Submersible tethered platform for undersea electrical power generation

The method of delivering and retrieving devices that convert the kinetic energy of sub-surface aquatic current into a transmissible or transportable form of energy, between an accessible position at or above the water surface and an operational depth and angular position within the water column, by means of a submersible payload-bearing platform, comprising the steps of:

• (a) engaging of pre-positioned mooring lines to said platform's winch assemblies while said platform is at surface, said mooring lines having their upper ends retained at surface by buoyant structures;
• (b) lowering of the platform by means of i) decreasing buoyancy via an on-board ballast control system and ii) the simultaneous mechanical action of said winch assemblies upon said mooring lines;
• (c) remote commanding of the platform to a preferred operational depth and angular attitude ranging from horizontal to vertical;
• (d) operating and monitoring of said platform, while at depth, by a remote facility;
• (e) operating and monitoring of said energy-conversion devices, while at depth, by a remote facility;
• (f) ascending of said platform and its payload of energy-conversion devices in a manner substantially in the reverse of the above, for maintenance, equipment upgrades, or avoidance of adverse environmental conditions;
• (g) surface disengagement of said mooring lines from said winch assemblies in the event that transport to another location is necessitated by operational, environmental or servicing requirements.

The method of emergency surfacing of a submersible, variably-buoyant and engageably-tethered platform assembly equipped with devices that convert the kinetic energy of submarine aquatic current into a transmissible or transportable form of energy, comprising:

• (a) passively and statically displacing volumes being incorporated into the platform assembly, such volumes assisting the elevation of said platform assembly from a submarine depth to a position near the surface, regardless of other sub-system functionalities;
• (b) the said platform assembly having been engageably-tethered by means of a plurality of winch assemblies mechanically engaged with associated mooring lines;
• (c) the release of such mooring lines from said winch assemblies being accomplished by hydraulic valve actuation, allowing the drum or drums of said winch assemblies to freely rotate, though at a speed controlled by flow-limiting valves of the hydraulic circuit;
• (d) a supply of stored electrical energy for the energizing of critical components on-board the platform, such that certain control sub-systems, valve operators, communications sub-systems, sensors, and other components designated as critical to an emergency surfacing operation may be remotely commanded and energized regardless of the presence of normal power sources;
• (e) an on-board supply of stored and pressurized air that displaces certain variably-displaceable volumes of the platform to promote its overall buoyancy.