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bgytr

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Dunno, it might really work??

 

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

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Dunno, it might really work??

 

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

 

You sounds like you know what you are talking about so you are probably on the wrong website.

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Is a beam reach the ideal, or would a run or near-run be? Maybe less self- blanketing that way (though more from the accommodation house). And crank the windspeed up to 30?

 

I'm an English major so obviously I would know.

 

If it could get up nearer to a 10% thrust benefit, industry might take notice in times of much higher fuel costs. But I bet the deck officers would hate all the sticks and sails for visibility-ahead reasons. Plus the maintenance headaches.

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Many variations of this have been pumped out in recent years. Another reason they don't work is Philippino deckies make crap mainsail trimmers.

 

Just reading it again, it claims SAVINGS of $60m a year in fuel costs, when a conventional

Ship would spend less than $10m TOTAL for fuel in a year. Too many other wild cleans to mention.

 

The biggest question is, what's it rate?

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Is a beam reach the ideal, or would a run or near-run be?

 

Post number 1717

 

Hmm.

 

Can I suggest a little more time on the water, a little less time at the keyboard?

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It'll never sail to rating unless you figure out a way to tack the oil. Perhaps if they installed 400 of those water ballast systems they have in the new Catalina 250...

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Back when I was working with Dave at KiteShip (2006) we did these analyses as well. A big (75,000ft2/7,500m2) helium-stabilized traction kite was by far the most efficient way of providing additional power to slow VLCCs, especially on the mostly downwind run from Venezuela to Galveston Bay, or California to Hawai'i, developing sometimes up to 50% fuel savings. The multiple-mast soft/hard sail option just wasn't a contender.

 

But in the end, neither were we.

 

Ship owners hate complexity and added risk. Ship masters hate it even more. The idea of having to look out the windows at something complex, fragile and different was a complete deal-killer. Pass the increased fuel costs to the customer every time, in the way of increased freight charges. A no-brainer.

 

All this is wonderful in theory, but it's a technology without a paying market. And that's no way to run a business.

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Dunno, it might really work??

 

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

 

 

I have a couple comments on your calculations:

 

"assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2"

They state 5000 sq m, which is almost 2700 sq ft per sail. So the force from one sail (using all of your other assumptions) then becomes over 7200 lb, and for 20 sails is almost 145,000 lb. Applying your 0.7 correction for “efficiency” results in about 100,000 lb of total thrust from the sails.

 

"A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust."

You don’t define this power, but since very few (actually no one) talk about effective power, it is reasonable to assume that this is brake power. Thus we need to apply a propulsive coefficient (efficiency) when calculating the thrust produced, which you seem to have missed. Using a generous 0.667, we then get => 1.0 million lb of thrust (resistance).

 

However, they claim typical power is half of your value: 30 MW = 40,230 hp. So now the total thrust / resistance is => 500,000 lb.

 

"60,000 / 1,500,000 = 0.04, or a 4% thrust benefit."

100,000 / 500,000 = 0.20, or 20% benefit.

 

They then claim further resistance reduction (required thrust) from “previous” ships through other means such as higher length-to-beam ratio and air lubrication of the hull. So the 500,000 lb resistance number goes down and the percentage obtained from the sails will be even higher (at least for this ideal case).

 

I'm not saying it's feasible...

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Dunno, it might really work??

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

I have a couple comments on your calculations:

 

"assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2"

They state 5000 sq m, which is almost 2700 sq ft per sail. So the force from one sail (using all of your other assumptions) then becomes over 7200 lb, and for 20 sails is almost 145,000 lb. Applying your 0.7 correction for efficiency results in about 100,000 lb of total thrust from the sails.

 

"A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust."

You dont define this power, but since very few (actually no one) talk about effective power, it is reasonable to assume that this is brake power. Thus we need to apply a propulsive coefficient (efficiency) when calculating the thrust produced, which you seem to have missed. Using a generous 0.667, we then get => 1.0 million lb of thrust (resistance).

 

However, they claim typical power is half of your value: 30 MW = 40,230 hp. So now the total thrust / resistance is => 500,000 lb.

 

"60,000 / 1,500,000 = 0.04, or a 4% thrust benefit."

100,000 / 500,000 = 0.20, or 20% benefit.

 

They then claim further resistance reduction (required thrust) from previous ships through other means such as higher length-to-beam ratio and air lubrication of the hull. So the 500,000 lb resistance number goes down and the percentage obtained from the sails will be even higher (at least for this ideal case).

 

I'm not saying it's feasible...

ya, I eyeballed the sail size by estimating the mast height from the ht of the deckhouse, maybe I underestimated a bit. But HP I estimated as power at the props, so maybe your cut down factor is a little much on the power.

 

The air lubrication thing is total bullshit.

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Back when I was working with Dave at KiteShip (2006) we did these analyses as well. A big (75,000ft2/7,500m2) helium-stabilized traction kite was by far the most efficient way of providing additional power to slow VLCCs, especially on the mostly downwind run from Venezuela to Galveston Bay, or California to Hawai'i, developing sometimes up to 50% fuel savings. The multiple-mast soft/hard sail option just wasn't a contender.

 

But in the end, neither were we.

 

Ship owners hate complexity and added risk. Ship masters hate it even more. The idea of having to look out the windows at something complex, fragile and different was a complete deal-killer. Pass the increased fuel costs to the customer every time, in the way of increased freight charges. A no-brainer.

 

All this is wonderful in theory, but it's a technology without a paying market. And that's no way to run a business.

How often would a vlcc carry oil from California to Hawaii?

When would a vlcc be anywhere near Galveston Bay, and why would you need air brakes to slow it down?

Is there usually a contractual requirement to perform at a minimum speed?

 

Just curious.

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Dunno, it might really work??

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

I have a couple comments on your calculations:

 

"assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2"

They state 5000 sq m, which is almost 2700 sq ft per sail. So the force from one sail (using all of your other assumptions) then becomes over 7200 lb, and for 20 sails is almost 145,000 lb. Applying your 0.7 correction for efficiency results in about 100,000 lb of total thrust from the sails.

 

"A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust."

You dont define this power, but since very few (actually no one) talk about effective power, it is reasonable to assume that this is brake power. Thus we need to apply a propulsive coefficient (efficiency) when calculating the thrust produced, which you seem to have missed. Using a generous 0.667, we then get => 1.0 million lb of thrust (resistance).

 

However, they claim typical power is half of your value: 30 MW = 40,230 hp. So now the total thrust / resistance is => 500,000 lb.

 

"60,000 / 1,500,000 = 0.04, or a 4% thrust benefit."

100,000 / 500,000 = 0.20, or 20% benefit.

 

They then claim further resistance reduction (required thrust) from previous ships through other means such as higher length-to-beam ratio and air lubrication of the hull. So the 500,000 lb resistance number goes down and the percentage obtained from the sails will be even higher (at least for this ideal case).

 

I'm not saying it's feasible...

ya, I eyeballed the sail size by estimating the mast height from the ht of the deckhouse, maybe I underestimated a bit. But HP I estimated as power at the props, so maybe your cut down factor is a little much on the power.

 

The air lubrication thing is total bullshit.

So is 17 knots in 90 pct of vlcc reality world

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Back when I was working with Dave at KiteShip (2006) we did these analyses as well. A big (75,000ft2/7,500m2) helium-stabilized traction kite was by far the most efficient way of providing additional power to slow VLCCs, especially on the mostly downwind run from Venezuela to Galveston Bay, or California to Hawai'i, developing sometimes up to 50% fuel savings. The multiple-mast soft/hard sail option just wasn't a contender.

 

But in the end, neither were we.

 

Ship owners hate complexity and added risk. Ship masters hate it even more. The idea of having to look out the windows at something complex, fragile and different was a complete deal-killer. Pass the increased fuel costs to the customer every time, in the way of increased freight charges. A no-brainer.

 

All this is wonderful in theory, but it's a technology without a paying market. And that's no way to run a business.

How often would a vlcc carry oil from California to Hawaii?

When would a vlcc be anywhere near Galveston Bay, and why would you need air brakes to slow it down?

Is there usually a contractual requirement to perform at a minimum speed?

 

Just curious.

 

 

OK, answers....

 

1. Never. My error. But Matson and others tug loads of slow barges on that route

2. For Galveston bay, read US Gulf Coast. And air brakes? What part of my post suggested such nonsense?

3. Speed is a hull, machinery, design and operational decision. Slow speed ships should benefit more from sail assist. Fast ships don't. Simply a matter of a wider range of usable apparent wind angle.

 

Cheers, J

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Dunno, it might really work??

 

Naw....

As a nav. arch. student, I did a thesis paper on wind assist for commercial ships. Basically the price of fuel needs to be so high for it to work that it is not feasible.

 

Also, tankers routinely take green water over the deck. Those little sails would have to be pretty dern heavy to stand up to that. And just everyday industrial conditions on a tanker are pretty friggin rough. Maiteneance costs of another system onboard- not reasonable.

 

A simple computation... under ideal beam apparent wind at 20 knots...

assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2

lift= 0.5 r*v^2*A*C

C: lift coefficient (give a fairly generous C of 2.0)

r: air density taken as 0.0023769 slug/ft^3

v: 20 knots = 33.8 ft/s

A: area = 1600 ft^2

 

force from one sail = 4300 lb of thrust per sail. x 20 sails = 86000 lb of thrust.

 

A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust.

 

multiply the sail thrust by about .7 since the leeward sails will be in the wash of the windward sails => 60,000 lbs of sail thrust under ideal conditions.

 

60,000 / 1,500,000 = 0.04, or a 4% thrust benefit. Not worth it when you factor the drag under headwind conditions, maintenance costs, weight, etc. And that calc was for pretty much ideal circumstances. Actual thrust benefit under a range of conditions would be way less.

I have a couple comments on your calculations:

 

"assume those sails are roughly 80 feet high by 20 feet chord. = 1600 ft^2"

They state 5000 sq m, which is almost 2700 sq ft per sail. So the force from one sail (using all of your other assumptions) then becomes over 7200 lb, and for 20 sails is almost 145,000 lb. Applying your 0.7 correction for efficiency results in about 100,000 lb of total thrust from the sails.

 

"A typical tanker of that size will crank out 80000 hp or more at about 17 knots => 1.5 million lb of thrust."

You dont define this power, but since very few (actually no one) talk about effective power, it is reasonable to assume that this is brake power. Thus we need to apply a propulsive coefficient (efficiency) when calculating the thrust produced, which you seem to have missed. Using a generous 0.667, we then get => 1.0 million lb of thrust (resistance).

 

However, they claim typical power is half of your value: 30 MW = 40,230 hp. So now the total thrust / resistance is => 500,000 lb.

 

"60,000 / 1,500,000 = 0.04, or a 4% thrust benefit."

100,000 / 500,000 = 0.20, or 20% benefit.

 

They then claim further resistance reduction (required thrust) from previous ships through other means such as higher length-to-beam ratio and air lubrication of the hull. So the 500,000 lb resistance number goes down and the percentage obtained from the sails will be even higher (at least for this ideal case).

 

I'm not saying it's feasible...

ya, I eyeballed the sail size by estimating the mast height from the ht of the deckhouse, maybe I underestimated a bit. But HP I estimated as power at the props, so maybe your cut down factor is a little much on the power.

 

The air lubrication thing is total bullshit.

So is 17 knots in 90 pct of vlcc reality world

Huh ?

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Tankers were smaller and faster decades ago, you might see 18 knots at sea trials and sail at around 14-15 loaded.

 

Nowadays with the really big girls and even the smaller ones, less so, making what, about 12-14 knots at sea on a typical voyage?:

 

http://www.bloomberg.com/news/articles/2015-02-19/supertankers-speeding-up-as-oil-price-rout-seen-adding-cargoes

 

We might some day see sail-assist, but as pointed out by many, the commercial, fuel, and crew factors would have to change a lot. Additional crew/overtime costs for tending to sailing spars and rig could also eat up much of any savings. The latest dream is about unmanned "drone" ships, which does not bode well for the complications of sail-assist technology or handling/maintenance.

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Tankers were smaller and faster decades ago, you might see 18 knots at sea trials and sail at around 14-15 loaded.

 

Nowadays with the really big girls and even the smaller ones, less so, making what, about 12-14 knots at sea on a typical voyage?:

 

http://www.bloomberg.com/news/articles/2015-02-19/supertankers-speeding-up-as-oil-price-rout-seen-adding-cargoes

Yes. Assumptions based on17knots while trading are silly. 14 is norm. Shipowners under contract to carry a cargo can't just choose to slow down to save fuel. There are various deadlines to meet. Not to mention the daily carrying costs of equipment that costs $100 million and a single cargo that could be worth between $100-200 million on its own. If the people developing these projects took more time to understand the businesses they were applying them to, they may have found they needed more than bad calculations to make them work. But I guess that's true in many cases.

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Unsure if these interesting designs ever will leave the drawing board, unless the current vessels are sanctioned heavily because of their negative environmental impact.

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Back when I was working with Dave at KiteShip (2006) we did these analyses as well. A big (75,000ft2/7,500m2) helium-stabilized traction kite was by far the most efficient way of providing additional power to slow VLCCs, especially on the mostly downwind run from Venezuela to Galveston Bay, or California to Hawai'i, developing sometimes up to 50% fuel savings. The multiple-mast soft/hard sail option just wasn't a contender.

 

But in the end, neither were we.

 

Ship owners hate complexity and added risk. Ship masters hate it even more. The idea of having to look out the windows at something complex, fragile and different was a complete deal-killer. Pass the increased fuel costs to the customer every time, in the way of increased freight charges. A no-brainer.

 

All this is wonderful in theory, but it's a technology without a paying market. And that's no way to run a business.

How often would a vlcc carry oil from California to Hawaii?

When would a vlcc be anywhere near Galveston Bay, and why would you need air brakes to slow it down?

Is there usually a contractual requirement to perform at a minimum speed?

 

Just curious.

OK, answers....

 

1. Never. My error. But Matson and others tug loads of slow barges on that route

2. For Galveston bay, read US Gulf Coast. And air brakes? What part of my post suggested such nonsense?

3. Speed is a hull, machinery, design and operational decision. Slow speed ships should benefit more from sail assist. Fast ships don't. Simply a matter of a wider range of usable apparent wind angle.

 

Cheers, J

Regarding #2, I mistakenly read your post the same way Edith did. When you wrote the sentence regarding power to slow VLCC's, we both interpreted "slow" as a verb instead of an adjective.

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Tankers were smaller and faster decades ago, you might see 18 knots at sea trials and sail at around 14-15 loaded.

 

Nowadays with the really big girls and even the smaller ones, less so, making what, about 12-14 knots at sea on a typical voyage?:

 

http://www.bloomberg.com/news/articles/2015-02-19/supertankers-speeding-up-as-oil-price-rout-seen-adding-cargoes

Yes. Assumptions based on17knots while trading are silly. 14 is norm. Shipowners under contract to carry a cargo can't just choose to slow down to save fuel. There are various deadlines to meet. Not to mention the daily carrying costs of equipment that costs $100 million and a single cargo that could be worth between $100-200 million on its own. If the people developing these projects took more time to understand the businesses they were applying them to, they may have found they needed more than bad calculations to make them work. But I guess that's true in many cases.

Ok i admit to using the 17kt speed based on the time I spent at sea on ARCO vlcc back around 1990. Actually we cruised at about 16.5..

Regardless even with a drop in speed, and an increase in thrust pct of the sails, it's still doubtful the sails are feasible.

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Unsure if these interesting designs ever will leave the drawing board, unless the current vessels are sanctioned heavily because of their negative environmental impact.

 

Exactly what are the negative environmental impacts of the most efficient form of cargo transportation known to man (along with trains, but they don't often compete on the same routes).

 

Do you think trucks are "better?" Do you think planes are "better?"

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Back when I was working with Dave at KiteShip (2006) we did these analyses as well. A big (75,000ft2/7,500m2) helium-stabilized traction kite was by far the most efficient way of providing additional power to slow VLCCs, especially on the mostly downwind run from Venezuela to Galveston Bay, or California to Hawai'i, developing sometimes up to 50% fuel savings. The multiple-mast soft/hard sail option just wasn't a contender.

 

But in the end, neither were we.

 

Ship owners hate complexity and added risk. Ship masters hate it even more. The idea of having to look out the windows at something complex, fragile and different was a complete deal-killer. Pass the increased fuel costs to the customer every time, in the way of increased freight charges. A no-brainer.

 

All this is wonderful in theory, but it's a technology without a paying market. And that's no way to run a business.

How often would a vlcc carry oil from California to Hawaii?

When would a vlcc be anywhere near Galveston Bay, and why would you need air brakes to slow it down?

Is there usually a contractual requirement to perform at a minimum speed?

 

Just curious.

OK, answers....

 

1. Never. My error. But Matson and others tug loads of slow barges on that route

2. For Galveston bay, read US Gulf Coast. And air brakes? What part of my post suggested such nonsense?

3. Speed is a hull, machinery, design and operational decision. Slow speed ships should benefit more from sail assist. Fast ships don't. Simply a matter of a wider range of usable apparent wind angle.

 

Cheers, J

Regarding #2, I mistakenly read your post the same way Edith did. When you wrote the sentence regarding power to slow VLCC's, we both interpreted "slow" as a verb instead of an adjective.
Ah yes. I was picturing slowing a dragster down.

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Tankers were smaller and faster decades ago, you might see 18 knots at sea trials and sail at around 14-15 loaded.

 

Nowadays with the really big girls and even the smaller ones, less so, making what, about 12-14 knots at sea on a typical voyage?:

 

http://www.bloomberg.com/news/articles/2015-02-19/supertankers-speeding-up-as-oil-price-rout-seen-adding-cargoes

Yes. Assumptions based on17knots while trading are silly. 14 is norm. Shipowners under contract to carry a cargo can't just choose to slow down to save fuel. There are various deadlines to meet. Not to mention the daily carrying costs of equipment that costs $100 million and a single cargo that could be worth between $100-200 million on its own. If the people developing these projects took more time to understand the businesses they were applying them to, they may have found they needed more than bad calculations to make them work. But I guess that's true in many cases.
Ok i admit to using the 17kt speed based on the time I spent at sea on ARCO vlcc back around 1990. Actually we cruised at about 16.5..

Regardless even with a drop in speed, and an increase in thrust pct of the sails, it's still doubtful the sails are feasible.

Up until this year, speed has been a huge factor in negotiations due to a very poor shipping market recently. Vlccs were doing about max 12 knots laden And ballasting back under 10. Market this year has been best since 2008 and cheap fuel so speeds back up to about 14. But yes 17 is max design on many.

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Unsure if these interesting designs ever will leave the drawing board, unless the current vessels are sanctioned heavily because of their negative environmental impact.

 

Exactly what are the negative environmental impacts of the most efficient form of cargo transportation known to man (along with trains, but they don't often compete on the same routes).

 

Do you think trucks are "better?" Do you think planes are "better?"

 

Basically the problem is mostly lack of or insufficient regulations that leads to unnecessary high pollution from ships even if they potentially should be the most efficient

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Unsure if these interesting designs ever will leave the drawing board, unless the current vessels are sanctioned heavily because of their negative environmental impact.

 

Exactly what are the negative environmental impacts of the most efficient form of cargo transportation known to man (along with trains, but they don't often compete on the same routes).

 

Do you think trucks are "better?" Do you think planes are "better?"

 

Basically the problem is mostly lack of or insufficient regulations that leads to unnecessary high pollution from ships even if they potentially should be the most efficient

 

 

How they're propelled is what we're talking about. Spills and pollution are a different topic. If we ship oil, whether by ship, barge, truck, airplane, or rail, the potential for a spill is there. Much less so with all vessels being double-hulled now. The sail-propulsion idea isn't dependent on oil being the cargo. Could be grain, ore, general cargo. Shipping by water is way more efficient per ton-mile than the other modes.

 

Personally, I had expected sailing cargo ships to reappear from whence they last disappeared--coastal cargos where speed or certainty of ETA isn't as important as getting it there eventually and without burning fuel. But it hasn't happened yet.

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Unsure if these interesting designs ever will leave the drawing board, unless the current vessels are sanctioned heavily because of their negative environmental impact.

 

Exactly what are the negative environmental impacts of the most efficient form of cargo transportation known to man (along with trains, but they don't often compete on the same routes).

 

Do you think trucks are "better?" Do you think planes are "better?"

 

Basically the problem is mostly lack of or insufficient regulations that leads to unnecessary high pollution from ships even if they potentially should be the most efficient

 

 

How they're propelled is what we're talking about. Spills and pollution are a different topic. If we ship oil, whether by ship, barge, truck, airplane, or rail, the potential for a spill is there. Much less so with all vessels being double-hulled now. The sail-propulsion idea isn't dependent on oil being the cargo. Could be grain, ore, general cargo. Shipping by water is way more efficient per ton-mile than the other modes.

 

Personally, I had expected sailing cargo ships to reappear from whence they last disappeared--coastal cargos where speed or certainty of ETA isn't as important as getting it there eventually and without burning fuel. But it hasn't happened yet.

 

Was thinking of atmospheric pollution. like NOx, SOx, particles etc. Lots of ships worldwide still on the cheaper HFO.

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ETA's aren't necessarily critical with the things anymore.

 

http://www.wsj.com/articles/worlds-largest-traders-use-offshore-supertankers-to-store-oil-1421689744

 

 

I suspect it might be viable but for "motor sailing". Don't look at it as primary propulsion at all. As an adjunct it stands to cut fuel and engine wear and tear. I kinda doubt it because I expect big storms to de-install them. I wonder how many they get stuck in per decade. Anybody know?

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Personally, I had expected sailing cargo ships to reappear from whence they last disappeared--coastal cargos where speed or certainty of ETA isn't as important as getting it there eventually and without burning fuel. But it hasn't happened yet.

 

 

Gimmickly but it happens:

http://fairtransport.eu/

 

And this was unfortunately not a financial sound project, but it sailed for years, have seen it countless times sailing with cargo.

http://albatroswells.co.uk/history/

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I reckon the example shown here isn't one of the best, but there will be viable options. Even ignoring the CO2 emissions of what is a very efficient but large industry, the NOx and SOx emissions cause tens of thousands of premature deaths a year. Because of this many areas are setting up Emission Control Areas where basically more expensive, less polluting fuel must be used. So in these areas the economics of shipping are changed. The economical ship size on short sea routes is smaller compared with longer routes due to the balance of unloading/loading time to voyage time and consignment size. This then makes ships of 20000-25000 tons viable, which are achievable without too big a technical stretch. Also on this type of route there is more chance that owner and charter will be one and the same, or that there will be a long term arrangement so the 'conflict' between the owner wanting to minimize capex and the charterer wanting to minimize opex will have a different solution making wind power more of an option.

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