QinetiQ GRC have completed the initial sizing model of the Subhub and Turbine Module using their Paramarine software. It has concluded that both the Subhub main hull and Turbine Module would pass IMO and MCA stability standards. These results surpass all expectations at this stage of the development and provides a high level of confidence in forging ahead with the feasibility study. The next stage will review the dynamics and motion characteristics of the Subhub and Turbine Module which will explore the safe operating limits of these large marine structures to realistic environmental loads.
Below is the initial stability for the Subhub in its deployment role which includes the Turbine Module. It has a massive initial stability and peaks at approximately 15 degrees and remains positively stable until 80 degree heel angle.
To provide some feeling of how stable this platform is, below, is a picture of the GZ curve including heel angles that have been imposed from 100 knot gusts. It uses a tiny fraction of its 8.0 m GZ righting arm at just over 0.1 metre. This also suggests that it performs equally well on the seabed under turbulent tidal stream conditions.
Pictured below is the Turbin Module floating on both the light ship and with the main hull section flooded. This is the condition used for the maintenance and swop over of modules and are the waterlines used to tow it back to port.
The picture below shows the Turbine Module after it has been disconnected from the Subhub platform which remains firmly anchored to the seabed with over 1000 tons of ballast holding it in position.
Below is the initial stability assessment of the Turbine Module with all the tanks full and shows that it is very stable at the surface in this condition and capable of supporting more intrusive operations on the turbines generator or electrical conditioning equipment or towed back to port.