Lifting device and a method of lifting a tubular pile

1. A lifting device for lifting a tubular pile, comprising

a hoisting member including a centreline,

a plurality of engagement elements which are moveably mounted to the hoisting member at an angular distance with respect to each other about the centreline,

actuators for moving respective to said engagement elements with respect to the hoisting member, wherein the engagement elements are moveable in a longitudinal direction of the centreline along respective guides of the hoisting member, said guides are inclined with respect to the centreline such that the engagement elements move in a radial direction relative to the centreline when being moved in the longitudinal direction of the centreline, and 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, and

mounted to the hoisting member is a means for contacting an upper end of a monopile when at least a portion of the lifting device including the engagement elements is inserted in the monopile to allow the lifting device to rest on the monopile.

2. The lifting device according to claim 1 , wherein the actuators comprise hydraulic cylinders including respective pressure chambers, which communicate with each other.

3. The lifting device according to claim 2 , wherein each of the engagement elements has a wedge shape including an outer side which is directed away from the hoisting member and which extends substantially parallel to the centreline.

4. The lifting device according to claim 3 , wherein the means for contacting the upper end of the monopile is a flange.

5. The lifting device according to claim 4 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

6. The lifting device according to claim 3 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

7. The lifting device according to claim 2 , wherein the means for contacting the upper end of the monopile is a flange.

8. The lifting device according to claim 7 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

9. The lifting device according to claim 2 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

10. The lifting device according to claim 1 , wherein each of the engagement elements has a wedge shape including an outer side which is directed away from the hoisting member and which extends substantially parallel to the centreline.

11. The lifting device according to claim 10 , wherein the means for contacting the upper end of the monopile is a flange.

12. The lifting device according to claim 11 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

13. The lifting device according to claim 10 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

14. The lifting device according to claim 1 , wherein the means for contacting the upper end of the monopile is a flange.

15. The lifting device according to claim 14 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

16. The lifting device according to claim 1 , wherein each of the engagement elements is provided with a resilient cover at a side of the engagement element which faces away from the hoisting member.

17. A method of lifting a tubular pile by means of a lifting device which is provided with:

a hoisting member including a centreline,

a plurality of engagement elements which are moveably mounted to the hoisting member at an angular distance with respect to each other about the centreline, wherein the engagement elements are moveable in a longitudinal direction of the centreline along respective guides of the hoisting member, said guides are inclined with respect to the centreline such that the engagement elements move in a radial direction relative to the centreline when being moved in the longitudinal direction of the centreline, and

mounted to the hoisting member is a means for contacting an upper end of a monopile when at least a portion of the lifting device including the engagement elements is inserted in the monopile to allow the lifting device to rest on the monopile, and

wherein the method comprises the steps of

inserting the lifting device into the tubular pile,

moving the engagement elements simultaneously in a direction in which they also move towards an inner wall of the tubular pile,

stopping the movement of a first one of the engagement elements when it generates a counterforce which is higher than a counterforce of a second one of the engagement elements, and;

moving the second one of the engagement elements further.

18. The method according to claim 17 , wherein the second one of the engagement elements is stopped when the counterforce of the second one of the engagement elements achieves a predetermined level.