Offshore access systems are growing in sophistication, driven by the needs of the offshore oil and gas and offshore wind markets
Having started out as fairly rudimentary gangways, walk-to-work systems are evolving quickly to meet the requirements of the offshore oil and gas and offshore wind industries.
Early first-generation walk-to-work systems provided the ability to transfer personnel from the deck of a vessel to a fixed structure, but a new generation of walk-to-work technology has recently been introduced that enables technicians and their equipment to be transferred – even from different deck levels. There’s no need to carry heavy equipment either when you can push a trolley across a gangway. Get up in time for your shift, pick up your gear and take an elevator to the gangway, which takes you to your place of work. It’s like taking the underground or the subway to work, but at sea. That’s the kind of ease and convenience that the latest systems provide.
Manufacturers of offshore access gangways say clients are looking for systems with greater capacity – including transferring equipment – and the ability to work at a range of heights while having a minimal footprint. In both sectors, ‘stepless transfer’ is the key, making it safer and easier for personnel to move from a ship to their place of work.
The height at which transfers need to be undertaken can vary significantly, according to the height of the platform, turbine or substation. Large tidal variation is not uncommon in the offshore wind sector, for instance, and this has led to the development of more capable systems that incorporate elevators of the type mentioned above.
First-generation walk-to-work systems weren’t really integrated into a vessel in any way – effectively, they were just bolted on deck – but the next generation of equipment is likely to be integrated into a ship’s dynamic positioning and platform management systems. The first example of this kind of integrated approach has been ordered by Olympic Shipping in Norway and will see a K-Walk motion compensated gangway installed on the vessel Olympic Orion and integrated with a Kongsberg information management system, the ship’s K-Pos DP system.
But greater integration and the ability to transfer personnel and equipment isn’t the end of the story. Ampelmann has just unveiled an improved version of its A-type offshore access system that is designed to transfer personnel and cargo. The A400 has been redesigned in conjunction with leading operators to include greater capacity for equipment transportation between vessels and wind turbines but is equally suitable for use in the offshore oil and gas industry.
A wider gangway supports the use of trolleys that can carry up to 400 kg of cargo on Euro-sized industry standard pallets. In addition, the system can transfer multiple personnel at a time and includes an elevator to support ‘no-step’ policies. The capacity for transferring pallets via the gangway system alleviates the need for operators to install platform cranes.
Friso Talsma, Ampelmann’s sales and business development manager for offshore wind, said “By working closely with our customers we have been able to develop a system that meets their needs and allows them to work safely and more effectively. Providing a full system that includes a gangway capable of transporting a pallet, a trolley and elevator is something we believe will be of great benefit to the offshore wind sector.”
With a width of 120 cm, the A400 gangway is twice the width of earlier versions, has full motion compensation and the no movement gangway operates in a sea state of up to 3 m. A single operator is required to use the system, and all cargo and personnel can be transferred using the elevator.
The accompanying Cargo400 electric trolley transports equipment weighing up to 400 kg between a vessel and offshore structure. Featuring an easy loading design, the system can be manoeuvred by one person, is speed adjustable and includes an auto-brake.
Ampelmann has also recently unveiled a walk-to-work system designed for operation in extreme conditions. The N-type Ampelmann, nicknamed Icemann, is designed to transfer crew in extreme icing and temperatures as low as -28°C. The fully enclosed and insulated system can operate in sea states up to 3.5 m significant wave height.
Another new transfer system, the Safeway walk-to-work system, was demonstrated to industry last month and received excellent reviews. One of those present, Runar Vågnes, vice president sales and marketing at ship designer and builder Vard, said he believed that Safeway’s ‘free-float’ mode is a key selling point. This enables the access system to ‘float’ just above the entry point onto the platform without actually touching it. “Knowing how much documentation is asked of a shipowner to land on some oil and gas installations, I think this is definitely a feature many offshore operators will appreciate,” he said.
Another well known manufacturer, Osbit, told OSJ and OWJ that it continues to build on its track record for the delivery of innovative and reliable access systems in the offshore oil and gas and renewables markets, with the supply of its fourth crew-transfer solution, which will be employed on a new Chinese windfarm development.
The Northumberland, UK-based company is delivering an improved MaXccess T12 system to be installed on a 20 m crew transfer vessel, which is currently under construction by the Aurora Yachts shipyard in Dalian, China. The vessel will be deployed later this year by the State Power Investment Corporation (SPIC), which is one of China’s top five power suppliers, as part of its Binhai windfarm projects.
The T12 system will provide engineers with safe access to turbines and can operate in 2 m significant wave height conditions. It is part of Osbit’s growing range of active and passive modular access systems, with systems designed to support both catamaran hullform crew transfer vessels and larger service operation vessels (SOVs) and jack-up accommodation vessels. Another of Osbit’s offshore access solutions – a T18 MaXccess system – has been successfully operating at the Fukushima offshore windfarm in Japan for the past three years.
Ben Webster, sales and marketing manager at Osbit, said “We are seeing continuing demand for SOVs from the projects we’re involved in and, in some cases, a consolidation of resources where single vessels are being deployed to more than one offshore windfarm. This requires flexible access solutions with options such as variable height pedestals to enable operations in multiple locations and environments. We are also increasingly incorporating elevator systems within our MaXccess solutions to support the transfer of both crew and equipment at height.”
Uptime in Norway recently signed contracts for its 23.4m gangway with adjustable pedestal integrated into the elevator tower for personnel and cargo transfer. The company is also due to launch the new Uptime 30m active motion-compensated gangway.
The new gangway has what the company describes as “a totally new design” that it believes will be a “game changer” in the offshore oil and gas and offshore wind industries. It is being offered with several different setups: on a fixed pedestal, adjustable pedestal, with elevator tower amidships or in centre of vessel, as add-on system on existing elevator towers and on a skid.
“This gives optimal and customized workability for different projects,” said Uptime. The gangway will be operated from the wheelhouse wing or from the gangway itself. “Our Uptime 23.4m will still be offered and can of course still be the best option for some projects and setups,” the company concluded.