A ring-shaped cofferdam and temporary pit excavation structure using tapered square pipes includes a plurality of tapered square pipes a trapezoidal cross-section, in which the plurality of tapered square pipes each have a coupling protrusion or a coupling groove formed in a longitudinal direction on a first side, the plurality of tapered square pipes each have a coupling protrusion or a coupling groove formed in the longitudinal direction on a second side, the plurality of tapered square pipes are assembled by coupling the coupling protrusions and the coupling grooves, a long side of two parallel sides of the trapezoid is disposed outside, and a short side is disposed inside.

A vessel and a method for installation of a pile adapted to support an offshore wind turbine are described. The method includes a) suspending the pile from a hoisting cable in a substantially vertical orientation; b) providing a lower end of the pile in a pile holding system limiting horizontal motion of a pile portion held by the pile holding system; and c) lowering the pile with the pile being held by the pile holding system. The lowering includes at least lowering the pile through a splash zone of a body of water, and during step c), two tugger lines are directly or indirectly connected to the pile at a location between the pile holding system and the hoisting cable, said tugger lines being operated to damp motion of the pile in two respective horizontal directions.

A vessel and a method for installation of a pile adapted to support an offshore wind turbine are described. The method includes a) suspending the pile from a hoisting cable in a substantially vertical orientation; b) providing a lower end of the pile in a pile holding system limiting horizontal motion of a pile portion held by the pile holding system; and c) lowering the pile with the pile being held by the pile holding system. The lowering includes at least lowering the pile through a splash zone of a body of water, and during step c), two tugger lines are directly or indirectly connected to the pile at a location between the pile holding system and the hoisting cable, said tugger lines being operated to damp motion of the pile in two respective horizontal directions.

A method includes mounting a first jacket connector block (400) to an apparatus. The first jacket connector block includes a first frame (415), a plurality of first conductor tubes (405) connected to the first frame, a first plurality of releasable connectors (420) coupled to first ends of the first conductor tubes, and a second plurality of releasable connectors (420) coupled to second ends of the first conductor tubes and engaging the apparatus.

A method includes mounting a first jacket connector block (400) to an apparatus. The first jacket connector block includes a first frame (415), a plurality of first conductor tubes (405) connected to the first frame, a first plurality of releasable connectors (420) coupled to first ends of the first conductor tubes, and a second plurality of releasable connectors (420) coupled to second ends of the first conductor tubes and engaging the apparatus.

The invention relates to an apparatus for noise attenuation in an impact pile driving device wherein the apparatus comprises a pile guide being attachable to the lower end of a hammer of an impact pile driving device. The apparatus according to the invention comprises compressing arrangement in connection with the pile guide having at least one compressing element and mechanical, hydraulic or pneumatic compressing means for compressing a pile fitted in to the pile guide transversally by means the at least one compressing element. The invention relates also an impact pile driving device and a method for noise attenuation in an impact pile driving device.

The invention relates to an apparatus for noise attenuation in an impact pile driving device wherein the apparatus comprises a pile guide being attachable to the lower end of a hammer of an impact pile driving device. The apparatus according to the invention comprises compressing arrangement in connection with the pile guide having at least one compressing element and mechanical, hydraulic or pneumatic compressing means for compressing a pile fitted in to the pile guide transversally by means the at least one compressing element. The invention relates also an impact pile driving device and a method for noise attenuation in an impact pile driving device.

A method of installing foundation elements, in particular (mono)piles having a diameter of five meters or more, in an underwater ground formation includes lowering a leader from a surface vessel with at least the tip of the leader into the water, and lowering a foundation element and/or a noise mitigation screen along the leader.

A method of installing foundation elements, in particular (mono)piles having a diameter of five meters or more, in an underwater ground formation includes lowering a leader from a surface vessel with at least the tip of the leader into the water, and lowering a foundation element and/or a noise mitigation screen along the leader.

The invention relates to a pile-driving device and a method for driving driving material into a ground, wherein, for the purpose of driving-in, the driving material is clamped and held by means of a clamping means on a pile-driving power unit and prior to clamping the driving material is connected by means of a flexible securing element, in particular a securing chain, to the pile-driving power unit. In accordance with the invention a pressing element is provided which is displaced relative to the pile-driving power unit towards the driving material and, in doing so, a pressing force is applied onto an upward-directed front face of the driving material.