Offshore

We offer the offshore market Vibro technology with clear advantages over conventional piling methods. Vibro technology is flexible, has a high installation speed and has limited pollution in emission and noise.

We offer the offshore market Vibro technology with clear advantages over conventional piling methods. Vibro technology is flexible, has a high installation speed and has limited pollution in emission and noise.

Vibration technology is very attractive for offshore applications. With a focus on the installation of Monopiles, Anchor piles and Pin piles Dieseko Group can already build on an extensive track record of previous projects.  Speed and handling are superior to traditional methods. Dieseko Group has 45 years of experience with this technology, and with the power of our innovative approach, we have already devised many smart solutions such as upending, whereby the vibratory hammer can tilt and a horizontal tube can be placed upright.

It is precisely at the project level where we are in constant dialogue with large contractors to jointly develop tailor-made solutions for the challenge of delivering reliably, safely and on time. The vibratory-driving method represents a suitable alternative installation technique. The execution reveals clear advantages comparing to the conventional impact hammering. Both, the noise emission and the installation time can be decreased.

Certification & Staff

The core of the Dieseko supply is existing and field proven components such as gearboxes, hydraulic clamps, and HPU’s. In a new development and to facilitate the installation of large monopiles Dieseko has come up with an ingenious up-ending mechanism which is capable of handling monopile with top diameters of up to 8 meter. All the load bearing parts of the system are designed, tested and certified in accordance with DNV Lifting Appliances.

Vibro Technology

The vibratory hammer is a mechanical sine-wave oscillator with weights rotating eccentrically in opposite directions. The effect of the vibrations is an oscillating vertical force classified to frequency and amplitude. Vibratory hammers work by eliminating soil resistance acting on the pile.

PVE 300M
ICE 250NF at offshore job in China
ICE 170NF

Installing and decommissioning

A large rental fleet of different types of heavy vibratory hammers including certified staff is available for anchoring, extracting or decommissioning. Certainly for this type of work the advantages are considerable. For example by using the vibro hammer as a lifting tool, and the possibility to deploy in submerged conditions, up to hundreds of meters underwater.

Installation speed compared

The vibratory-driving method represents a suitable alternative installation technique. The execution reveals clear advantages comparing to the conventional impact hammering. Both, the noise emission and the installation time can be decreased.

Vibrating versus Hammering
This video was made during a comparison test between an impact hammer and a PVE vibratory hammer in Cuxhaven. What you see is the actual piling speed.

Vibro driven pile bearing capacity

The Vibro installation technique had already been used before for predominantly axially loaded piles. In the offshore renewable sector, monopiles are also axially loaded. Commonly the use of vibratory hammers lead to a slight reduction of the axial loading capacity, which is usually compensated by impact–driving the pile for the last few meters.

Characteristics: Vibratory driving noise emissions

The noise emissions occurring during offshore pile driving is an important aspect of environmental care. The potential damage to sea life caused by these emissions is evident. The German authorities have set a threshold level on these emissions of SEL 160 dB re 1μPa2 and SPLpeak-peak 190 dB re 1μPa2 at a distance of 750m from the source. Acoustic measurements were conducted during the offshore decommissioning of 4 wind turbine foundations using a Dieseko PVE500MU vibratory unit.

The measured sound levels of both the Sound Exposure Level (SEL) and the peak-to-peak Sound Pressure Level (SPL peak-peak) were found to be substantially lower than the threshold levels set by the German authorities. The industry is rapidly developing models to assess the noise emission on projects based on the vibratory hammer capacity, pile geometry and soil response. More information is available on request.

Monopile installation

The handling of monopiles offshore using vibratory equipment is a great benefit for installation contractors. Dieseko has developed an active upending tool with this in mind. There is no need to separate the upending and pile driving operations as required for impact hammers. The obvious benefits being a continuous process from stabbing the monopile top up to reaching the final penetration depth.

Anchor piles

Dieseko is involved in a first offshore pilot for installation of a heavy duty anchor pile.
The project is the final stage of a new and revolutionary methodology to deliver anchor piles with high holding power. This is to provide a solution for the fast market for floating wind foundations.
With its partners Dieseko will provide the expertise to drive the anchor piles at any location on the seabed.

PIN piles

Similar to the installation of monopiles, Dieseko is geared up to deliver the right equipment for the installation of pin piles. With the same features such as high installation speed, low noise emissions and active pin pile up-ending, the Dieseko equipment can be quickly mobilized for projects around the globe.

Decomissioning

Similar to the installation of monopiles, Dieseko is geared up to deliver the right equipment for the installation of pin piles. With the same features such as high installation speed, low noise emissions and active pin pile up-ending, the Dieseko equipment can be quickly mobilized for projects around the globe.

PVE 500M dismantles wind farm Lely in only three hours. This 500 kgm eccentric power Vibratory Hammer is also available with an Upending tool.

Submerged operations

The deployment of Dieseko’s Vibratory tools in submerged conditions is absolutely no problem. All our vibratory hammers are designed for subsea usage. The hydrostatic overpressure is compensated during the lowering and recovery of the tool subsea. This way no real limitations exist to the operational water depth when being deployed.

Clear advantages

  • Short pile driving times
  • Accurate positioning and possibility for correction during insertion
  • Much lower noise levels
  • Reduction of installation costs by deploying fewer and more economical tools
  • Increase of design life of MP’s due to different energy impact
  • MP designed with thinner Wall Thickness leading to significant material savings and handling costs
  • Possibility to extract piles
PVE 200M normal frequency vibratory hammer

More information about Dieseko Group offshore solutions

Download offshore brochure