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# motorcycle escape chute

Emergency escape/stop mechanism for speed runs
 (+2, -2) [vote for, against]

Some people try to set land speed records by driving motorcycles on the salt flats. That is probably the safest possible place to attempt such records, but even there, a cyclist who loses control has no good way to stop. If his path is well chosen, he may avoid hitting anything in his multi-mile skid, but stopping somewhat more quickly would be desirable.

I would suggest that the cyclist wear safety harness connected via short rope to a box which contained some rope and a dispensing mechanism (see below). That rope would connect to a second similar, but smaller box. That would in turn connect to a similar third box, which would in turn connect to a parachute.

Each box would be constructed so as to dispense rope from a spool at a controlled tension. The tension for each box should start around 800lbs and increase toward about 1200lbs until the rope pulls tight.

The third box would have about 20 feet or so of rope (it may be possible to omit the spool with that small a quantity). It would begin dispensing rope as soon as the parachute opens. Since the third box box would be small and light, it would quickly accelerate and start pulling with 800-1200lbs of tension on the rope from the second box which would hold 200 feet. That would be on a somewhat heavier spool, but it should be able to get up to speed before the rope from the first box is exhausted. The second box would in turn pull the first box, which would have 5,000 feet of rope. That in turn would pull the driver.

A driver traveling at 249mph would travel about 500 feet with a deceleration of 4g; it would take about 3 seconds to stop. While a 4g deceleration would be uncomfortable, I would expect that with a properly-designed harness it should be survivable. While parachutes are not generally designed to open at high speed, limiting the tension on the rope to 1,200lbs should allow for safe operation.

The third box would contain 5,000ft of rope to allow for the possibility that the driver might be caught on the vehicle. In that scenario, a 1000lb tension would not slow things down nearly as effectively as it would pulling just the driver. A 5,000ft spool should suffice to allow an effective slowdown of a 2,000lb bike. Not exactly a fun maneuver, but still possibly survivable.

 — supercat, Sep 06 2008

http://www.kansasci...n/story/784244.html [coprocephalous, Sep 06 2008]

All the equipment I'VE ever needed. http://www.motorcyc...s/Rollie_Free01.jpg
Rollie Free is a HERO! [Letsbuildafort, Sep 08 2008]

Wow... http://en.wikipedia.org/wiki/Rollie_Free
[normzone, Sep 09 2008]

Arai http://www.araiamericas.com/
[normzone, Sep 15 2008]

BRS5 Balllistic Recovery system http://www.ultralig...rs/brs_softpack.htm
Just a little ways down the page [normzone, Sep 15 2008]

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Annotation:

That's a more of a drogue, isn't it?
 — phoenix, Sep 06 2008

I suspect the rider has very little choice about ditching if the bike goes over at 200+ mph. At that speed skidding, rolling, or tumbling end over end are all possibilities. If the bike is spinning or rolling or flipping a chute will fail. On a closed body bike the rider is safer with a long spinning scrape and on an open bike the rider and the bike will separate the moment the bike goes down indicating the need for some sort of armor and hope that bike and rider stay apart not get tangled together.
 — WcW, Sep 08 2008

Whats wrong with safety equipment like swim trunks and goggles? <pic>
 — Letsbuildafort, Sep 08 2008

How about shorts and flipflops with a heavy coat of sunscreen?
 — normzone, Sep 09 2008

Stylish [LBAF], Veeerry Stylish!
 — gnomethang, Sep 09 2008

 The recent crash is what inspired the idea. My thought is that, while I don't know the details of the recent crash, on many of the videos I've seen of spills on speed run attempts, there was a significant time between when control became unrecoverable and the driver actually spilled.

 Obviously there would be a number engineering details that would need to be worked out, since even with a safety harness and parachute, a spill at 249mph is going to hurt and could be fatal. The hope would be that it would hurt less than an uncontrolled skid.

 Regarding the chute vs. drogue distinction, I would think that a parafoil which would lift the driver off the ground would be ideal, but there are a couple caveats: (1) it would be necessary to ensure that the chute and rope didn't act like a pendulum, causing the driver to fly high into the air and then free-fall into the ground; (2) ensuring that the parafoil actually opened upward might be a challenge, depending upon when it was deployed.

 The latter issue might be resolvable with some electronics including gyroscopic accelerometers. The former issue might be more difficult, but perhaps the rig could be controlled by spotters in a chase vehicle some distance away.

One of the difficulties with a drogue, which this idea would be designed to combat, is that the drag produced by a drogue varies considerably with speed. A drogue which is sized to produce optimal survivable deceleration at 249mph will only provide a quarter of the optimal deceleration at 125mph. Using controlled-tension rope dispensers would avoid this difficulty.
 — supercat, Sep 09 2008

arguably that isn't anything like as large a problem as the chance that the rope will garrote or otherwise entangle the rider. Fatal high speed motorcycle accidents are not clean affairs where the primary problem is bringing the vehicle to a halt they are stunning macabre tumbles somersaults and deconstructions that occur without warning and far faster than a drivers reaction time.
 — WcW, Sep 10 2008

I'd rather slide for a few hundred feet with leathers on than fall from 4 feet with leathers on. Highsides suck enough!
(Thank you, Arai.)
 — Letsbuildafort, Sep 15 2008

How about one of the systems they use for ultralights that fall apart in midair? (link)
 — normzone, Sep 15 2008

It is crazy that the best we can do for motorbike riders is leathers and hope.
 — williamsmatt, Sep 15 2008

 // I would think that a parafoil which would lift the driver off the ground would be ideal //

 Me too. I've thought about escape parafoils for a while, though in the context of hover bikes…

 // but there are a couple caveats: (1) it would be necessary to ensure that the chute and rope didn't act like a pendulum, causing the driver to fly high into the air and then free-fall into the ground; (2) ensuring that the parafoil actually opened upward might be a challenge, depending upon when it was deployed. //

 Would a ballistic parachute's launch mechanism help? (Edit: Oh, that's the BRS5 link.)

Maybe also put some rockets on the rider to aid separation. (At that point, maybe just add a zero-zero ejection seat.)
 — notexactly, Jun 13 2015

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