Damen shipyards designs heavy-lift carrier13 September 2012 by Cristina Brooks
Damen Shipyards Group introduced a design for its Damen Offshore Carrier 7500 (DOC), which may be used with a heavy-lift crane.
Damen Shipyards developed the new vessel in cooperation with Singapore based heavy lift transport specialist Hans van Mameren, managing director of Ha-Ce Engineering.
It was designed to replace tug and barge transport systems carrying smaller heavy modules on deck over medium and long distances, offering an alternative that is faster and sustains higher sea states.
A heavy lift crane manufacturer for the new carrier design is yet to be announced, says Damen.
"We haven't got a particular preference for a crane type or manufacturer.
"It can be a 250-400 t offshore crane, but it could be much bigger."
The DOC can offload cargo either with its own crane or with the crane of a nearby vessel.
Damen Shipyards said it could mount a bargemaster on the deck so that heave compensation would become much easier.
During a cargo lift to another vessel, the deck cargo on the DOC would stay in relation to the supporting vessel.
Damen Shipyards said that the new DOC is multi-purpose with flexible applications in shipping and offshore, loading for a transport voyage or feedering purposes, or providing offshore installation or support.
This includes transporting and installing offshore wind turbine parts such as monopiles.
Damen said the DOC has an endurance of 65 days, a large, flat and unobstructed 2,300sq m deck, a deck strength of 20t per sq m.
Remko Bouma, sales manager of Damen Shipyards Bergum, said, "When we decided to realise a new design together, we wanted to create a vessel that was able to carry modules and cargo on an open deck over medium and long distances, complying the demands of today's market.
"I think this vessel will be 'the' alternative for the more time consuming tug and barge transportations.
"Tug-barge combinations are not able to cope with the challenging seas so easily. Deviation from course and reduced speeds can have great impact on the schedule.
"Therefore, Damen set out to find an alternative. The DOC offers much lower fuel cost and is better able to maintain course and speed, typically averaging 10-12 knots, where a tug and barge would average only 5-7 knots."