Aunt Bea
SF VIP
- Location
- Near Mount Pilot
A friend sent these videos to me and they just amaze my tired old mind.
Zipper Trucks
- Thread starter Aunt Bea
- Start date
RadishRose
SF VIP
- Location
- Connecticut, USA
Very cool, Aunt Bea!
Pappy
Living the Dream
I’ve often wondered how they move those barriers so fast on bridges.
Mrs. Robinson
Well-known Member
- Location
- Nampa,Idaho
Yep-just saw the zipper truck on the Golden Gate Bridge last weekend. Sure wish they had those barriers when I commuted over it weekly for 18 years-way too many close calls!
Those are interesting. Thanks.
It looks to me that the construction engineers used the same mathematical knowledge that the Romans did. They discovered that the strongest support was the same shape as the form a chain takes when one attaches it to a wall and then let it become somewhat slack. It is an inverted catenary. I suppose all you mathematics geniuses know that a catenary is close to the form of a parabola, but slightly different, the reason being that the weight is such that it pushes, not downward, but against itself. Hence the bridges can support more weight, even more than the weight that makes up the bridge itself. Think, Arch in St. Louis, for example. Those Romans were very smart (except when they let Nero become ruler, of course)
However, if something goes wrong, it will difficult to "fix". My wife laughs at me everytime I have a zipper that malfunctions and I have to get it repaired. I've said several times: "I'd like to meet the man who invented the zipper, so I can give him a piece of my mind!" I can just see myself going through one of those and something goes awry, and I have to call for help. I'l just say: "Where's the man who............? for sure.
It looks to me that the construction engineers used the same mathematical knowledge that the Romans did. They discovered that the strongest support was the same shape as the form a chain takes when one attaches it to a wall and then let it become somewhat slack. It is an inverted catenary. I suppose all you mathematics geniuses know that a catenary is close to the form of a parabola, but slightly different, the reason being that the weight is such that it pushes, not downward, but against itself. Hence the bridges can support more weight, even more than the weight that makes up the bridge itself. Think, Arch in St. Louis, for example. Those Romans were very smart (except when they let Nero become ruler, of course)
However, if something goes wrong, it will difficult to "fix". My wife laughs at me everytime I have a zipper that malfunctions and I have to get it repaired. I've said several times: "I'd like to meet the man who invented the zipper, so I can give him a piece of my mind!" I can just see myself going through one of those and something goes awry, and I have to call for help. I'l just say: "Where's the man who............? for sure.