Jet Sled

Over at Bayou Reconnaissance Man, there's a fun video of some Swedes with their steam powered dogsled. The advantage of this is that you are no longer limited by the speed of a running dog. The obvious disadvantages are that first, steering seems a bit iffy, possibly limited to crude bending of the frame, similar to the ever-popular Flexible Flyer.

The second thing is the charging procedure, which seems to involve filling the attached pressure tank with water, then dropping the whole sled onto a briskly burning fire until the water reached some 400 degrees Celcius, according to the comments. Go here to see the original, with comments.

Superheated water will flash to steam and drop it's temperature almost immediately to 212 degrees, so the exhaust is (relatively) safe. Heating a steel container to 750 degrees (F) will reduce the heat-treatment properties of the metal, rendering the tank weaker that it was before. There are videos of steam locomotives suffering boiler failure out there.

Evidently there is an official record for powered sleds, which these fellows are looking to break. I'm thinking that if the thing ran on inline runners, with just a bit of rubber to provide suspension, it would ride much like a motorcycle, and the driver would be less likely to learn what it was like to slide across a frozen lake at 100 mph, on his butt.

I'm not discouraging the effort, just suggesting that a bit more thinking might be in order here. It's a fine line, sometimes between a gold medal on a platform, and a Darwin award on the Internet.