H Nordic maritime turbines mount to the vessel's existing deck structure using bolted connections. The ~800 kg unit weight imposes structural loads well within the capacity of most commercial vessel deck structures. A structural assessment confirms load compatibility at each mounting position before installation proceeds.
Each turbine base is bolted to the deck using a flanged mounting plate. The mounting plate distributes the load across multiple bolt positions, spreading the static and dynamic forces across a section of deck plating and the underlying structural members.
Bolted connections are preferred over welded connections for several practical reasons. They allow the turbine to be removed if the vessel changes service or if the operator wishes to transfer units to another vessel. They are reversible -- leaving the vessel's structure intact if the installation is ever decommissioned. And they do not require hot-work permits or the safety procedures associated with welding in confined or potentially hazardous areas.
The mounting structure must resist two types of load: the static weight of the turbine and the dynamic loads generated by vessel motion and wind forces.
Static load. At ~800 kg per unit, the static load is modest. A single 20-foot shipping container weighs approximately 2,200 kg empty and 24,000 kg fully loaded. Deck structures designed for cargo are substantially over-specified for turbine mounting loads.
Dynamic loads. At sea, the vessel pitches, rolls, and heaves. This imposes additional acceleration forces on the turbine and its mounting -- the turbine mass is effectively multiplied by the vessel's motion. The structural assessment calculates these forces using standard naval architecture methods, taking the vessel's motion characteristics and the turbine position into account.
Wind loading at the turbine position is also calculated -- the rotor generates reaction forces in the mounting structure as well as electrical output, and the mounting must resist these forces in the worst-case wind and vessel motion combination.
The structural assessment is conducted for each vessel as part of the delivery scope. It covers:
The assessment is carried out to the standards applicable to the vessel's flag state and class society. H Nordic works with the vessel's classification society to obtain any approvals required for the modification.
On most commercial vessels with deck structures designed for cargo or equipment loads, no structural reinforcement is required for H Nordic turbine installations. The load profile is well within normal deck capacity.
Reinforcement may be required in two circumstances: where a turbine position falls on a section of deck that is locally thinner than the surrounding structure -- typically an access hatch or a section with existing damage -- or where a vessel has unusual motion characteristics that produce very high dynamic loads.
These are identified in the structural assessment and resolved before installation proceeds.
See also: Does installation require drydock? · Compatible vessel types
Tell us your vessel type and we will outline the mounting approach and structural requirements for your specific deck.
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