Holmatro is one of the world’s leading manufacturers of high-pressure hydraulic equipment for rescue, industrial and tactical applications worldwide. As an original Dutch company our ambition is to find result-orientated solutions that combine working with extreme forces with controllability, convenience and safety. Also, when it comes to offshore wind hydraulic solutions.
Over 50 years’ experience
After more than 50 years of 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, we have significantly expanded our product range for offshore wind applications. Besides hydraulic solutions to level wind turbine foundations, we have proven ourselves in the field of TP fixation, jacket fixation, cutting applications, seafastening equipment and skidding solutions. Besides that, 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.
TP levelling and fixation
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 ideal 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 a special solution for pre-tensioning the bolts stat of tensioning by means of torque tools.
Time is of the essence for our clients and Holmatro is constantly in consultation with the users and owners making sure their operations during installation run smoothly and without any complications, enabling them to do the job in a safe and controlled manner, which saves them valuable time during installation.
Seafastening
Seafastening solutions are used when transporting MPs, TPs and related installation equipment overseas to a wind farm. Many years ago, Holmatro designed the first seafastening systems suitable for extreme conditions for Seajacks and GeoSea. Holmatro has been improving and co-developing new types of systems ever since. It is especially for this application that Holmatro has designed and patented a double-acting locknut cylinder that allows for fixating and releasing of the object in a controlled manner and can even be used for alignment purposes. Holmatro also has its fair share of fixating systems for Hydrohammers and Noise Mitigation Systems.
Lifting, weighing and levelling
CNGS Group installed the topside of the LAM-E Platform in the Caspian Sea, offshore Turkmenistan in August 2016. After completing the construction of the LAM-E topside the 2,400 m offshore platform needed to be transported to her location in the Caspian Sea. Once it had arrived, the topside had to be levelled on the jacket construction. Because the total weight of the topside was unknown at the start of the project, CNGS required an integrated weighting function in the cylinders with a total capacity of 4,000t. Holmatro developed 500t cylinders, each provided with a pressure transmitter. The pressure transmitters were connected to a portable data logger using measuring cables. To level the topside on the jacket construction, Holmatro produced 150t pulling cylinders.
Holmatro cylinders are regularly used during the construction of offshore platforms to lift, weigh or level the platforms or parts thereof. For example, for the jacket construction of the Wikinger wind farm substation, the foundation was a six-legged jacket structure with a total weight of 2,400t. For support purposes during construction, Holmatro delivered 400t double-acting pulling cylinders. To anchor and position the six legs of the structure, 150t double-acting cylinders were used.
Load-cell calibration
The Snorre oil field is located in the Norwegian North Sea, 200km from the coast. One of the platforms, the Snorre A, is anchored (TLP) to the seabed with steel cables. In order to retain, measure and monitor the pre-tensioning of the cables, each leg of the platform includes constructions that are fitted with load-cells. These load cells are periodically recalibrated. To accomplish this, the weight of the platform is lifted off of the load cells. The cylinders and accompanying products had to meet an enormous package of requirements due to the harsh conditions on the oil platform. Holmatro supplied 64 cylinders for the TLP system, each with a capacity of 536t. Besides cylinders, the corresponding control and storage for the hydraulic system was also delivered. And the required documentation was drawn up in line with the legal requirements for the offshore platform.
Roller box lifting
One of the main characteristic features of a pipe-laying vessel is the "stinger". Roller boxes are designed to carry the welded pipeline on the stinger and support it into the water. For this reason they have to be adjustable in different height positions, according to the calculated allowable bending curve. Standard steel pulling cylinders turned out to be too heavy for the crew to handle, since they had to be relocated quite often. In cooperation with Allseas, Holmatro designed an easy-to-handle lightweight aluminium pulling cylinder. The height setting of the roller boxes at Allseas’ vessels is now executed more user-friendly and safe.
Topside Lifting System (TLS)
During the construction of the world’s largest lifting vessel, the Pioneering Spirit, the need arose for extra support for the lifting system to allow safe dismantling, installation and transport of large drilling platforms. To compensate for the interplay of forces, the inner supports (Inboard Support) of the 16 lifting beams (TLS beams) were equipped with 52 (gray coloured) Holmatro cylinders, each with a lifting capacity of 280t. The cylinders, classified by Lloyd’s Register, were coated with offshore-grade surface treatments which made them suitable for use in the most extreme conditions. High-grade composite bearings have been included in the design, in order to prevent metal to metal contact in the cylinders, thus increasing durability.
Skidding systems
Nowadays, available deck space is a high priority among the installation companies. This in combination with the desire to take on more load in one go plus the ever growing dimensions of TPs and MPs has created a need for proper and innovative solutions. Taking on more load often means putting items on deck outside the reach of the crane. Once loaded and on location these items need to be shifted horizontally over the deck to come into the reach of the crane. Making use of third parties with SPMT’s to execute the work isn’t always in favour of space, availability and operational speed. Holmatro has designed a modular skidding system that allows installation companies to execute these operations by themselves in a controlled and safe manner. Due to the modular setup of this system and its components the possibilities are endless. Therefore it is the must have when it comes to any kind of horizontal displacement of heavy loads offshore.
Dutch quality and reliability
Holmatro products are developed, manufactured and tested in-house. The result: traditional Dutch quality, durability, reliability and solidness. Essential to all Holmatro products is the control of immense power. You must be able to rely on that for every application under any circumstances. To ensure this, regular maintenance and periodic certification is essential; as well as the deliberate and safe use of your hydraulic equipment. Working safely is not only more efficient but also contributes to the increased lifespan of the tools. Our tools are high quality and extremely durable, not least because of our extensive service programme.
(Inter)national sales network
Besides the head office in the Netherlands, Holmatro has manufacturing plants and sales offices in the Netherlands and the US. We have representative offices in the People’s Republic of China, the UK and Poland, as well as local sales engineers in Germany, Croatia, and India. Together with Holmatro’s global sales and service dealer network – fully trained in Holmatro’s own training center – we guarantee the same Holmatro standard of quality and a perfect after sales service for all our products all around the globe.