150 ton active heave compensation system aboard diving
support vessel
SBM uses special vessels to position valuable and sensitive equipment on the seabed at depths down to 3,000
metres. The use of a 150 ton active heave compensation
system from Bosch Rexroth enables SBM to carry out
this work in a more reliable, efficient and safe manner.
The system is located below deck and is fully able to
withstand the harsh marine environment.
Demanding application
Active heave compensation for
wave movements of ± 3 m.
Advanced solution
The development, assembly, testing
and commissioning of an active
heave compensation system that
uses hydraulics to compensate for
dynamic aspects and air to compensate for the static load.
To perform work at depths greater than
Linear heave compensation
3,000 m below sea level, the ships
SBM’s active heave compensation
used by SBM are equipped with many
system operates continuously based
advanced systems and technologies.
on measurements made by the Motion
One of these is the active heave com-
Reference Unit, or MRU. These mea-
pensation system. This system, which
surements describe the vertical move-
compensates for heave caused by
ments of the ship, and thereby the
ocean swell, allows sensitive equip-
wave motion that needs to be compen-
ment or other loads to be placed on
sated for. An advanced and extremely
Effective
the seabed – gently, and under full
fast controller processes this data and
Based on MRU measurements, the
control. At the same time, it protects
uses it to control a hydraulic cylinder.
system achieves a compensating
the hoisting cable from potential
The cylinder is extended or retracted to
capacity of no less than 90% of the
breakage due to internal resonance
tighten or relax the hoisting cable, such
load movement at the overboard
caused by wave movement.
that the load is suspended motionless
point.
in relation to the seabed.
Facts
►► Accumulator for energy conservation
►► Wave amplitude: ± 3 m
►► Mean wave periodicity: 10 s
►► Depth: 3,000 m
►► Maximum acceleration: 7m/s2
►► Compensating capacity for at
especially developed for offshore
Combined hydraulics and air
applications. In addition, essential
Mounted below deck, the system can
system components are dual or multi-
achieve a compensating capacity of at
ple-redundant; for example, to guaran-
least 90%. What makes this solution
tee the continuity, reliability, and safety
unusual is the specially-designed
of employees and the costly load of up
compensation cylinder, which com-
to 150 tons, the Bosch Rexroth CIMS
bines both a pneumatic and hydraulic
measuring system integrated into the
cylinder. The pneumatic compartment
cylinder is equipped with three sen-
bears and compensates for the static
sors.
load, while the hydraulic compartment
least 90% of the load movement
provides the dynamic forces to almost
From design to commissioning
(less than 10% residual move-
entirely compensate for movements of
Bosch Rexroth developed the entire
ment)
the load. Thanks to this unique combi-
system for SBM, also providing the
nation, the required hydraulic capacity
required system components, which
is only a fraction of the theoretical peak
were virtually all manufactured in-
capacity that would be required from
house. These include the drive section
the winch if there were no heave com-
including the hydraulic power unit and
pensation installed. This has resulted
the hydraulic cylinder, the air supply
in considerable energy savings.
unit, all pipework, plus the control
To ensure reliable operation under
section with software, control cabinets
harsh conditions at sea, the hydraulic
and operator panels. Bosch Rexroth
cylinders have been treated with
also performed the commissioning.
Enduroq 2200 surface technology, an
The second system delivered to SBM
extremely wear-resistant and corro-
incorporates additional features, such
sion-resistant cylinder rod finish,
as remote monitoring.
►► Capacity: 150 ton
►► HPU capacity is a fraction of
winch theoretical peak capacity
Bosch Rexroth
Products & Services
►► Concept, system and software
engineering
►► Project & quality management
►► Certification
►► Control panel
►► Cylinders on mounting frame
with guide
►► Hydraulic Power Unit on mounting frame
►► Control system including Motion
Reference Unit
►► Air system with air management
►► Compressors & air treatment
equipment
►► Valve blocks
►► Accumulator sets
►► Installation, commissioning and
supervision
►► Sea trials