We understand you’re busy tendering for projects, looking for suitable vessels, hiring crews, securing piles for your project, chasing payments and maybe even dodging creditors, but don’t just rent any vibro. For each mono pile you’ll need the vibro hammer 8 times. EIGHT TIMES. Why invest in the reliability of the impact hammer that waits around most of the time while just renting the first vibro that you find lying around without any concern for its reliability?

20 sea miles off the coast of Zhuanghe, Liaoning province Three Gorges New Energy’s Zhuanghe III Offshore Windfarm Project is taking shape. A fleet of installation vessels and work boats is on site to install mono pile foundations for this 300MW park before winter weather sets in.

The mono piles, with a top diameter of 5500mm and a bottom diameter in the range of 6100-6500, are driven by Menck MHU2400S hydraulic hammer. The mono piles have a length of 69 to 86 meters. The working method calls for a four-legged positioning frame to be driven and extracted by vibratory hammer. For this task the ICE 250NF was selected.

What appears to be a smooth mirror surface, harbors quite significant wave action with long submerged rolling waves with a length of 100 meters often reaching 1.5 meters in height. The installation method employs two vessels, one a working platform, the other a floating crane. The 1500mm surges make work hard, positioning of the impact and vibro hammer are challenging with the rolling of the ship and large horizontal movements. As the speed of the hook on the floating crane is slow and can’t be quick released when the impact hammer sits on the pile, the hammer jolts up and down with the waves and may slam the top of the pile before veering up again. Impact hammers have a large pile sleeve that can function better under these conditions, but a vibro is designed with clamps which need to slide around the casing wall with care. At a working height of over 50 meters and volatile lifting hook this poses extra difficulties. For this reason, work is suspended until calmer seas at the end of the afternoon and work is continued throughout the night.

Offshore working conditions are more challenging, and down time costlier then piling work on land. Some adjustments were made for the clamping systems, mainly to better secure the clamps on the beam. The standard hydro-locks used to position the clamps on the beam proved insufficient for the battering forces it received while positioning the hammer on the extracted pile. The working method was also adjusted, a visual was needed to direct the position of the hammer, now an operator is hoisted in a cage to direct the crane driver.

The positioning piles used on this project have a length of 60m, a diameter of 2420mm and are driven around 20 meters into the seabed. Water depth varies from 16-30 meters. The vibratory hammer used for driving the positioning piles is one of the auxiliary equipment that make or break a job. ICE has a growing fleet of 250NF in China, working for various installation companies. These companies chose ICE for reliability, and attractive operation daily costs. ICE hammers are the largest single hammers available in the market, competitive solutions often resort to twin or tandem use of vibro’s where a single ICE hammer can do the job.

The positioning frame is an ingenious frame that allows for the installation of foundations from a floating vessel. At the bow of the vessel the deck is extended with two platforms jutting out into the sea, one on each side leaving space in the middle for the mono pile and positioning frame. The installation frame rests on the platforms during sailing, once arrived at the installation location, a large 250NF vibro drives the 4 legs into the sea bed, the floating crane then moves in to lift the frame and hook it to the 4 legs, so the frame sits firmly on the sea floor. The frame is fitted with hydraulic positioning arms that keep the pile within limitations during impact driving. After the monopile is in position the legs are vibrated up and locked in transport site, ready for the next site. In good weather this procedure allows a foundation to be built in two days.

As the industry is moving from multi-pile foundations to monopiles, the demand for new types of equipment is growing. The focus has been on impact hammers, how to get your hands on a hammer, which size class to buy, and how to use it to its full potential. The market is becoming competitive and the difference on time and late delivery is starting to depend on auxiliary equipment. We look forward to serving this market and reducing the challenges of working offshore for our clients.

The benefits of the ICE 250NF as reported by clients are its reliability (this eliminates down-time), and easy handling (increases installation efficiency and speed). These benefits may seem old and tired, but in an aggressive offshore environment they make or break a project. We’ve built vibratory hammers since the 1970’s and know what we are doing. We offer the largest single hammer available in the market, that brings the advantage of light weight, no synchronization needed, easily upgradable to a double decker hammer.

We understand you’re busy tendering for projects, looking for suitable vessels, hiring crews, securing piles for your project, chasing payments and maybe even dodging creditors, but don’t just rent any vibro. For each mono pile you’ll need the vibro hammer 8 times. EIGHT TIMES. Why invest in the reliability of the impact hammer that waits around most of the time while renting whatever vibro that is easily available without a thorough analysis?

Choose ICE if you want to profit from quality that comes through decades of experience and don’t want to lose money and don’t want to be shouted out at by your client. The equipment is available for sale or rent from stock.

You can meet Arjen at CHINA WINDPOWER (17-19 October) at the Holland Pavilion.

ICE Booth number : W1 A05

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