The shipping industry continues to point out that moving freight by cargo ship is the most energy-efficient means of transporting cargo, vastly superior to trucking or rail on a ton-per-mile basis.
But the industry also realizes that changes are coming. The International Association of Independent Tanker Owners, which represents about 70 percent of independent tanker owners, and the Pacific Merchant Shipping Association favor ending the use of bunker fuel (see story, left), which emits a high level of toxic contaminants. Ships would switch to marine diesel oil (MDO), a fuel similar to that used by many trucks, buses, and cars. The cost of MDO, however, is currently about twice that of bunker fuel.
"A lot of companies have already embraced this [changeover to MDO]," says T.L. Garrett, vice president of the Pacific Merchant Shipping Association in San Francisco. "It is a public health issue. The industry is sensitive to that."
All that shipowners ask is for one consistent international standard for emissions that would apply worldwide – a "level playing field," Mr. Garrett says. Currently, ports in California, Canada, and Europe have tried to set their own emissions limits, essentially banning bunker fuel, because the IMO has been seen as moving too slowly.
Any increase in the fuel economy of ships would also cut emissions, so companies now have two motivations for trying new techniques.
Innovative propulsion – through bubbles and ballast tanks