Night blasting for the Sellwood Bridge project has been rescheduled from tonight to next Wednesday, March 20. The blasting subcontractor postponed tonight's blast to perform more work on the next section of rock that will be blasted.
The first two blasts last night (at 11:40 pm and 3:35 am) were very successful in fracturing rock on the hill west of Highway 43. Multnomah County received no complaints about noise from the blasts or traffic delays. The blasting is needed for the excavation work that will widen Highway 43 for a new interchange with the bridge.
Next week several blasts are planned the evenings of March 20 and 21. The blasting is expected to take four weeks to complete, with blasts several nights a week.
For more information, visit the blasting page.
Drivers crossing the Sellwood Bridge over the next month will be instructed to turn their cell phones off. But, as Kristian Foden-Vencil reports, authorities say there's no risk if you don't.
A couple of nights a week, for the next month, engineers will be blowing up massive boulders at the west end of the bridge. It's to make room for a big new junction.
But while the blasting is going on, there'll be big orange signs telling people to turn off their cell phones and two-way radios.
Don Hamilton of the Oregon Department of Transportation says it's a case of bureaucracy lagging behind technology.
Hamilton says, "In the past when the blasting involved electrical blasting caps, there might have been a risk that there was some interference. But now with the use of microprocessors, there's absolutely no risk ... from two-way radios or cell phones."
Night time blasting is scheduled on March 13 and 14 as part of the Sellwood Bridge construction project. The contractor is excavating the hill on the west side of Highway 43 north and south of the bridge. Blasting is needed to fracture underground rock into smaller pieces that can be excavated during the work day.
The bridge project will construct a new Highway 43 interchange at the new bridge that will be wider than the existing interchange. The west hillside will be excavated over the next few months and then retaining walls will be built to hold back the slope. By 2014, traffic lanes will shift to the west and the contractor will begin rebuilding the east side of the interchange.
The contractor expects rock blasting will be needed as many as four weeks this spring. Normally, blasting will happen on two or three weeknights in a week. On a blasting night, two or three blasts will typically be detonated. The first blast will happen close to 9 p.m. and the later blasts will usually happen between midnight and 3 a.m.
Highway and bridge traffic will be held for five to 20 minutes for each blast to keep the public out of the blast area. The outside southbound lane of Highway 43 will be closed near the bridge from as early as 7 p.m. to as late as 5 a.m. on blast nights. Travelers can avoid delays by using alternate routes.
Blasting is scheduled at night to minimize impacts to traffic. Blasts happen late at night due to procedures the contractor must follow for documenting the first blast and setting explosive charges before each blast.
Five minutes and one minute before each blast, a warning siren will sound. The siren will likely be louder than the blast itself, which happens deep underground. Click here for more information about blasting.
- Day: The outside southbound lane of Hwy. 43 is closed from 7 am to 4 pm weekdays between SW Taylors Ferry Road and the bridge while the contractor excavates the hillside west of the highway.
- Night: Blasting is scheduled on March 13 and 14 as part of the work to widen Highway 43 for the new bridge interchange. On blast nights, intermittent closures of traffic lanes and the highway and bridge will happen between 7 pm and 5 am. Highway and bridge closures will last from 5 to 20 minutes for each blast. Five minutes and one minute before each blast, a warning siren will sound. The siren will probably be louder than the blast itself. Two or three blasts are scheduled each night between 9 pm and 3 am. Travelers can avoid delays by choosing alternate routes on blast nights. Click here for more information about blasting.