FOLLOWUP: SDOT still investigating ‘anomalies’ after West Seattle’s ‘low bridge’ breaks down twice in 5 days

| Transportation | West Seattle news

(SDOT camera image from Thursday evening)
Last night, for the second time in five days, the West Seattle “low bridge” – aka the SW Spokane Street Swing Bridge – suffered a “malfunction” that left it off-limits to traffic, both surface and marine, for more than an hour and a half (WSB coverage here). We failed to follow up after the Sunday incident (WSB coverage here) but sent an inquiry to SDOT first thing today. The communications team obtained and forwarded this reply from Paul Roberts, SDOT’s Structural Operations and Maintenance Manager:

Last night the bridge operator prepared to open the bridge for marine vessels. Once the traffic control gates were deployed, an operational anomaly occurred. This caused the bridge’s systems to fully stop, a process that prevents unintentional public safety issues or unnecessary risk/damage to the bridge itself during a system anomaly. Anomalies can occur because of (but not limited to) power supply surges, sensor alignment, controller system conflicts or component failure.

Bridge technicians were immediately summoned to the bridge to assess the incident and regain operational control. Although the bridge technicians were able to return operational control to the bridge operator, the cause of the anomaly is still under review.

The bridge technicians will continue working on the problem to identify the cause and contributing factors, and to figure out how these types of anomalies can be minimized.

Our archives show two bridge breakdowns in the span of less than a month last summer – in July, a gate pin was blamed for an hour-plus bridge outage; in June, a computerized measurement device used during bridge “docking” was blamed for a two-hour-plus outage.

SIDE NOTE: The “low bridge” is the only option bicycle riders and walkers/runners have for crossing the Duwamish north of the 1st Avenue South Bridge (aside from a bus or the Water Taxi). It’s been in service since the early ’90s.

Mike Lindblom May 8, 2015 (3:07 pm)

We who live in West Seattle are fortunate to have WSB patrolling our bridges, so to speak.

ChefJoe May 8, 2015 (3:10 pm)

(I’m recalling all the cyclists gloating “what slowdown” after the viaduct fish/spool incidents)
Yep, it sure stinks when infrastructure issues interfere with your needs.

WSB May 8, 2015 (3:18 pm)

In this case, cars couldn’t get across either, and what we noticed, walking out onto the bridge during Sunday’s outage, is that there is no way to notify people who are waiting at either end, whether cars, trucks, bikes, walkers … maybe some sort of BRIDGE MALFUNCTION: GO AROUND sign would be in order. As it was, I had to stop myself from trying to shout at the sadly waiting car at the west end on Sunday, GO BACK! IT’S BROKEN! Otherwise, you’re just sitting there, and if you don’t know to, for example, check here, you could wind up waiting a looong time.

MrsL May 8, 2015 (4:41 pm)

Was the malfunction tweeted on the SDOT bridges twitter page? Although, not everyone follows this or knows that there is such a page.

WSB May 8, 2015 (4:45 pm)

Yes, it was. https://twitter.com/SDOTbridges/status/596475074321887232 and others after that.

wetone May 9, 2015 (9:33 am)

City quote, “Last night the bridge operator prepared to open the bridge for marine vessels. Once the traffic control gates were deployed, an operational anomaly occurred. This caused the bridge’s systems to fully stop, a process that prevents unintentional public safety issues or unnecessary risk/damage to the bridge itself during a system anomaly. Anomalies can occur because of (but not limited to) power supply surges, sensor alignment, controller system conflicts or component failure.”

They left a couple things out, poor design and proper maintenance as seen in many cases around city with infrastructure. Needed money is being spent elsewhere. One thing I noticed while sitting in line to cross bridge Friday evening was bicyclist had no problems going underneath gates to cross bridge on their own with no city people around. Great law obeying people they were. No one should be crossing until city official gives ok for safety, no if’s and’s or butt’s……