By Tracy Record
Editor, The South Park News
Two weeks ago tonight, a King County Road Division manager told the North Highline Unincorporated Area Council‘s monthly meeting in White Center that the South Park Bridge project was running a few months behind schedule. It was a response to a question – not a scheduled presentation – but it led to a formal announcement the next day, and something of a collective sigh from a neighborhood that’s already waited more than two years for a bridge.
Tonight in South Park, a county team including project manager Tim Lane, new Road Services director Brenda Bauer, and bridge-project communications liaison Ashley DeForest presented a more detailed look at where the project stands and what kind of timeline they’re expecting – minus the big date everyone’s looking for, a revised completion date. (Representatives were there from the city and from County Councilmember Joe McDermott‘s team.)
Lane described this as a preview to the next “photo show” in January – the periodic type of update they’ve been presenting to the community. He focused tonight on the caissons – the hidden (underwater) parts of the bridge piers.
The South Park side of the bridge goes down 70 feet to the “dense” riverbed, while the other side goes down half again as much, 105-foot depth.
In the river, “we’re constructing things, and promptly burying them,” Lane explained.
In the process of burying one of the caissons, they hit medium-to-dense clay and a digger called a “clam bucket … just was bouncing off this material,” unable to dig. So they lowered a giant chisel to try to break through and “it failed miserably,” Lane admitted. “It took several days before that idea was scrapped.”
Next thing they tried: Water jetting, to pump high-pressure water into the base of the caisson, “to try to dislodge it.” The water-jet equipment was 75 feet tall, and it didn’t work that well immediately, so they went into overdrive, overtime, double shifts six days a week. Still, using the water jet to blast away underwater “was a pretty slow process,” he explained. Every cycle would get them an inch of depth, even methodically going back and forth inside the cells of the caisson. Once they’d loosened enough material to scoop up, the jet had to come out of the water, scooping ensued, then jetting resumed – all a very slow process.
At that point, one business owner interjected that he had only seen a few workers at the site at a time.
Lane went on to say they couldn’t double up by working in two areas – the construction had a very specific sequence. For one, once the caisson was in place, its walls had to be poured, from the bottom up, getting ready to install the draw span. Then there’s the demolition work that needs to be done; one crane that had long sat on the old bridge has now been removed. It’ll be used to work on one of the piers – once a trestle is built for it to rest on.
The entire bridge over the water has to be removed before new girders can be brought in.
And also, they had a sequence where they’d alternate between piers – but when one caisson “got bogged down,” that sequence was disrupted. He showed a spreadsheet showing they’ve “made many attempts to resequence work to make up lost time,” but just can’t. The “fish window” when in-water work is prohibited is a factor too.
He also recapped what HAS been done – approach spans are done on both sides; an underground drainage vault on the Boeing side and other drainage structures; a tunnel 40 feet under the river bed connecting the main piers. No, this is nothing like the Alaskan Way Viaduct replacement – it’s a 26-inch diameter tunnel for power cables, 200 feet long.
A mile downriver, they’re putting together draw spans and supporting towers, with components assembled in Montana and Utah, “to the ten-thousandth of the inch,” brought in by truck. And in a warehouse off West Marginal Way, electrical,mechanical, structural steel parts have been fabricated, measured, tested, approved – they too have come from different parts of the country.
Though the caissons “have given us trouble,” he wrapped up, they “have both been sunk within an inch of the desired location.” And the sinking is now complete. “The good news is, we’re done digging in the dirt, and we’re coming up where things are more predictable.”
The lost time happened during the summer, Lane clarified – starting around Memorial Day.
Getting back to the question of why it didn’t look like many people were working on the bridge at some points, Lane mentioned that for example, the aforementioned boring involved a machine run by three people at a time – and other activities, he insisted, were happening “out of sight.”
That wasn’t much consolation for the businessperson. “You guys need to move it, you know?” Lane said at that point that some parts of the project are going back to double shifts.
They were asked how soon the demolition would start on this side – watch for the “little brick tower” to come down, Lane said, and then for crews to go into the guts of the bridge, leaving just a “steel frame” which will be pulled out with a crane, preserving some art elements to be used on the new bridge. Then “just the frame of the old truss” will remain. “There’ll be a lot of spectacular things to see in the next six months,” he concluded. (That work, Lane said later, will start as soon as next week.)
Going back to the LAST six months, another business owner said, “It would have been really nice back in May, or June, to have known (about the problem), since it affects the whole community. … We have been hit tremendously by only a four-month warning that the bridge was going to be closed (in 2010), and now this setback. The business community has had a really tough time.”
Lane explained, “When June came and they were trying to chisel trying to jet, we had every hope along with the rest of you that things would get caught up and start working … we truly didn’t know where we would be until toward the end of it … then they went into this big scheduling exercise, trying to rearrange things … We had to wait until we knew for sure, and then we started to get the date out.”
DeForest said, “And we still don’t have a date (for completion) … which is a very uncomfortable place to be …”
Another attendee wondered if there had been enough communication about the meeting; DeForest said they had circulated flyers, used online sources, updated the media, used a mailing list of about 1,000 people they have, but they couldn’t use postal mail this time because this meeting wasn’t arranged till about a week ago.
“For this delay, who pays and how much?” another attendee asked.
“We’re in discussions with the contractor about reasons for the delay,” answered another county manager, saying that the focus, though, remains “making sure we get the project done. … It’s a complicated issue. We’re trying to work through that with the contractor” and they’re not close to figuring out “who’s responsible.”
Once it does open, it’ll be in phases – one lane each way, then all lanes driveable, then finally completion – so even if some are driving on it in early 2014, it won’t be completely done.
“Getting cars going down 14th again is the main focus,” DeForest reiterated.
And again, they reiterated, there is no ballpark estimate for when that will happen.
They’re just trying to plow ahead – especially considering that they are in a “fish window” where they can do in-water work, till February 15th.
P.S. We reported earlier that the city is planning to add $150,000 to its budget to help businesses; the county says it’s trying to add some money to that, too.