenching a submerged elongate means as defined in claim 1 wherein: each of said pair of tubular conduits comprising said alternate fluid jet cutting means is provided with a single aperture therein for directing a unitary fluid jet therefrom generally toward the forward end of said frame and into the water bed.
Claim 4
Dependent Claim
84 words
An apparatus for entrenching a submerged elongate means as defined in claim 2 wherein: said apertures in said pair of tubular conduits comprising said alternate fluid jet cutting means are fashioned at a mutually convergent angle such that unitary fluid jets emanating from said apertures will each intersect the vertical plane extending longitudinally through the submerged elongate means at approximately the intersection of said plane and a second vertical plane lying normal to said plane and extending through the fore end of said frame.
Claim 5
Dependent Claim
51 words
An apparatus for entrenching a submerged elongate means as defined in claim 1 wherein said means for selectively actuating comprises: a valve positioned in each conduit of said pair of primary fluid jet tubular conduits; and a valve positioned in each conduit of said pair of alternate fluid jet tubular conduits.
Claim 6
Independent Claim
183 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; primary fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first alternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; and means connected to said primary cutting means, said first alternate cutting means and said second alternate cutting means for selectively actuating one of said primary cutting means, said first alternate cutting means, or said second alternate cutting means.
Claim 7
Independent Claim
183 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; primary fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first alternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; and means connected to said primary cutting means, said first alternate cutting means and said second alternate cutting means for selectively actuating one of said primary cutting means, said first alternate cutting means, or said second alternate cutting means.
Claim 8
Independent Claim
228 words
An apparatus for entrenching a sumberged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; first primary fluid jet emitting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second primary fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first alternate fluid jet means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; and means connected to said first primary cutting means, said secondary primary cutting means, said first alternate cutting means and second alternate cutting means for selectively actuating one of said first primary cutting means, said second primary cutting means, said first alternate cutting means, or said second alternate cutting means.
Claim 9
Independent Claim
228 words
An apparatus for entrenching a sumberged elongate means within the bed of a body of water comprising: a frame having a fore end and an aft end operable to be lowered adjacent to and transported along a submerged elongate means to be entrenched; first primary fluid jet emitting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second primary fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first alternate fluid jet means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; and means connected to said first primary cutting means, said secondary primary cutting means, said first alternate cutting means and second alternate cutting means for selectively actuating one of said first primary cutting means, said second primary cutting means, said first alternate cutting means, or said second alternate cutting means.
Claim 10
Dependent Claim
143 words
An apparatus for entrenching a submerged elongate means as defined in claim 6 wherein said first primary fluid jet cutting means each cOmprise: a pair of tubular conduits operable to extend with one of said pair of conduits on one side of a vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with said pair of tubular conduits of said first and second primary fluid jet cutting means having a plurality of apertures therein for directing a plurality of fluid jets generally toward the fore and aft ends respectively of said frame and into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means.
Claim 11
Dependent Claim
169 words
An apparatus for entrenching a submerged elongate means as defined in claim 7 wherein said first and second alternate fluid jet cutting means each comprise: a pair of tubular conduits operable to extend with one of said pair of conduits on one side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with each of said tubular conduits having at least one but less than the total number of apertures in a corresponding conduit of said first and second primary fluid jet cutting means for directing one or more fluid jets generally toward the fore and aft ends respectively of said frame and said pair of tubular conduits being operable to direct fluid jets into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched.
Claim 12
Dependent Claim
50 words
An apparatus for entrenching a submerged elongate means as defined in claim 8 wherein: each of said tubular conduits comprising said first and second alternate fluid jet cutting means is provided with a single aperture therein for directing a unitary fluid jet therefrom generally toward and into the water bed.
Claim 13
Dependent Claim
157 words
An apparatus for entrenching a submerged elongate means as defined in claim 9 wherein: said apertures in said pair of tubular conduits comprising said first alternate fluid jet cutting means are fashioned at a mutually convergent angle such that unitary fluid jets emanating from said apertures will each intersect the vertical plane extending longitudinally through the submerged elongate means at approximately the intersection of said plane and a second vertical plane lying normal to said plane and extending through the fore end of said frame; and said apertures in said pair of tubular conduits comprising said second alternate fluid jet cutting means are fashioned at a mutually convergent angle such that unitary fluid jets emanating from said apertures will each intersect the vertical plane extending longitudinally through the submerged elongate means at approximately the intersection of said plane and a second vertical plane lying normal to said plane and extending through the aft end of said frame.
Claim 14
Dependent Claim
58 words
An apparatus for entrenching a submerged elongate means as defined in claim 6 wherein said means for selectively actuating comprises: a valve positioned in each of said first and second primary and said first and second alternate cutting means for selectively actuating any one of said first and second primary and said first and second alternate cutting means.
Claim 15
Independent Claim
265 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a floating vessel; a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submergible vehicle including, a frame having a fore end and an aft end; primary fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first aLternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; means connecting said fore end of said submergible vehicle with said floating vessel for inducing movement of said submergible vehicle in response to movement of said floating vessel; means connected to said floating vessel for pressurizing fluid; means for connecting in fluid communication said means for pressurizing fluid and said primary fluid jet cutting means, said first alternate fluid jet cutting means and said second alternate fluid jet cutting means; and means connected to said primary, said first alternate and said second alternate fluid jet cutting means for selectively controlling the flow of fluid from said means for pressurizing fluid to said primary, said first alternate and said second alternate fluid jet cutting means.
Claim 16
Independent Claim
265 words
An apparatus for entrenching a submerged elongate means within the bed of a body of water comprising: a floating vessel; a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submergible vehicle including, a frame having a fore end and an aft end; primary fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; first aLternate fluid jet cutting means connected to said frame and directed toward the fore end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; second alternate fluid jet cutting means connected to said frame and directed toward the aft end thereof for forming a trench within the water bed generally beneath the submerged elongate means to be entrenched; means connecting said fore end of said submergible vehicle with said floating vessel for inducing movement of said submergible vehicle in response to movement of said floating vessel; means connected to said floating vessel for pressurizing fluid; means for connecting in fluid communication said means for pressurizing fluid and said primary fluid jet cutting means, said first alternate fluid jet cutting means and said second alternate fluid jet cutting means; and means connected to said primary, said first alternate and said second alternate fluid jet cutting means for selectively controlling the flow of fluid from said means for pressurizing fluid to said primary, said first alternate and said second alternate fluid jet cutting means.
Claim 17
Dependent Claim
282 words
An apparatus for entrenching a submerged elongate means as defined in claim 12 wherein: said primary fluid jet cutting means comprises, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of a vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with said tubular conduits having a plurality of apertures therein or directing a plurality of fluid jets generally toward the fore end of said frame and into the body of water on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched; and said first and second alternate fluid jet cutting means each comprise, a pair of tubular conduits operable to extend with one of said pair of conduits on one side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched and with the other one of said pair of conduits on an opposite side of the vertical plane extending longitudinally through the submerged elongate means to be entrenched with each of said tubular conduits having at least one but less than the total number of apertures in a conduit of said primary fluid jet cutting means for directing one or more fluid jets generally toward the fore and aft ends respectively of said frame and said pair of tubular conduits being operable to direct fluid jets into the water bed on generally opposite sides of the vertical plane extending longitudinally through the submerged elongate means to be entrenched.
Claim 18
Dependent Claim
47 words
An apparatus for entrenching a submerged elongate means as defined in claim 13 wherein each of said tubular conduits of said first and second alternate fluid jet cutting means is provided with: a single aperture therein for directing a unitary fluid jet generally toward the water bed.
Claim 19
Dependent Claim
39 words
An apparatus for entrenching a submerged elongate means as defined in claim 14 wherein: said means connecting said fore end of said submergible vehicle with said floating vessel is connected to said floating vessel at a fore end thereof.
Claim 20
Dependent Claim
38 words
An apparatus for entrenching a submerged elongate means as defined in claim 14 wherein: said means connecting said fore end of said submerged vehicle with said floating vessel is connected to an aft end of said floating vessel.
Claim 21
Independent Claim
208 words
A method for entrenching a submerged elongate means within the bed of a body of water utilizing a floating vessel, a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary fluid jet cutting means connecTed to said frame and directed toward the fore end thereof; and an alternate fluid jet cutting means connected to said frame and directed toward the end thereof, comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; and selectively actuating at one time only one or the other of the primary or the alternate cutting means for eroding away a portion of the water bed positioned beneath the submerged elongate means including the step of, selectively directing a flow of high pressure fluid into the primary fluid jet cutting means comprising a pair of tubular conduits having a plurality of jetting apertures therein or, in the event a tough or hard water bed formation is encountered, into the alternate fluid jet cutting means comprising a pair of tubular conduits having a lesser number of jetting apertures therein than the primary fluid jet cutting means.
Claim 22
Independent Claim
208 words
A method for entrenching a submerged elongate means within the bed of a body of water utilizing a floating vessel, a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary fluid jet cutting means connecTed to said frame and directed toward the fore end thereof; and an alternate fluid jet cutting means connected to said frame and directed toward the end thereof, comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; and selectively actuating at one time only one or the other of the primary or the alternate cutting means for eroding away a portion of the water bed positioned beneath the submerged elongate means including the step of, selectively directing a flow of high pressure fluid into the primary fluid jet cutting means comprising a pair of tubular conduits having a plurality of jetting apertures therein or, in the event a tough or hard water bed formation is encountered, into the alternate fluid jet cutting means comprising a pair of tubular conduits having a lesser number of jetting apertures therein than the primary fluid jet cutting means.
Claim 23
Independent Claim
205 words
A method for entrenching a submerged elongate means within the bed of a body of water utilizing a floating vessel; a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary cutting means connected to said frame and directed toward the fore end thereof; and an alternate cutting means connected to said frame and directed toward the fore end thereof, comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; actuating the primary cutting means for removing a portion of the water bed lying beneath the submerged elongate means; towing the submergible vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the water bed; deactuating the primary cutting means upon encountering a tough or hard formation of the water bed; actuating the alternate cutting means for eroding away the tough or hard formation of the water bed; and towing a submergible vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the tough or hard portion of the bed of the body of water.
Claim 24
Independent Claim
205 words
A method for entrenching a submerged elongate means within the bed of a body of water utilizing a floating vessel; a submergible vehicle operable to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary cutting means connected to said frame and directed toward the fore end thereof; and an alternate cutting means connected to said frame and directed toward the fore end thereof, comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; actuating the primary cutting means for removing a portion of the water bed lying beneath the submerged elongate means; towing the submergible vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the water bed; deactuating the primary cutting means upon encountering a tough or hard formation of the water bed; actuating the alternate cutting means for eroding away the tough or hard formation of the water bed; and towing a submergible vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the tough or hard portion of the bed of the body of water.
Claim 25
Dependent Claim
63 words
A method for entrenching a submerged elongate means as defined in claim 18 and further comprising the step of: deactuating the alternate cutting means upon passing through the tough or hard portion of the bed of the body of water; and reactuating the primary cutting means for forming a trench beneath the submerged elongate means within the bed of the body of water.
Claim 26
Dependent Claim
75 words
A method for entrenching a submerged elongate means as defined in claim 19 wherein said steps of actuating and deactuating the primary and alternate cutting means comprises: controlling the flow of high pressure fluid into the primary cutting means comprising a pair of conduits having a plurality of jetting apertures therein or into the alternate cutting means comprising a pair of conduits having a lesser number of jetting apertures therein than the primary cutting means.
Claim 27
Independent Claim
262 words
A method of entrenching a submerged elongate means resting upon the bed of a body of water at an obstruction, such as a valve section, pipeline cross over, or the like, utilizing a floating vessel; a submergible vehicle operated to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary cutting means connected to said frame and directed toward the fore end thereof; a first alternate cutting means connected to said frame and directed toward the fore end thereof; and a second alternate cutting means connected to said frame and directed toward the aft end thereof; comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; actuating the primary fluid jet cutting means for eroding away a portion of the water bed lying beneath the submerged elongate means; towing the submergiblE vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the water bed; upon reaching an obstruction, deactuating the primary fluid jet cutting means; actuating the first alternate fluid jet cutting means for removing a portion of the water bed beneath the obstruction; deactuating the first alternate fluid jet cutting means; transporting the submergible vehicle over the obstruction to a location adjacent to but downstream from the obstruction; actuating the second alternate cutting means for removing the remaining portion of the water bed beneath the obstruction to form a trench within the seabed beneath the submerged elongate means at the obstruction.
Claim 28
Independent Claim
262 words
A method of entrenching a submerged elongate means resting upon the bed of a body of water at an obstruction, such as a valve section, pipeline cross over, or the like, utilizing a floating vessel; a submergible vehicle operated to be lowered adjacent to a submerged elongate means to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; a primary cutting means connected to said frame and directed toward the fore end thereof; a first alternate cutting means connected to said frame and directed toward the fore end thereof; and a second alternate cutting means connected to said frame and directed toward the aft end thereof; comprising the steps of: lowering the submergible vehicle adjacent to a submerged elongate means to be entrenched; actuating the primary fluid jet cutting means for eroding away a portion of the water bed lying beneath the submerged elongate means; towing the submergiblE vehicle along the submerged elongate means to form a trench beneath the submerged elongate means within the water bed; upon reaching an obstruction, deactuating the primary fluid jet cutting means; actuating the first alternate fluid jet cutting means for removing a portion of the water bed beneath the obstruction; deactuating the first alternate fluid jet cutting means; transporting the submergible vehicle over the obstruction to a location adjacent to but downstream from the obstruction; actuating the second alternate cutting means for removing the remaining portion of the water bed beneath the obstruction to form a trench within the seabed beneath the submerged elongate means at the obstruction.
Claim 29
Dependent Claim
70 words
A method for entrenching a submerged elongate means as defined in claim 21 and further comprising the steps of: subsequent for forming a trench beneath said obstruction actuating said second alternate cutting means; actuating said primary fluid jet cutting means; and towing the submergible vehicle along the submerged elongate means to be entrenched to form a trench beneath the submerged elongate means within the bed of the body of water.
Claim 30
Dependent Claim
103 words
A method for entrenching a submerged elongate means as defined in claim 22 wherein said steps of actuating and deactuating the primary, first and second alternate cutting means comprises: controlling the flow of high pressure fluid into the primary cutting means comprising a pair of conduits having a plurality of jetting apertures therein or into the first alternate cutting means comprising a pair of conduits having a lesser number of jetting apertures therein than the primary cutting means or into the second alternate cutting means comprising a pair of conduits having a lesser number of jetting apertures therein than the primary cutting means.
Claim 31
Independent Claim
231 words
A method for entrenching a pipeline riser within the bed of a body of water utilizing a floating vessel; a submergible vehicle operable to be lowered adjacent to the bottom bend to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; first primary cutting means connected to said frame and directed toward the fore end thereof; second primary cutting means connected to said frame and directed toward the aft end thereof; first alternate cutting means connected to said frame and directed toward the fore end thereof; second alternate cutting means connected to said frame and directed toward the aft end thereof, comprising the steps of: lowering the submergible elongate means from a bow portion of the floating vessel to a position adjacent a bend in the pipeline riser with the aft end of the submerged vehicle in a position adjacent the pipeline riser; selectively actuating the second primary or the second alternate cutting means for forming a trench beneath the bend section of the pipeline riser within the bed of the body of water; selectively actuating the first primary cutting means or the first alternate cutting means for forming a trench beneath a submerged elongate means connected to the riser; and towing said submergible vehicle along the submerged elongate means to entrench the submerged elongate means within the bed of the body of water.
Claim 32
Independent Claim
231 words
A method for entrenching a pipeline riser within the bed of a body of water utilizing a floating vessel; a submergible vehicle operable to be lowered adjacent to the bottom bend to be entrenched, said submerged vehicle including a frame having a fore end and an aft end; first primary cutting means connected to said frame and directed toward the fore end thereof; second primary cutting means connected to said frame and directed toward the aft end thereof; first alternate cutting means connected to said frame and directed toward the fore end thereof; second alternate cutting means connected to said frame and directed toward the aft end thereof, comprising the steps of: lowering the submergible elongate means from a bow portion of the floating vessel to a position adjacent a bend in the pipeline riser with the aft end of the submerged vehicle in a position adjacent the pipeline riser; selectively actuating the second primary or the second alternate cutting means for forming a trench beneath the bend section of the pipeline riser within the bed of the body of water; selectively actuating the first primary cutting means or the first alternate cutting means for forming a trench beneath a submerged elongate means connected to the riser; and towing said submergible vehicle along the submerged elongate means to entrench the submerged elongate means within the bed of the body of water.
Claim 33
Dependent Claim
92 words
A method for entrenching a pipeline riser as defined in claim 24 wherein said steps of actuating and deactuating the first and second primary and the first and second alternate cutting means comprises: controlling the flow of high pressure fluid into the first or second primary cutting means each comprising a pair of conduits having a plurality of jetting apertures therein or into the first or second alternate cutting means each comprising a pair of conduits having a lesser number of jetting apertures therein than the first or second primary cutting means.