Motion compensation has been one of the key technology trends in the offshore vessel industry for several years, as the winner of the 2017 Innovation of the Year award at the 2017 Annual OSJ Conference, Awards & Exhibition demonstrated
OSJ’s Innovation of the Year award is awarded to an innovative product, system or service that is considered to have made a significant impact on the design, build and/or operational aspects of offshore support vessels in service during 2016.
The 2017 award went to MacGregor’s 3D Motion Compensator (3DMC) and was the third Innovation of the Year award awarded to the company. MacGregor won the same award in 2014 for its three-axis motion compensated crane and in 2012 for its Chain Wheel Manipulator.
The 3DMC is a retrofit device designed to enhance the load-handling precision of offshore cranes.
“We are obviously delighted to have won this peer-reviewed industry recognition from one of the most reputable forums in the international offshore sector,” says John Carnall, executive VP, global lifecycle support at MacGregor. “Winning the award for a third time really demonstrates our ability to develop and introduce new concepts to the market that have the capability of genuinely transforming offshore operations.
“We know how tough market conditions are. We have focused a great deal of effort in developing systems that can cost-effectively improve the equipment that operators already own so that they can become more competitive,” said Mr Carnall.
“Any investment must deliver demonstrable operational advantages, and the 3DMC retrofit option does exactly that, allowing a shipowner to expand the load-handling capabilities of a crane far beyond its original limitations. This means that the crane – and vessel on which it is installed – can be used for more assignments, and owners will be able to bid on a wider range of contracts.”
MacGregor’s standard active heave compensation (AHC) offering, supplied through a crane’s winch, compensates for a vessel’s vertical movements. However, when very accurate load positioning is required – such as landing loads on small, fixed platforms – the 3DMC can be used. It compensates for the roll, pitch and heave motions of the vessel to minimise any movement of the load in relation to a fixed point in space.
The 3DMC can be fitted to the knuckle jib of a broad spectrum of new or existing MacGregor subsea/offshore cranes. It has been designed for easy installation and makes use of the crane’s existing hydraulic power unit and control system. The 3DMC/crane interface is designed so that the unit can be swiftly mobilised to a crane with the relevant fittings. This allows for flexibility within a fleet of vessels, so that one or several 3DMCs can be shared between them.
When not required, the 3DMC simply remains fixed to the side of the crane’s main knuckle jib without interfering with the normal lifting capabilities of the main and whip winches.
MacGregor also recently introduced a crane compensation system for offshore ship-to-ship load transfers, offering substantially larger operating windows as well as safer and faster load transfers.
“This robustly tested technology can offer considerable commercial advantages to the offshore industry,” said Ivar Fjermeros, senior sales manager, advanced offshore solutions. “MacGregor understands the complexity of ship-to-ship load transfers and the limitations imposed by unpredictable, non-synchronised movements in a seaway. With the systems currently available, a crane’s capacity is effectively de-rated because of the conservative approach required to minimise risks associated with the relative movements of the vessels.”
The new compensation system employs a motion reference unit on the deck of the secondary vessel. This transmits motion data to the crane on the primary vessel via a high speed redundant wireless link. Combining motion data from both vessels, the system calculates and applies the winch compensation necessary to minimise hook movement at the load-handling zone on the secondary vessel.
The system has precise tension and position control for accurate load hook-on, pick-up landing and hook-off. Safety is much improved for the deck crew working in the load-handling zone. Load pick-up and landing is precise, fast and smooth. It allows the operator to employ a less conservative approach to calculating the maximum load that can be safely handled in any given sea state.
“The safety benefits mark a significant improvement for offshore transfer operations,” said Mr Fjermeros. “When these are combined with maximising the crane’s lifting capacity, improved load transfer times and a substantial real-world increase in weather windows for ship-to-ship operations, this system really does offer some groundbreaking benefits.”
Another of the shortlisted companies for the OSJ Innovation of the Year award was Safeway for the CargoSafe motion compensation system for cranes, which can also be used to upgrade cranes on offshore vessels to 3D motion compensated functionality
First unveiled in late 2016, The Netherlands-based CargoSafe can be used to upgrade shipboard/offshore cranes to full 3D motion compensated functionality. It uses a new 3D-crane jib from Van Aalst Group and comes as a cost-efficient compact add-on, which fits any existing crane. Hydraulically powered by the crane, the unit provides an additional auxiliary hoist, which compensates for ship motions. The controls are integrated into the crane cabin.
“All vessel owners know the dangers related to swinging loads due to a vessel’s motions. This causes dangerous situations for the crew and limits vessels’ overall working capabilities. With CargoSafe, a vessel owner can use their vessel for more jobs offshore. The CargoSafe is a logical step in development from our Safeway 3D technology. We’ve been asked by clients to increase the lifting capacity on our motion compensated gangway, but based on the trend of increased load-handling requirements, we found it useful to develop a smart, special-purpose 3D cargo-handling tool,” said Wijnand van Aalst, CEO of van Aalst Group.
The basic design of CargoSafe has been completed, and a patent application has been submitted. Detailed design was due to be completed at the end of February 2017.
Other recent news in the offshore crane sector saw manufacturer Liebherr announce that it is to supply a massive crane for DEME Group’s new turbine installation/decommissioning vessel Orion. The company is to build a heavy-lift crane with a lifting capacity of 3,000 tonnes at more than 50m outreach with a maximum lifting height in excess of 170m. The crane is the largest developed by Liebherr to date. It will be built at Liebherr’s plant in Rostock, Germany. Delivery will be spring 2019.
“It is a great honour to work with both DEME and Cosco (who will build the vessel) on such a revolutionary project,” said Liebherr Offshore Cranes sales director Gordon Clark. “We see a promising future in the heavy-lift sector, with growth in both the green energy sector and offshore decommissioning.”
“The extension of our heavy crane range allows us to compete in a sector with only a few players where there has been little competition of late, and we look forward to winning some of that market share,” said Liebherr Maritime Cranes managing director Leopold Berthold.
Apart from the main crane, the deal also includes two of Liebherr’s RL-K 4200 knuckleboom cranes and an offshore crane simulator.
Liebherr’s close competitor, The Netherlands-based Huisman, started 2017 at work on the world’s largest bearings at its production facility in China. The two 30m diameter bearings are intended for what will be the world’s largest tub cranes, two 10,000-tonne Huisman-designed cranes that are under construction for Heerema’s new semi-submersible crane vessel Sleipnir.
Unlike traditional tub cranes, which make use of either bogies or large wheels for their slew system, the Huisman-designed cranes make use of large bearings of Huisman’s own design, which are manufactured inhouse. The benefit of a bearing is that it allows for a substantial weight saving of the crane. The two bearings for the 10,000-tonne tub cranes for Sleipnir are segmented. The design of the bearings allows for inspection of the rollers without disassembly of the bearing. The assembly of the first bearing has been completed at Huisman China, and the assembly of the second bearing is scheduled to start in March of this year.