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Rocket Powered Uphill Sleds

A much more efficient way to get up sledding hills
 
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Sledding is fun. Well, it can be fun. But sliding down a hill only to take a long trek back up it can be both tedious and tiring, and a whole bunch of other stuff I can't think of right now.

BUT THERE MAY BE A SOLUTION! And a simple one at that. If there are no ski lifts or automatic-teleportation pads then simply strap a few dozen model rocket engines to the back, sit down, light em, and away you go!

If you only do one or two, their force will be nowhere near enough to get you up the hill. If you get alot though... THEN it can get fun!

Before you blast off, make sure that your sled is angled right up the hill and not into a forest or something. (Colliding with a tree can be painful at high speeds)

Also, remember to yell for everybody to get out of the way. Or just use a foghorn. Running over people can result in injury to both you and them, and can lead to very messy lawsuits. (And you'd rather be sledding, right?)

One problem that might occur when you get to the top is stopping. If you are unsure whether you will stop or not, I suggest a drag chute and a crash helmet. And some kneepads too. Maybe full body armor...

Anyway, here is an idea to make winter much more fun and exciting! Perhaps painful, but very enjoyable nonetheless.

(I take no responsiblity for any injury resulting from stupidity resulting from the result of this article. Cheers!)

getslostalot21, Nov 12 2003

Pulsejet http://www.aardvark...nz/pjet/pjetkit.htm
They make one hell of a racket too. (This is the same guy who is doing a DIY cruise missile) [Klaatu, Oct 04 2004]

[link]






       Isn't this kinda what they invented snowmobiles for...?
DrCurry, Nov 12 2003
  

       Unfortunately your number of runs would be limited for a particular hill ... the hot exaust of the rockets would melt the snow as you made your ascent ...
Letsbuildafort, Nov 12 2003
  

       Yeah, but rocket powered sleds are so much more fun than snowmobiles. And I see your point, Letsbuildafort. Maybe you could attach a supersnowmaking machine to the back of it too, so it snows right over your trail. Not just a regular one though. A supersnowmaking one.
getslostalot21, Nov 12 2003
  

       laughing too hard ... to ... make ... serious anno ...
Letsbuildafort, Nov 12 2003
  

       We really need to get Steve Smith and crew to visit here. Maybe if we post more duct-tape ideas...
RayfordSteele, Nov 12 2003
  

       [Mr Burns] Should have used some JB Weld, or Bailing wire, or something to suppliment the tape
Letsbuildafort, Nov 12 2003
  

       Mr. Burns... ha ha ha... can't write anything else... hahaha
getslostalot21, Dec 08 2003
  

       Those model rocket engines aren't nearly powerful enough, the largest ones produce something like 5lbs of thrust for a few seconds. At 20 bucks for a pack of three, that is might expensive. YOu'd probably be better off making your own rocket engine.
sjruckle, Jan 25 2004
  

       Assuming I just did this quick bit of physics correctly, your rocket would need to generate thrust greater than THIS:   

       F > mg(sin(theta) + u*cos(theta))   

       ...where 'u' is the coefficient of snow/sledrunner friction, and 'theta' is the angle of inclination of the hill (0=flat; 90=vertical).   

       For a 90 kg person/sled combination (about 200 lbs) on a 45 degree slope, and a googled coefficient of friction of 0.03 (given actually for skis on snow; sled runners may have a higher 'u'), you'd have to produce thrust in excess of 642 N, or 143 LBS. Using sjruckle's figure of 5 LBS thrust for a large model rocket engine, that would require 29 engines. And that's not to go forward; that's just to keep from sliding back down.   

       It is however possible to make a large 100 LB thrust reedvalve pulsejet (not a rocket) without TOO much difficulty. So two of these babies (which, by the way, are so loud that I hear it hurts to sit next to one for an extended period even when wearing industrial hearing protection, and which can be heard for miles) could get you going. Except you DO also have to accelerate the mass of your propane tanks... so maybe not. :-(   

       I don't know what kind of thrust people have been able to produce using real homebuilt rocket engines.   

       Well, that's it for now...
TerranFury, Jan 26 2004
  

       With the rocket motor on the back of your sled, why do you need the hill? (edit) After looking at Klaatu's link... About 4 of the 100 pounders on the back of a sled, tearing through the serene wilderness, a 200dB nightmare on runners, terrifying man and animal alike. That's about perfect.
DonBirnam, Jan 27 2004
  

       I may have just what you need. <link>
Klaatu, Jan 27 2004
  

       But half the fun is dodging the other sleders careening down the hill...
thelambs, Jan 28 2004
  
      
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