Spotlight on Heave Compensation

Heave compensation and its associated equipment, is high on the agenda of the International Marine Contractors Association (IMCA). The Association has recently held a highly successful workshop involving manufacturers and users/owners, and is now producing pragmatic operational guidance in the use of heave compensation systems in the great diversity of its usage. “Our workshop arose from discussions in the sub-group of the IMCA Crane and Winch Operations workgroup (CWOW) tasked with the development of guidance on crane integrity management, where a number of issues associated with heave compensation were identified,” explains Hugh Williams, Chief Executive of IMCA. “Initially it was... (read more)

2010-05-12 01:55:10

Qualifying Heave Performance at Sea

Comparison of ORE MEMS-based MRU Heave Measurement with RTK-GPS

When accelerometer-based heave units were developed, there were limited options for verifying their performance at sea with a recognised standard. With real-time kinematic (RTK) global positioning system (GPS) devices, surveyors today can achieve accuracies of 2cm in altitude measurement. With the advent of small, low-cost, low-power, micro-electrical mechanical systems being employed for motion-sensing, a compact and cheaper alternative is available to measure heave. We have verified the heave of our motion reference units at sea with RTK-GPS. View Larger Map ORE Offshoreadded heavemeasurement to their pitch-and-roll motion reference units (MRU) in April 2009, which use micro-electrical mechanical system (MEMS) sensors.... (read more)

2009-06-26 12:00:00

IXSEA to Introduce SAFE HEAVE

IXSEA introduces features with OCTANS III, a complete firmware and hardware redesign of the renowned through the industry motion sensor and gyrocompass Octans. SAFE HEAVE, Self-Adaptive Filtered Estimated Heave, is a dynamically tuned new heave filter concept that can assess heave parameters in true real time. As a result, not only the behaviour of the heave filter is always optimal, whatever the conditions and whatever the size of the vessel but also it does not require any set-up from the user. Using the latest progress in mathematical techniques, SAFE-HEAVE is particularly well adapted to changing swell conditions like harbour waves,... (read more)

2004-04-05 12:00:00

Intelligent Active Heave Compensation Module

Seatools has introduced an intelligent active heave compensation module: HeaveMate, an easy-to-integrate system for both new-build as well as existing offshore and subsea equipment like winches, cranes, and launch and recovery systems (LARS). HeaveMate is available as an OEM package with the essentials for heave compensation (black box controller with sensors and software) or as part of a complete turn-key system, including mechanical and hydraulic hardware. Seatools’ simulation capabilities are applied to ensure proper performance of the overall system in any sea condition and situation (including failure cases), and pre-tune the controller prior to commissioning, thus saving valuable vessel time.... (read more)

2016-05-30 10:17:14

Bibby Athena’s d’ROP Winch Heave Compensated

To fulfil its contractual obligations M/V Bibby Athena had its ROV winch upgraded with Scantrol AHC while in operation. In order to perform continuous mapping of the seabed and cables while still operational, Bibby HydroMap needed to heave compensate its d`ROP Survey ROV winch. The AHC control system was delivered and tested in the space of just 3 weeks this summer, and the vessel is now running AHC operations up to 24 hours a day. In June 2015 the new Scantrol AHC system was received, an AHC upgrade from Scantrol, which is a cost-effective and proven system with a short lead... (read more)

2015-11-24 10:20:31

Heave Compensation and INS Ensured Successful Arctic Surveys

Calesurvey had been commissioned to conduct survey work in the seas around Greenland, where challenging, long-period swells are common. The company required a motion sensor, especially focussing on heave compensation performance, to use in conjunction with a variety of instruments, one of them being a R2Sonic multibeam echosounder (MBES), onboard the DP-2 geophysical survey vessel Kommandor Stuart. iXBlue's ROVINS units were proposed to provide the necessary input required by the MBES. ROVINS is based on iXBlue's innovative fibre-optic gyroscope technology and is an underwater product intended for use by the offshore industry in water depths of up to... (read more)

2011-10-03 10:45:43

TrueHeave Technology for POS MV

Applanix has announced that its POS MV product line has been enhanced by the introduction of TrueHeave technology. This improved filtering tool provides much more accurate heave estimation, even in the most challenging survey conditions. This results in a significant reduction in heave artefacts in survey data and eliminates the need to tune the heave filter to produce optimal results. In addition, TrueHeave reduces filter settle time as compared to a traditional heave filter, almost completely eliminating the need for line run-ins. This means a saving of several minutes per survey line and translates into savings of hours or even... (read more)

2003-10-23 12:00:00

Kongsberg Seatex Motion Reference Products

At Oceanology International 2012, two Motion Reference Units from Kongsberg Maritime’s position reference specialist division, Kongsberg Seatex, Norway, have been showcased. The MRU 3 is a completely new model within Kongsberg Seatex’s 5th generation of roll, pitch and heave motion sensors. It is especially designed for heave compensation applications including real-time heave compensation of echo sounders and active heave compensation of offshore cranes. It provides heave measurements to meet IHO standards and achieves high reliability by using solid state sensors with no rotational or mechanical parts. Another new model to the fifth generation of MRUs, the new MRU E, is... (read more)

2012-04-16 10:37:23

SBG Products Supported by Software Suppliers

The Ekinox Series (surface and subsea sensors) by SBG Systems (France) is supported by Hypack and QPS hydrographic software. The Ellipse Series of miniature inertial sensors is supported too as it shares the same protocol as the Ekinox. Additionaly, the sbgCenter now delivers a CARIS-compatible export format. HYPACK has recently completed HYPACK and HYSWEEP device drivers for the SBG Systems Ekinox Inertial Navigation Systems. Ethernet and Series connection is available and all parameters are supported: roll, pitch, heading, position, heave, delayed heave, UTC, etc. The Ekinox Series and Subsea Series and the new Ellipse Series are totally supported by the... (read more)

2014-12-15 10:29:15

New Models Added to Octopus Range of Precision Attitude and Positioning Systems

CodaOctopus has introduced several new models to its range of precision attitude and positioning systems. The new products are launched on the strength of the success of the Octopus F180 Precision Attitude and Positioning System which creatively reapplies technology originally developed for the extreme world of motor racing. The newly expanded Octopus F180 series includes new variants with enhanced performance to meet the widest range of requirements and now comprises: Octopus F190 – with dual frequency GPS and integral satellite differential receiver Octopus F185 – with dual frequency GPS and 1cm RTK capability Octopus F180 – standard system with 20cm... (read more)

2005-07-22 12:00:00