Installation and Removal

Tow-out

The advantage of buoyant designs is that they can be floated into place, removing the need for craneage and barges which are impractical in the tidal flows found in waters such as the Pentland Firth. With the Triton platform no cranes, barges, jack-up rigs or divers are required for any part of the operation - only a workboat with moderate lift capabilities.

A workboat tows a Triton into position into the prevailing current

For transportation, the swinging arm of the platform is stowed between the main spar buoys so that the turbine can be towed into position with minimum draft. The spar buoys comprising the main body of the TidalStream platform are at full buoyancy for float-out. The gravity base in the images below has been pre-installed on the seabed and is marked by a guide wire and buoy.

The Deployment Sequence

The base has been pre-installed with electrical cables in place. This base is either a piled structure or, if as in the Pentland Firth the seabed is too rocky to allow this, a gravity base consisting of a flooded concrete caisson - as shown below - or a tray that is filled with rock ballast once in position. The base is equipped with a guide wire and stabbing pin to accept the swivel ring at the end of the SST swinging arm.

Removal is simply a reversal of the above procedure with ballast water being pumped out of the spar buoys

The gravity base is sunk into position with a guide wire marker.

The SST is brought into position over the base

Initial installation

The swinging arm is lowered down the guide wire and electrical cabling (not shown)

The  swinging arm is locked and the cable connections made. The platform is now in its maintenance position

Transition to operation

For the turbines to assume their operating position, water ballast is admitted into the main spar buoy causing it to sink down in the water

As the ballast water is added the SST continues to settle rolling around to the upright operating position

The platform completes its transition and is ready for operation. Note: the spars never actually touch the seabed

TidalStream TRITON

The enabling technology for tidal turbine deployment

Provides the most cost effective and  efficient turbine deployment system

Up to 10MW from a single installation

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