The electrical variable-speed
rack-and-pinion jacking system
Enhancing efficiency on jack-up rigs with an alternative to conventional hydraulic systems
© Siemens AG 2015. All rights reserved.
Design (1)
Jacking systems
Each jacking unit driven by electric motors
to drive input / output planetary gearboxes and
special designed 7 teeth pinions.
Certification
The jacking systems can be delivered
with certificates from recognized Classification
Societies such as ABS, DNV, Lloyds.
© Siemens AG 2015. All rights reserved.
Design (2)
Pinion load is controlled by the
system, not depending on special
slip-motor
 Reduced wear on the rack
Control system holds platform
until all brakes are lifted
 Avoid high pinion load,
Speed is reduced to zero before
brakes are applied
 Avoid brake wear
Jacking system integrated into the
jacking structure
 Reduce critical stress levels
Reduced dimensions
 Improved constructability and
torsional stiffness
© Siemens AG 2015. All rights reserved.
 Avoid brake slipping
Design (3)
• No overdesign
• High accuracy of load sharing over the pinions
• Less power and less cooling capacity required
• Integrated rack phase difference monitoring
• Redundancy, reliability, availability
© Siemens AG 2015. All rights reserved.
Results
• High-speed jacking from 0.45 to 1.8 m/min
• Durable by optimized load sharing over the pinions = Less
wear in gearbox / pinions
• Emergency operation possible when facing reduced power
• Accurate and integrated leg position indication and RPD safeguarding
• Redundant control system
• Use of standardized materials
• No need for special motors with high-slip requirements
© Siemens AG 2015. All rights reserved.
Not only drilling rigs !
© Siemens AG 2015. All rights reserved.
Major clients:
Major clients:
• CMHI
• JURONG
• DALIAN SIOC
• SAMSUNG
• LAMPRELL
• DDWPaxocean
Major clients:
• Seadrill
• Statoil
• Bestford
Capital
• Noble Drilling
• TS Drilling
• COSL
• Seajacks
number
35
30
25
20
15
10
5
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Scope Siemens includes delivery of gear boxes Siemens IND MD (formerly Flender)
© Siemens AG 2015. All rights reserved.
Scope of supply Siemens
• Siemens will engineer
and deliver the electrical
and control systems to
drive the pinions that will
lower and raise the
platform.
• The automation scope consists PCS7 hardware / software, fully tested at our workshop
in Zoetermeer. The drives & motors consist of standard materials with customer specific
modifications and offshore ratings.
© Siemens AG 2015. All rights reserved.
Technical characteristics
Separate safety layers:
• 1) over speed
• 2) brake release
• 3) motor control
Precise load sharing over the pinions = less wear and tear
0,0 m/min is a controlled state = pre-torque without manual
intervention
Multi layer safety= low power availability, jacking operation
(up or down) continued.
Rack Phase Difference monitoring (cm’s)
© Siemens AG 2015. All rights reserved.
Differences (1)
Increased availability by “layer concept”. In case of limited power supply,
jacking will still be possible by decreasing the jacking speed:
There is a choice to operate the system with reduced performance
when a complete layer fails
© Siemens AG 2015. All rights reserved.
Differences (2)
Load is always shared equally across the motors/pinions per leg.
There are no step changes in the load or torque on the system.
Smooth raising and lowering of the platform.
Load
1 Chord
Speed
1 Chord
© Siemens AG 2015. All rights reserved.
Differences (3)
Ease of operation
• Operability: speed and precise control of the leg
handling.
• Operator control via joysticks, pushbuttons
and two touch screens (one man show).
• Status and set point interface is via a dedicated
HMI located in the central control desk.
• Ultimate limit switches and over speed switches
protect the system from inadvertent operational
errors.
© Siemens AG 2015. All rights reserved.
Differences (4) : Enhanced safety
Safeguarding:
Each leg is equipped with an over-speed switch.
This is a dominant safeguarding loop (SIL 2 design):
if non-energized, an over speed switch generates a full stop in any mode of operation.
Continuous autonomous control functions:
Drive control and control of brakes are done by the autonomous control
system which means that the system won’t be able to release its brakes
in case operations are not determined as being “healthy”.
We achieve this by means of:
• the continuous measurement of input variables
• the continuous control of output values
© Siemens AG 2015. All rights reserved.
We are happy to answer your questions!
© Siemens AG 2015.
2013. All rights reserved.