Currently, bobsledding is on ice; technically, skating at high speeds down an icy halfpipe in a bullet-shaped vehicle. Ice has low friction; very low friction in this manner, but still there is friction. Instead, make a maglev chute, and leave it up to the teams to design their vehicles in their entireity: The aerodynamic shape, magnet placement, and everything else. Then, the teams would have to learn how to control their craft, and how to use the extremely high speed frictionless slope to its fullest extent. See link for high powered magnets.-- Shrimp, Aug 05 2006 United Nuclear http://unitednuclear.com/magnets.htmA source for everything fun. [Shrimp, Aug 05 2006] This would be amazing. The chutes would be quite expenive and if a bobsled wandered too far to a side, there would be a very forceful magnetic trubulence and possible 'derailing'. Make the chute an airtight cylinder (provide stopping room, of course), place magnets evenly all around the tube and bobsled, then pump all of the air out. Even less friction. Almost no terminal velocity. Bun anyway.-- jellydoughnut, Aug 05 2006 Ooh, yes, airtight equals no friction whatsoever! Indeed! However, how much would it cost to make a bobsled pod with its own life support system? Or maybe no people in the pod...-- Shrimp, Aug 05 2006 Not that much for a run that might cover a few miles within seconds. The bobsled wouldn't even have to be sealed (it should be, though to allow for the even placement of magnets); each of the four members would need a small tank of compresed oxygen, a quarter of the size of a SCUBA tank.-- jellydoughnut, Aug 05 2006 Why not just use a regular sized tank with four hookups built right into the bobsled? And for braking, how about a long series of rubber rollers. Underneath them the magnets could be of the opposite polarity of the rest of the track, therefore making the bobsled have a greater pull down on the rollers, stopping it faster. Or would a skidplate be better, like steel, and have small wheels on the sled for this purpose?-- Shrimp, Aug 06 2006 It would seem a difficult task to replicate a curved track using magnets, at least one that could slow down a 300kg sled moving at 100km/h.
Also won't this generate huge amounts of potential if you hurl this conductive shell through an intense magnetic field?-- Cuit_au_Four, Aug 06 2006 Maybe, but if you change the material of the sled to say, maybe fiberglass, it should be OK. However, I will put that into consideration.-- Shrimp, Aug 07 2006 A cheaper version of this might be to use the same principles that you find in an air-hockey game. i.e. Lots of small holes expelling air, upon which something flat hovers, cushioned on the air.-- zen_tom, Aug 07 2006 I think an air hockey table only works because of the high surface area in contact with table-to-weight ratio. If you tried wadding up a piece of paper into a sphere of the same mass as a puck, it would not be levitated. This could work for a different ice sport, like luge or skeleton.
It would be cheaper still to put the small, air-expelling holes on the underside of the sled. But still not flat enough to levitate. One big air output with a skirt. Hoversled?-- jellydoughnut, Aug 07 2006 I have made a hovercraft before, and indeed, they are almost frictionless. But the skirt still drags, which causes some friction, and you have to bakance precisely to keep the body of the craft from dragging. In maglev, there is no ground friction, and less balancing is required. However, a hoversled would be an extremely cheap alternative; however you would have to mount an engine on the sled...-- Shrimp, Aug 08 2006 Coming back to a concept I used in a previously fishboned idea, the electro hydro dynamic (EHD) thruster uses a difference between high voltage positive and negative elements to direct a solar wind downward. It requires high power supply but the device itself has a low mass compared to an engine. However, its effectiveness relies directly on how much oxygen (potential ions) are in the environment, so would be useless in vacuum.-- jellydoughnut, Aug 08 2006 The Japanese have now decided that their Shinkansen (bullet trains) aren't fast enough and are going to replace them with maglev trains which travel at about 500 km/h (about 300 mph). Anyway, a nice idea.-- hippo, Aug 08 2006 I think you should have a flat ramp at the end, with a target of some gratifyingly smashable material. The team would have to steer the bobsled to smash the target for extra points, and bail out midair en route. Still more extra points if your chute deploys in time.-- +mw+, Aug 09 2006 //some gratifyingly smashable material//
Like a pile of bricks or barrels full of water...
Now that you mention this, a chute like this, if a long portion of it were in vacuum, might make a decent space ramp.-- jellydoughnut, Aug 09 2006 Well how about using the maglev train idea, the way it works is simple. use electromagnets and when they want to slow down you just switch the polaritys of the electromagnets. use this idea at the end of the bobsled run so it would be vastly more effective and not hurt the vechile. on a sidenote shrimp if you tryed attracting the rubber rollers from the sled to the track it would both rip up the sled and the track, so fishbone. but other than that it would be a sweet idea, i would build this track somewhere cold so the magnets would work better. it would be difficult to build and it would take alot of physics and knowledge of electrophysics but it is possible to make as many turns as you wish. doughnuts idea for the oxygen tank would work... although, in distance it should probally be at a much bigger scale, i mean sure a few miles in a few seconds, but who wants to watch that...-- hyra1, Sep 17 2007 //some gratifyingly smashable material//
A fruit & veg stall.-- marklar, Sep 18 2007 Put the run in orbit. No air, no friction, no gravity.(*)
You wouldn't have to run "downhill" but could run in any direction. The sled would only have whatever kinetic energy the team managed to put into it at the beginning, but speed could vary with tighter or looser curves. The bobsledders could gain traction for starting the sled by holding handles on the sled and bracing their feet against the tubular track.
(*) Yes, I know. But you know what I meant.-- Xenophile, Jan 26 2010 random, halfbakery