Steel also has a characteristic that causes it to deteriorate in water. It gets wet.
So WashDOT likes to replace several cables regularly so that they are all fresh and no older than their useful life. In the case of the Evergreen Point Floating Bridge they will replace 15 of 58 cables this year.
These cables get attached to anchor blocks securely stuck on the bottom of the lake. The other end is snaked into the pontoons and cinched up to 65 tons tension. That provides a stable and motion free bridge. It won’t bounce up and down in heavy waves like those second rate floating bridges.
The process requires replacing one cable at a time. First they detach the old cable and haul it off to the scrap yard where it will be returned to the steel mill. Then it gets made into consumer goods such as toasters. Now I know why my toast is always soggy.
The high paid divers paddle down in 200 feet of water dodging rainbow trout and giant octopi to reach the bottom anchor. Using a Swiss Army knife they snip off the old cable. This is only done on the first one. The rest will have their 65 tons of tension released before being snipped off in 200 feet of water.
The upper anchor is inside a pontoon. It takes several days studying engineering drawings to figure out how to get into one of those things. Then they release the tension and slip the cable out so the divers can snip the lower ends.
Once the old cable has been pulled from the water and loaded on the scrap barge they get to work installing the new one. The process takes one day per cable. After the initial week or so fumbling with the first one, that is.
You probably think it’s a waste of time replacing cables on the SR 520 bridge since it’s due to be replaced very soon. By the year 2000 I think is the goal. Well those WashDOT folks are realists. They know this bridge replacement process could take years. They don’t want the cables rusting out and allowing the old bridge to break loose and float up to Kirkland.
Besides they need to keep the old bridge in use for most of the construction period to maximize the toll revenue. It wouldn’t do any good to stick a toll on it and then close it right away.
So my suggestion is that if you like that bridge then you need to go drive on it right now before they get the tolling installed and before they close it off for 12 years.
The Seattle mayor, Mike, wants to delay the replacement and revise the plans to add tracks for future light rail and make the HOV lanes for transit only – no car pools. He says allowing a lot more cars into Seattle from the north Bellevue area will cause a shortage in parking places in Seattle.
Actually Seattle parking shortages are self correcting. They just increase the cost to park in Seattle until the number of cars equals the number of spaces. So reducing the current number of cars on those bridges would just be a matter of raising the parking rates. Simple solutions for simple minds. Just before they close it for the replacement they could raise parking fees in Seattle to $100 a day and $120 in Bellevue. Everyone would switch to transit on I-90.
Please don’t share this with any elected officials because they might think it’s a good idea.
Another thing the steel mills make with the old cables is steel for transit vehicles. So get ready to ride a bus made out of old floating bridge cables. Don’t you just hate the damp seats?
Al
No comments:
Post a Comment