Abstract: A method and apparatus for joining pipe sections (102, 104) together to form an underwater pipeline. The pipe sections (102, 104) are in an abutting position and have a generally vertical orientation. The apparatus comprises at least two welding equipment carriers (148, 152) and at least two welding heads (110, 112). Each welding head is connected to an equipment carrier (148, 152) by means of at least one umbilical (130, 132). The apparatus further comprises a welding head guide assembly (113) which is adapted to be fixed to one of said upper of lower pipe sections. The welding head guide assembly (113) guides the welding heads about the pipe sections (102, 104). The apparatus further comprises a guiding device (133) which guides the welding equipment carriers (148, 152) around said welding area (115). The welding equipment carriers (148, 152) are movable independently from one another.

Abstract: With a method and device for producing a channel in the ground, in a first step, an excavating device is positioned at the starting point of a channel to be produced. The excavating device has an excavating head which is provided with one or more liquid jetting devices. Then, a mixture of soil and water is formed by spraying liquid from the liquid jetting devices. This mixture is discharged. The excavating head advances in the excavating direction while the liquid is being sprayed. Thus, the channel is produced. When the end point of the excavation has been reached, at least a part of the excavating device is uncoupled and moved back to the starting point of the channel, so it can be used again.

Abstract: A method and apparatus for joining pipe sections (102, 104) together to form an underwater pipeline. The pipe sections (102, 104) are in an abutting position and have a generally vertical orientation. An upper end (108) of the most recently joined pipe sections (104) is to be welded to a lower end (106) of a new pipe section (102). The apparatus comprises at least two welding equipment carriers (148, 152) and at least two welding heads (110, 112). Each welding head is connected to an equipment carrier (148, 152) by means of at least one umbilical (130, 132). The apparatus further comprises a welding head guide assembly (113) which is adapted to be fixed to one of said upper of lower pipe sections. The welding head guide assembly (113) guides the welding heads about the pipe sections (102, 104). The apparatus further comprises a guiding device (133) which guides the welding equipment carriers (148, 152) around said welding area (115).

Abstract: With a method and device for producing a channel in the ground, in a first step, an excavating device is positioned at the starting point of a channel to be produced. The excavating device has an excavating head which is provided with one or more liquid jetting devices. Then, a mixture of soil and water is formed by spraying liquid from the liquid jetting devices. This mixture is discharged. The excavating head advances in the excavating direction while the liquid is being sprayed. Thus, the channel is produced. When the end point of the excavation has been reached, at least a part of the excavating device is uncoupled and moved back to the starting point of the channel, so it can be used again.

Abstract: An excavating device configured to form a channel of predetermined cross section in the ground in an excavation direction. The excavating device includes an assembly of jet excavating units which together define the cross section of the channel and are each provided with at least one jet device. The excavating device also includes at least one sensor which is connected to at least one of the jet excavating units for measuring a force which is exerted on the jet excavating units by the ground substantially parallel to the excavation direction. A controller is provided for controlling the excavation by the excavating device on the basis of the force measured by the at least one sensor. The controller is adapted to set a flow rate of jet liquid which is used in at least one jet device.

Abstract: An excavating device configured to form a channel of predetermined cross section in the ground in an excavation direction. The excavating device includes an assembly of jet excavating units which together define the cross section of the channel and are each provided with at least one jet device. The excavating device also includes at least one sensor which is connected to at least one of the jet excavating units for measuring a force which is exerted on the jet excavating units by the ground substantially parallel to the excavation direction. A controller is provided for controlling the excavation by the excavating device on the basis of the force measured by the at least one sensor. The controller is adapted to set a flow rate of jet liquid which is used in at least one jet device.