Wednesday, April 17, 2019

A dirty job, but somebody’s got to do it

By Joe Calabro

They told me it would be gross. They said it belonged on that show "Dirty Jobs." I'd be covered in dirt, and feel it my teeth, they warned.

They were right.
A look up at a Ship Canal Bridge expansion joint. Vehicles pass over at highway speeds.

Twice a year, we delay the opening of the I-5 express lanes through Seattle for a particular type of weekend maintenance. Crews use the morning closures to clean the drains on the Ship Canal Bridge. These drains, known as scuppers, collect whatever comes off the I-5 mainline and through the expansion joints.

If we don't clean the drains regularly, water can spill out the sides or find its way to the express lanes, creating a safety hazard for drivers.

A team effort
So why close the express lanes and not the upper bridge deck itself? Crews approach the scuppers from below, in the express lanes. A lift takes a team of three — two to clean and one to operate the lift and carry a high-powered hose — to each of five box beam girders that span east to west below the bridge's surface. After being harnessed and lifted 30-40 feet into the air, crewmembers crawl through a hole in each girder with shovels and hose in hand.
Maintenance crews are lifted up to a narrow hole in the girder where they crawl through.

Their mission is to clear the two drains located in each girder and confirm the downspout (about the diameter of a golf hole) is draining smoothly.

It's surprisingly roomy inside the girders. I'm 6-foot-5 and I was able to stand upright, as was our 6-foot-4-inch supervisor. There's almost enough space to stand shoulder-to-shoulder, but not quite. Two other scuppers are about half the size of this one.

And yes, it was gross.

A trough with water at shin-level ran the length of the girder. Piles of sludge had formed. Cigarette butts and a few pieces of plastic floated around us. The noise of semis, buses, motorcycles and passenger vehicles just inches above our heads made it tough to communicate. It was eerie to see the shadows of highway-speed vehicles appear, then disappear in an instant.
The hole crews crawl through now is much wider than the previous entrance behind the shovel

A hose and shovels are used to collect and remove sediment.

After clearing the drains, one crewmember uses a shovel to collect the sediment and push it toward the drain, while the other maneuvers the hose to break it up so it flows down the drain. Loose sediment often escapes the trough and falls to the express lanes during this process. This is the most important reason to keep the lanes closed. The debris could crack a windshield, startle a driver or affect visibility. At ground level, a vacuum truck collects whatever the crew pushes into the drains.
A cleared drain and the downspout that leads to ground level. The downspout is about the diameter of a golf hole.

Crews close the express lanes because debris often spills out during the cleaning.

Safety is job No. 1
Crews are pressed for time during each of the cleanings. It's safer to work when it's light out, so they generally start later than other maintenance operations.

The crew takes a number of safety precautions when they head into the girders, including wearing personal protective equipment and harnessing themselves to the lift as they head up and into the girder. Unfortunately, there's also the added risk of a wrong-way driver who enters the express lanes. A fourth member of the crew stays in the water truck below to supervise.

While cleaning a drain may sound simple, I saw first-hand it's not easy, or pleasant. But it was impressive to watch our workers tackle it. It's not just a dirty job, worthy of a visit from Mike Rowe; it's an important one.