Hydraulics go Dutch offshore
The world of high-pressure hydraulics is constantly in motion. Within this dynamic the Dutch hydraulics specialist Holmatro is continuously developing high-quality solutions for industrial applications. After more than 50 years’ experience as a supplier to the shipbuilding and oil & gas industries, Holmatro developed the first TP levelling set in 2009, used in the construction of the Belgian offshore wind farm Belwind. The set proved to be so successful that they were also used during the construction of subsequent offshore wind farm projects, such as Walney, London Array, Westermost Rough, Dudgeon and many more.
Since the introduction of the TP levelling set in 2009, Holmatro has significantly expanded its product range for offshore wind applications. Besides hydraulic solutions to level wind turbine foundations, the company has proven itself in the field of TP fixation, jacket fixation, cutting applications, seafastening equipment and skidding solutions. Holmatro tools are also used for the lifting, weighing and levelling of offshore platforms, the calibration of tension-leg platform (TLP) load cells and are integrated on pipe-laying vessels to support heavy lifting and moving applications.
Wind turbine foundations consist of two large steel structures: a monopile (MP) that is driven into the seabed and a transition piece (TP) that is placed on top of the MP for accessibility and final alignment. When positioning a TP on a MP special custom-made cylinders are used. The Holmatro cylinders have an enormous lifting capacity and operate on 720 bar. By making use of a high-pressure system it is possible to use relatively small and compact cylinders which make it ideally for these applications as available space is a key point during construction. Once perfect horizontal levelling is achieved, the TP is fixed in place by means of hydraulic fixation cylinders. Grout is poured into the hollow space between the TP and MP to permanently anchor the two elements to each other. During the curing process, the cylinders keep the elements precisely in position, regardless of weather conditions. Another method of installing is by means of flange connection. Holmatro can also be of added value on this part providing special solution for pre-tensioning the bolts stat of tensioning by means of torque tools.