Tools of the trade

Cost-cutting. A combination of words warmly greeted in the offshore wind industry and for that matter also the outcome of marine service provider Houlder’s pile upending tool recently delivered for work on the Rampion Offshore Wind Farm development, off the Sussex coast in the English Channel.

Construction of the Rampion Offshore Wind Farm has commenced and the first offshore foundation was installed in February of this year. Work to prepare the seabed for the 116 turbines began in September last year and the ongoing offshore construction work will be project managed from temporary offices in the port of Newhaven until the wind farm’s operations and maintenance base is completed in 2017.

More offshore involvement

In a much earlier phase of development Houlder won the tender to deliver, among others, the pile upending tool to the project. Andy Lovell, project director at Houlder, says: “Our company has been operating for over 150 years now in the offshore environment and more recently have been supplying equipment to the offshore wind and oil and gas industries. We know E.ON well and have worked with them on previous projects. When the Rampion Offshore Wind Farm development started to develop they contacted us to see what was possible. We later won the tender and got the contract early June last year.”

The pile upending tool was designed by Houlder specifically to meet Eon’s requirements. It has been designed for safer and faster offshore wind farm installation operations. Lovell comments: “The remote controlled hookup and release system engages directly with the foundation’s top flange. This eliminates the need for additional lifting points or straps – the optimal solution where the lifting point overhangs the deck or is out of reach. It is a selfcontained system with rechargeable hydraulic and electric supplies. Recharging is carried out at a deck-mounted docking station, avoiding the need for additional connections or power lines during lifting operations. The use of high strength steel provides a robust and lightweight structure with clear and easy access to all inspection and maintenance areas. The control system ensures both simplicity of use, as well as fail-safe operations.”

Taken to the next level

“What our tool offers is very advanced, essentially we have taken this piece of equipment to the next level. Fully automated, allowing access to monopiles overhanging the side of the vessel wirelessly. The tool upends itself, meaning that no human intervention or additional crane wires are required – an added bonus on the side of safety. This is what we had in mind, for the tool to be intrinsically safe. In fact, we mean it when we say no human interaction. It is possible, although clients often do still perform a final physical check. Next to that, the wireless autoengagement means the tools help reduce crane times and installation costs”, says Lovell.

He continues: “The remote controlled hook-up and release system, a self-contained system with rechargeable hydraulic and electric supplies, engages directly with the foundation pile flanges. The recharging is carried out at a deck-mounted docking station, avoiding the need for additional umbilical connections or power lines during lifting operations. The tools are compatible with 855 ton, five metre diameter piles. Remember, these are not small pieces of equipment and handling them offshore, let alone upending them from zero to 90 degrees, is one of the riskiest operations during wind farm construction. The tool is incredibly robust, yet also lightweight enough to ensure easy integration with existing craneage. Some very ingenious design work has gone into the steel structure and hydraulics. It also goes without saying that the control system needed to be simple to use but also be completely fail safe.”

Modified to meet the needs

As to whether the tool is ‘one size fits all’ or tailor-made, Lovell states: “Well, it is modified to suit for each specific project, but that modification is very straight forward.” An increase in diameter of monopiles should be no problem according to Lovell.

In terms of the future, Houlder feels cost-cutting and safety will remain hot topics. Mike Carter, marketing manager at Houlder, comments: “When we as a company design a tool we look at how we can make it more straightforward. You don’t want people running around deck in harms way. This is a driving force when developing our equipment: keep safety in mind. And also, to remain in close contact with out clients to find out what they need at the right cost. We need to balance cost and weigh in the safety factor on equipment the offshore wind industry requires. What drives an offshore wind farm development is the cost of vessel operations, so if we can help reduce this by designing the right tools, our goal to reduce time on site is achieved.”

The first pile upending tool was installed on the MPI Discovery in January and the second tool will be installed on the Pacific Orca installation vessel in June, alongside other Houlder handling equipment. This includes a second pair of 200t pile handling and restraint arms currently being constructed by the team.