The growth of wind power
in Europe is running out
of space, both at inland
and coastal locations.
Logically, the next step is to develop offshore wind farms at sea.
These installations are placed several kilometres off the coast and
fixed to the continental shelf. There
they are free-standing in the wind
and so can achieve a high energy
yield. However, constructing and
operating these installations poses
unprecedented challenges for the
technology used. Where water is
up to 60 m deep, stable foundations have to be built on the sea
bed and the construction of the
wind turbines themselves, with
their tower, power house and
rotor blades, requires elaborate
assembly. It cannot be done from
an unstable ship or platform, for
obvious reasons.
In order to get around these
problems, the VAN OORD Group
decided to place an order at the Sietas shipyard in Hamburg to build a special
assembly ship. Not only can the 139-metrelong ship be positioned on the seafloor with
4 hydraulic columns, the ship, which has been
named “AEOLUS”, also features a staggeringly large deck crane made by TTS NMF in
Hamburg. The boom is constructed from a
double length of grid segments and can lift
900 tonnes for a load radius of 30 m. When
using the maximum radius of 80 m, it can
still lift an enormous 240 tonnes. NMF would
not compromise when it came to selecting
the hoisting and adjusting ropes and picked
CASAR products as proven, reliable components for this application. For the hoisting
rope, there is a CASAR POWERPLAST with
a 66 mm diameter and 8-ply reeving with a
heavy-duty cylinder. As well as having outstanding rotation resistance, this rope stands
out thanks to the special plastic casing of its
core rope with excellent corrosion protection
of the inner strands and substantial insensitivity to dynamic loads. The crane boom is adjusted with a CASAR TURBOPLAST, also with
a 66 mm diameter, which is another popular
and proven choice of rope for deck cranes.
Both of these rope types have compacted
outer strands, thereby offering high breaking
strength, excellent coiling and drum compression resistance for multiple layer coiling. With
Aeolus, the top priority was maximum operational safety and reliability for all components.
Tough operating conditions in the North Sea
will push the ship, its crane and ultimately its
ropes to their limits when performing the often
difficult assembly manoeuvres.
In addition to the Aeolus, 2 semi-submersible
flotels known as AXIS VEGA and AXIS NOVA
will also be used, serving as stationary accommodation for the construction and service
staff and designed to cope well with extreme
weather conditions. For the necessary hoisting
work, the flotels will also be "tted with appropriate crane equipment from TTS NMF. The
planned 70-tonne cranes will operate a similar combination of products as the AEOLUS,
with a 42 mm CASAR POWERPLAST as the
main hoisting rope and a 42 mm CASAR TURBOPLAST as the adjusting rope. The ropes
also include a 30 mm CASAR POWERPLAST
as a secondary hoisting winch.
CASAR wishes the Aeolus safe sailing at all
times and may there always be a hand of water
under your keel.