The present invention relates to a template for use in installing a plurality of foundation elements , in particular anchor piles , relative to one another in an underwater ground formation, comprising a frame and a plurality of guides for guiding respective foundation elements during driving them into a seabed, which guides are connected to the frame at an angular distance from each other about a centreline of the frame .

Such a template is known from the European patent application EP 2 402 511 . The known template is suitable to install anchor piles in a predetermined formation with the template remaining stationary on the seabed . The template can be re-used for installing further foundation elements on other sites since after installing the anchor piles the template is li fted over the ends of the installed piles that proj ect upwardly from the seabed and moved to the next installation site . The installed anchor piles may receive a j acket as a base for a wind turbine , for example a tripod j acket .

An obj ect of the invention is to provide an improved template .

This obj ect is accomplished with the template according to the invention, wherein the guides are translatable with respect to the frame such that the distances between the respective guides and the centreline are adj ustable between a first operational condition and a second operational condition, wherein the distances between the respective guides and the centreline of the frame are larger in the second operational condition than in the first operational condition .

An advantage of the template according to the invention is that the footprint of the guides can be adj usted without performing a time consuming operation to modi fy the structure of the template . Since the guides are translatable with respect to the frame it is possible to create a robust coupling between the guides and the frame , for example a slidable connection .

In the first operational condition and in the second operational condition the guides may be located at equiangular distance from each other . In a particular embodiment the guides are arranged rotational symmetric about the centreline of the frame in the first operational condition and in the second operational condition . The means that the foot print in both the first operational condition and the second operational condition have a similar shape , but the footprint of the guides in the second operational condition covers a larger area .

Each of the guides may be translatable with respect to the frame by an angular displacement about the centreline of the frame along a path which deviates from a circle about the centreline . This means that each of the guides can be translated along a path which is transverse to the radial direction with respect to the centreline .

The path may be linear .

In a practical embodiment each of the guides is translatable along a cooperating guide rail which is mounted to the frame .

The guide rails may be arranged such that they form at least portions of respective substantially linear sides of a regular polygon, for example an equilateral triangle , a square or the like .

In a preferred embodiment the guide rails are part of respective sides of the frame , since the sides of the frame can form a robust support for the guide rails .

Each of the guide rails may only extend between a corner and the middle of the corresponding side . Applying the guide rails also along the rest of the side would have the same ef fect of varying the footprint of the guides . It is even possible to apply the guide rail at a distance from the middle of the corresponding side since the variation of the distance between the centreline of the frame and the guide around the middle is relative small .

The frame may form an equilateral triangle as seen from above . Nevertheless , the frame may have an alternative shape as seen from above , for example rectangular, square or another polygonal shape .

The frame may extend in a main plane and its centreline may extend perpendicularly to the main plane . The guides may have respective centrelines which are parallel to the centreline of the frame .

The template may be provided with at least an actuator for displacing at least one of the guides with respect to the frame , for example a hydraulic cylinder, rack-and-pinion or the like .

In an embodiment each of the guides comprises a sleeve and a foot , wherein under operating conditions the foot rests on the seabed and supports the sleeve , wherein the foot and the sleeve are movable with respect to each other in at least a direction which is parallel to the centreline for levelling the frame with respect to the seabed when the feet are resting on the seabed . The sleeve is suitable for guiding a foundation element . The feet of the respective guides and the corresponding sleeves can be moved with respect to each other such that in case of an uneven seabed the frame can be levelled with respect to the seabed in order to create a vertical centreline under operating conditions , for example . The foot and the sleeve may be movable with respect to each other through a linear actuator, for example a hydraulic cylinder . The feet may comprise plateshaped bodies for providing appropriate stability when they are placed on the seabed .

In a particular embodiment the foot and the sleeve are tiltable with respect to each other such that the feet of the respective guides can accurately match an uneven seabed . This embodiment may have at least two actuators through which the sleeve and the foot are movably coupled to each other, for example at least two hydraulic actuators which are controllable independently from each other .

Each of the guides and the frame may be lockable with respect to each other through a locking system .

In an embodiment each of the guides is provided with a slider for sliding along the corresponding guide rail and the locking system is provided at the slider and the guide rail . It is also conceivable that the locking system is located at the guide rail and the guide at a distance from the slider .

The locking system may comprise a movable pin which fits in a hole in at least one of the guide and the frame in order to simply lock the frame and the guide to each other . The invention will hereafter be elucidated with reference to very schematic drawings showing an embodiment of the invention by way of example .

Fig . 1 is a perspective view of an embodiment of a template according to the invention .

Fig . 2 is plan view of the embodiment as shown in Fig . 1 on a smaller scale .

Fig . 3 is a similar view as Fig . 2 , but showing a di f ferent condition of the template .

Fig . 4 is a side view of the embodiment as shown in Fig . 1 on a smaller scale .

Fig . 5 is an enlarged view of a part of the embodiment as shown in Fig . 4 , which is indicated by V in Fig . 4 .

Figs . 1-4 show an embodiment of a template 1 according to the invention . The template 1 is suitable for use in installing a plurality of foundation elements (not shown) relative to one another in an underwater ground formation with the template 1 remaining stationary on a seabed . The foundation elements may be anchor piles for receiving a j acket as a base for a wind turbine , for example a tripod j acket . The template 1 can be re-used for installing further foundation elements on other sites since after installing the anchor piles the template 1 can be li fted over the ends of the installed anchor piles that proj ect upwardly from the seabed and moved to the next installation site .

The template 1 comprises a frame 2 , which is a three- dimensional truss in this case , but the template 1 may have an alternative mechanical structure . As seen from above the frame 2 has a contour of an equilateral triangle including three substantially straight sides 3 . A li fting element 4 is fixed to an upper side of the frame 2 and serves to hoist the template 1 by means of a crane (not shown) . The li fting element 4 is located at a centreline CL of the frame 2 . The frame 2 extends in a main plane , which is usually hori zontal under operating conditions , and the centreline CL extends perpendicularly to the main plane .

The template 1 also comprises three guides 5 for guiding respective foundation elements during driving them into the seabed . Each of the guides 5 comprises a sleeve 6 which has a flared upper portion 7 which facilitates inserting a foundation element into the sleeve 6 . A foot 8 is mounted to a lower end portion of the sleeve 6 and movable with respect to the sleeve 6 by means of hydraulic cylinders 9 . The movable feet 8 at the respective sleeves 6 provide the opportunity to level the frame 2 including the sleeves 6 with respect to the seabed when it is placed thereon . In the embodiment as shown in Figs . 1-4 the sleeves 6 have parallel centrelines which extend parallel to the centreline CL of the frame 2 and are located at an angular distance from each other about the centreline CL of the frame 2 . Each of the sleeves 6 is movably mounted to one of the corresponding sides 3 of the frame 2 through a pair of guide rails 10 which extend parallel to each other at di f ferent height level along the corresponding side 3 .

Fig . 2 shows a first operational condition in which the guides 5 are at respective first positions along the corresponding pairs of guide rails 10 and Fig . 3 shows a second operational condition in which the guides 5 are at respective second positions along the corresponding pairs of guide rails 10 . Figs . 2 and 3 show that in the second operational condition the guides 5 are located closer to the corners of the frame 2 than in the second operational condition . Consequently, the distance between the centreline CL of the frame 2 and each of the centrelines of the respective sleeves 6 in the first operational condition is smaller than in the second operational condition, whereas the centrelines of the sleeves 6 are located at equiangular position with respect to each other about the centreline CL of the frame 2 in both the first and second operational conditions . Furthermore , in both the first and second operational conditions the guides 5 are arranged rotational symmetric about the centreline CL of the frame 2 .

The guides 5 are displaceable along the respective pairs of guide rails 10 by means of actuators (not shown) , for example hydraulic cylinders or the like .

Fig . 5 shows a mechanical connection between one of the guides 5 and one of the guide rails 10 . It can be seen that the guide 5 is provided with a slider or a claw 11 which engages the guide rail 10 and which can slide along the guide rail 10 . Fig . 5 also shows a locking pin 12 for locking the guide 5 and the frame 2 with respect to each other . In an alternative embodiment the guide 5 and the frame 2 may be locked to each other through a clamp or the like .

In the embodiment as shown in Figs . 1-4 the guides 5 are displaceable with respect to the frame 2 along paths which are linear and extend parallel to the respective guide rails 10 . In more general terms , each of the guides 5 is translatable with respect to the frame 2 by an angular displacement about the centreline CL of the frame 2 along a path which deviates from a circle about the centreline CL of the frame 2 . The path must deviate from a circle about the centreline CL of the frame 2 in order to enable adj ustment of the distance between the centreline CL of the frame 2 and the guide 5 .

The length of each guide rail 10 along the corresponding side 3 is smaller than the corresponding side between neighbouring corners of the equilateral triangle . Each of the guide rails 10 extends from a corner of the triangle and a position remote from the middle of the corresponding side 3 such that its length is smaller than hal f of the length of the side 3 .

The frame 2 forms an equilateral triangle within the main plane , but alternative embodiments which form a regular polygon within the main plane , are conceivable ; for example , a square-shaped frame including four linear sides along which respective guide rails are provided, may provide a similar ef fect of varying distances between the centreline of the frame and the guides .

The invention is not limited to the embodiment shown in the drawings and described hereinbefore , which may be varied in di f ferent manners within the scope of the claims and their technical equivalents . For example , it is also conceivable that the guides are translatable in radial direction of the centreline .