View Full Version : Hard to believe

Michael Weber

02-06-2018, 12:45 PM

A true scale model of the Eiffel Tower that was 1 foot tall would only weigh as much as a nickel. About 7 grams, about 1/4 ounce.

The air in a cylinder containing the Eiffel Tower weighs more than the tower itself. The Tower weight is reportedly 9400 tons and air in the cylinder is 11,200 tons at sea level.

If all the iron in the Tower were melted into a single square bounded by the base of the Tower it would only be 6 cm or about 2 1/2 inches thick

Wade Lippman

02-06-2018, 2:10 PM

I always wondered why the Nazis didn't tear it down for scrap iron. Perhaps there wasn't enough to bother.

Pat Barry

02-06-2018, 2:40 PM

Interesting. Do you know the math to figure the weight of air in the cylinder?

Doug Garson

02-06-2018, 3:39 PM

That's very impressive basic engineering, when I was an engineering student we did a project challenge where we built a tower from popsicle sticks. The goal was to build the lightest tower that could support a given weight. Looks like the designers of the Eiffel Tower would have been very competitive in that challenge.

Calculating the weight of air in the cylinder is a 2 step process, first calculate the volume of the cylinder using the formula V= Pi x r x r x h, where r is radius and h is height of cylinder, then calculate the density of air which is dependent on the pressure, temperature and moisture content of the air.

https://www.brisbanehotairballooning.com.au/wp-content/uploads/moist-air-density-formula.png

and no I didn't have all that memorized, I Googled it.

Michael Weber

02-06-2018, 4:05 PM

Interesting. Do you know the math to figure the weight of air in the cylinder?

π x r sq x h. Is the formula for volume of a cylinder. The towers base would fit in a circle 296.5 feet. 3.14159 x 296.5 x 296.5 x 1052 = 290,398,777 cubic ft times the weight of a cubic foot of air at sea level of .0807 = 123,435,181 pounds / 2000 = 11,717 tons or thereabouts.

And yes, Mr. Eiffel wanted to show how a very large structure could be built very lightly using modern material and engineering. Interestingly it was almost demolished in 1909 but was saved only because of the communication antenna installed at the top.

Chet R Parks

02-06-2018, 4:37 PM

Wow, this is all vary impressive, a lot of smart people here. Over in the Neanderthal Haven of SMC there trying to keep a vise from racking maybe some of you could help out over there :eek: I'm just kidding

Michael Weber

02-06-2018, 4:58 PM

Wow, this is all vary impressive, a lot of smart people here. Over in the Neanderthal Haven of SMC there trying to keep a vise from racking maybe some of you could help out over there :eek: I'm just kiddingin all fairness, I just read those facts and posted it here because it was, well hard to believe. I flunked high school algebra so don't accuse me of being smart.:o You can talk to Doug though:)

Pat Barry

02-06-2018, 5:55 PM

π x r sq x h. Is the formula for volume of a cylinder. The towers base would fit in a circle 296.5 feet. 3.14159 x 296.5 x 296.5 x 1052 = 290,398,777 cubic ft times the weight of a cubic foot of air at sea level of .0807 = 123,435,181 pounds / 2000 = 11,717 tons or thereabouts.

And yes, Mr. Eiffel wanted to show how a very large structure could be built very lightly using modern material and engineering. Interestingly it was almost demolished in 1909 but was saved only because of the communication antenna installed at the top.

Crazy, with all that weight above us it surprising we are not all crushed like bugs.

Pat Barry

02-06-2018, 5:56 PM

Wow, this is all vary impressive, a lot of smart people here. Over in the Neanderthal Haven of SMC there trying to keep a vise from racking maybe some of you could help out over there :eek: I'm just kidding

They've got plenty of 'experts' over there. LOL

John K Jordan

02-06-2018, 6:34 PM

...

If all the iron in the Tower were melted into a single square bounded by the base of the Tower it would only be 6 cm or about 2 1/2 inches thick

Incredible. When I stood underneath looking up I was amazed by the size and apparent massiveness of the structural support. The thing is so big it is hard to photograph from the ground. My pitiful little snapshots can't begin to capture the feeling, even when I'm reminded of the scale by the people in the center of the base in the third photo.

378482 378479 378480

JKJ

Mel Fulks

02-06-2018, 7:29 PM

It was the tallest structure until the Empire State Building

Larry Frank

02-06-2018, 7:47 PM

The math comes up with the right answer but you typed in an extra one.

It should be 23,435,181/2000 and not 123,435,181/2000.

Peter Kelly

02-06-2018, 7:58 PM

The structural iron in the tower itself weighs 7,300 tons. When you include passenger elevators, mechanical systems, shops, restaurants, bar, antennae the total weight of the structure is approximately 10,100 tons.

Was the tallest structure until the Chrysler Building.

https://en.wikipedia.org/wiki/Eiffel_Tower#Design

Larry Frank

02-07-2018, 7:20 AM

And.....Eiffel designed the structural part of the Statue of Liberty. He was an amazing engineer.

Michael Weber

02-07-2018, 11:59 AM

The math comes up with the right answer but you typed in an extra one.

It should be 23,435,181/2000 and not 123,435,181/2000.

�� Neither a mathematician nor typist be I.

Stephen Tashiro

02-07-2018, 2:30 PM

A true scale model of the Eiffel Tower that was 1 foot tall would only weigh as much as a nickel

One of the great disappointments of childhood is learning that scale models are too fragile to be good toys. The pieces of scale models are often thicker than they ought to be and yet they still break.

Powered by vBulletin® Version 4.2.5 Copyright © 2019 vBulletin Solutions Inc. All rights reserved.