Sunday, June 16, 2013

To Build a Bridge Part I - Intro

Whose bridge is it?

The bridge carrying Greenfield Avenue over USH 45 in Milwaukee County, Wisconsin
The above is the bridge to be replaced in this little series.  It is aging and showing it.  Right now it is structurally just fine (even if parts of it don't really look like they are) but it's old and will soon be far too small.  So it will be be taken down and replaced with a new, better, bigger bridge.

But whose bridge is it?  The taxpayers (largely through the gas tax, but also with state and federal money) will be paying for it, the state department of transportation (WisDoT: Wisconsin Department of Transportation) owns it.  Which is another way of saying the people own it.  The state legislature passed the bill that payed for it and it was the Governor that pushed it through and signed it.  A construction company got the contract and will actually build it; them and their subcontractors.

Anyone on that list can call it their bridge and be right.  But I'm the designer: I ran the calculations and assembled the plans and laid the whole thing out so it's my bridge.  Not mine alone, but it's certainly mine.  And what I'll try to do here is explain some basic things about bridges using this one as an example.

If anyone has questions about what I say, wants a clarification, or wants to suggest another subject they'd like to know more about, feel free to leave a comment.