Gallery: Installing and removing Universal Foundation's mono-buckets

DENMARK: Universal Foundation's (UF) mono-bucket foundation is set to be installed at the 18MW Icebreaker project in the US, but the design itself has been used in the offshore industry for some years.

by David Weston 28 August 2015

  • Universal Foundation's mono-bucket design combines gravity base, suction bucket and monopile foundations

    Universal Foundation's mono-bucket design combines gravity base, suction bucket and monopile foundations

  • In February 2013, two of Universal Foundation mono-buckets were installed at the Dogger Bank Zone

    In February 2013, two of Universal Foundation mono-buckets were installed at the Dogger Bank Zone

  • One of the Dogger Bank foundations was installed in a record seven hours (pic: CHPV and Forewind)

    One of the Dogger Bank foundations was installed in a record seven hours (pic: CHPV and Forewind)

  • UF uses a Click on Unit (CoU) suction pump (the blue box) to help secure the foundation to the seabed

    UF uses a Click on Unit (CoU) suction pump (the blue box) to help secure the foundation to the seabed

  • In 2009, a mono-bucket foundation was installed at the Horns Rev 2 site

    In 2009, a mono-bucket foundation was installed at the Horns Rev 2 site

  • That foundation was decommissioned in July 2015 - UF said the seabed was left unmarked (pic: DBB Jack up services)

    That foundation was decommissioned in July 2015 - UF said the seabed was left unmarked (pic: DBB Jack up services)

  • The buckets measure approximately 15 metres wide and 7.5 metres high

    The buckets measure approximately 15 metres wide and 7.5 metres high

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In 2002, a prototype version of the foundation was installed to support a Vestas V90 3MW turbine in Frederikshavn, Denmark.

The design was developed further and in 2009 a new foundation was installed at the Horns Rev 2 offshore project to support the met mast. The bucket measures 15 metres wide and 7.5 metres high. 

After six years of operation, the foundation at Horns Rev was decommissioned in July 2015. UF said the foudation left the seabed unmarked and returned to its original state. 

UF's design incorporates a monopile, a suction bucket and a gravity base foundation into one design. It can be floated to the project site, requiring just two tug boats instead of a large and expensive installation vessel.

Installation is quick: its record is just seven hours. It uses a bespoke suction pump to secure the base to the seabed.

The foundation will be installed at the 18MW Icebreaker project in Lake Erie, Ohio, US. Six 3MW turbines will be installed at the site but the design has been certified to hold 8MW turbines in 55-metre deep waters, UF said.