A trencher includes a trencher body; a cable detection mechanism disposed at a front portion of the trencher body; a chain mechanism and a jet mechanism disposed in the center of a bottom portion of the trencher body; a first track mechanism and a second track mechanism, the first track mechanism being disposed on a first side of the bottom portion of the trencher body, and the second track mechanism being disposed on a second side of the bottom portion of the trencher body; and a soil discharging component disposed at a rear portion of the trencher body.

A trencher includes a trencher body; a cable detection mechanism disposed at a front portion of the trencher body; a chain mechanism and a jet mechanism disposed in the center of a bottom portion of the trencher body; a first track mechanism and a second track mechanism, the first track mechanism being disposed on a first side of the bottom portion of the trencher body, and the second track mechanism being disposed on a second side of the bottom portion of the trencher body; and a soil discharging component disposed at a rear portion of the trencher body.

An apparatus for forming a trench in a sea floor and/or displacing material on the sea floor is disclosed. The apparatus comprises a body and front skids mounted to the body for engaging the sea floor and supporting the body. The front skids are adjustable between a first mode, in which the front skids engage the sea floor, and a second mode, in which the front skids engage the sea floor adjacent the trench and at the trench walls.

A seabed trenching plow has a chassis, a sled and a towing assembly. The towing assembly has a pair of wings extending laterally from each side of the chassis. The wings are aligned on an axis transverse to the chassis and adapted for connection to a towing line. The transverse axis is forward of the center of gravity of the plow and rearward of the sled, affording an over the stern releasable and retrievable trenching plow of sufficient weight and strength to excavate a three meter trench in a single pass. To assess the protective capabilities of the trench, a threshold signal indicative of a desired composition of seabed-trench soil is compared with a real-time data signal indicative of the actual to produce an alarm signal when the real-time data signal is not protective-capability compliant with the threshold signal.

A BAS plow creates a V-trench along the linear route of a pipeline path and an instrumented bottle moving with the BAS plow collects BAS data indicative of the pitch, roll, heading, yaw, three dimensional positioning, speed and depth of the chassis, the shearing force applied to the seabed material and the applied tow force. The bottle can be swapped to collect the acquired data or an umbilical can be used to provide a real time stream of data. The BAS plow can simultaneously backfill the created trench, leaving an undisrupted seabed, or the pipeline can be laid in the BAS trench, which can also be made deeper and wider by additional trench cutting passes, significantly reducing the total time required for combined BAS and pipeline laying processes. The BAS plow can be released and retrieved over-the-stern of a towing vessel.

A trenching assembly lays a continuous pipeline in a trench dug in a bed with uneven bathymetry, the trenching assembly including a trench digging device having a main body; at least four ground contact units, each unit having a height adjustment device, to position each ground contact unit with respect to the main body independently. A trench cutting tool digs in the bed includes a cutting depth adjustment device, for positioning the cutting tool with respect to the main body. A detection device detects bed bathymetry. A control device simultaneously allows cooperation between the detection device, the height adjustment device of each ground contact unit, and the cutting depth adjustment device. A command device cooperates with the control device to adjustment each ground contact unit and the cutting depth adjustment device, to obtain a trench having a height difference lower than a predefined tolerance and a predetermined burial depth.

A seabed trenching plow has a chassis, a sled and a towing assembly. The towing assembly has a pair of wings extending laterally from each side of the chassis. The wings are aligned on an axis transverse to the chassis and adapted for connection to a towing line. The transverse axis is forward of the center of gravity of the plow and rearward of the sled, affording an over the stern releasable and retrievable trenching plow of sufficient weight and strength to excavate a three meter trench in a single pass. To assess the protective capabilities of the trench, a threshold signal indicative of a desired composition of seabed-trench soil is compared with a real-time data signal indicative of the actual to produce an alarm signal when the real-time data signal is not protective-capability compliant with the threshold signal.

A seabed plow capable of over-the-stern release and retrieval is usable in any of boulder clearing, trench cutting and backfill modes. In its boulder clearing mode, the plow uses its skid in torquing configuration followed by moldboards to push boulders out of the path to be trenched. In the trench cutting mode, the plow uses the skid in the same configuration with its share and moldboards for initial trench depth and the same share and moldboards with moldboard extensions for increasing trench depth in subsequent passes. In the backfill mode, the plow uses its skid in trench-straddling configuration following a blade with a passage designed to discharge fragmented spoil directly onto the pipe being covered. Thus, a single plow can be reconfigured for all modes for release and retrieval to and from a relatively small vessel without use of heavy lifting equipment.

An assembly for installing a subsea cable, the assembly comprising a submersible apparatus and a submersible cable holder comprising the subsea cable, the subsea cable being connectable to the submersible apparatus through the connector for transmission of electric power and/or data to the submersible apparatus; wherein the assembly is configured to install the subsea cable while the submersible apparatus is electrically powered through said subsea cable. And a method for installing a subsea cable with a submersible apparatus, the method comprising: supplying electric power and/or transmitting data through the subsea cable to the submersible apparatus; and laying the subsea cable in a sea with the submersible apparatus.

A seabed plow capable of over-the-stern release and retrieval is usable in any of boulder clearing, trench cutting and backfill modes. In its boulder clearing mode, the plow uses its skid in torquing configuration followed by moldboards to push boulders out of the path to be trenched. In the trench cutting mode, the plow uses the skid in the same configuration with its share and moldboards for initial trench depth and the same share and moldboards with moldboard extensions for increasing trench depth in subsequent passes. In the backfill mode, the plow uses its skid in trench-straddling configuration following a blade with a passage designed to discharge fragmented spoil directly onto the pipe being covered. Thus, a single plow can be reconfigured for all modes for release and retrieval to and from a relatively small vessel without use of heavy lifting equipment.