Damen Shipyards presents a new shipping concept to the market, the Damen Offshore Carrier (DOC) 7500, specifically designed as a smaller heavy transport, offshore installation and ro-ro platform suitable for multiple markets. The DOC aims to provide flexibility and year-round utilisation.
Damen developed the new vessel in cooperation with Singapore based heavy lift transport specialist Hans van Mameren, managing director of Ha-Ce Engineering Pte Ltd. The DOC has an endurance of 65 days, a large, flat and unobstructed deck of 2300 m², a deck strength of 20 t/m² and is fuel-efficient.
Open Deck for Medium and Long Distances
Remko Bouma, Sales Manager of Damen Shipyards Bergum, says: ‘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 with the demands of today’s market. I think this vessel will be "the" alternative for the more time consuming tug and barge transportations.’
Higher Sea States
The DOC is able to handle higher sea states, whilst maintaining course and speed and, by that, being more economical and reliable. The vessel can also run on HFO380. ‘Tug-barge combinations are not able to cope with challenging seas so easily. Deviation from course and reduced speeds can have great impact on the schedule,’ says Bouma. The DOC is better able to maintain course and speed, typically averaging 10-12 knots, where a tug and barge would average only 5-7 knots.
Sleek Bow and Slender Hull
Damen’s R&D Department’s extensive model test programs show that the vessel reduces fuel consumption by 50-75 per cent compared to a tug-barge combination. In the design process particular attention was paid to the bow and hull form. The new distinctive, sleek bow and slender hull enables the vessel to sustain its speed and course in head seas, as well as helping to reduce fuel consumption. The bow design diminishes accelerations and reduces slamming to a very low level, improving comfort and safety for the vessel, crew and cargo.
Multifunctional
A multifunctional ability was a key part of the design. It had to be able to find deployment in several markets, hence its suitability for shore-to-(off)shore transport, ro-ro operations and installation work. The large unobstructed deck is free of any manholes, exhaust and de-aeration pipes. Ro-ro operations are unobstructed and modules can be stowed and secured everywhere on deck. The vessel also has an efficient ballast system and can handle ro-ro over the stern and sides.
DP2
The DOC is equipped with DP2, which makes it stable for safe offshore loading/unloading operations. DP3 can also be implemented. The vessel is suited for a replenishment role and could be used for bunkering fuel and other consumables to vessels/installations working in the field as well as for crew exchanges. The DOC can comfortably accommodate thirty people, which can be expanded when in installation mode.
Transport and Installation
The offshore wind and tidal energy markets are other focus areas. The DOC can be used in a feedering solution for offshore wind farms, transporting nacelles, transition pieces and monopiles. Its 2300 m² platform with 20 t/m² load capacity can be used for a wide variety of offshore installation work such as cable laying, subsea installation, reel laying, floatover installation and other methods. For these purposes the vessel can be outfitted with all necessary installation equipment. This can be either a modular solution at a particular stage in the vessel’s operational life or an integral solution part of the initial shipbuilding process.
Submersible
The DOC can also be built as a semi-submersible vessel, equipped with buoyancy casings. Additionally, it can be fitted with a Damen Deep Dredge giving owners a deepsea dredging and mining solution up to 200 m water depth.
Ship Particulars
Currently, the DOC is 27.5 m wide. Already Damen is considering a larger version of 32.5 m wide. The vessel has a Green Passport and a Zero Dumping certification and the fuel tanks are protected with cofferdams. The first DOC 7500 can be delivered in 2014.
