Ships and boats

[numerobis]

Drive power per tonne doesn't seem to me to be a useful metric. The Model S has an engine that's built to accelerate a car from 0-60 fast enough to brag in marketing literature. The CdM engine supports marketing of being able to go through an icy route.

[gerontocrat]

Drive power per tonne doesn't seem to me to be a useful metric. The Model S has an engine that's built to accelerate a car from 0-60 fast enough to brag in marketing literature. The CdM engine supports marketing of being able to go through an icy route.

That is the point! Ships use less power per tonne so the power required is less per tonne which makes the use of electricity as the power source much more viable as an alternative to fossil fuel. Required range between refuelling becomes the more important parameter.
Also as energy density of  batteries improves then viability improves.

[numerobis]

Wikipedia puts the Maersk E-class engines producing about 5 kWh per kg of heavy fuel oil. Batteries store about 0.2 kWh per kg. So whatever amount of fuel a ship burns, multiply by 25 to get the mass of batteries you need.

Meanwhile, this page indicates about 6000t of fuel capacity on a Panamax. Multiply by 25 to see 150kt of batteries are required to match that. You're gonna need a bigger boat.
https://response.restoration.noaa.gov/about/media/how-much-oil-ship.html

The amount of engine power per mass is not relevant to this calculation, so I was confused why it entered into yours.

[gerontocrat]

Wikipedia puts the Maersk E-class engines producing about 5 kWh per kg of heavy fuel oil. Batteries store about 0.2 kWh per kg. So whatever amount of fuel a ship burns, multiply by 25 to get the mass of batteries you need.

Meanwhile, this page indicates about 6000t of fuel capacity on a Panamax. Multiply by 25 to see 150kt of batteries are required to match that. You're gonna need a bigger boat.
https://response.restoration.noaa.gov/about/media/how-much-oil-ship.html

The amount of engine power per mass is not relevant to this calculation, so I was confused why it entered into yours.

I have been looking for an energy density per kg of batteries compared with the black stuff for ages - and just like that you did it. A must-have piece of data. Many thanks.

What I forgot about was drag. A car moves through air - a big ship has to shove many tons of water aside continuously. Hence vast energy demand.

So one is driven to conclude that until the energy density of batteries increases many-fold battery power for long distance sea traffic is a dead duck?

[ghoti]

Don't forget that electric motors are 2.5 to 3 times more efficient than the most efficient internal combustion engines. This reduces the weight of required batteries.

[numerobis]

I already took the efficiency into account into that 5 kWh/kg number for the heavy fuel oil.

I did *not* take efficiency of all-electric motors into account though; I assumed no leakage from the batteries, 100% efficiency, and 100% depth of discharge.

[Bob Wallace]

So one is driven to conclude that until the energy density of batteries increases many-fold battery power for long distance sea traffic is a dead duck?

I worked through the numbers for Shanghai to LA ocean freight using 400 W/kg batteries (we're now at ~ 250 W/kg) and it just was too large a load of batteries.

The solution is probably to do much more manufacturing 'on continent' and ship by electrified rail or Hyperloop.  Ship only what must be shipped and then we might be able to use biofuel or some sort of synfuel.

Manufacturing closer to market will become more economically possible as we automate and living standards (wages) equalize around the world.

[wili]

I haven't been following the whole thread, and I'm all for 'local' even if that just means 'on the same continent'...

But have you included wind assisted transport. It seems to me I heard that this is coming back and can cut fuel needs by a considerable percentage.

[Neven]

It should be possible to put a considerable amount of solar panels on a container ship. But with storms and everything...

I also remember seeing designs for container ships with sails a few years ago.

[numerobis]

Sailing ships are far slower, but for some goods that might be fine. You'd need to mechanize a lot: you don't want to pay for a huge crew to manage the sails.

Solar panels: the triple-e is about 24,000 m^2 so it could generate on average a few hundred kW, maybe a handful of MW at peak. But it's using ten times that much power. It might make sense anyway to add some solar panels (even on today's ships), it's just not going to be a game-changer. Similarly I've seen proposals for small wind turbines mounted perpendicular to the direction of travel, to catch cross-winds and make a bit of electricity from it.

[magnamentis]

a few knots less and that battery reqirements could be reduced significently. add what neven said plus a skite sail or two and perhaps the reduced long term costs would become attractive for some goods ?

just throwing in a few thoughts but i think that sooner or later efficiency and environmental concerns should overrule speed at all costs.

[Bob Wallace]

Sailing ships are far slower, but for some goods that might be fine. You'd need to mechanize a lot: you don't want to pay for a huge crew to manage the sails.

If we don't come up with a better solution then, yes, slower sailing ships moving raw materials might be part of the answer.  Just launch them 'just in time' full of raw/processed material and do the manufacturing where it can be moved to market with electricity.

Sail assist has been done but doesn't seem to be catching on.

I assume that the world, in general, will become so concerned about climate change that we will insist that fossil fuel use is cut drastically and rapidly.  That point might be 10 years from now, 20 years from now, or ?. 

The tipping point might be Arctic sea ice summer melt out if that drives an abrupt change in weather.  Maybe it will take massive flooding of valuable real estate such as multiple major coastal cities.  Maybe it will take a series of killer heatwaves that wipe out tens or hundreds of thousands in just a few days.

Maybe it will only take the die off of the people who didn't learn about climate change as children and who haven't allowed themselves to learn much of anything since.

[Adam Ash]

Using super slow steaming to conserve fuel, and to usefully reduce emissions, modern cargo ships travel at speeds which are similar to those of clipper ships. Clipper ships had crews of up to 50 to work the sails.

Upcoming problem with reverting to sail for global commerce is found in Hansen's Storms of Our Children, wherein it is apparent that increased storm intensity will make venturing on to the seas unsafe and commercially unviable within the significantly more energetic climate we are creating. 

[Bob Wallace]

We don't need large crews to handle sails if that is the route we happen to take. 

If storms do greatly increase in strength we'll have to avoid traveling during storm season. 

[Adam Ash]

A Sunday diversion for you...

[numerobis]

There's tradeoffs for sailing speed. If you go half as fast, you need twice as many ships to carry the same amount of goods, and twice as much crew. It was worth it five years ago to sail much slower, with high fuel prices -- but it might not be today. Assuming free combustion waste disposal that is; carbon taxes would help push towards more efficiency.

I doubt cities getting eaten up by the rising seas is what's going to convince shippers to sail slower and cleaner. Instead they'll reduce the volume of shipments, on account of the city no longer being there to receive the goods.

[Bob Wallace]

There's tradeoffs for sailing speed. If you go half as fast, you need twice as many ships to carry the same amount of goods, and twice as much crew. It was worth it five years ago to sail much slower, with high fuel prices -- but it might not be today. Assuming free combustion waste disposal that is; carbon taxes would help push towards more efficiency.

I doubt cities getting eaten up by the rising seas is what's going to convince shippers to sail slower and cleaner. Instead they'll reduce the volume of shipments, on account of the city no longer being there to receive the goods.

We could sail ships with very small crews.  And if we can't afford the carbon output from bunker oil engines paying for more hulls might be the answer.

Shipping could well be the last job we tackle.  But I do believe we are likely to reach a point at which we'll attack all fossil fuel use.  The most concerned countries could simply add a meaningful carbon tariff based on how products and materials arrive.

The reaction would likely drive more manufacturing 'on continent' and send shippers looking for low carbon options for powering ships.

[rboyd]

We may very well end up shipping much less of the goods which have low value per ton, carbon taxes could easily drive then "on continent" or simply out of the market. There is currently a huge amount of trade in "cheap crap" that could be removed without leaving a dent in consumers' wellbeing. May leave a big dent in the likes of Walmart and Dollarama though.

[numerobis]

One of my ideas for small business on the side in Iqaluit is setting up an easier way for people to shop for cheap crap to send up on a boat. Right now, people order from Amazon and it comes in on a plane (free shipping!). It's ludicrous.

[Bob Wallace]

We may very well end up shipping much less of the goods which have low value per ton, carbon taxes could easily drive then "on continent" or simply out of the market. There is currently a huge amount of trade in "cheap crap" that could be removed without leaving a dent in consumers' wellbeing. May leave a big dent in the likes of Walmart and Dollarama though.

Much of that "cheap crap" stuff could be made by machines if shipping costs rise.

People want to buy stuff.  No just in the US,  but everywhere I've been in the world.  Some cultures will pay more for quality and buy a bit less, but they still buy stuff.

We need to accept how people behave and look for low carbon, sustainable, affordable ways to allow them to continue as they are.  That's more winnable battle than getting billions of people to change their behavior.

[Bob Wallace]

One of my ideas for small business on the side in Iqaluit is setting up an easier way for people to shop for cheap crap to send up on a boat. Right now, people order from Amazon and it comes in on a plane (free shipping!). It's ludicrous.

A distribution center.  Figure out what people buy in large amounts and talk to Amazon about establishing a distribution center there if you have enough trade.  That is something Amazon is working on but they will likely work on larger markets first.

[ghoti]

A distribution center.  Figure out what people buy in large amounts and talk to Amazon about establishing a distribution center there if you have enough trade.  That is something Amazon is working on but they will likely work on larger markets first.

I think you might not realize the scale in Nunavut. The population of the entire territory is 37,500 spread over very widely distributed hamlets. The largest community is Iqaluit at about 7,700.

[numerobis]

An Amazon distribution centre doesn't solve a problem that Iqaluit has. We can get Amazon stuff just fine, and we do -- we've got apparently the most Amazon packages per capita and just about the busiest post office in Canada to handle them. It's all flown in "for free"; they hide the shipping cost in the unit prices. They have very sharp supply chain management and logistics, so I expect they make a profit on every sale despite the high shipping cost, and despite drastically undercutting the local stores.

Boats can only come here for a couple months of the year, so I doubt it's worth Amazon's while to shoulder the additional management cost of putting some things on boats in hopes it'll sell, and the cost of putting in a building and heating it.

That's the global problem in a nutshell: flying canned tomatoes is ridiculous on its face, but according to economics it makes perfect sense.

[Bob Wallace]

It's all flown in "for free"; they hide the shipping cost in the unit prices.

Amazon prices the goods before they ask where they're delivering.

For Prime's 'free delivering', Amazon has worked out some sort of averaging that puts cost of the extreme deliveries on everyone's cost of purchase.  (Which may be what you were saying.)

[numerobis]

There are communities where Amazon does not deliver, so they have the ability to block off overly-rural places. But they don't block off Iqaluit, which means they're making a profit here. Maybe not on every item, but on average.

[oren]

There's tradeoffs for sailing speed. If you go half as fast, you need twice as many ships to carry the same amount of goods, and twice as much crew. It was worth it five years ago to sail much slower, with high fuel prices -- but it might not be today. Assuming free combustion waste disposal that is; carbon taxes would help push towards more efficiency.

I doubt cities getting eaten up by the rising seas is what's going to convince shippers to sail slower and cleaner. Instead they'll reduce the volume of shipments, on account of the city no longer being there to receive the goods.

We could sail ships with very small crews.  And if we can't afford the carbon output from bunker oil engines paying for more hulls might be the answer.

Shipping could well be the last job we tackle.  But I do believe we are likely to reach a point at which we'll attack all fossil fuel use.  The most concerned countries could simply add a meaningful carbon tariff based on how products and materials arrive.

The reaction would likely drive more manufacturing 'on continent' and send shippers looking for low carbon options for powering ships.

In economic terms it's pretty simple. Cost of fuel should rise to take into account the associated pollution. A tax on fuel, that is used for a CCS operation, can bring shipping with fuel to parity with shipping using electricity and batteries.
I guesstimate that shipping with fuel will still be more economical than twice the ships at half the speed, but that shipping volume will decrease as some of the shipped items will be manufactured closer to where they are sold.

[Bob Wallace]

Cost of fuel should rise to take into account the associated pollution. A tax on fuel, that is used for a CCS operation, can bring shipping with fuel to parity with shipping using electricity and batteries.

The cost of fuel may drop as oil demand drops.

There is no ability to establish a global carbon tax. 

And there will probably always be a nation corrupt to allow bunker oil to be sold at an attractive price.

Here's what could easily happen.  Many countries put a high carbon tax on bunker oil. Corrupt oil-producing country becomes an exporter of bunker oil.  Tankers load its oil and head out to sea where them become floating fuel stations and refill ship tanks in international waters.

[oren]

Cost of fuel should rise to take into account the associated pollution. A tax on fuel, that is used for a CCS operation, can bring shipping with fuel to parity with shipping using electricity and batteries.

The cost of fuel may drop as oil demand drops.

There is no ability to establish a global carbon tax. 

And there will probably always be a nation corrupt to allow bunker oil to be sold at an attractive price.

Here's what could easily happen.  Many countries put a high carbon tax on bunker oil. Corrupt oil-producing country becomes an exporter of bunker oil.  Tankers load its oil and head out to sea where them become floating fuel stations and refill ship tanks in international waters.

In that case, your solution (use electric-driven ships at double the hulls and half the speed) will not work either. If most shipping companies use slower and more expensive but non-polluting methods, but some rogue country has a polluting shipping company, and no global penalty is incurred on pollution, then I bet most shippers would choose the polluting but faster and cheaper alternative, as businesses sadly do today in a variety of other economic choices. So a global enforcement mechanism is needed for any shipping solution, which means it's probably best to leave this problem for last.

[numerobis]

There's precedent for international regulation for shipping. And countries can unilaterally ban bunker fuel from being used in their waters, or can ban docking for illegal ships.

[rboyd]

THE IMO’S 2020 GLOBAL SULFUR CAP

"The International Maritime Organization (IMO) made a historic decision last Thursday, finalizing its plan to dramatically reduce the global sulfur limit of marine fuels by 85 percent in 2020. When the plan is implemented, the global cap in sulfur in marine fuels will drop from the current 3.5% to 0.5%."

The International Maritime Organization already passed regulations to reduce the level of sulphur in bunker fuel. No reason (except power politics of course) why that could not be extended to require higher efficiency/use of non-fossil propulsion etc.

The irony is that the reduction in sulphur content will reduce SO₂ emissions, as its supposed to, but that will also reduce global dimming. In the relatively unpolluted air of the oceans, a little SO₂ can have an outsized impact.

https://www.nrdc.org/experts/barbara-finamore/why-imos-2020-global-fuel-sulfur-limit-significant

https://www.platts.com/IM.Platts.Content/InsightAnalysis/IndustrySolutionPapers/SR-IMO-2020-Global-sulfur-cap-102016.pdf

[rboyd]

From reductionism to systems thinking: How the shipping sector can address sulphur regulation and tackle climate change

"Abstract
The shipping sector is required to reduce fuel sulphur content to 0.1% in Emission Control Areas by 2015 and to 0.5% globally by 2020. Although this is demanding, a greater challenge for all sectors is climate change. However, the three options to comply with sulphur regulation do little to address this challenge. With a deep-seated change to the type of fuel burnt in marine engines, this should be seen as an opportunity to explore co-benefits of sulphur and carbon reduction – instead of taking a short-sighted approach to the problem. It is argued here that the upcoming sulphur regulations should be postponed and instead, a co-ordinated suite of regulations should be implemented that tackles cumulative CO2 emissions and localised SOx emissions in chorus. This would ensure that less developed, yet more radical, step-change forms of propulsion such as wind, battery and biofuels are introduced from the outset – reducing the risks of infrastructure lock-in and preventing the lock-out of technologies that can meaningfully reduce absolute emissions from the sector."

"Highlights
• Shipping sector is taking a short-sighted approach to address sulphur emissions.
• It should consider postponing current sulphur regulations.
• Instead a coordinated suite of policies should tackle CO2 and SOx emissions in tandem.
• Ensuring more radical, step-change forms of propulsion are initiated from the outset.
• Reducing risk of lock-in and preventing lock-out of future lower carbon technologies."

http://www.sciencedirect.com/science/article/pii/S0308597X13001516

[rboyd]

Shipping Emissions: From Cooling to Warming of Climates and Reducing Impacts on Health

Increased use of shipping has had a cooling effect due to the SO₂ emissions. By reducing the SO₂, with no action on CO₂ etc., the IMO is turning shipping into a driver of warming. Another kick to climate change, to be fully in place by 2020! Its going to get warmer over the oceans, and in the ports.

"International shipping has been a fast growing sector of the global economy and its share of total anthropogenic emissions is significant, having effects on climate, air quality, and human health. The nature of the contribution to climate change iscomplex: In addition to warming by CO2 emissions, ship emissions of sulfur dioxide (SO2) cause cooling through effects on atmospheric particles and clouds, while nitrogen oxides (NOx) increase the levels of the greenhouse gas (GHG) ozone(O3) and reduce the GHG methane (CH4), causing warming and cooling, respectively. The result is a net global mean radiative forcing (RF) from the shipping sector that is strongly negative (1), leading to a global cooling effect today (Box 1). However, new regulations of SO2 and NOx, while reducing air pollution and its harmful effects on health and water/soil acidification (2), will reduce this sector’s cooling effects (3). Given these reductions, shipping will, relative to present-day impacts, impart a “double warming” effect: one from CO2, and one from the reduction of SO2. Therefore, after some decades the net climate effect of shipping will shift from cooling to warming."

http://pubs.acs.org/doi/pdf/10.1021/es901944r

We could be looking at a quick jump in forcing as the aerosols get cut by the shipping industry, and by the electricity generators. The early years of the 2020's could be quite a surprise as a chunk of the aerosols disappear. The odd 0.1^oC is important when we are already close to 1.5^oC.

[Bob Wallace]

Cost of fuel should rise to take into account the associated pollution. A tax on fuel, that is used for a CCS operation, can bring shipping with fuel to parity with shipping using electricity and batteries.

The cost of fuel may drop as oil demand drops.

There is no ability to establish a global carbon tax. 

And there will probably always be a nation corrupt to allow bunker oil to be sold at an attractive price.

Here's what could easily happen.  Many countries put a high carbon tax on bunker oil. Corrupt oil-producing country becomes an exporter of bunker oil.  Tankers load its oil and head out to sea where them become floating fuel stations and refill ship tanks in international waters.

In that case, your solution (use electric-driven ships at double the hulls and half the speed) will not work either. If most shipping companies use slower and more expensive but non-polluting methods, but some rogue country has a polluting shipping company, and no global penalty is incurred on pollution, then I bet most shippers would choose the polluting but faster and cheaper alternative, as businesses sadly do today in a variety of other economic choices. So a global enforcement mechanism is needed for any shipping solution, which means it's probably best to leave this problem for last.

Countries cannot control where ships buy fuel.  But they could control the ships allowed into their ports.  Just bar any freight that was shipped by oil during any part of the trip from origin to destination.

[rboyd]

The International Maritime Organization has shown that it CAN control what type of fuel ships use. It could do the same to CO₂ emissions but has decided not to.

[numerobis]

This is bullshit. SO2 rains out; CO2 stays for a hundred thousand years. You can't offset global warming by burning high-sulfur fuel.

[rboyd]

This is bullshit. SO2 rains out; CO2 stays for a hundred thousand years. You can't offset global warming by burning high-sulfur fuel.

You completely misunderstand. We have been burning high-sulfur bunker fuel and the IMO is forcing a move to low sulfur fuel - i.e. reducing the atmospheric level of SO₂. That has a warming effect, as the SO₂ will rain out very fast. They should have also driven for reductions in CO₂ emissions at the same time to at least offset the warming effect.

Previously shipping emissions offset about 7% of man-made CO₂ emissions, due to the SO₂, from 2020 they will add about 3-4%.

[Bob Wallace]

This is bullshit. SO2 rains out; CO2 stays for a hundred thousand years. You can't offset global warming by burning high-sulfur fuel.

Global dimming. 

SO2 into the atmosphere as a solar block is the most effective geoengineering idea we have at the moment.  (Obviously comes with it's own set of problems.)

[sidd]

get rid of the SO2 since it rains as sulphuric acid into the ocean. global dimming will bite, but id rather not have Canfield oceans.

[oren]

And maybe, just maybe, a sharp rise in temps by 2020-2025 due to loss of aerosol cooling will drive the world to sharply cut on carbon.
IOW, get rid of global dimming now and face the full scale of the problem, rather than having it waiting in the wings to give the killing blow when temps are already much higher 50 years from now.

[numerobis]

The time to emit sulphates is likely never -- we put in all those scrubbers for a reason. We don't want to lock in a necessary amount of deadly pollution to fight global warming.

There isn't a conflict between making fuel (modestly) cleaner and the fight against global warming. Cleaner fuel is more expensive, so greedy capitalists will try harder to burn less of it. That makes the switch to electrification or to carbon-neutral fuels come earlier.

[Neven]

Yesterday my daughter and I kayakked to the nearest town. We're on a peninsula with just one bridge to the mainland and the infrastructure is so horrible that it takes at least one hour to get off the peninsula. If you're lucky.

So, we decided to go with the sit-on kayak we bought last year. It was 5 km to get to the local market (that's around three miles) and that took us one hour. We bought what we needed, waved to the dozens/hundreds of cars in the queue, and went back.

What was also interesting, were all the sailing yachts that almost never use their sails. They're doing everything by engine. Of course, they're on a holiday! 

As they passed us by, my daughter remarked that we were using so much less fuel to get the shopping. And so I had to think of this thread. 

[Sigmetnow]

<snip>
As they passed us by, my daughter remarked that we were using so much less fuel to get the shopping. And so I had to think of this thread. 

Although I would never wish a big storm on you...  as we've seen, it's becoming more and more likely that a gasoline supply could be cut off.  Then, people stranded in their cars (or struggling to sail successfully) will be envious of your mode of transportation!

[sesyf]

I have a sailing boat where the old diesel engine was replaced with electric inboard motor with largish batteries in 2004. Year ago I upgraded the old solar panel that had taken care of the house batteries for more than 15 years with more efficient panels so that now I can charge also the engine batteries at 24 volts with a suitable controller. In theory I could now use the panels to directly move the boat at one knot in calm weather... usually I wait for the wind...
This of course requires different attitude to sailing, as the batteries can move the boat for something like 5 to 30 sea miles, depending on the used speed. Usual mode for diesel using sailing boats is to start the iron genoa when speed drops to somewhere like 2 to 4 knots or would require beating into wind - for me it's better to accept even very slow sailing and contemplate the sea, islands etc...

[rboyd]

The time to emit sulphates is likely never -- we put in all those scrubbers for a reason. We don't want to lock in a necessary amount of deadly pollution to fight global warming.

There isn't a conflict between making fuel (modestly) cleaner and the fight against global warming. Cleaner fuel is more expensive, so greedy capitalists will try harder to burn less of it. That makes the switch to electrification or to carbon-neutral fuels come earlier.

There use of SO₂ is only one of many aerosol geo-engineering possibilities, given the obvious acid rain and health issues with sulfate aerosols. There is a geo-engineering thread for such discussions, so will stop my OT statements now.

[Sigmetnow]

Soooo many things wring with this picture.

A Russian tanker plowed through the Arctic without an icebreaker for the first time.

The merchant vessel was built to bust through ice on its own, significantly speeding up the Arctic journey from Norway to South Korea. The company that owns the tanker says it made the trip 30 percent faster than previous voyages.

Not a good thing. Take the tanker as your daily reminder that Arctic sea ice is steadily melting. Oceanographer Simon Boxall told the Guardian that “even if we stopped greenhouse emissions tomorrow, the acceleration in the loss of Arctic ice is unlikely to be reversed,” so building for the Arctic is a “safe bet.”

The tanker is ferrying liquified natural gas. The Russian government expects the route’s usage to increase tenfold by 2020.

http://grist.org/briefly/a-russian-tanker-plowed-through-the-arctic-without-an-icebreaker-for-the-first-time/amp/

[TerryM]

I have a sailing boat where the old diesel engine was replaced with electric inboard motor with largish batteries in 2004. Year ago I upgraded the old solar panel that had taken care of the house batteries for more than 15 years with more efficient panels so that now I can charge also the engine batteries at 24 volts with a suitable controller. In theory I could now use the panels to directly move the boat at one knot in calm weather... usually I wait for the wind...
This of course requires different attitude to sailing, as the batteries can move the boat for something like 5 to 30 sea miles, depending on the used speed. Usual mode for diesel using sailing boats is to start the iron genoa when speed drops to somewhere like 2 to 4 knots or would require beating into wind - for me it's better to accept even very slow sailing and contemplate the sea, islands etc...

A wonderful setup!


I noticed any number of sailboats on Georgian Bay a few weeks back. Almost all were under power, or sailing with a furling jib only.
I can't understand why they didn't crack the main sail. Seems as if it would take so much of the enjoyment away.


Terry

[Bob Wallace]

When you put up the sails the boat tilts to one side and your drink slides off the table.

[Neven]

When you put up the sails the boat tilts to one side and your drink slides off the table.

 

Looks like Elon Musk needs to come up with yet another solution. 

[bligh8]

I noticed any number of sailboats on Georgian Bay a few weeks back. Almost all were under power, or sailing with a furling jib only.
I can't understand why they didn't crack the main sail. Seems as if it would take so much of the enjoyment away."


Folks do not put up their main sails because they’re lazy. Why add the extra work when your ghosting around a lake.  I’ve seen this offshore where someone does not raise the
Msail often enough and the result is a broken mast, typically the top third down to the lower stays breaks off. Sails properly trimmed do not heel a vessel over more than 5deg.

The problem with batteries is water displacement; these bulk carriers displace way too much water for batteries or sails, sails even more so. Not one single shipping company today plans routs in conjunction with wind direction.

Typical turn around time for a commercial ship in port is 12 hrs, that’s for loading and unloading and necessary repairs….after all,  time is money.  20 years ago 12 kts was considered your most efficient speed; today it’s 22 or 23kts, again, it’s time & money.

bligh

[Bob Wallace]

My experience with cruising boats is that many people buy boats too large for the crew that usually sails them.  It's common for couple to buy 40' or larger boats which really need a couple of people to handle a sail change and putting both the people on board on the foredeck in rough conditions is not at all wise.  So lots of people raise sails only in favorable conditions, elsewise they tend to motor.

I'm not sure how that relates to getting us off fossil fuels, but I guess we need to make sure that FF replacements don't require much or any additional effort.

If we had batteries with high enough capacity to power a freighter from LA to Shanghai we could swap out discharged batteries and swap in charged ones just like we unload and load containers.