Glad to see this proposal.

I cannot find evidence of an EIR adequate to address the transitions that have occured in total, through out the closing of the Navy base through current heavy use, in Long Beach and Los Angeles. find area piecemeal reports that list only parts of the problems addressed, and no real sollution for the heavy haze of Small Particle Pollution, Smog and CO2 that affect all in California who live in areas where air is degraded by the ports, be they in Northern or Southern California.

The large two-stroke marine diesels in container ships are the most efficient of all internal engines, bar none. Peak thermodynamic efficiency is around 52%, so there's no room for significant improvement. Besides, what else are you going to do with the bunker oil coming out of the refineries? Note that its very hard (read: fuel-intensive) to remove sulfur from these heavy residues.

To get a sense of just how massive the main engine in a modern container ship is, look at the following video. The crankshaft directly drives the propeller, in this case at 86 RPM.

http://video.google.com/videoplay?docid=1858759987129849967

One way to improve on the status quo would be to leverage the waste heat streams over and above the usual register turbochargers. A secondary steam boiler and turbine or motor could increase overall thermodynamic efficiency, but these would take up a lot of valuable cargo space and add complexity - which invariably reduces reliability.

Refrigeration ships could use a secondary absorption chiller run off the coolant and/or exhaust heat. However, the porous membrane technology required to make these robust against vibrations and gross motion is still in development. Free-piston Vuilleumier machines are another option, but no-one has ever built one of the scale required. Again, complexity is an issue.

Cruise ships have such high hotel loads that they feature a series electric layout. The engine coolant heat may be used to heat passenger cabins and fresh water. The exhaust enthalpy can be used to produce fresh water on board by distillation. Thermally powered air conditioning and refrigeration would be attractive but for the technical hurdles (see above). Besides, total CO2 emissions from cruise ships are dwarfed by those from the world's container ship fleet.

An entirely different approach is to change the shape of the hull to reduce drag. Normally, a monohull will pitch ~3 degrees on average, i.e. the vessel is constantly trying to climb up its own bow wave. Redistributing buoyancy to level the pitch at cruise speeds is possible, e.g. by shaping the underwater portion of the bow like a traditional monohull and that of the stern like a catamaran, with a blended cross-section in-between. This shape can be used to reduce fuel consumption or, to support a high-speed marine cargo service that can reduce the need for air cargo, which consumes a lot more fuel per ton.

http://www.fastshipatlantic.com/innovativeshipdesign.html

Easy solution to this problem.

Buy American made products. It would curb Ocean going greenhouse gasses and reduce the trade defficit.

Even buying North American made products would help.

"Easy solution to this problem.

Buy American made products."

easy? ever tried to buy an American-made power supply, motherboard or just about anything electrical? they just don't exist. globalisation has evolved in tandem with cheap fossil fuels, which is how we got to the situation where it is cheaper to make something half a world away and ship it to markets in NA and EU.

All US submarines and aircraft carriers emit no CO2 from their propulsion systems. The military reactors used would not be cost effective for commmercial service however. The Russians operate a couple of nuclear powered ice breakers in addition to their naval vessels.

A nuclear powered merchant ship, Savanna, was a technical success but was not an economically optimized design back in the '60s. (It was more of a show boat and technology demonstrator than a real attempt at a profitable ship.) It was mothballed because it could not compete with oil based fuel at 20cents/gal.

"Adams Atomic Engine" and a similar Dutch proposal are pebble bed nuclear reactors intended for marine service which would be much more economic than military ones. They exist only on paper at this time.

The time may be ripe to prototype one or both of these engines.

I remember an article in Popular Science about new sail assist systems for commercial shipping. They tried some rigid sail systems in the early 80s. Under the right conditions they can supposedly cut fuel use by 30%.

Here's an example on PopSci's web site.

Other than the requirement to use low-sulphur diesel, the rest of this is a waste of taxpayer money. Ship owners are keanly aware of their fuel costs and do everything they can to improve the hydrodynamics and engine efficiencies.

This may be some kinda non-tarrif trade barrier ploy.

I heard a report about this on NPR today. Someone claimed that if the ships slowed down 20%, they could reduce fuel use by 50%. That sounds optimistic, IMHO. The shippers probably have a good idea of speed vs fuel consumption for their vessels, and have probably already calculated the most profitable speed. This is where a carbon tax would come in handy.

Rafael:

Sea water distillators using exhaust heat are standard feature on ocean going merchant vessels. Adsorption chillers are also quite widespread (for refrigeration and air conditioning). Not much heat is available from exhaust gases for steam boiler. First, it is already not very hot due to high efficiency of marine two-stroke and high air/fuel lambda (usually more than 2.5). Second, if exhaust gases are cooled to the dew point of sulfuric acid (there are a lot of sulfur in bunker fuel!), condensed sulfuric acid will eat the metal in no time.

As you said, not much efficiency gain is possible for marine vessels. And whatever is possible, is utilized quite agressively, because price of fuel constitute large portion of ton/mile tariff.

I remember a guy from Mærsk, the worlds largest container shipping firm, saying that a modern large container ship uses about 3-4 horsepower per container, whereas a truck uses roughly 300. So shipping is vastly superior in terms of efficiency when it comes to moving goods over long distances.

Ship owners are acutely aware of efficiency, since fuel cost is the single most important factor on the cost side. On the income side, higher speed means more turnover, which is why some container ships travel fast enough to waterski behind them (but don't fall in the water because it takes 2 hours for the ship to turn around ;-) ).

Regarding CO2 emission, the best bet would be to decrease speed and downsize the engine. However that's not always a good idea with existing ships, because the length of the hull, bow wave frequency and ship velocity are all tuned to each other to ensure high efficiency (destructive interference between bow and stern waves). So at certain speeds below design cruise speed, the fuel consumption is actually higher.

Mega container freighters and tankers have are being built and ordered at a frantic pace for the past several years, so we might see a period of supply surplus, in which case freight rates will fall and shipping firms may profit from lowering the cruise speed. However, with world production located in Asia and consumption in USA and Europe, long-distance transport of goods can only be seen to sky-rocket, and shipping related CO2 emissions will follow. Only a global recession or serious political intervention can stop this megatrend.

Regarding sulpur emission, the best way to go would be scrubbing the exhaust gas. I heard a guy from Statoil (large Norwegian oil company) say that it costs the same amount of money to remove sulphur from bunker oil as turning the bunker oil (heavy fuel oil) into diesel and petcoke, where the latter option turns out a much higher profit. Therefore, he did not see any significant supply of low-sulphur fuel oil available for ships. This means that shipowners are left with a choice of using diesel in coastal waters or installing scrubbers to remove the sulpur.

Bill:

Thanks for mentioning our engine.

For the rest of you, this is a very interesting and technically astute discussion about the natural limitations of large diesel engines. As Rafael pointed out, the only real changes that are available for marine diesel propulsion yield only marginal improvements. The diesel is a great machine, but it is nearing the asymptote of its technological curve.

If you want zero emissions, high speed, and large vessels, you should consider what ice breakers, submarines and aircraft carriers can accomplish with their uranium fueled engines. The most recent class of submarines, for example, is designed to operate for a full, 30-year lifetime without new fuel.

Of course, those specialty ships with their low production rate engines are extremely expensive, but that is where other developers come in. The technology of capturing fission heat is well developed and proven, but the refinement of that technology for a commercially viable machine is still in its infancy.

As Clay Christensen might say, atomic ship propulsion is at the beginning of its s-curve defined climb. The long flat portion of basic knowledge acquisition is nearly complete, what is now ahead is the steep increase in the number of applications that can be served as the technology is refined, the production rates increased, and the knowledge disseminated to a much wider base of developers.

Rod Adams
Adams Atomic Engines, Inc.

@ Rod Adams -

afaik, several US and Russian nuclear submarines are rusting away at the bottom of the sea. The US even tried and failed to raise one with the Glomar Challenger in 1968. Another wreck in the North Atlantic is reportedly slowly leaking plutonium.

If nuclear propulsion technology were applied to commercial container ships, they would instantly become a prime target for terrorists.

Finally, the vexed issue of the long-term storage of nuclear waste remains unsolved. In a nuclear power plant, you can at least buy yourself time by keeping it in a holding tank for a few decades and securing the perimeter of the facility. That wouldn't be possible for marine applications.

Rafael,
I agree nuclear powered commercial shipping would not be feasible because of the threat of terrorism.

However the US Navy has been safely removing nuclear power plants from ships and submarines for over a couple decades now.
http://www.oregon.gov/ENERGY/NUCSAF/subfact.shtml

@ gary -

I don't doubt that with sufficiently careful handling, the risk of an accident involving nuclear waste in transit can be minimized. This applies especially to spent reactor components, which are less hazardous than spent fuel rods.

However, just because there is a process in place does not mean it is safe. Dumping radiactive materials into an open pit out of sight or else, at the bottom of the sea (as was one in the past), doesn't strike me as an acceptable solution for the long term. Radioactive waste remains dangerous for many millenia, far longer than the typical lifespan of most human stuctures - or human civilizations, for that matter.

From the page you refer to:

"Since 1986, the U.S. Navy has disposed of reactor compartments from deactivated nuclear-powered submarines at the Hanford Site in Washington state.

[...]

The Hanford Site occupies 586 square miles of south central Washington desert. The reactor compartments are placed in a large open pit in the 200 East area of the Site, which is on a plateau about seven miles from the Columbia River. Eventually, the pit will be covered with dirt.

Through September 2007, 117 reactor compartments have been taken to Hanford. On average, between six and eight shipments had been made each year; however, in recent years, that has dropped to only one or two each year, with no shipments in 2005, one in 2006 and two in 2007.

The reactor compartments are classified as low-level radioactive waste. They do not contain loose radioactivity or contaminated fluids and their exteriors are not contaminated. The iron and metal alloys within the reactor vessel have become radioactive after years of reactor operations.

Before deciding on Hanford as its disposal site, the Navy considered other U.S. Department of Energy sites. The Navy also considered disposing of the compartments by sinking them in the ocean. After evaluating the costs and environmental impacts of both ocean disposal and land burial, the Navy determined that land burial at Hanford was the preferred option."

Rafael,

The US has lost 2 nuclear powered subs (May God have mercy on the souls aboard the Thresher and the Scorpion). Neither boat was lost because of the propulsion system. From what I understand, neither sub is a source of sea water contamination.

Obsolete US nuclear vessels are defueled and the fuel stored in a manner similar to used commercial fuel.

The pressure vessel and other structurals which have become radioactive from neutron radiation are buried as low level waste. Induced radiation such as this material is relatively short lived. I believe the same fate has been visited upon the pressure vessels from dismantled commercial nuclear plants.

I do not believe that the US has ever disposed of used fuel or radioactive components at sea. (Unfortunately some process waste used to be dumped.) The Soviet/Russians have been more cavalier with their waste.

Naval used nuclear fuel is no more (and no less) a disposal problem than commercial nuclear fuel except that it contains almost no plutonium or other transuranics. Presumably, commercial marine fuel would be low enriched and would contain transuranics equivalent to commercial power fuel.

Ultimately a high level waste repository will be necessary. It may or may not be Yucca mountain. Other than politically, the need is not urgent. It would be best if the high level repository were limited to fission fragments because of recycling but this is not imperative.

Bill

"From what I understand, neither sub is a source of sea water contamination."

I sure hope you're right. If the US has to make nuclear subs for strategic reasons, it's imperative we make every effort in the design to make them as recoverable as possible, and as leak and rot and even dynamite resistant as possible, ready for a thousand years in salt water. We really should spare no expense in that direction, and we should make active attempts to survey and recover or embed/sequester these things when they sink.

Using nuclear in civilian energy when there are safer alternatives though just doesn't ring true with me. Wind, wave and solar power just don't have these risks. They just don't.

Anonymous (whoever posted at 9:01 AM on October 5)

If I am not mistaken, this thread is about ship propulsion systems. There is zero feasibility for propelling large, high speed trading vessels on the world's oceans using wind, wave, or solar power.

With regard to sunken reactors - water is a wonderful radiation shield. Just a couple of feet are enough to provide protection against the high intensity emissions from an operating nuclear reactor. There is no chance that anyone will ever be harmed by radiation emitting from the left overs from propulsion reactors that were on board the sunken submarines.

Rafael - all ships carrying high value cargo are potential terrorist targets. So are the multitude of ships that carry dangerous industrial chemicals, petroleum, and LNG. Since reactors need a strong, solid containment structure they are less vulnerable than you might imagine - they essentially operate inside a vault with only electronic monitoring devices. It is pretty simple to design them to be fail safe. The ship might be taken over by pirates, but the reactor will not be a danger to people.

When it comes to waste, I strongly prefer a system where the waste material is so small that it can be completely contained, monitored and inventoried. On the submarine that I used to operate, the active portion of the core could fit easily inside my spare bedroom - including all of the required shielding. That core powered a 9000 ton submarine for more than 15 years. When it was finished, it was stored in monitored storage.

A couple of decades ago, it would have been recycled, but the Clinton Administration closed the plant in Idaho where naval fuel was recycled. According to Hazel O'Leary (a former natural gas marketing executive) we had plenty of enriched uranium and we no longer needed to recycle. I generally fail to understand the logic of people who advocate taking the time to collect aluminum cans for recycling but press the rest of us to consider highly energetic material like uranium to be waste.

I understand the anti-nuclear industry a bit better if I remember that some of those people like selling fossil fuels - it is a pretty profitable business that is threatened by allowing nuclear power to flourish. When money can be gained, people can make decisions that appear to be quite illogical.

I wonder what would be the cost in money and energy to scrub the exhaust gasses with seawater. It wouldn't take out a lot of CO2, but it could easily scrub out most of the sulfur oxides and most of the soot.
could it be as simple as spraying seawater in the chimney.

Anonymous,

The fuel in the sunken reactors is sealed inside a very corrosion resistant zirconium alloy. If the fuel was not mechanically damaged in the sinking, the probability of leakage years later is pretty low.

Naval reactors are extrordinarily robust. A Los Angeles class nuclear sub (NSS San Francisco) ran into an uncharted sea mount (underwater mountain) while running at full speed about 2 years ago. About half the crew was injured and one was killed in the collision. The reactor never missed a beat. It brought the boat back to port without assistance. It was checked later in dry dock and was undamaged.

Get them to use bio diesel and they become CO2 neutral.