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Interesting to note that the first customer is going to use it to supply remote regions of the frozen north (think Ice Road Truckers). I wonder how these vehic

Interesting to note that the first customer is going to use it to supply remote regions of the frozen north (think Ice Road Truckers). I wonder how these vehicles will perform in sub-freezing weather. Will the helium compress? Liquify? Lose some of their lift? If so, this could prove to be a huge boon to supplying building material and other resources to isolated places that can't support airstrips for instance

ColinWright 15y ago
The helium certainly won't liquify. The denser air in colder climes will increase the lifting power. The volume of the envelope remains the same, and the increased density of helium at lower temperatures is negligible.
- deleted 15y ago
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  - DaniFong 15y ago
    Not so, The helium will be denser, but it has a molecular weight of 4 as opposed to ~29. Suppose it is 20% cooler -- thus occupying 20% less of the volume at equal pressure, thus being 1.25 as dense. Lift will be proportional to 29 * 1.25 - 4 * 1.25 = (29-4) * 1.25 As opposed to lift at our reference temperature 29 - 4 = (29-4) * 1 Showing clearly that there's 25% more lift. The bigger problem is if the envelopes collapse, but clever people have already solved this by having an internal bladder filled with air to take up the slack.
euroclydon 15y ago
I'd be more concerned with how they perform in high winds. Unlike conventional aircraft that use massive propulsion to cut through the air as quickly as possible, these vehicles are designed to just hang out in the air.
- billswift 15y ago
  From what I read about airships' use in the 1920s, high winds aren't a serious problem, but unexpected storms can be, because they can't maneuver out of the storm's path as well as a heavier-than-air craft. Most of the US Navy's airships were lost to relatively small, local storms if I am remembering correctly. Which would be a plus for high latitude use, since their are fewer storms there.
  - deleted 15y ago
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  - tsotha 15y ago
    The US airships were overly susceptible to bad weather because they were based on a wartime German design in which airworthiness had been sacrificed for altitude. From here: http://sped2work.tripod.com/zeppelins.html http://sped2work.tripod.com/zeppelins.html "Unknown to the French and American engineers at the time the height climbers were made from thinner gauge material and, except for the machine guns, stripped of armaments and even one engine. They did not realize they were being specially built in response to mounting losses and were super risky to fly, being very much on the edge of sound structural rigidity. The Americans copied the L-49 almost exactly not knowing how close the Germans had pushed the boundaries of minimal structures and a major reason she, the Shenandoah, broke up in bad weather."
- lukev 15y ago
  It says they can fly at up to 115mph so adjusting course to compensate for leeway, I imagine they could handle some pretty stiff winds even if it cost them speed. Probably safer in a storm than a heavier-than-air craft, since the wind won't be able to knock them over and stall them, or steal their lift. Worst you'd have to worry about would be the passengers getting seasick, as long as you can maintain altitude.
dhughes 15y ago
The cold would be a problem sure I learned in ground school the temperature drops 1.98C for every thousand feet you go up so it's going to be cold anyway even in the Summer. Although -40C to -60C is pretty cool! I would be more worried about wind since it's pretty windy up north which makes sense since there aren't any trees or even a shrub to stop it. Maybe now people in the north won't have to pay $30 for Kraft Dinner and $20 for a litre of milk.
mebesilly 15y ago
It will be cold day in Sheol before it becomes a problem. Helium liquifies at 4.2 K. (Some people free associate too much and fail to think before posting )
notatoad 15y ago
if they didn't perform well in sub-freezing weather, they wouldn't be much use anywhere. as you gain altitude, things generally get pretty cold.
tsotha 15y ago
Airships are actually more efficient in cold climates. The craft gets its lift from the difference in density between air and helium. As the temperature drops air gains more density (in absolute terms) than helium. In the early days of airships this caused quite a problem, since it meant you had to vent hydrogen at night when your ship was too light, and then drop ballast in the morning when it was too heavy. As the day progressed the sun would warm up the helium, making the ship too light again. That's the big benefit of hybrids - since the ship is heavier than air it's tolerant of temperature-induced changes in buoyancy.

ColinWright 15y ago

The helium certainly won't liquify. The denser air in colder climes will increase the lifting power. The volume of the envelope remains the same, and the increased density of helium at lower temperatures is negligible.

deleted 15y ago
[deleted]
- DaniFong 15y ago
  Not so, The helium will be denser, but it has a molecular weight of 4 as opposed to ~29. Suppose it is 20% cooler -- thus occupying 20% less of the volume at equal pressure, thus being 1.25 as dense. Lift will be proportional to 29 * 1.25 - 4 * 1.25 = (29-4) * 1.25 As opposed to lift at our reference temperature 29 - 4 = (29-4) * 1 Showing clearly that there's 25% more lift. The bigger problem is if the envelopes collapse, but clever people have already solved this by having an internal bladder filled with air to take up the slack.

euroclydon 15y ago

I'd be more concerned with how they perform in high winds. Unlike conventional aircraft that use massive propulsion to cut through the air as quickly as possible, these vehicles are designed to just hang out in the air.

billswift 15y ago
From what I read about airships' use in the 1920s, high winds aren't a serious problem, but unexpected storms can be, because they can't maneuver out of the storm's path as well as a heavier-than-air craft. Most of the US Navy's airships were lost to relatively small, local storms if I am remembering correctly. Which would be a plus for high latitude use, since their are fewer storms there.
- deleted 15y ago
  [deleted]
- tsotha 15y ago
  The US airships were overly susceptible to bad weather because they were based on a wartime German design in which airworthiness had been sacrificed for altitude. From here: http://sped2work.tripod.com/zeppelins.html http://sped2work.tripod.com/zeppelins.html "Unknown to the French and American engineers at the time the height climbers were made from thinner gauge material and, except for the machine guns, stripped of armaments and even one engine. They did not realize they were being specially built in response to mounting losses and were super risky to fly, being very much on the edge of sound structural rigidity. The Americans copied the L-49 almost exactly not knowing how close the Germans had pushed the boundaries of minimal structures and a major reason she, the Shenandoah, broke up in bad weather."
lukev 15y ago
It says they can fly at up to 115mph so adjusting course to compensate for leeway, I imagine they could handle some pretty stiff winds even if it cost them speed. Probably safer in a storm than a heavier-than-air craft, since the wind won't be able to knock them over and stall them, or steal their lift. Worst you'd have to worry about would be the passengers getting seasick, as long as you can maintain altitude.

dhughes 15y ago

The cold would be a problem sure I learned in ground school the temperature drops 1.98C for every thousand feet you go up so it's going to be cold anyway even in the Summer. Although -40C to -60C is pretty cool! I would be more worried about wind since it's pretty windy up north which makes sense since there aren't any trees or even a shrub to stop it. Maybe now people in the north won't have to pay $30 for Kraft Dinner and $20 for a litre of milk.

mebesilly 15y ago

It will be cold day in Sheol before it becomes a problem. Helium liquifies at 4.2 K. (Some people free associate too much and fail to think before posting )

notatoad 15y ago

if they didn't perform well in sub-freezing weather, they wouldn't be much use anywhere. as you gain altitude, things generally get pretty cold.

tsotha 15y ago

Airships are actually more efficient in cold climates. The craft gets its lift from the difference in density between air and helium. As the temperature drops air gains more density (in absolute terms) than helium. In the early days of airships this caused quite a problem, since it meant you had to vent hydrogen at night when your ship was too light, and then drop ballast in the morning when it was too heavy. As the day progressed the sun would warm up the helium, making the ship too light again. That's the big benefit of hybrids - since the ship is heavier than air it's tolerant of temperature-induced changes in buoyancy.