GustoMSC Variable-speed drive solution
for Rack & Pinion jacking systems
www.siemens.com /oilgas
Combined strengths
GustoMSC is one of a leading design and engineering
company involved in all types of mobile units/vessels for
the offshore industry, including the delivery of associated
equipment. The innovative solutions are cantered on all
types of jack-up units, semi-submersibles and mono-hull
vessels.
Siemens has been, for over three decades, a main supplier
in process control and electrical systems for offshore
applications. Delivering motors, drives, HV/LV power
supplies, automation and instrumentation.
GustoMSC and Siemens have entered into a long-term
partnership combining the experience, knowledge and
expertise of both companies which enables GustoMSC to
freely access the latest developments regarding drive and
automation technology.
History
One of the first successful results of this partnership was
the delivery of the first series of variable speed drive rack
& pinion jacking systems.
GustoMSC rack and pinion jacking systems have been
applied over the last three decades to an array of jack-up
drilling units, well-servicing and maintenance barges as
well as drilling rigs for arctic conditions. Jacking systems
for six CJ46-X100-D drilling rigs and six NG2500X self
propelled Jack-up vessels are currently constructed.
The Challenge
With the need to improve efficiency, operability and
reduce relocation times of offshore jacking units, speed
and precise control of the leg handling system are of
paramount importance. In cooperation we aim to fulfil
these needs.
The GustoMSC jacking system offers a safe operation due
to the multi layer safety and control systems to protect
both people and equipment.
The range of jacking systems suits the GustoMSC CJ- and
NG-series but can be easily customized to any other jackup rig design. The jacking system is also suitable for
operations in conjunction with the GustoMSC leg fixation
system.
Jacking System Features
Step-less speed control
The electric motors of the rack and pinion systems are
driven by Siemens’ individual variable speed drives (VSD’s).
This arrangement allows for step less speed control
between zero and maximum speed and very accurate
control of the motor torque and therefore pinions torque.
By ensuring the torque is equally shared by all motors and
pinions the operation is smoother with less stress and
wear.
Rack phase difference (RPD)
One potential challenge is if the spudcan, at the bottom of
the leg, encounters an uneven sea-bed it can deflect the
leg, this deflection causes RPD. The GustoMSC jacking
system uses Siemens’ encoders on the motors to monitor
the position of each chord on a leg to detect RPD before
damage occurs.
Torque control
Pre-torque to each pinion can be applied without manual
intervention. By means of the Siemens PCS7 automation
platform, providing central torque control functions the
GustoMSC jacking system can limit sudden leg
movements, for instance when a leg is extracted from the
sea-bed or prior deployment of the fixation system, using
the invertors at very low speed.
The electric VSD driven rack and pinion systems offer the
following operational characteristics:
• Variable and slow / zero speed control
• Optimized load sharing over the pinions
• Use of standard, offshore type electric motors, without
special high-slip requirements
• Easy retorqing through the VSD drives
• Automatic platform leveling during lifting and lowering
• Leg position indication and rack phase difference (RPD)
• Redundant PLC system
• Load measuring through the VSD drives and optionally
through load measuring devices in the upper shock pads
for floating units
• Increased leg handling speed
Certification
The jacking systems can be delivered with certificates
from recognized Classification Societies such as ABS, DnV,
Lloyds.
After Sales Service
Through its worldwide network the GustoMSC/Siemens
partnership provides 24/7 after sales service.
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Technical Characteristics
Each jacking unit consists of a special design, 7 teeth
pinion, driven by an electric motor through an input- and
planetary gearbox.
In general, the jacking units, assembled in a floating
jacking frame, engage with a rack of the jack-up legs. The
floating jacking frame is equipped with rubber pads on
upper and lower end, allowing the units to follow the rack.
In the rubber pads, load measuring devices can be
incorporated. Alternatively, the jacking units are mounted
in a fixed jacking structure, depending on the overall jackup design.
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Gusto MSC, Netherlands
P.O. Box 11, 3100 AA Schiedam
Tel. +31 (0)10 232 0000
Email: Marketing@GustoMSC.com
Siemens Nederland N.V.
Prinses Beatrixlaan 800
2595 BN Den Haag
Tel: +31 (0)70 333 3333
Email: oilgas.nl@siemens.com