Tidal stream energy is the most predictable source of renewable energy (Neill & Hashemi, 2018) and has not been deployed in large arrays to achieve economies of scale. Different energy extraction devices are currently under development; however, the horizontal axis tidal stream turbine will be the focus of this research. Energy extracted from a 4.5 m/s moving water can be the same as a 40 m/s wind turbine for a turbine of similar dimensions (Alternative Energy Tutorials, 2020). The levelized cost of energy for tidal stream turbines are very design-dependent, since most of the companies developing these turbines have unique designs, and a standardised tidal stream turbine design has yet to evolve. First strike prices are expected to be under £200/MWh (Milne, 2020), as first offshore wind strike prices shared that upper limit when they were first introduced in 2014. To do so, reliability must be improved, and the structure needs to withstand the stresses throughout the desired lifespan of these devices