Balsa Wood Bridge vs Twin Tower Efficiency of Safety Factor of 4,400 vs. 5 = NYC Code

Comment

Comment by Chuck Boldwyn on March 11, 2011 at 11:07pm

Error correction:

 

Octagons should be Octahedrons

 

Triangles and "X" cross-bracing are also of extreme importance in desinging very, very strong flat surface structures.

Closeness of vertical support columns with unheard of redundancy is one of the greatest support strength features of the Twin Towers.

Comment by Chuck Boldwyn on March 11, 2011 at 10:50pm

I taught the Scientific and Physics Engineering principals of both Balsa Wood model Bridge building and Balsa Wood model Square-based Tower building, just like the Twin Towers, for about 10 years at the Senior High and Junior High levels.

The 2 most important factors in building a very, very strong Balsa Bridge or Balsa tower are:

1. 3-D Design of Structure - meaning composed of the Buckminister Fuller Octet design, meaning the structure is composed of alternating octagons and tetrahedrons, in 3-d space, all interconnectd perfectly for the strongest design possible, exactly like the carbon atoms in a diamond crystal are structured, the diamond being the hardest known natural material and with a stupendous melting point.

 

2.  How well the actual Bridge of Tower is constructed: perfect angle cuts, excellent glueing skills, excellent symmetry, good technical skills patience for models building. Staying within the rules of the competition.

 

Of course the same model would be far, far stronger if it were made out of steel, instead of Balsa wood and the total weights of the models were kept constant, the same.

I have never heard of a real Bridge of Tower being tested to see how much load bearing weight it will hold before it will collapse, to discover how many times its own weight it will support before failure.

 

In fact this real Bridge or Tower testing has never been done in the history of Engineering due to the expense associated with real life product testing. It is all done with Engineering Guestimate calculations, which may or may not be correct, and in most cases the calculated guestimates are wrong by a very wide margin.

That is the case for the Twin Towers Safety Fator guestimate, which some Engineers claim to be only a "3" or a "5", meaning that the Twin Tower Safety Factor Guestimate is way, way off,especially when compared to classroom results for model bridges and towers, both and the college level and the high school levels.

 

Newtons Laws apply to all models whether they be very small or very, very large and heavy.

 

F = mg

and

PE = mgh

and

p = mv

and

KE = (1/2)mv^2

all apply equally to small model bridges and towers and to very, very large and heavy bridges and towers.

 

This photo is of me testing a Balsa Bridge for an International Bacculaureat Physics class, to where this particular bridge supported 4,400 times its own weight.

 

It is preposterous that a Twin tower could only have a support factor or Safety Factor of "3" or "5". most especially since the tower is made of very, very strong steel and not balsa wood.

 

Newton's Laws do not change when the size of the model being tested changes as long as everything is scaled up proportionately and only dealing with inanimate items and not living persons or animals

 

Many Engineers claim that when a model is very greatly scaled up the same exact Laws of Physics do not apply.

I am here to say that those Engineers can produce no proof for their non-physics based claims...

 

I rest my case and please try, if you can, to debunk this.....

by:  Chuck Boldwyn

       Retired Physics Teacher