# 1891 Proposal for a bullet ride dropped from the Eiffel Tower

On his science book blog John Ptak posted an entry entitled, "Dreaming of the 10-Ton Eiffel Tower Bullet, 1891," about a proposed fun ride in which people would sit inside a giant bullet and freefall from the top of the Eiffel Tower into a pool of water.
Physics of impact aside for the moment, M.Carron’s bullet capsule would be released from the top of the interior of the Tower, about 1000 feet high, and released to fall into an excavated pool 150’ across and 200’ deep.  The idea was that in addition to the springs inside the capsule, the water would act as a “shock absorber”, and so “the shock felt by the occupants on landing will be in no way unpleasant”.

[Okay, so the thing would hit at 178mph or so, and, assuming that the whole thing didn’t get completely crushed on impact, I’m not so sure that 200’ of depth is very much wiggle room for the thing to come to a halt (if it didn’t deform). Also it would have to not have any wind deflection so as to not veer off its perfect entry into the water.  And so on.  Calculating the force of impact is difficult without knowing how far down the bullet would go, but hitting the water at 80 m/s and stopping at 30 meters would yield something like 28,600,000 KE and 1,274,000 N. There are lots of problems…]

The thing is, though, the thing that made this so appealing, is that for the 20-francs that get a person a seat in the bullet, that they would each get to go twice as fast as any human had ever traveled before ( 65 miles per hour was about the speed of the fastest train constructed).

Dreaming of the 10-Ton Eiffel Tower Bullet, 1891

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1. mdh says:

extrÃªme!

2. Anonymous says:

Here’s a quick way to estimate the average deceleration G’s of a falling object landing: FreefallDistance/DecelerationDistance = # of G’s.

So for example: 1000 ft drop stopped in 200ft would be 1000/200 = 5 G’s

Falling into water means viscous drag, which is a function of velocity squared (ignoring other odd effects). So deceleration would be highest at impact and tapering to zero at the end. So peak deceleration is well above 5 G’s. Probably 10 to 20 if I bothered to do the math.

3. Anonymous says:

That would be great (great human jelly & jam, that is). Anyone know of good sources of royalty free clipart like this? Looking for some cut & paste sources for victorian & earlier themes…

4. Anonymous says:

Having just been to the top of the Eiffel Tower today — it just wouldn’t work.

If you dug a hole that big, one of the guys selling keychains underneath the Tower might fall in and drown.

Or get splashed by the bullet falling down.

It would, of course, make for a splendid new keychain.

You people are so skeptical! The second linked image clearly shows that the people are sitting on a platform that is mounted on sturdy springs; obviously, this would ensure the people inside a soft, pleasant landing. Don’t you watch Bugs Bunny cartoons?

6. Anonymous says:

@5: *Everything* is better when mounted on sturdy springs!

7. Anonymous says:

@2, @Mark… I think you guys might have your estimates off… I calculate all you need is 2.2 Gs to stop an object going 180 mph in under 200 feet. BTW, skydivers do that every day…

8. Anonymous says:

@5 yes, then they get shot back through the roof of the bullet at 10 times the speed, giving them a nice arc right over the eiffel tower (even though they are direclty under it) and landing in the arms of some skinny chick in a short skirt who can withstand the downward forces of a locomotive TRAIN falling on her.

THAT is how warner brothers would have done it!

9. Bindlestick says:

Anonymous @ #3:
This, I think, is what you’re looking for:
http://www.amazon.com/gp/product/0486254453

I assure you it will be the best clipart investment you ever make. There is no band flyer, no corporate newsletter, no greeting card, no Powerpoint presentation that can’t be improved by tucking a few bits of exotic Victorian hardware into the margins.

Why yes, that’s pretty much my whole design philosophy. What of it?

10. Anonymous says:

Freedom Falls!

11. johnocomedy says:

“…they would each get to go twice as fast as any human had ever traveled before ( 65 miles per hour was about the speed of the fastest train constructed).”

as fast as any human had ever traveled before… and lived.

i’m sure they had suicide in 1891. I imagine quite a few humans reached terminal velocity jumping from that very tower

12. Keith says:

Eiffel Tower of Terror?
I-Fell Tower?

13. stegodon says:

“The origin of speed skiing dates to 1898 when a Californian, Tommy Todd, allegedly zipped to 87 mph. However the first recorded official world record was set in 1932 when Italian skier Leo Gasperi was clocked at 89 mph by the International Ski Federation (FIS) in St. Moritz, Switzerland.” http://hypertextbook.com/facts/2000/IgorFridman.shtml

14. Anonymous says:

Anonymous: That’s because he didn’t use 180mph.

This means of measuring deceleration is crude, but extremely easy to do with basic physics:
You have the kinetic energy created by a 1000 foot drop. You have to dissipate it in 200 feet. During that 1000 foot drop, the acceleration used to make that kinetic energy was 1 G. So you have to dissipate that 1 G * 1000ft in 200ft… creating 5 G.

You could certainly create a “ride” similar to this using period methods that isn’t fatal – it just requires a better engineering approach. Excavate more, build a higher water tower above your pit, fill the bottom with heavier-than-water mineral oil, employ a series of parachutes, use impact plates & pulleys to smooth out the other parts of the transition (as if it was a semi-freewheeling elevator).

You could certainly rob Earth’s gravity well of 500 feet of 1G in exchange for 500 feet of avg 2G – the human body can withstand the peaks of 4 or 5 G that would occur using materials of that time.

15. Anonymous says:

I like how the interior of the bullet featured a suspended light fixture. As if getting crushed wasn’t enough – you also get to be sprayed with glass shards!