In July, we put out an all points bulletin for Captain Nemo, Jules Verne's intrepid submariner, as we revealed Maris International's concept for a modular seabed drilling system. Hamburg engineer Hans Kühn responded.

The conquest of the deep proceeds apace, as we learned of the successful testing of an ultradeepwater power pack in Germany. Developed under the framework of the Thermie Program and supported by the Minister of Trade and Commerce of the City of Hamburg, the power pack was successfully tested recently, operating at full load under 500 Bar external water pressure for several hours. The test pressure is equivalent to that found at 16,400 ft (5,000 m) water depth.

Amazingly compact, the power pack module takes electrical energy and converts it to hydraulic power for use in driving any number of subsea tools or applications. The prototype was rated to 30 KW load capacity, but Kühn says that production models will be scalable. Potential applications include operating cutting tools to perform shearing, sawing or milling operations, driving piles, or other activities associated with seabed construction or abandonment. The power pack could also be used to energize a seabed seismic source say the inventors.

Scalable modules, configurable for almost any application, are elegant in their simplicity. They consist of a submersible electric motor, a hydraulic pump, a connecting adaptor and the pack body comprised of the hydraulic fluid reservoir tank. The tank provides structural integrity, thus eliminating the need for a bulky or expensive supporting frame. For larger demands, two or more power packs can be connected in series or in parallel. The result is a unit that is versatile, lightweight and easily configurable for specific applications.
Electrical power is supplied by an umbilical, leading to a highly efficient design. The mode of low-loss electrical energy transmission followed by a short-coupled hydraulic circuit is more energy efficient and economical. The short-coupled hydraulic circuit is less susceptible to leaks, and in any event the entire system requires only a few gallons of fluid which means less risk to the environment.

With the successful pressure/load test, the ultradeepwater power pack module has passed a major hurdle. The next logical step is to check out the unit after "cold soaking" it to typical deepwater seabed temperatures and checking IR drops using a real umbilical cable. Then start fielding calls from subsea equipment manufacturers looking for power to efficiently operate their gear. Admittedly an oversimplification, the point is that anything is possible where inventive minds are at work. As they say in Hamburg, "Ganz bestimmt!"

Thinking back to the modular seabed drilling unit, one can think of dozens of potential applications of a subsea power pack to operate robotics on board the seabed rig. In my original editorial, I (rather brashly) predicted that the industry should expect to see results, meaning successful development of a modular seabed drilling unit, shortly. The ultradeepwater power pack could be a huge step in helping to achieve this objective.

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