Vestdavit mission accomplished on Ramform safety
Seatrials are underway in Japan involving Ramform Hyperion, the last of four ships built to the seismic sector’s all-time highest specifications, completing a project that shows the way distinctive design also demands innovation from the equipment keeping ships safely in service.
Reckoned to be the widest monohulls at the waterline ever built, the Petroleum Geo-Services (PGS) vessels need a unique Vestdavit dual point boat handling solution to lift and lower tender boats in wave heights up to sea state 6. The boats work as Fast Rescue Craft with six crew, as tenders with 20 persons on board and as lifeboats with capacity for 40.
Ramform Hyperion, under delivery by Mitsubishi Heavy Industries, features a distinctive ‘5th generation’ hull form that is 104m in length and an extraordinary 70m across the beam, designed to deploy ultra-wide streamer tows aft. As a result, it has only a short, flat parallel ship side for tender boat launching and retrieval, necessitating a 12m outreach painter boom - the largest ever from Vestdavit or any other supplier.
“A standard davit solution was not compatible with the design of the ship itself; to work, it would be necessary for the vessel itself to be longer,” says Atle Kalve, Development Director, Vestdavit. “Involvement at an early stage of vessel design led us to a one-of-a-kind solution for workboat/lifeboat/FRC davit operations. From the outset, we also knew that davits used daily by ships expected to work two years at sea without interruption meant that no equipment downtime would be acceptable.”
Like its predecessors, Ramform Hyperion is fitted with two Vestdavit H – 10000S dual point hydraulic davits, one on each side, with a dual winch system specifically developed for the application. Both the boom and the davits are computer-controlled and feature in-built auto tension and shock absorption optimising safety and crew comfort on launch and recovery in high seas. A 200 tonne Vestdavit shock absorber system takes peak loads out of the paravane doors during seismic operations to prevent the holding ropes from snapping.
“From the pure equipment point of view, we have delivered a motion compensating, multi-davit solution featuring dual winches, shock absorbers and synchronous lifting and lowering,” says Kalve. “From the user’s point of view, what sets the Vestdavit H – 1000S solution apart is its self-levelling capability, without which it would not be possible to handle this extraordinary ship type’s boats in such high sea states.
“Our primary concern is always safety, but davits are also integral to everyday efficiency on these ships. We are handling expensive equipment and we need to eliminate shocks to make the process of deployment and recovery as smooth and efficient as possible.”