The invention relates to a watercraft having a hull (10), an introduction installation (20) for an object (70) to be anchored in the water, said introduction installation (20) being disposed on said hull (10), and at least one compressor (30) having at least one compressed-air line (40) which leads into the water and is coupled to at least one compressed-air distribution installation (45) which has a horizontal extent and for generating a bubble curtain (50) below the hull (10) has a multiplicity of mutually spaced apart outflow openings (46), characterized in that the hull (10) has at least two sub-hulls (11, 12) which are disposed so as to be mutually spaced apart and connected to one another, and a void (15) which is at least partially surrounded by the bubble curtain (50) is situated between the sub-hulls (11, 12).

A method of and a noise mitigation system for installing a foundation element, in particular a (mono)pile, includes a screen to be placed about a foundation element, in particular a (mono)pile, during driving of the foundation element in an underwater ground formation, to reduce noise input resulting from the driving into the surrounding water, e.g. a river or sea. The method and system comprise a further screen to be deployed about the (first) screen.

A device for damping hydrosound in liquid having a frequency range emitted from a sound-emitting body in the liquid includes: a plurality of individual gas volumes distributed in the liquid in an area of the sound-emitting body and at a distance from each other, each of the individual gas volumes being operable to reduce the hydrosound through resonant oscillations; and at least one mass body disposed in the liquid, the individual gas volumes being connected to the at least one mass body so as to prevent the individual gas volumes from rising up in the liquid.

A device is provided for damping hydrosound in liquid emitted from a sound-emitting body in the liquid. The device includes a plurality of gas-filled bodies distributed in the liquid in an area of the hydrosound-emitting body and at a distance from each other. Each of the gas-filled bodies has a natural frequency that corresponds to an emitted frequency range of the hydrosound so as to dampen the hydrosound through resonant oscillations.

A foundation pile end piece is provided that includes a ring-shape connection housing, where a proximal end of the ring-shape connection housing is configured to secure to a bottom end of a foundation pile, a moveable tip, where a distal end of the ring-shape connection housing is configured to fixedly hold the moveable tip, where the moveable tip is disposed to oscillate transversely with respect to a central axis of the ring-shape connection housing, where the moveable tip is configured to displace soil from the bottom end of the foundation pile according to actuation of the oscillation.

The invention relates to a watercraft having a hull (10), an introduction installation (20) for an object (70) to be anchored in the water, said introduction installation (20) being disposed on said hull (10), and at least one compressor (30) having at least one compressed-air line (40) which leads into the water and is coupled to at least one compressed-air distribution installation (45) which has a horizontal extent and for generating a bubble curtain (50) below the hull (10) has a multiplicity of mutually spaced apart outflow openings (46), characterized in that the hull (10) has at least two sub-hulls (11, 12) which are disposed so as to be mutually spaced apart and connected to one another, and a void (15) which is at least partially surrounded by the bubble curtain (50) is situated between the sub-hulls (11, 12).

A frame for guiding and supporting a foundation element, such as a pile, during installation in an underwater ground formation comprises a plurality of guide mechanisms that are movable between an extended position to engage a pile located inside the frame and a retracted position. At least one of the guide mechanisms comprises a slider, a path supporting the slider, a rotatable link, and an actuator to move the slider along the path and the link between said extended and retracted positions.

A non-contact strain and/or displacement measurement system for use with structural objects having an optical device, a data store and an image arrangement that is fixed relative to the structural object to be tested, the optical device including an image receiving device for receiving visual images and the data store being configured to record the received visual images, the image receiving device being spaced from the image arrangement by an optical spacing such that the image receiving device has a visual range that includes a portion of the structural object and the image arrangement being within the portion, the image arrangement having at least one image element wherein movement of the at least one image element during a measurement period provides image data to calculate structural object strain and/or structural object displacement.

The invention relates to a method for producing a contiguous frozen mass in an area of ground wherein at least one first cooling lance is introduced into the area of ground in which the contiguous frozen mass is to be generated, wherein a first fluid coolant is fed into the at least first cooling lance to support the formation of a contiguous frozen mass which surrounds the at least first cooling lance, the first coolant evaporates during formation of the contiguous frozen mass and the evaporated coolant is displaced out of the at least first cooling lance into a means for holding and/or dissipating the evaporated coolant. In this context, it is provided according to the invention that noise emissions generated during the creation of the contiguous frozen mass are minimised by a soundproofing means. The invention relates further to a device for performing the method according to the invention.

A foundation pile end piece is provided that includes a ring-shape connection housing, where a proximal end of the ring-shape connection housing is configured to secure to a bottom end of a foundation pile, a moveable tip, where a distal end of the ring-shape connection housing is configured to fixedly hold the moveable tip, where the moveable tip is disposed to oscillate transversely with respect to a central axis of the ring-shape connection housing, where the moveable tip is configured to displace soil from the bottom end of the foundation pile according to actuation of the oscillation.