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PostPosted: Sep 03, 2011 1:38 pm 
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Perhaps a Naval Corp of Engineers for staffing these submersible power plants?


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PostPosted: Oct 26, 2011 3:10 pm 
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The U.S.S. Savannah was pretty well accepted, and it was a nuclear cargo ship.


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PostPosted: Oct 26, 2011 4:17 pm 
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Yes, but you could reasonably argue that the world was different place then and as nice and beautiful as she was, I don't think that the N.S. Savannah or a modern equivalent would receive general public acceptance today. Collectively we know that things can and do go wrong with nuclear power plants, I think that in the court of public opinion it would be very hard to get past that for a commercial go anywhere cargo ship. Sadly.


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PostPosted: Oct 29, 2011 5:15 am 
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Lindsay wrote:
Yes, but you could reasonably argue that the world was different place then and as nice and beautiful as she was, I don't think that the N.S. Savannah or a modern equivalent would receive general public acceptance today. Collectively we know that things can and do go wrong with nuclear power plants, I think that in the court of public opinion it would be very hard to get past that for a commercial go anywhere cargo ship. Sadly.


There was also an economics problem with the Savannah. It didn't carry that much cargo to be worth it. More cargo would be needed especially in today's market with bigger and bigger ships, which means a bigger reactor that would cost a dear penny. If you look at the cost of the small modular reactors that may be applicable such as NuScale, they add substantially to the cost of the ship and would only make sense with sustained very high oil prices - maybe 200 dollars a barrel sustained over years could push the economic incentive to the right area.


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PostPosted: Nov 09, 2011 3:55 pm 
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Actually, when Savannah retired, oil was $3/Bbl. Now it's >$80. I think we're already well into the nuclear zone, myself.


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PostPosted: Feb 21, 2012 12:22 am 
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There has been resistance to and agitations against nuclear power generally wholly unjustified. Latest problems are of course caused by earthquake and tsunami causing irreparable damage to three reactors at Fukushima in Japan. I have made a suggestion to Indian DAE that I want to repeat here.
Create a standardized design of a floating medium size power plant. It can be built in a shipyard where such problems are not there or have been managed. One or two can be kept ready to meet emergency requirements or as a flexible part of power infrastructure of a big coastal city.
When there is a requirement, the plant is towed to the required location within a few weeks. Once used to new or added power, the need and convenient fulfillment will overpower any resistance.
Small plants could be similarly placed on trailers for road or rail transport and unloaded when or where required.


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PostPosted: Apr 16, 2012 1:31 pm 
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Wikipedia has some entries of interest:


http://en.wikipedia.org/wiki/List_of_ci ... lear_ships

http://en.wikipedia.org/wiki/Otto_Hahn_%28ship%29

This one is still operating:

http://en.wikipedia.org/wiki/Sevmorput

Cost of these things is really high. Sevmorput, $260 million for 11468 net tonnage.

That's $22671/net ton of capacity.

Compare this to the Emma Maersk, 55396 net tonnage,

http://en.wikipedia.org/wiki/Emma_maersk

Costs $190 million IIRC. $3430/net ton of capacity. 6 or 7 times cheaper than the nuclear alternative...

Concluding, oil was too cheap and the nuclear vessels were built too small. Today, if you built them big, with today's oil prices, it should already be highly economical. Though realistically you'd be competing against a natural gas fuelled vessel alternative as well.


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PostPosted: Apr 17, 2012 8:28 am 
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With the Arctic Sea becoming more free of ice, I can see more demand for nuclear powered icebreaker ships. There may be other Arctic Sea vessels that would be prime for nuclear propulsion, such as rescue vessels. Russia would be the country most likely to take the lead in this area - they have experience with nuclear-powered icebreakers, IIRC, and they are not shy about exploiting the Arctic, nor shy about using nuclear power..


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PostPosted: Apr 17, 2018 9:15 pm 
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A global deal to slash CO2 emissions from shipping may be a very good reason to change to nuclear ship propulsion:

UN body adopts climate change strategy for shipping

Deal struck to slash climate emissions from global shipping

Quote:
The agreement by more than 170 countries, which comes at the end of two weeks of talks at the UN’s International Maritime Organisation (IMO) in London, is the first time the shipping industry has signed up to climate targets. It pledges to ensure shipping emissions peak as soon as possible and be reduced by at least 50% by 2050 on 2008 levels, while pursuing efforts towards phasing them out in line with global goals to limit temperature rises. The move means all new ocean-going vessels are likely to be using alternative fuels – such as sustainable biofuels, batteries or hydrogen – from the 2030s, experts said.


Uh, sorry sport, you aren't going to power ships on batteries, and you sure aren't going to do it on fluffy hydrogen. No way. You might do it with biofuel, but it will be incredibly expensive. It will basically be nuclear energy or....or....or....

OK, it will be nuclear energy. Guess we'd better brush up on the basics again:

Nuclear Ship Propulsion, (PDF, 40MB)


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PostPosted: Apr 17, 2018 10:45 pm 
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There is the unique corner case of stupidly high TEU capacity cargo ships and fast steaming schedule cargo ships.

Many operators (Maersk particularly) are so heavily focused on profitability that they are refitting some older vessels for slower cruising speeds, going so far as "nose jobs" to replace bulbous bows designed for lower speeds, propeller swaps, and sometimes even engine swaps.

That said, there are certain routes that demand fast passage ships, though the global trend of retiring fast cargo ships is creating a de facto slow boat situation. Getting back to big and fast could reopen certain routes/markets, making them interesting alternatives.

I suppose one interesting route would be asia to the the southern or eastern US, via the new third locks at the Panama canal. A NewPanamax ship with nuclear propulsion that can go at 1.6x+ conventional fleet speed would make certain deliveries more time competitive compared to offloading on the west coast and traveling by rail, even with the slowdown to pass through Panama.

Though as evidenced by the lifecycle issues of fast cargo ships, running at such high speed is going to be brutal on the structure of the ship.


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PostPosted: Apr 21, 2018 12:03 pm 
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Kirk Sorensen wrote:
A global deal to slash CO2 emissions from shipping may be a very good reason to change to nuclear ship propulsion:

Deal struck to slash climate emissions from global shipping

Quote:
The agreement by more than 170 countries, which comes at the end of two weeks of talks at the UN’s International Maritime Organisation (IMO) in London, is the first time the shipping industry has signed up to climate targets. It pledges to ensure shipping emissions peak as soon as possible and be reduced by at least 50% by 2050 on 2008 levels, while pursuing efforts towards phasing them out in line with global goals to limit temperature rises. The move means all new ocean-going vessels are likely to be using alternative fuels – such as sustainable biofuels, batteries or hydrogen – from the 2030s, experts said.


Uh, sorry sport, you aren't going to power ships on batteries, and you sure aren't going to do it on fluffy hydrogen. No way. You might do it with biofuel, but it will be incredibly expensive. It will basically be nuclear energy or....or....or....

OK, it will be nuclear energy. Guess we'd better brush up on the basics again:

Nuclear Ship Propulsion, (PDF, 40MB)


You could certainly power cross channel ferries on batteries. Batteries appear to be economical for journeys of up to 2 hours for most forms of transport.

Nuclear energy would make sense for really big ship requiring 60MW or so. Something like a NuScale 60MW unit.


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PostPosted: Apr 22, 2018 5:02 am 
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Cross Channel ferries are more likely to simply be abolished for the most part and replaced with subsidised container/swap body forwarding on the Chunnel.


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PostPosted: Apr 22, 2018 9:43 pm 
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Kirk Sorensen wrote:
Uh, sorry sport, you aren't going to power ships on batteries, and you sure aren't going to do it on fluffy hydrogen. No way. You might do it with biofuel, but it will be incredibly expensive. It will basically be nuclear energy or....or....or....


Or wind?

As far back as I can recall every mention of reducing CO2 production from transoceanic shipping there's some mention of wind powered ships. This might take the form of reviving and updating the old "windjammers" that had only a small coal or oil fired generator for running winches, lights, and such. They were replaced by steam ships by the 1930s, but some hung on into the 1950s by carrying low profit goods. I'm not sure what a modern windjammer would look like but making them profitable would likely be a challenge.

More often there's claims of some new kind of sail that can be put on the decks of ships to augment a more traditional propulsion system. Greenpeace likes to talk about their "sailing yacht" with it's "electric hybrid backup propulsion". It's a pretty typical diesel boat from what I can tell. They put sails on it and in a good wind it might get 5 knots with wind power alone. I don't recall how they planned to put sails on a container ship, where the deck is full of cargo and no place to put a sail that I could see.

I'm not a sailor but I've talked with people that owned boats on problems with ethanol as fuel. Running a boat on fuel with ethanol in it can be a problem because water dissolves in the fuel and can render it unable to run the engine. With gasoline or diesel the water can be separated off with some kind of filter because water and (fuel) oil don't mix. Methanol, another popular fossil fuel alternative, will have similar problems of water contamination as water would dissolve in the fuel.

Any "fluffy" (I love that description) fuels like hydrogen or methane are problematic for needing to be contained in pressured tanks or tanks of incredible volume. That's not practical on ships carrying cargo.

Any kind of synthesized fuels like "fluffy" hydrogen needs an energy source to produce. Ships might not have nuclear reactors on board but they are likely to be nuclear powered by running on fuels synthesized from nuclear power. How's that US Navy project on synthesizing fuel oil from seawater going? There's your carbon neutral fuel right there.

_________________
Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


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PostPosted: Apr 23, 2018 3:43 am 
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Kurt Sellner wrote:
Kirk Sorensen wrote:
Uh, sorry sport, you aren't going to power ships on batteries, and you sure aren't going to do it on fluffy hydrogen. No way. You might do it with biofuel, but it will be incredibly expensive. It will basically be nuclear energy or....or....or....


Or wind?

As far back as I can recall every mention of reducing CO2 production from transoceanic shipping there's some mention of wind powered ships. This might take the form of reviving and updating the old "windjammers" that had only a small coal or oil fired generator for running winches, lights, and such. They were replaced by steam ships by the 1930s, but some hung on into the 1950s by carrying low profit goods. I'm not sure what a modern windjammer would look like but making them profitable would likely be a challenge.

More often there's claims of some new kind of sail that can be put on the decks of ships to augment a more traditional propulsion system. Greenpeace likes to talk about their "sailing yacht" with it's "electric hybrid backup propulsion". It's a pretty typical diesel boat from what I can tell. They put sails on it and in a good wind it might get 5 knots with wind power alone. I don't recall how they planned to put sails on a container ship, where the deck is full of cargo and no place to put a sail that I could see.

I'm not a sailor but I've talked with people that owned boats on problems with ethanol as fuel. Running a boat on fuel with ethanol in it can be a problem because water dissolves in the fuel and can render it unable to run the engine. With gasoline or diesel the water can be separated off with some kind of filter because water and (fuel) oil don't mix. Methanol, another popular fossil fuel alternative, will have similar problems of water contamination as water would dissolve in the fuel.

Any "fluffy" (I love that description) fuels like hydrogen or methane are problematic for needing to be contained in pressured tanks or tanks of incredible volume. That's not practical on ships carrying cargo.

Any kind of synthesized fuels like "fluffy" hydrogen needs an energy source to produce. Ships might not have nuclear reactors on board but they are likely to be nuclear powered by running on fuels synthesized from nuclear power. How's that US Navy project on synthesizing fuel oil from seawater going? There's your carbon neutral fuel right there.


Kitesails, using a controllable parafoil from the bow for downwind/beam sailing work, is suitable if you are plying tradewind routes, but won't help going upwind.

http://www.skysails.info/

Flettner rotorsails are starting to become more common in europe apparently, with one fitted on a large ferry just recently, as well as a number of cargo ships.

https://www.norsepower.com/rotor-sail-solution


Generally, with the IMO frowning on high sulphur fuel oil diesel engines, we are starting to see LNG fueled diesel engine ships starting to come into vogue. Nuclear LNG production would be a path to fueling them, with some progress on the fuel cell front (some movement trying to combine gas turbines with a fuel cell "combustor" topping cycle, running an integrated electric ship propulsion plant with electric motors accepting power from a multitude of sources).


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PostPosted: Apr 24, 2018 1:35 am 
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Kirk Sorensen wrote:
A global deal to slash CO2 emissions from shipping may be a very good reason to change to nuclear ship propulsion:
Uh, sorry sport, you aren't going to power ships on batteries, and you sure aren't going to do it on fluffy hydrogen. No way. You might do it with biofuel, but it will be incredibly expensive. It will basically be nuclear energy or....or....or....

OK, it will be nuclear energy. Guess we'd better brush up on the basics again:

Nuclear Ship Propulsion, (PDF, 40MB)

Western Hemisphere was discovered on wind via sail powered ships. Now, you could have electric propulsion with batteries charged by wind or sun or even both. Nuclear power could help in ports by plugging in. You travel without any fuel and producing no CO2.


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