I keep thinking about buying an avalung, but am put off by the price. After all aren't they more or less a piece of tubing (a la camelbak ) with lots of holes, in a bit of insulated tubing with a 1 way valve? the 1 way valve is probably similar to those used on dust masks & could probably be achieved using the mouth-piece of a party balloon.
I suspect the key thing is the hole size & spacing so air is drawn from the maximum volume & not just a small area at one end of the tube. The DIY approach might have an advantage here since the tubing length could be tailored to the size of ones favourite rucsac.
Any other engineers in Eagles had similar ideas?
Some might say what price for a life etc, but I think if I were to make a few using low cost components, a lot more of my friends would consider carrying them.
PaulCooper
On a similar basis what is the difference between an inflating lifejacket (£60), and a ABS airbag (£600) apart from the volume of the bag? Technology is the same except that the lifejacket is more complex as most also have a water and/or pressure sensive release as well as the manual option.
Anonymous (not verified)
interesting comparison Paul, ski safety gear does seem expensive for what it is sometimes? Only counter argument I suppose would be that life jackets are made in larger volumes.