Re: Bridge Contests

[Larry Smith <Larry.Smith@snow.edu>]

At 3:52 PM -0500 8/21/97, brian whatcott wrote:
> At 08:19 8/21/97 -0400, Ron Curtin wrote:
> > I am thinking of doing some type of bridge building competition as a
> > cooperative effort between one of my Physics classes and one of the design
> > classes in our art department.  I know that I did such a thing several
> > years ago with my students building bridges with glue and popcycle sticks,
> > but I can't remember the specifics.(How many sticks allowed, the size of
> > the bridge, the size of the opening in the bridge, etc.)  Does anyone out
> > there have specifics of a bridge building competition they used
> > successfully?

> I would suggest you act as an enlightened system specifier - that is,
> specify the desired result and the cost criterion.
> Example: Build a bridge to span to pillars spaced 24 inches apart, which
> can carry a weight suspended by a sling from its midsection of at least 5 lbs.
> The devices will be tested with a bucket of water with incremental water
> loads.
> The devices will be evaluated at x cents per stick used in the
> construction, etc.

When I was in high school the local university (Brigham Young University)
began such bridge building contests.  They ran them at the university for
the engineering students and also took their bridge breaking (and load
testing) apparatus around to the high schools for contests there as well.
(I must parenthetically say that although my bridges held greater loads
each year my ranking dropped each year as my classmates improved more than
I did.)

Anyway, the university sold pre-packaged kits for a couple of bucks that
had the cardboard bridge deck, two small square base blocks, some long thin
sticks of balsa wood, and a tube of airplane glue.  The kits were all
supposed to be uniform (but sometimes we'd buy two kits and try to combine
the best sticks into the equivalent of one kit).

> The criterion could reasonably be
> load at failure   divided by notional cost of components.

Since I was in high school the rules have changed slightly to where the
winner isn't merely the bridge that holds the greatest load, but the
greatest load divided by the weight of the bridge.

I imagine that the appropriate engineering departments at BYU could give
you specs on their kits (or the source of them).

HTH,
Larry

> Regards
>
>
> brian whatcott <inet@intellisys.net>
> Altus OK