1732: "Earth Temperature Timeline"

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DanD
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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Tue Oct 04, 2016 7:24 pm UTC

omgryebread wrote:So if you put sails or turbines on top of a cargo ship, where do you put the cargo?


Same place you did on a sailing cargo ship. Above it. In the specific case we were discussing, the sail is a kite, and the feed mechanism is a small structure in the bow, forward of efficient cargo space.

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Re: 1732: "Earth Temperature Timeline"

Postby Soupspoon » Tue Oct 04, 2016 7:45 pm UTC

HES wrote:More to the point, who uses gas ovens? Even in the places I've lived that had gas hobs, the oven was electric.

Gas oven, gas hobs, gas grill, here, in the one unit. Not unusual.

(Also, however, there is a separate not-gas toaster. And a not-gas toastie-making thing. Ditto the George Foreman-type thing. It's also not a gas microwave. And the fridge-freezer is only gas insofar as its internals. The washing machine, naturally, is plumbed and wired to only the non-gas utilities.)

((And the UK term for the 'whole stove' is, at least round these 'ere parts, a "cooker". But covers a whole host of appliances of varying and multiple heating types, so long as it is hobbed and oven and/or grill-equipped, at least by my estimate.))

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Re: 1732: "Earth Temperature Timeline"

Postby orthogon » Tue Oct 04, 2016 7:55 pm UTC

Soupspoon wrote:And the fridge-freezer is only gas insofar as its internals.

Gas (powered) fridges are a thing, of course. They're often used on narrowboats where the supply of electricity is limited. They're a triumph of engineering cleverness; I read the Wikipedia page several times and couldn't fully grasp how they work, let alone how some genius came up with the design. They're also brain-melting for people who don't accept that a fridge warms up the room it's in, even with the door open.
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Re: 1732: "Earth Temperature Timeline"

Postby HES » Tue Oct 04, 2016 7:57 pm UTC

Eebster the Great wrote:First time hearing the word "hob," too.

It's a specifically British English term.
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Re: 1732: "Earth Temperature Timeline"

Postby omgryebread » Tue Oct 04, 2016 8:17 pm UTC

DanD wrote:
omgryebread wrote:So if you put sails or turbines on top of a cargo ship, where do you put the cargo?


Same place you did on a sailing cargo ship. Above it. In the specific case we were discussing, the sail is a kite, and the feed mechanism is a small structure in the bow, forward of efficient cargo space.
Kites are pretty good at providing some fuel savings. Current tests are on fairly small container vessels though. I think in 10 or so years, you'll see plenty of them, but global shipping is a very slow industry to adapt.

Sails or turbines are a different matter. Modern cargo ships stack the cargo on the top deck. A ship with equipment on top of that would be incredibly tall, which makes it less safe. Most shipping companies would also want their ships to be under 61.3 meters in height, because that's the clearance under the Bridge of the Americas in Panama. Post-Panamax ships aren't going to care, but I'm not sure how feasible wind power would be on ships of that size. The safety concerns alone would probably delay any implementation for a long time.


Sadly, the amount of money and political pressure available is limited, and I think its a lot more important to work on developing other ways to combat carbon emissions. Specifically speaking on global shipping, developing low-carbon, low-cost manufacturing would probably have a larger impact on the fuel usage of shipping than anything you could do with the ships themselves.
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Re: 1732: "Earth Temperature Timeline"

Postby Tyndmyr » Tue Oct 04, 2016 8:29 pm UTC

You also don't want to put your sail mount point too high for physics reasons. Disregarding panamax, etc limitations, moving your mount point higher means having to deal with a longer lever of sorts affecting the stability of the boat. Sailing ships often have stability features like prominent keels to counteract the stability issues inherent in sails. Getting 5% of your power from sails isn't going to present a big problem, but getting 100% of your power from them...well, you're back to running a sailing ship, and dealing with the problems inherent in that. It isn't simply adding twenty times more sails. It's adding in everything else that makes a sailing ship work.

I'm not sure how much keel you'd need on a supertanker that's powered entirely by wind, but the scale isn't going to be small, and it's the sort of massive redesign that's going to require changes to harbor operations. Increased dredging, for one. Slapping crap on the bottom of your ship is going to increase draft.

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Re: 1732: "Earth Temperature Timeline"

Postby rmsgrey » Tue Oct 04, 2016 8:35 pm UTC

The gas cookers I've interacted with have been 100% gas for heating (gas oven, gas hobs, gas grill) but use electric-sparks to ignite the gas. Why? Because gas is a cheaper heat source than electricity (at least in marginal cost) - which is also why we use gas for our central heating rather than electricity, though our boiler is also hooked up to mains power.

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Re: 1732: "Earth Temperature Timeline"

Postby morriswalters » Tue Oct 04, 2016 9:01 pm UTC

Gas burner then. In either case all the burners are rated by the heat energy they can produce. Hysteresis is introduced to keep the system from short cycling. The temperature on the knob is a proxy for the heat energy being produced. The idea is to heat the food to the center without burning the outside. Temperature is an indirect measurement of that heat transfer. The probe is accurate but all it does is measure the heat it sees. It can't measure the temperature of the meat(or pie or cake or whatever). I'm pretty sure that the temperature sensors of any given manufacturer are precisely alike and will act exactly the same, current industrial tolerances are pretty good. I was responding to this.
A physical example of this might be your oven temperature. You might bake something by having the control knob at 180. That's a somewhat arbitrary number. It may mean that the heating element is kept at precisely 180° C, or that the air temperature at the top (or some other part) of the oven stays at 180° C, or that the surface of the baking tin stays at that temperature. You don't know and don't care. This is why your friend might say that they set their oven to 190. The number does not represent a particular physical quantity, but depends on many and therefore cannot be precise, since the thing it represents is inherently vague.
Who brought up the issue by saying this.
Consequently, when referring to something such as "global surface temperature" in a serious scientific context, it's essential to either define exactly what that means, or to have a broadly accepted definition that everyone can refer to.

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Re: 1732: "Earth Temperature Timeline"

Postby Eebster the Great » Tue Oct 04, 2016 9:57 pm UTC

I would call the combined oven/stovetop a "range" and the individual appliances an oven and a stove (or stovetop or cooktop). Based on my recent shopping experience, that seems to loosely match the names people in the kitchen appliance business give them.

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Re: 1732: "Earth Temperature Timeline"

Postby orthogon » Tue Oct 04, 2016 10:11 pm UTC

I was leaving out the detail mentioned by rmsgrey, that actually, even gas hobs and ovens are likely to have a mains (=outlet) power connection these days, just to power the igniters and presumably the fan. One thing that I think might have changed is that electric ovens can run off an ordinary 13A socket, i.e. they consume less than 3kW. Perhaps they're much better insulated. Combined cookers with hobs still need their own circuit from the fusebox, though, and that is a faff.

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Re: 1732: "Earth Temperature Timeline"

Postby Pfhorrest » Tue Oct 04, 2016 10:14 pm UTC

orthogon wrote:They're a triumph of engineering cleverness; I read the Wikipedia page several times and couldn't fully grasp how they work, let alone how some genius came up with the design.

Is it for some reason more complicated than just using a gas engine to drive the compressor, being careful to vent the hot exhaust from the engine away from the parts you're trying to make cold?
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Re: 1732: "Earth Temperature Timeline"

Postby sonar1313 » Wed Oct 05, 2016 12:36 am UTC

Earlier the discussion about sails or turbines atop cargo ships touched on the obvious inefficiency of being unable to sail straight into the wind. It needs to be mentioned that while racing sailboats can't get much closer than 45 degrees off the wind (maybe you can point them to about 42 or 43 given ideal conditions), hull shape drastically affects pointing ability. Boats designed for cruising are fat and tubby compared to racing boats (and yet, sometimes not all that much different-looking to the untrained eye), and may only point as close as 50 degrees. And all this requires a certain minimum and maximum wind speed; and sea state (which of course gets greater with wind and distance from shore) hinders your pointing too. Oh - and so does crew inattentiveness. Right now, merchant ships are incredibly lightly manned. You can't just set-and-forget your sails the way you can run an engineer down to the engine room every so often. The added crew required to man sails would be a huge extra cost.

Ships designed to carry cargo, of course, would be even fatter and tubbier than the aforementioned cruising sailboats, and be sailing in a large sea state much of the time. There's a reason the shipping industry put engines of some kind in their ships as soon as they could figure out how. There's also a reason that even though shipbuilders of the past knew about triangular sails (required for sailing into the wind) most sails on sailing vessels remained square. Tacking back and forth into the wind was nowhere near as efficient as sailing long distances out of the way to find a running breeze and following seas. Sails are actually a great way to move boats around the ocean if all you want to move is people (and don't give a fig for their comfort.) They suck at moving lots of stuff quickly.

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Re: 1732: "Earth Temperature Timeline"

Postby ps.02 » Wed Oct 05, 2016 2:45 am UTC

Pfhorrest wrote:
orthogon wrote:They're a triumph of engineering cleverness; I read the Wikipedia page several times and couldn't fully grasp how they work, let alone how some genius came up with the design.

Is it for some reason more complicated than just using a gas engine to drive the compressor, being careful to vent the hot exhaust from the engine away from the parts you're trying to make cold?

I'm not sure if it's more or less complicated than that, but it certainly isn't that. Essentially, you've got a glorified kerosene lamp, and the hot exhaust in the chimney somehow powers the refrigeration. I never understood it either. It's small and quiet (quieter than a compressor), nothing at all like a diesel engine.

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Re: 1732: "Earth Temperature Timeline"

Postby Angua » Wed Oct 05, 2016 6:49 am UTC

Most people at home have gas ovens. The power goes out so often that you wouldn't want to rely on electricity for your food.

It gets delivered in tanks about 5 feet tall.
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Re: 1732: "Earth Temperature Timeline"

Postby Eebster the Great » Wed Oct 05, 2016 6:57 am UTC

The principle is similar. The refrigerant still evaporates inside the fridge to cool it down, but instead of passing through a compressor on the other side (providing resistance to flow, requiring an electric pump), it is absorbed into a salt solution. Outside the fridge, the mixture is heated by the burning fuel (or whatever), causing the refrigerant to evaporate again out of the mixture. Then it passes through a compressor and some heat exchange coils. Then it passes back into the fridge to start the process over.

So it's still just evaporating inside the fridge to extract heat and condensing outside to release it, but instead of being pumped by a motor, it is driven by a heat source. The refrigerant follows this cycle:

Cold part | Hot part
------------------------
Liquid ↓ .|← Liquid
Gas ↓ . . | Gas
Solute → |Solute

The black ones are roughly room temperature (due to heat exchange with the surroundings), the blue ones are cold (due to evaporative cooling), and the red one is hot (due to the heat source). I made the solute slightly warmer than the gas inside the fridge because I assume there is some positive but small enthalpy of solution.

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Re: 1732: "Earth Temperature Timeline"

Postby HES » Wed Oct 05, 2016 12:18 pm UTC

sonar1313 wrote:The added crew required to man sails would be a huge extra cost.

Why can't you have a computer do it?
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Re: 1732: "Earth Temperature Timeline"

Postby Soupspoon » Wed Oct 05, 2016 12:51 pm UTC

Hard sails ('sailwings') would be best for that. So long as they are mechanically sound, their actuators working as they should be, etc, they'd need as much/little manning as a RoRo ramp (less, without the finer point of having to land on a quayside/pontoon-top that the ship is only so accurately positioned w.r.t., assuming that there's nothing needing to avoid hitting).

For canvas (or equivalent) sail and of course also the kite system as suggested, the whole ropes and flexible expanse thing is going to be less easily 'hands free'. Look at trawler crews, and their needing to deal with snags and line-breaks and fouling, but maybe toned down a bit unless and until you end up actually dunking your cloth in the water. Only strictly necessary for the times of excitement (letting out, drawing in, recovering from some unexpected failure), but its not as if you can set those extra crew to hand-gutting fish (or use your hand-gutters as assistant rope-wranglers on a temporary basis, to look at it the other way) so difficult to imagine the economies of a modern profit-driven operation having to have double the current crew and perhaps still only need Cpt/1stMt, Chief Engineer and maybe a Watch or two on duty most of the time, but when the wind changes a whole bunch of riggers are jolted into action.

Maybe add a floating scrimshaw-factory (ethically sourced, of course!), or a shanty academy, to copy the way the labour was divided in the past?

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Re: 1732: "Earth Temperature Timeline"

Postby morriswalters » Wed Oct 05, 2016 1:10 pm UTC

A computer controls the kite and flies it in a rough figure eight. The attachment point is low enough so it doesn't cause the ship to heel, which is at least one problem with a mast of any type.

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Re: 1732: "Earth Temperature Timeline"

Postby Soupspoon » Wed Oct 05, 2016 4:20 pm UTC

morriswalters wrote:A computer controls the kite and flies it in a rough figure eight. The attachment point is low enough so it doesn't cause the ship to heel, which is at least one problem with a mast of any type.

Whilst safely in flight (though even simple and uncomplicated flight needs some complexity of sense/control), that might work.

During deployment and retrieval (and retrieval after unforseen de-flighting) people will clearly need to supervise the process, at the bare minimum, to deal with all the various failure modes that can happen, like ropes trailing in the water, catching on superstructure, catching on another vessel, tangling with another kite's lines (other vessel/same vessel), an 'antigust'/lull dropping the kite completely out of the sky, unseen damage to the kite body giving way, etc...

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Wed Oct 05, 2016 6:29 pm UTC

Soupspoon wrote:
morriswalters wrote:A computer controls the kite and flies it in a rough figure eight. The attachment point is low enough so it doesn't cause the ship to heel, which is at least one problem with a mast of any type.

Whilst safely in flight (though even simple and uncomplicated flight needs some complexity of sense/control), that might work.

During deployment and retrieval (and retrieval after unforseen de-flighting) people will clearly need to supervise the process, at the bare minimum, to deal with all the various failure modes that can happen, like ropes trailing in the water, catching on superstructure, catching on another vessel, tangling with another kite's lines (other vessel/same vessel), an 'antigust'/lull dropping the kite completely out of the sky, unseen damage to the kite body giving way, etc...


Just like Spirit and Opportunity needed human intervention?

I'm not saying it won't ever need maintenance or human intervention, but the "in transit" intervention can be kept well within the duties of the normal on-board maintenance crew. In case you missed it, there are fully automated pleasure sailing vessels that can be operated by a single human at the helm.

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Re: 1732: "Earth Temperature Timeline"

Postby Soupspoon » Wed Oct 05, 2016 6:59 pm UTC

DanD wrote:Just like Spirit and Opportunity needed human intervention?

Spirit and Opportunity and the rest don't trail tethers all over the sky. Curiosity safely disposed of its trailing chords used in various stages of descent (parachute, sky-crane umbulical) away from it. It has been strongly suspected that Beagle 2's 'petal-deployment' (or, prior to to being proven otherwise, even the safe descent) was impeded due to either tethers or deflated airbag material (see also complications with the deployment of Spirit from its lander platform) preventing the unfolding.

There are a finite (countable) number of ranges of movement in the various rovers, while a trailing/pulling/loose rope has far more complexity and practically just the single option to pull it and hope it does not snag or knot or twist. Untangle your headphone chords with even a complex robot arm (programmed to do so automatically, really, but through manual/remote control if you must...) and then let's talk about not needing hands-on people.

Automated (classical) rigging depends on everything being kept as taut as necessary, to simplify things. Perfect kite-launches and perfect kite-retrievals are similar, but there's so much that can go wrong. Tethered only at one end, the force of the breeze relied upon to keep the system in useful and predictable tension. As any human kite-flyer can testify. And while computer control can be made 'expert' in quickly dealing with challenging changes in condition, it's not a trivial problem.

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Re: 1732: "Earth Temperature Timeline"

Postby Tyndmyr » Wed Oct 05, 2016 7:32 pm UTC

I highly doubt that robotic space probes are a good model for affordable cargo ships.

Automation is always great, and when possible to do so with savings, is wonderful. That doesn't negate the fact that sailing ships require more people than powered ships. Even if reverting to the age of sail were reasonable, any given level of automation is going to require more crew and more cost, and additionally be a good bit more wind dependent. A calm day is a calm day, no matter how much AI you put aboard.

There is this strange tendency in eco-engineering, at least at the armchair level, to entirely disregard initial costs. Tossing in "automated sailing ships at a level comparable to nasa probes" is a wee bit ludicrous. If that's a requirement, then the cost to carry out this mad scheme just spiked astronomically. It has made your proposal less reasonable, not more.

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Wed Oct 05, 2016 7:48 pm UTC

Soupspoon wrote:
DanD wrote:Just like Spirit and Opportunity needed human intervention?

Spirit and Opportunity and the rest don't trail tethers all over the sky. Curiosity safely disposed of its trailing chords used in various stages of descent (parachute, sky-crane umbulical) away from it. It has been strongly suspected that Beagle 2's 'petal-deployment' (or, prior to to being proven otherwise, even the safe descent) was impeded due to either tethers or deflated airbag material (see also complications with the deployment of Spirit from its lander platform) preventing the unfolding.

There are a finite (countable) number of ranges of movement in the various rovers, while a trailing/pulling/loose rope has far more complexity and practically just the single option to pull it and hope it does not snag or knot or twist. Untangle your headphone chords with even a complex robot arm (programmed to do so automatically, really, but through manual/remote control if you must...) and then let's talk about not needing hands-on people.

Automated (classical) rigging depends on everything being kept as taut as necessary, to simplify things. Perfect kite-launches and perfect kite-retrievals are similar, but there's so much that can go wrong. Tethered only at one end, the force of the breeze relied upon to keep the system in useful and predictable tension. As any human kite-flyer can testify. And while computer control can be made 'expert' in quickly dealing with challenging changes in condition, it's not a trivial problem.


No, it's not trivial. But it is soluble. And you, yourself, implied the solution. As long as the system is under tension, it doesn't have unlimited degrees of freedom. And as long as the controlling winches can respond and physically retract sufficiently quickly, keeping the cords under tension is not that difficult. That is something that humans are not so good at, but a robotic system can do easily.

Again, I'm not saying it's something I could do tomorrow, but a company does exist. They have run proof of concept, and they are starting to install on commercial ships, which suggests they have most of the problems, if not solved, at least minimized.

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Wed Oct 05, 2016 8:05 pm UTC

Tyndmyr wrote:I highly doubt that robotic space probes are a good model for affordable cargo ships.

Automation is always great, and when possible to do so with savings, is wonderful. That doesn't negate the fact that sailing ships require more people than powered ships. Even if reverting to the age of sail were reasonable, any given level of automation is going to require more crew and more cost, and additionally be a good bit more wind dependent. A calm day is a calm day, no matter how much AI you put aboard.

There is this strange tendency in eco-engineering, at least at the armchair level, to entirely disregard initial costs. Tossing in "automated sailing ships at a level comparable to nasa probes" is a wee bit ludicrous. If that's a requirement, then the cost to carry out this mad scheme just spiked astronomically. It has made your proposal less reasonable, not more.


You're right. It's far easier to justify the cost of developing automation when you're going to install it on thousands of units, instead of 1. It's also cheaper to buy the components. Fuel costs for running an (old) panamax ship run around 9 million/year. That's a lot of money that can be spent on automation if it eliminates fuel.

That being said, I've never been in this on the "fully automatic, no crew, fully wind driven" side of the argument. If you get a partially wind driven solution without requiring additional crew, and it saves the 4% of fuel that Sky Sails is claiming for their version of the same (and that's 4% net savings, not 4% while it's active), then you've got $165k/year to justify the installation cost. Given the average corporate numbers for justification, you're looking at $330-828k installed cost for it to be considered viable. Given that the materials and construction cost of the unit probably doesn't run more than $200k (that's probably a little high, but it's hard to find equivalents), there's enough profit there to cover development costs.

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Re: 1732: "Earth Temperature Timeline"

Postby Eebster the Great » Wed Oct 05, 2016 8:26 pm UTC

The bigger point is that even if you can get these ideal figures the company claims and even if the cost is justifiable, it is still just 4 percent savings. It does not substantially change the picture of pollution from shipping. If a company wants to do this, that's fine. But I would not put much public money into developing it.

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Wed Oct 05, 2016 9:05 pm UTC

Eebster the Great wrote:The bigger point is that even if you can get these ideal figures the company claims and even if the cost is justifiable, it is still just 4 percent savings. It does not substantially change the picture of pollution from shipping. If a company wants to do this, that's fine. But I would not put much public money into developing it.


Why not? Of course if the cost is justifiable, you don't have to put public money into it. But 4% fuel savings from one technology, in the first generation, is huge. (And 4% isn't idealized, it's from real world tests.) Big problems are never solved 100% at once. They are solved a few percent at a time.

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Re: 1732: "Earth Temperature Timeline"

Postby ijuin » Wed Oct 05, 2016 10:58 pm UTC

If the first generation of these SkySails can save 4% of fuel requirements, then it is quite possible that future bigger and better designs could save 10-20%, which would start to put a dent in overall cargo shipping fuel costs.

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Re: 1732: "Earth Temperature Timeline"

Postby Eebster the Great » Wed Oct 05, 2016 11:07 pm UTC

DanD wrote:
Eebster the Great wrote:The bigger point is that even if you can get these ideal figures the company claims and even if the cost is justifiable, it is still just 4 percent savings. It does not substantially change the picture of pollution from shipping. If a company wants to do this, that's fine. But I would not put much public money into developing it.


Why not? Of course if the cost is justifiable, you don't have to put public money into it. But 4% fuel savings from one technology, in the first generation, is huge. (And 4% isn't idealized, it's from real world tests.) Big problems are never solved 100% at once. They are solved a few percent at a time.

It's not a free 4% savings. It is an extremely costly 4% savings. There is a reason the company only employs four dozen people and the only ships that use the technology are niche, low-risk shipping companies just exploiting it as a marketing opportunity (and still only sticking them on a single ship). This isn't a breakthrough technology, it's five years old and the company has been losing money. There are already better ways to save fuel, and they are being used in a similar manner. And these "real world tests" are reported by the company itself.

ijuin wrote:If the first generation of these SkySails can save 4% of fuel requirements, then it is quite possible that future bigger and better designs could save 10-20%, which would start to put a dent in overall cargo shipping fuel costs.

I have no idea how you reach that conclusion.

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Re: 1732: "Earth Temperature Timeline"

Postby Cougar Allen » Thu Oct 06, 2016 3:50 am UTC

Tyndmyr wrote:Sails don't scale indefinitely. That's why we stopped using them.


For what it's worth, we stopped using sails because wages for the crew of a sailing ship cost more than coal for a steamship. That doesn't necessarily apply any more; now we could automate most of the work.

The shipping industry has changed a lot since then, and currently the cheapest way to transport cargo is in a few very large ships. That isn't an immutable economic law, though; it's just the current situation.

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Re: 1732: "Earth Temperature Timeline"

Postby orthogon » Thu Oct 06, 2016 9:10 am UTC

Eebster the Great wrote:The principle is similar. The refrigerant still evaporates inside the fridge to cool it down, but instead of passing through a compressor on the other side (providing resistance to flow, requiring an electric pump), it is absorbed into a salt solution. Outside the fridge, the mixture is heated by the burning fuel (or whatever), causing the refrigerant to evaporate again out of the mixture. Then it passes through a compressor and some heat exchange coils. Then it passes back into the fridge to start the process over. [...]

I had another look at the Wikipedia pages (the second has a better diagram) and I kind of get it. There's hydrogen in the mix, too; I think it's there to keep the total pressure constant whilst the partial pressure of the liquid ammonia drops, causing it to evaporate and cool. Why hydrogen? Because it's light so will stay at the top? Insoluble in water?

The description gives me the impression that the gas fridge is to the electric fridge as the two-stroke engine is to its four-stroke cousin. You can kind of see that broadly the same sorts of things are going on, but whereas one has separate bits to do specific things, the other spreads functions across different parts and some parts do more than one thing (e.g. the heated tube is an evaporator, distiller and pump in one; the piston is also a valve). And the whole thing relies on the exact shape of components and surfaces to try to encourage the fluids to move the right way on average.

It's a good example of how there's a continuum in engineering from mechanical/process stuff at one end to software at the other. The gas fridge and two-stroke engine would be seen as hilariously bad bits of engineering if they were software. And yet, they're quite cuspy designs. Electronic engineering is somewhere in between.

EDIT: fixed some typos
Last edited by orthogon on Thu Oct 06, 2016 3:34 pm UTC, edited 2 times in total.
xtifr wrote:... and orthogon merely sounds undecided.

DanD
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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Thu Oct 06, 2016 3:13 pm UTC

Eebster the Great wrote:
DanD wrote:
Eebster the Great wrote:The bigger point is that even if you can get these ideal figures the company claims and even if the cost is justifiable, it is still just 4 percent savings. It does not substantially change the picture of pollution from shipping. If a company wants to do this, that's fine. But I would not put much public money into developing it.


Why not? Of course if the cost is justifiable, you don't have to put public money into it. But 4% fuel savings from one technology, in the first generation, is huge. (And 4% isn't idealized, it's from real world tests.) Big problems are never solved 100% at once. They are solved a few percent at a time.

It's not a free 4% savings. It is an extremely costly 4% savings. There is a reason the company only employs four dozen people and the only ships that use the technology are niche, low-risk shipping companies just exploiting it as a marketing opportunity (and still only sticking them on a single ship). This isn't a breakthrough technology, it's five years old and the company has been losing money. There are already better ways to save fuel, and they are being used in a similar manner. And these "real world tests" are reported by the company itself.


Wow. 5 years to get a brand new technology adopted? Especially in an industry as inherently conservative as the shipping industry? And a start-up losing money?

If you really think that's unusual, you've never been anywhere near a startup. Definitely not one that was developing a physical product. The fact that they have any commercial adopters at the five year mark means they're doing okay. Once that company gets some tests back, then there might start to be some ramp up.

And you also seem to be confusing cap-ex and op-ex. I never said it was free. I said that 4% fuel savings, given the sort of equipment involved, should cost justify in a year or two, which is usually sufficient short for corporate adoption once the early adopters show it works.

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Re: 1732: "Earth Temperature Timeline"

Postby Eebster the Great » Thu Oct 06, 2016 4:04 pm UTC

No, I am saying there is substantial operational expense. When that kite fails to fly itself, somebody has to reel it in. Somebody has to clean it. Somebody has to fix it if it tears. Somebody has to monitor the weather and wind and make decisions about when to deploy it. Even an "automated" sail isn't really automatic.

Also, a kite sail is not a brand new technology, and while startups do tend to lose money, they also tend to introduce bad products.

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Thu Oct 06, 2016 5:01 pm UTC

Eebster the Great wrote:No, I am saying there is substantial operational expense. When that kite fails to fly itself, somebody has to reel it in. Somebody has to clean it. Somebody has to fix it if it tears. Somebody has to monitor the weather and wind and make decisions about when to deploy it. Even an "automated" sail isn't really automatic.

Also, a kite sail is not a brand new technology, and while startups do tend to lose money, they also tend to introduce bad products.


So you missed the fact that it reels itself in. Yes, repair has to happen. Yes, basic maintenance. And yes weather tracking. Those all happen on a ship in transit anyway, and the amount to maintain a kite sail will be fairly minimal.

And an automated kite sail sized for a cargo vessel absolutely is new technology.

And no, it may not work. But you don't have evidence beyond "it's new".

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Re: 1732: "Earth Temperature Timeline"

Postby sonar1313 » Thu Oct 06, 2016 5:37 pm UTC

DanD wrote:
Soupspoon wrote:
morriswalters wrote:A computer controls the kite and flies it in a rough figure eight. The attachment point is low enough so it doesn't cause the ship to heel, which is at least one problem with a mast of any type.

Whilst safely in flight (though even simple and uncomplicated flight needs some complexity of sense/control), that might work.

During deployment and retrieval (and retrieval after unforseen de-flighting) people will clearly need to supervise the process, at the bare minimum, to deal with all the various failure modes that can happen, like ropes trailing in the water, catching on superstructure, catching on another vessel, tangling with another kite's lines (other vessel/same vessel), an 'antigust'/lull dropping the kite completely out of the sky, unseen damage to the kite body giving way, etc...


Just like Spirit and Opportunity needed human intervention?

I'm not saying it won't ever need maintenance or human intervention, but the "in transit" intervention can be kept well within the duties of the normal on-board maintenance crew. In case you missed it, there are fully automated pleasure sailing vessels that can be operated by a single human at the helm.


Yes, sailing pleasure vessels, not ships that need to get from one place to another as quickly as possible. Singlehanding sailboats isn't a new thing, but it's well-known to sacrifice a lot of speed.

I don't think the vagaries of the winds are something you can automate. Sailing is one thing where if you want full efficiency, you have to be constantly trimming and re-trimming sails, and take it from someone who races boats: The instruments are absolute ass at telling you what to do with the sails, and autopilots cannot come close to human drivers when it comes to going as fast as possible. Plus you'd be surprised at how often you have to MacGyver some shit together to keep the boat going. Sails are not things you can just turn on and turn off - dropping a spinnaker, for example, is absolutely fraught with peril in heavy winds. Automation in most areas of industry increases efficiency. Automation in sailing decreases it.

For what it's worth, we stopped using sails because wages for the crew of a sailing ship cost more than coal for a steamship. That doesn't necessarily apply any more; now we could automate most of the work.


We stopped using sails so that ships didn't have to travel hundreds of extra miles to get favorable winds, or sit in the middle of the ocean for days waiting for the wind to come up. Had little to do with wages vs. coal. In fact, ships weren't really much less manned than before, and coal costs more than sails. But predictability and reduced delivery times was well worth it.

A computer controls the kite and flies it in a rough figure eight. The attachment point is low enough so it doesn't cause the ship to heel, which is at least one problem with a mast of any type.


Actually, a certain amount of heel is usually desirable, although not as much when going downwind as you would with a kite.

But you don't have evidence beyond "it's new".


I would suggest that that's the main problem with your own argument. "It exists, therefore it can be automated" is what I see it boiling down to.

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Re: 1732: "Earth Temperature Timeline"

Postby DanD » Thu Oct 06, 2016 6:18 pm UTC

sonar1313 wrote:
I would suggest that that's the main problem with your own argument. "It exists, therefore it can be automated" is what I see it boiling down to.


Um, yeah. Because it can. Sometimes it's simple. Sometimes it's not. Sometimes it's economical, sometimes it's not. But yes, it can be automated.

However, my argument in this case is: Because it appears to have already been automated. I don't have a solid handle on the economics, but the feasibility is there.

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Re: 1732: "Earth Temperature Timeline"

Postby morriswalters » Fri Oct 07, 2016 10:04 pm UTC


rmsgrey
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Re: 1732: "Earth Temperature Timeline"

Postby rmsgrey » Fri Oct 07, 2016 11:50 pm UTC

orthogon wrote:It's a good example of how there's a continuum in engineering from mechanical/process stuff at one end to software at the other. The gas fridge and two-stroke engine would be seen as hilariously bad bits of engineering if they were software. And yet, they're quite cuspy designs. Electronic engineering is somewhere in between.


There are still corner-cases where impenetrable hacks are considered good software engineering - situations where there are actual constraints on the code rather than the usual modern situation of the main costs associated with code being development and maintenance costs rather than operating costs, meaning the simplest solution that works is preferred, rather than the one that works best in routine operation.

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Re: 1732: "Earth Temperature Timeline"

Postby clouds » Wed Jan 25, 2017 6:11 am UTC

Randall, can you make this lovely graph with time on the horizontal axis, please? In that orientation, it would be a great thing to post on a classroom wall, or school hallway, etc. In this orientation, folks could more easily see the change you are pointing out. I know, the vertical view is cool, I really do like it, but the classrooms in my school do not have 16 foot walls from which i can suspend your work. I'm envisioning something akin to long posters of world events that often adorn school hallways outside history classrooms. "If you make it, they will pay you!" Yes, i do believe that a horizontal version would be a hot seller in schools. And besides, you of course know that the independent variable is most often displayed on the horizontal axis, not the vertical, and the dependent variable is on the vertical axis. And I'm considering time to be the independent variable and carbon dioxide the dependent variable. So, waddayathink? Thanks for listening. :)

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Re: 1732: "Earth Temperature Timeline"

Postby lyagooshka » Wed Feb 01, 2017 7:21 pm UTC

Eebster the Great wrote:blah blah blah

That is SO cute.
Using a scientifically illiterate liberal propaganda rag like 'thinkprogress' or 'ecowatch' as actual "evidence".
Maybe for your next trick you can get a colonoscopy from Dr. Pepper?
:mrgreen:

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Re: 1732: "Earth Temperature Timeline"

Postby Geekoid » Wed Feb 01, 2017 7:50 pm UTC

nash1429 wrote:
Am I missing something? the graph in the comic doesn't change scale.


I assume the point is that the hockey stick we see at the end is just the sort of variation that we are not able to identify in the historical records (as Randall points out). It would be a more convincing argument if climate science actually stopped at "look, temperatures are rising!" (I realize that's where the science stops in the popular media, but seriously, read Assessment Report 5.)

Naah... the DJIA is a fractal curve. Aside from some very low-frequency shapes, it looks the same no matter how you zoom (semi-joke). If Randall had plotted on linear time, the curve at the end would have been brutally vertical.


Stock charts make a lot more sense if you look at them on a semilog plot. It says something about the numeracy of bankers that they talk about compounding percentage changes but plot them linearly.



It would be even more convincing of they reminded people that it's a testable fact CO2 captures IR,and it's a testable fact we are producing more CO2, and other green house gases, then nature can reabsorb on any rational timeline.

The rest is also science, but unless some proves CO2 doesn't absorb energy, cherry picking items in climate change is simply foolish.also, stupid.


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