A vibration excitation device comprises an input shaft, eccentric blocks and eccentric torque output shafts. The input shaft can drive the eccentric torque output shafts to rotate, and the eccentric blocks sleeve the outer sides of the eccentric torque output shafts. The eccentric blocks on the eccentric torque output shafts synchronously rotate along with rotation of the eccentric torque output shafts and generate a centrifugal force. The centrifugal forces of the eccentric blocks on one pair of exactly opposite eccentric torque output shafts are equal in magnitude and opposite in direction, but each pair of centrifugal forces forms a force couple. The magnitude and direction of the torque of each force couple periodically change based on the sine function rule over time, and under the action of the torques of the two pairs of force couples, the vibration excitation device generates an arc vibration in a horizontal direction.

A vibration excitation device comprises an input shaft, eccentric blocks and eccentric torque output shafts. The input shaft can drive the eccentric torque output shafts to rotate, and the eccentric blocks sleeve the outer sides of the eccentric torque output shafts. The eccentric blocks on the eccentric torque output shafts synchronously rotate along with rotation of the eccentric torque output shafts and generate a centrifugal force. The centrifugal forces of the eccentric blocks on one pair of exactly opposite eccentric torque output shafts are equal in magnitude and opposite in direction, but each pair of centrifugal forces forms a force couple. The magnitude and direction of the torque of each force couple periodically change based on the sine function rule over time, and under the action of the torques of the two pairs of force couples, the vibration excitation device generates an arc vibration in a horizontal direction.

A pile-driver assembly for driving a pile into the ground, preferably offshore, and a method of driving a pile into the ground using the pile-driver assembly is disclosed. The assembly includes a casing defining a chamber, the chamber being configured to house a fluid. The assembly further includes a positioning element configured to position the casing at or on the pile, wherein at least a portion of the positioning element is positioned between the chamber and the pile. The assembly further includes actuating means, wherein actuation of the actuating means displaces the chamber relative to the positioning element, such that the chamber moves away from the pile, and wherein the actuating means is configured to release the chamber for displacement towards the pile such that a force is exerted by the chamber on the positioning member, to controllably drive the pile into the ground.

A pile-driver assembly for driving a pile into the ground is disclosed. The assembly includes a casing defining a chamber configured to house a fluid; a positioning element configured to position the casing at or on the pile; and actuating means. Actuation of the actuating means displaces the chamber relative to the positioning element such that the chamber moves away from the pile to an elevated position. The actuating means is configured to release the chamber from the elevated position for displacement towards the pile such that a force is exerted by the chamber on the positioning member, to controllably drive the pile into the ground. The assembly further includes buffering means, the buffering means being configured to controllably buffer the force exerted by the chamber on the pile as the pile is driven into the ground. The buffering means is configured to rebound the chamber to a rebound position. Further actuation of the actuating means displaces the chamber relative to the positioning element, such that the chamber moves from the rebound position to the elevated position. A control system for controlling the pile-driver assembly and a method of driving a pile into ground using the pile-driver assembly are also disclosed.

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).

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 lifting device for lifting a tubular pile comprises a hoisting member including a centreline, a plurality of engagement elements which are moveably mounted to the hoisting member at angular distance with respect to each other about the centreline and actuators for moving the respective engagement elements with respect to the hoisting member. The engagement elements are moveable in longitudinal direction of the centreline along respective guides of the hoisting member. The guides are inclined with respect to the centreline such that the engagement elements move in radial direction of the centreline when being moved in longitudinal direction of the centreline. The actuators are functionally interconnected such that under operating conditions the actuators move the engagements elements simultaneously until a first one of the actuators reaches a counterforce which is higher than a counterforce of a second one of the actuators, after which the second one of the actuators is moved further.

A lifting device for lifting a tubular pile comprises a hoisting member including a centreline, a plurality of engagement elements which are moveably mounted to the hoisting member at angular distance with respect to each other about the centreline and actuators for moving the respective engagement elements with respect to the hoisting member. The engagement elements are moveable in longitudinal direction of the centreline along respective guides of the hoisting member. The guides are inclined with respect to the centreline such that the engagement elements move in radial direction of the centreline when being moved in longitudinal direction of the centreline. The actuators are functionally interconnected such that under operating conditions the actuators move the engagements elements simultaneously until a first one of the actuators reaches a counterforce which is higher than a counterforce of a second one of the actuators, after which the second one of the actuators is moved further.

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).

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).