The “Theseus” has become the first cargo ship in the latest series of new builds belonging to the Wessels Shipping Company of Haren/Ems to be equipped with SkySails propulsion. This towing-kite propulsion system is the first of the latest-generation SkySails-Systems, into whose development were channeled the many important lessons learned during pilot testing aboard the vessels “Beluga SkySails” owned by Beluga Shipping and Wessels’ own “Michael A.”

The “Theseus” is one of three new Rhine class ships being built for Wessels at the Komarno shipyard in Slovakia. The “Theseus” is the same type of ship as the “Michael A.” and is 90 meters long, has a capacity of some 3,700 dwt and a MaK main engine that produces 1,500 kW of power. A 160 m² SkySails propulsion system works to relieve the main engine of the “Theseus” the same way it does on board the “Michael A.”

Final installation and commissioning of the towing-kite propulsion system on the “Theseus” was completed in early August at SkySails’ manufacturing facilities in Wismar. The SkySails-System had previously been tested over a period of one and a half years aboard the 133-meter “Beluga SkySails” and the 90-meter “Michael A.”

“We’ve had some extremely promising results from pilot testing,” said Gerd Wessels, the managing partner of the Wessels Shipping Company based in Haren/Ems, “and with a good wind we achieved up to 8 tons of tractive force on the “Michael A.” using SkySails propulsion.” For comparison: The “Theseus” needs approximately 11 tons of thrust for full cruising speed.

SkySails propulsion has been integrated ideally into the ship’s operations; it required no major effort or expense to be installed onto the vessels. And, it has been proven that ships remain fully maneuverable while employing the SkySails-System. What’s more, trials have confirmed that present crew strengths are fully adequate for operating the system and that the operational concept works as intended.

The insights and experience gained by the shipping companies, crews and SkySails engineers during countless launches and recoveries while operating SkySails propulsion on board the ships were fed simultaneously into the SkySails product development effort. “The high seas taught us quite a few lessons,” remarked Stephan Wrage, the founder and managing director of SkySails, “and we were a long way off in terms of operating times during the first phase of pilot testing.” The Wessels Shipping Company summed the situation up by adding that, “The reasons for this can be found mostly in the limited launch opportunities during heavy seas and the degree of resilience and stamina exhibited by some of the components when exposed to harsh conditions at sea.”

SkySails’ solution was to rethink its system concept and develop what it calls the “SkySails Arrangement Module” (SAM), an integrated launch and recovery module in which all of the SkySails-System’s foredeck components (except the towing rope winch) are housed and protected from the force of the waves. This design led to a significant improvement in the system components’ endurance. The SAM also has a sea-state compensation feature that prevents the motions of the ship from being conveyed to the towing kite during the launch. This feature vastly improves the ability to launch the SkySails-System in rough seas.

First-hand use revealed a number of other important benefits that this module concept brings in its wake. Installation is now easier and faster since most of the system’s components can be assembled, mounted and tested right at the factory. Even operating the system has become simpler and easier for the crews. This module concept has shown itself to be so advantageous during practical testing that all ships will be equipped with it in the future.

As part of advanced product development, SkySails is working right now on perfecting system performance, and engineering the next larger SkySails propulsion system. Designated the SKS C 320, it will have an approximately 300 m² large towing kite and generate 16 tons of tractive force in good winds – and thus save twice as much fuel as an SKS C 160. Later this year the “Beluga SkySails” will become the first ship to be fitted with an SKS C 320, which of course also incorporates the new module concept.

SkySails is working full steam to expand production at the same time. In early 2009 SkySails, together with the renowned Zeppelin Group, established a joint venture company called “Zeppelin SkySails Sales & Service” to handle the worldwide sales and servicing of SkySails propulsion. The company started operations in March of this year and will use the existing service network of Zeppelin Power Systems, one of the most respected suppliers of marine engines, to ensure that all SkySails-Systems can be rapidly serviced and supplied with replacement parts across the globe.

Source: SkySails