Cheaper Parcel Post

[hermes]

I just had an idea. I was walking back from the post office where I had paid £4.52 to post a package, the value of the goods inside was about £2.00. The package was mostly hollow as the item inside was box-shaped and the cost of the postage is based on weight. By the time I had got back to the office I had a theory that someone could produce sealed bags of lighter-than-air gas that you could enclose in your parcel to bring down the postage cost. The same bag could be used over again. Then I thought, if I could put enough gas in the package so that the whole package was lighter-than-air then maybe the post office would pay me for posting it because it would allow their vans to take more weight and use less fuel! I realise that the huge volumes of gas involved may mean that all their vans would now be too small so perhaps not such a good idea after all.

 

[gcol]

The packaging would be too expensive and the gas would leak out, but that aside, the packaging would need to be enormous to provide any lift. Think how big a kids Helium balloon is and how hard it is to keep it down....i.e. not very.
I'm hoping this was a very tongue in cheek idea.
Keep thinking
Gcol

 

[AdamW]

Get your own back by letting their tyres down and refilling them with xenon or radon gas. The increased density will vastly increase their fuel consumption and thus make the delivery less profitable.

 

[securespark]

The Czech Chariot's tyres have been filled with Nitrogen at the tyre depot.... Why???

 

[notb665]

See this:

http://news.bbc.co.uk/1/hi/world/americas/3463679.stm

 

[andy]

I just had an idea. I was walking back from the post office where I had paid £4.52 to post a package, the value of the goods inside was about £2.00. The package was mostly hollow as the item inside was box-shaped and the cost of the postage is based on weight. By the time I had got back to the office I had a theory that someone could produce sealed bags of lighter-than-air gas that you could enclose in your parcel to bring down the postage cost. The same bag could be used over again. Then I thought, if I could put enough gas in the package so that the whole package was lighter-than-air then maybe the post office would pay me for posting it because it would allow their vans to take more weight and use less fuel! I realise that the huge volumes of gas involved may mean that all their vans would now be too small so perhaps not such a good idea after all.

try watchin brainiac. they tried this before, but it didnt work out too good

 

[2scoops0406]

Get your own back by letting their tyres down and refilling them with xenon or radon gas. The increased density will vastly increase their fuel consumption and thus make the delivery less profitable.

Radon gas don't reckon they would get far with that, all those covert radiation detectors going off

 

[Steve]

The Czech Chariot's tyres have been filled with Nitrogen at the tyre depot.... Why???

similar density to fresh air (well, nitrogen IS fresh air really, 70%ish), but the advantage is it leaks out more slowly than air alone, the molecules are bigger, they seep thru the rubber / valve slower

 

[AdamW]

The Czech Chariot's tyres have been filled with Nitrogen at the tyre depot.... Why???

Well... IIRC oxygen has a relative atomic mass of 16, and therefore a molecular mass of 32. However, nitrogen has a molecular mass of 28. One mole of gas takes up the same volume at any given temperature and pressure.

So, with air at 78% N2, 21% O2 and forgetting the other 1%, the density of 100% N2 would be less.

So, the air in your tyres would be approximately 2% less dense. Thus reducing fuel consumption slightly.

Of course, it could be because the insides of the tyre may be prone to oxidation.

This has an interesting discussion on the matter of nitrogen-filled tyres.

 

[2scoops0406]

Adam, you are of course correct, ignoring isotopic variances. I believe all aviation tyres are filled with nitrogen to prevent possible tyre explosion on landing. (nitrogen being accessible and pretty inert).

 

[AdamW]

From what I've read it is just easier to hoik around a tank of nitrogen than a compressor.

 

[empip]

FAA Airworthiness Directive 87-08-09

From the 'Toyo Tire & Rubber Group'
http://www.toyo.com.au/tech_info11.html