07 January 2010

Bridges news roundup

Architect plans Elliott Bay Bridge to replace viaduct
Here's a story that leaves me slightly confused. Seattle architect Roger Patten (pictured, right) has proposed a big bridge in place of a tunnel-and-viaduct proposal, and has been arguing for some years against the local state Department of Transportation. Criticising his scheme, the Washington DOT has stated [PDF] that "the bridge has a center span more than a half mile in length, longer than all but one completed suspension bridge in the world." Really? Half a mile is a piddling 805m, which is shorter than the top four cable-stay bridges and beaten by thirty suspension bridges.

While the DOT is therefore talking nonsense, it's unclear whether Patten's bridge makes much sense. Defending his concept, he noted: "They told Eiffel to take down his tower after the fair because it was an eyesore. They said the same thing about the Golden Gate Bridge. Maybe we should take that down, too." Hubris aside, his design relies on "buoyancy stabilised piers" (i.e. caisson foundations filled with air to offset the weight of the bridge), a daft idea that entirely ignores the fact that heavy foundations are normally required to stabilise the bridge pylons against overturning, which governs design more than the purely vertical load.

What will we name the new Forth bridge?
"Forth Replacement Crossing" is too dull; "Fourth Forth Bridge" likely to cause confusion because it's actually the Fifth Forth Bridge; so just what will they call it? Incidentally, according to the type of people who like to generate ridiculous newspaper headlines, the bridge is being designed by the same people who design Ferrari F1 cars.

Bridge petitioners declare victory
Reprieve expected for Victoria's Blue Bridge (see previous posts): campaigners against the Johnson Street Bridge replacement raise enough votes to put at least a temporary brake on their council's attempt to borrow CAN$42m towards the cost.

Bridges to prosperity
The always excellent Bridge Photo of the Day blog has several interesting posts on low-cost suspension bridges in Ecuador, which make a nice follow-on to my own posts on the same theme.

No comments: