Should Ships Slow Down, Go Back to Sails, or Use Nuclear Fission?

There was a time when commercial shipping was an emissions free transportation mode that required little or no fuel. Inventors, craftsmen, and engineers all worked to refine the hulls, sails and control systems and skilled people spent their entire careers figuring out weather patterns, determining efficient loading schemes, and recognizing opportunities for transporting goods with a long shelf life. When things went well, owning sailing ships was a lucrative investment.

Of course, there were some limitations of that technology that encouraged a number of very smart, number crunching businessmen and engineers to look for a better way. Sailing ship limitations included time consuming voyages, space and weight constraints, inability to maintain a schedule, dependence on poorly paid or forced labor, vulnerability to numerous natural hazards, and a high mortality rate caused by lack of good nutrition and clean water.

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In May, 1918, Captain Moses Roberts, Steven Vail and some unnamed investors formed a company called the Savannah Steam Ship Company and began the work necessary to build a ship that could cross the oceans using coal and wood heat to create steam power to assist the sails. S. S. Savannah made a successful two way crossing but was a financial failure. Sailing ships continued to dominate the seas, but engineers kept improving coal and wood heated steam engines for railroads and inland river travel.

Within twenty-five years after Savannah’s initial voyage steam ships began crossing the Atlantic regularly and within seventy years steam essentially replaced sails in commerce. I can testify that sails have never disappeared - I live in one of the world’s most sail addicted towns - but anyone who has ever operated both sail and power vessels understands that as a business vessel, a sailboat is a great hobby.

Not surprisingly, when fuel prices increase rapidly, people focus their attention on ways to save money on fuel purchases. They seek to reduce their specific fuel consumption and to find cheaper sources of fuel. Both can require trade offs.

One of the easiest ways to reduce consumption is to slow down, but slowing down reduces productivity. I know that some environmentally minded people might scoff and say, “so what”, but if all of the ships on the ocean slowed down by 10%, we would need 10% more ships to carry the same quantity of goods. Each of those ships would require materials and energy to build, they would be a bit less profitable and some of the owners might be tempted to find other ways to save money, like buying cheaper fuel.

With the large engines used on ships, there are often a variety of available fuel options at different price points, but the lower priced fuel often comes with some real environmental baggage. There has been a lot of attention paid - finally - to the fact that ocean going ships are prodigious sources of sulfur emissions and other noxious pollutants since they often burn the dregs left over from refining - a fuel known as residual fuel. Based on studies that made a big splash at the end of 2007, ship emissions are now considered to the source of about 60,000 early deaths every year.

A friend of mine pointed me to a post on Treehugger.com titled Slower Shipping Could Reduce GHG Impact that discussed additional options for reducing fuel cost and environmental impact. In addition to slower speeds, the post and associated comments mention schemes that add sails to assist in propulsion. When fuel prices are high enough, such schemes can provide a positive return on investment by cutting several percentage points of off some large fuel bills. (An ocean going ship with a 70 MW power plant would burn about 90,000 gallons of fuel every day. When marine diesel fuel costs $5 per gallon, a 5% fuel savings is worth $22,500 per day.)

My recommendation is different. Let’s get rid of all of the emissions, switch to a fuel that costs about 2% of the cost per unit heat (50 cents per million BTU versus $25 per million BTU) as marine diesel fuel, and increase shipping speed so that ocean going ships can more readily compete with aircraft for time sensitive shipments. It is possible to achieve that amazing feat using technology that has been in use for more than 50 years, all we have to do is to follow the example of another pioneering financial failure named Savannah.

Nuclear powered ships are well proven, there are tens of thousands of people around the world who know how to operate, build and maintain them, and they offer capabilities that the world needs today. Because nuclear ship propulsion plants would be much smaller than the commercial nuclear power plants that are currently either under construction or being planned, they would not necessarily have to wait in the same supply chain lines for large components.

There was a time (1962-1972) when the United States produced about 100 ocean going nuclear plants in just a decade; such an industrial effort today would yield great benefits. Just think about all of the emissions that would not be released and all of the oil that would no longer be burned at sea. The effect on the market price for the rest of us would be the same as finding a new deposit capable of expanding production to about 5-8 million barrels of oil per day. That is at least 2-3 times as large as ANWAR.

Update posted June 20, 2008: A couple of days after posting this, Joe Stroud contacted me to share an updated photo of the N.S. Savannah that was taken in Baltimore, Maryland on May 23, 2008. The date was 50 years to the day after her keel was laid in 1958. Until last year, Savannah had been slowly deteriorating in the James River Fleet, but the Maritime Administration has invested some money to stabilize and repaint her. Though her reactor has not operated for more than 30 years, she is still a pretty ship.

Photo credits: Schooner under full sail and Annapolis Sailboat Show from Rod Adams under Creative Commons.
N. S. Savannah under power from US Government archives.
Savannah moored in Baltimore, MD on May 23, 2008 with permission from Joe Stroud.

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