TTI Marine Renewables

TTI Marine Renewables

TTI has brought its extensive fibre rope and mooring design expertise to the benefit of the marine renewables industry, that is, the evolving floating offshore wind and hydrokinetic (tidal, river and wave power) technologies.

Services offered typically cover the range from conceptual design through to detailed engineering of the mooring system and its components. We use state-of-the-art analysis software including TTI Optimoor, Ansys Aqwa and OrcaFlex to develop, refine and verify mooring system designs to meet client and certification authority requirements. We also conduct CAD/FEA analysis of mooring components and have recently completed as study for the UK's Carbon Trust to design a range of scaleable connectors. TTI also offers detailed procurement specifications for purchases by tender, prepares manufacturing drawings, and provides QA/QC support throughout manufacture.

Research

One of our recent research projects, also funded by the Carbon Trust and partners, measured fibre rope axial stiffness and fatigue properties to provide state-of-art property data enabling the correct specification of materials and thus model mooring loads with confidence. Current mooring systems typically use polyester ropes, well proven for the offshore oil and gas market in permanent moorings. These polyester ropes work well in renewable moorings but may be relatively high in cost due to increased rope length and mooring scope to keep loads reasonable.

The next generation of mooring systems will tend to use lower cost nylon ropes. This has not previously been possible for permanent moorings due to the shorter fatigue life of nylon in 'traditional rope constructions'. Now, with a modified rope design developed in conjunction with Bridon Ropes, and data from our research, this option offers much potential.

Tri plate connector

Scaleable in-line connector designs

Mooring line nylon lined trumpet fairlead

Mooring line tensioner and anchor

FEA analysis inline connector

FEA analysis rope spool

Wave energy concept mooring designs