Dec. /10 - VETTER Krantechnik

Hoists on the
high seas
When it comes to offshore equipment, the issue that is always first
and foremost is one of challenging technology. So it was for
VETTER’s slewing jib cranes that were recently supplied to the USA:
with lifting capacities of 5 tonnes and outreaches of 12 metres,
they are used for maintenance work and tool replacement on a
platform off the Texan coast.
The challenge was that all the cranes and
hoists had to be explosion-proof. Hence,
the operator opted for air hoists. The hoists
are relocated using rack-and-pinion drives so
that the hoists can be moved even when they
are inclined (max. 5°). Two air-powered slewing
drives provide for slewing of the crane jib when
inclined.
Optimally protected and firmly secured
For offshore use, a special paint coating of
320 μm, corrosivity classification C5, was
needed, as the equipment has to contend
with condensation and a high degree of salt
contamination on-site. Another special feature
is the method of fixing the crane to the platform:
wall consoles specially developed for this
application were used to which a 1200 mm
diameter column section was securely welded
in each case. This section of column has a
flange on top which takes the jib’s ball bearing
slewing ring.
4 Lift it December 2010
Experience for all events
Cranes for offshore use are also increasingly of
interest to the wind power industry, e.g. for lifting
materials or personnel from ships onto the
platforms. This application also imposes special
requirements on the design of the crane system
due to the maritime environment. VETTER Krantechnik
has proved once again that even unusual
applications can be tackled with the right kind of
experience and expertise.
joerg.schachtschneider@vetter-cranes.com
Testing the jibs at the factory