# Macy's Thanksgiving Day Parade balloons q. **URL:** \ **Category:** Factual Questions\ **Created:** [November 27, 2019, 10:04pm UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090 "2019-11-27T22:04:59Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [November 30, 2019, 12:22am UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/21 "2019-11-30T00:22:48Z")
> [@RioRico](#): > > We’re still working on antigravity sleds. I was thinking more along the lines of something better than pressurized vinyl as a support structure. Maybe a semi-rigid shell made of lightweight materials like Kevlar that could distribute the load forces from wind more evenly between the people controlling the balloon. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [November 30, 2019, 3:59am UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/22 "2019-11-30T03:59:23Z")
> [@Kent\_Clark](#): > > You can take this cite for what it’s worth, but it says[the big balloons take 12,000 cu. ft. of helium “which can lift up to 750 pounds.”](https://www.mentalfloss.com/article/71548/16-fun-facts-about-macys-thanksgiving-day-parade) That’s total lift; minus 400 lbs of balloon (fabric) weight means only 350 lbs of ‘free’ lift; sounds about right because as the balloon rises it’s also lifting up the weight of the fabric. > [@Lumpy](#): > > I was thinking more along the lines of something better than pressurized vinyl as a support structure. Maybe a semi-rigid shell made of lightweight materials like Kevlar that could distribute the load forces from wind more evenly between the people controlling the balloon. Doubtful it could be lighter than fabric only. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [December 1, 2019, 3:15am UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/23 "2019-12-01T03:15:35Z")
> [@Broomstick](#): > > I’ve been in, or rather, carried under a hot air balloon. They are _enormous_. Bigger than the Macy’s parade balloons. But under TT-Bonham’s proposal the balloon has to lift only itself - no basket, and people, burners & fuel all stay on the ground. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [December 1, 2019, 8:25am UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/24 "2019-12-01T08:25:48Z")
I’m not sure how well it would work with, essentially, piping the hot air up to the balloon. That said - even lifting “just itself” the balloon is going to be huge because hot air isn’t as efficient a lifting gas as helium. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 1, 2019, 1:28pm UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/25 "2019-12-01T13:28:24Z")
Sure, hydrogen is flammable, but then, most things humans make are flammable. Nobody’s aghast at making things out of, say, wood. Even pure hydrogen is acceptably safe, as long as you don’t do anything stupid like make the envelope out of thermite. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 1, 2019, 6:39pm UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/26 "2019-12-01T18:39:34Z")
> [@Chronos](#): > > Sure, hydrogen is flammable, but then, most things humans make are flammable. Nobody’s aghast at making things out of, say, wood. Even pure hydrogen is acceptably safe, as long as you don’t do anything stupid like make the envelope out of thermite. Hydrogen is not only flammable, it’s among the leakiest substances known. Extraordinary precautions are required to use it; to float balloons in a public parade simply isn’t going to fly (no pun intended). ---
**Author:** ![Gray\_Ghost](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)\ **Post date:** [December 1, 2019, 8:02pm UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/27 "2019-12-01T20:02:07Z")
> [@Lumpy](#): > > Hydrogen is not only flammable, it’s among the leakiest substances known. Extraordinary precautions are required to use it; to float balloons in a public parade simply isn’t going to fly (no pun intended). Chronos (or Stranger On A Train, whenever he comes back) would know this, but wouldn’t even a modest portion of one balloon’s worth of hydrogen, mixed with atmosphere and ignited, be enough to shatter a lot of the windows along the parade route? That strikes me as a bad thing. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [December 1, 2019, 8:07pm UTC](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090/28 "2019-12-01T20:07:26Z")
> [@Tim\_T-Bonham.net](#): > > Hot air balloons are lifted by nothing but air, heated by propane burners. And they have to carry the buburners, and propane, and humans aloft with them. Would it be possible to have a Macy’s balloon tethered to a burner truck\*, which heats up the air and blows it through a large tube going up into the balloon? Possibly the noise of such an arrangement would make it unworkable, though. A hot air balloon flys because it’s roughly 100° degrees above ambient air temp. This is accomplished via a 12-15,000,000 BTU burner. A _small_ passenger hot air balloon is 77,000 cu ft, or (for size comtparison a basketball is 1 cu ft). Sure, they could be smaller w/o the weight of humans, baskets, tanks, & burners but not having the burner on board but having that air pumped in means one heckuva large fan. In a real hot air balloon if it gets too hot/we start rise when we don’t want to, we merely pull the vent line in the top of the balloon to let some of the hot air escape. The further the pilot is from that point, the tougher micro control would be; I fear an oscillating ride of too high (straining the handlers) & then hitting them in the head if too much hot air is released. > [@Lumpy](#): > > Hydrogen is not only flammable, it’s among the leakiest substances known. Extraordinary precautions are required to use it; to float balloons in a public parade simply isn’t going to fly (no pun intended). Hydrogen can be dangerous when filling but should be stable once in the balloon. A small leak would go up, into the atmosphere, away from people. However, a terrorist standing on a balcony on CPW with a flaming arrow could end that balloons trip in a hurry. I don’t see NYPD ever allowing this. [Previous page](https://boards.straightdope.com/t/macys-thanksgiving-day-parade-balloons-q/844090.md?page=1)