Abstract: A method of securing a pipeline to the bed of a body of water includes moving an underwater vehicle selectively, on the bed of the body of water, along the pipeline; transporting a plurality of fastening devices on the underwater vehicle; and driving each fastening device partly into the bed of the body of water, close to the pipeline, by a handling device mounted on the underwater vehicle, to confine the pipeline between the bed of the body of water and the fastening device.

Abstract: A device includes a digging device to cut the seafloor and with a device for hooking onto a pipeline and for sliding over the same. The device includes at least one float device constrainable to the pipeline for supporting it in span, connected to the back of said digging device with respect to the direction of the movement. The method includes excavating the seafloor by a digging device, collecting a float device from a storage base and transporting it to said pipeline, constraining the first float device to the pipeline behind the digging device and connecting the first float device to the digging device, when at least one portion of pipeline is in a suspended configuration, and when the portion of suspended pipeline increases, collecting a subsequent float device and constraining it to the pipeline and connecting the same to the float device previously constrained.

Abstract: A vessel for laying a pipeline includes a plurality of ramps in the region of the first end of the vessel. The plurality of ramps includes a first ramp which is disposed along the pipelaying path, whose inclination is adjustable and which has a first upstream end and a second downstream end, and a second ramp which is disposed along the pipelaying path downstream of the first ramp, whose inclination is adjustable and which has a first upstream end and a second downstream end. The downstream end of the first ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel and the upstream end of the second ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel.

Abstract: A vessel for laying a pipeline includes a plurality of workstations disposed along a pipelaying path that includes an upstream portion away from a first end of the vessel and a plurality of ramps in the region of the first end of the vessel. The plurality of ramps includes a first ramp which is disposed along the pipelaying path, whose inclination is adjustable and which has a first upstream end and a second downstream end, and a second ramp which is disposed along the pipelaying path downstream of the first ramp, whose inclination is adjustable and which has a first upstream end and a second downstream end. The downstream end of the first ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel and the upstream end of the second ramp is positioned inboard of the first end of the vessel and above the bottom of the vessel.

Abstract: A method of underground laying a continuous elongated member in a bed of a body of water, wherein the continuous elongated member lies on the bed of the body of water along a given path; the method including the steps of: fragmenting a soil mass in the bed along the given path and under the continuous elongated member, so as to form in the bed two scarp slopes bounding the fragmented soil mass by two soil masses susceptible to slide; advancing two supporting walls along the given path in an advancing direction, along the respective two scarp slopes, and transferring the fragmented soil mass between the two supporting walls, so as to promote sinking of the continuous elongated member between the two supporting walls.

Abstract: The present invention relates to a group and a method for laying and burying pipelines at the seafloor, wherein the laying and burying group according to the present invention comprises a digging device (11) provided with at least means for cutting the seafloor (20) and with means for hooking onto a pipeline (15) and for sliding over the same, and is characterized in that it comprises at least one float device (14) constrainable to the pipeline (15) for supporting it (15) in span, connected to the back of said digging device (11) with respect to the direction of the movement thereof (11).

Abstract: A method of temporarily supporting a soil mass susceptible to slide at a scarp slope bounding the soil mass includes advancing a supporting wall in an advancing direction along the scarp slope; and, in addition to the movement in the advancing direction, also moving a surface portion, in direct contact with the soil mass, of the supporting wall, so as to minimize friction between the soil mass and the supporting wall.

Abstract: A method of laying underwater pipelines in the bed of a body of water, the method including laying an underwater pipeline along a given path on the bed of the body of water; breaking up a ground mass along the path to a given depth in the bed; and fluidifying the broken ground mass beneath the underwater pipeline to sink the underwater pipeline into the fluidified ground mass.