The FMGC cast iron shells are being put to the test at the Centrales Nantes SEM-REV offshore test site Photo: Centrales Nantes
The third round of offshore tests for a new type of subsea electrical cable ballast have been undertaken at a depth of 30 metres on the Centrale Nantes SEM-REV offshore test site.
The FMGC cast iron shells (IBOCS) aim to protect, stabilise and restrict the bend of subsea electrical cables, even under heavy swell conditions.
These tests are part of the FORESEA project (Interreg Europe funding), which aims to help bring Marine Renewable Energy (MRE) technologies to market by providing access to the North-European network of offshore test sites, which includes SEM-REV.
These tests will also provide comparative data since three sections of test cables – two equipped with shells of different linear density and the third completely bare – were installed alongside each other.
Through regular on-site measurements, current measurements and cable movements, the impact of the cast iron shells can be easily assessed. The FMGC and SEM-REV teams will observe how the shells bear up against factors, including resistance and corrosion, in order to gain unique feedback in an environment representative of offshore wind-farm conditions.
Innosea, a Centrale Nantes spin-off, worked with FMGC on shell design methods to calculate the optimal mass required to ensure cable stability on the sea floor.
FMGC previously equipped the Floatgen foundation – the first offshore wind turbine in France – with clump weights, which are attached to the anchor lines, providing stability to the floating structure.
It’s the third company to make use of the Centrale Nantes offshore test site, following on from NEREIS Environnement’s acoustic sensor and the Floatgen floating wind turbine – a European research project involving Ideol, Bouygues TP and Centrale Nantes.
By Anne-Marie Causer
Source: Maritime journal