Apr 17, 2017
Launched in 1851 the “Flying Cloud” was the fastest clipper ship under sail. Making the run from New York to San Francisco in 89 days 8 hours, she set the record as the fastest Packet ship afloat, a record which would stand for 100 years. In 1838 the SS Great Western became the first trans-Atlantic passenger liner to integrate steam with sail. By the mid 1800s the Peninsular and Oriental Steam Navigation Company (P&O) was challenging the idea of long distance sailing routes with service to and from the Far East. The age of the commercial steamship was born.
A New Twist in Sail Technology
Marine architects however remained fascinated with commercial wind propulsion through the early 20thcentury. In 1924 German engineer Anton Flettner combined cylindrical “sails” with a rotary turbine which not only produces power to the generators but also forward drive. The rotation of the cylinder creates a force known as the Magnus effect which is similar to the spin on a baseball. The resulting force pulls the ship ahead adding speed and motion. Recently this technology has been refined and incorporated into a modern design from Norsepower Corporation of Finland. Under favorable conditions the sail allows the vessel to maintain speed while reducing power to her main engines. The net effect is both a savings in fuel and a reduction of carbon emissions. Norsepower Rotor Sails incorporate computer sensors which continually monitor wind across the sail, adjusting them as needed. They can be installed on new builds or retrofitted to existing vessels. Offering a total solution to auxiliary propulsion, Norsepower provides delivery, installation, and maintenance of their rotors.
Maersk will test the technology
Last month AP Moller signed an agreement with Norsepower to retrofit one of their Long-Range Product Tankers with two 98’ tall, 16’ wide cylindrical rotors. Fitting out the 109,647-deadweight ton vessel will begin in Q-2-18 with sea trials to last through 2019. The project is being funded in part by the UK Institute of Energy Technologies, Maersk Tankers and Norsepower. Shell Oil will act as project coordinator overseeing operational aspects of the sea trials. Norsepower’s CEO Toumas Riski indicated that they anticipate a 7 to 10% savings in fuel per year which equates to about 1,000 tons.
Continued Fascination with Sail Power
Maersk is not the only company to test “new sail” technology. Viking Lines will fit out one of their cruise ferries, the 57 ton MS Viking Grace, with Norsepower rotors in the second half of 2018 as well. Prompted by growing concern for carbon emissions and renewed interest in sustainable technology, CE Delft’s maritime division recently released a report entitled,“Study on the Analysis of Market Potentials & Market Barriers for Wind Propulsion Technologies for Ships.”The report was commissioned by the European Directorate General for Climate Action. It looked at four types of wind propulsion systems: rigid sails, towing kites, rotors and wind turbines.
Introduced in 2007 by Skysails, Towing Kites presented an alternative power source capable of generating 5,000 kilowatts of power lowering fuel consumption by an average of 10 to 35%. The system requires launching and retrieval mechanisms and storage space for the kite. The technology was first tested on the MS Beluga Skysails, a small inter-coastal container ship. In 2013 the Ardmore Shipping Group began installing Skysail technology across its fleet of 17,500 to 50,000 dead weight ton product and chemical tankers.
When is a Sail not a “Sail” at all?
When we think of fixed sails, we visualize masts, spars and rigging. Indeed, there has been some consideration of fitting out container ships with modern masts and sails. The University of Southampton, for example, has been working in conjunction with B9 Shipping a division of B9 Energy Corp to test fixed sail technology for cargo ships. A project which began in 2012 is still in the “model” stage with no construction date in site for a working vessel.
But when is a sail not a sail? What if the ship’s hull was its fixed sail? Norwegian designer Terje Lade began looking at this alternative in 2015 when he proposed an ultra-high freeboard design which would act as a fixed sail. Sporting a liquefied natural gas engine, the sides of the “Vindskip” as it is called creates lift much like an airplane wing. The engine moves the ship from a dead stop so that wind against the hull can create thrust. The symmetrical hull allows wind off the port and starboard sides to create forward motion. Initial designs are modeled after ro/ro vessels which themselves have a high freeboard (amount of hull above the waterline). Lade claims his design can realize a 60% savings in fuel while reducing harmful emissions by 80 percent.
Blowing against the wind
The fascination in sustainable energy continues to fuel wind alternatives for marine power, some more fanciful than others. Towing Kites, for example, require deployment, retrieval and storage mechanisms, not essential to cargo stowage. Tests were conducted on vessels up to 50,000 DWTs. What size sail would be required for the Maersk Tanker mentioned above? “Super Hulls” such as the Vindskip require computers to find the most favorable winds as with sailing vessels of old. Their design seems more fitting for ro/ro cargo than containers. The Norsepower rotor can be mounted on any vessel configuration with nonessential space kept to a minimum and with no alteration of hull design. They seem practical but will the technology take hold on a large enough scale to make a difference?
Paul Simon wrote “who am I to blow against the wind”*. The same might be said of sail. Will wind power find its place in modern marine technology? Or are we just blowing against the wind?