(Added: Newly released WSDOT video recorded by a drone inside the tunnel and tunneling machine)
12:06 PM: “Tunneling is going very well.” So said Chris Dixon of Seattle Tunnel Partners, the state’s contractor on the Highway 99 tunnel, during a media conference call wrapped up a short time ago. He said there’s been no problems – “no adverse effects, no settlement, no movement” either with the machine or with the ground through which it’s tunneling and the first Viaduct “bent” under which it’s gone. As for the distance they’ve gone – 117 feet so far, of the 380 that will get them to the other side of the Viaduct’s underside – he said it’s about what they’ve expected. We’ll have full details in a bit.
12:30 PM: More details from the call: They’ve now mined 17 “rings” since leaving “Safe Haven 3,” the stop before going under the Viaduct. The “bent” under which the machine has gone is numbered 98W – “W” for west, and it’s now under 97W, with 96E next, “the column in the intersection of Yesler and Alaskan Way … after we pass that, (they go under) 95E, the foundation on the east side.” The next one is the one to which the machine gets within 15 feet, as much mentioned prior to this phase of tunneling. They’re expecting to average about 4 rings a day but Dixon warned not to be alarmed if a day shows less progress than that, because they are stopping the machine here and there along the way for maintenance and for replenishment of the soil conditioners they’re using while moving ahead – the first day of this phase was 1 ring, then three on the 30th, seven on the 1st, and six yesterday.
Its average speed, Dixon said, is 30 millimeters per second, with the capacity to go twice that fast, and indeed they expect to go faster once the machine is past this phase – averaging six rings a day in the next phase. In response to another question, he stressed again, “we’re right where we anticipated we would be.” And he said they’re far enough out of “Safe Haven 3” that there’s no longer any concern of a sinkhole or other disturbance atop that area.
No traffic updates, since this focus was on the tunneling itself, but WSDOT did say, don’t get complacent and go back to your old ways – “please find different ways to be out there ‘off peak’.”
P.S. We’ll again have special afternoon/evening commute coverage here on WSB, starting around 4 pm. In the meantime, the commute conversation continues in comments following our Tuesday morning coverage.
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