‘It’s like a ballet’: Tunnel cleaning major PennDOT priority
Ben DeVore likes to keep his office clean.
Unlike most office workers, though, the safety of thousands of motorists depends on the cleanliness of his workspace. Mr. DeVore’s office is the Fort Pitt Tunnel.
The tunnel maintenance manager for the Pennsylvania Department of Transportation says clean tunnel walls are necessary to keep traffic flowing smoothly.
“Washing tunnels is very important because light in a tunnel is a major issue for motorists, and it keeps them moving,” Mr. DeVore said. “The darker the tunnel gets, the slower they go. And if the lights aren’t on in the tunnel, they’ll stop. So the tile in the tunnel, part of their use is to reflect light from the light fixtures in the tunnel to keep it bright in there.”
A crew of three PennDOT workers and a supervisor washes the Fort Pitt, Liberty and Squirrel Hill tunnels in a rotation from April through November. It also cleans the Stowe Tunnel and Bates Street underpass twice a year. Overnight Wednesday and Thursday, the crew washed the inbound side of the Fort Pitt Tunnel.
The cleaning process forces PennDOT to shut down a lane of traffic overnight as the crew works. Although the lane restrictions might cause a delay for motorists, Mr. DeVore said washing the walls is a necessary part of maintaining the tunnel.
“The exhaust that sticks to the walls, the salt that sticks to the walls, all that stuff that works its
way into the structure itself is very dangerous and can lead todeterioration,” he said.
The crew begins its night’s work putting on reflective vests and hard hats and making sure its equipment is working properly. PennDOT employees can request to be placed on the wash crew each year, and are trained to use the equipment if they are selected.
The truck that the crew uses to clean the tunnels holds 500 gallons of water and is equipped with a special boom that can move 180 degrees. At the end of the boom are four scrubbers as well as a water spray bar and a soap spray bar.
Before PennDOT got the wash truck with the capability to spray water and soap and scrub, a crew would have to use three trucks for each part of that process. PennDOT bought the truck 13 years ago from Ohiobased Diamond Specialized Inc.
One of the crew members drives the wash truck at about 2 mph through the tunnel.
Another worker controls the boom on the truck, making sure the walls are getting a proper cleaning. The third crew member drives a socalled crash truck — a dump truck with a crash cushion on the back — behind the wash truck to protect the crew and equipment in case a vehicle swerves into their lane.
“Working on any roadway at night has its inherent dangers,” Mr. DeVore said. “We have crash trucks behind our workers as well so that if a motorist were to drift out of their lane, they’ll hit that truck rather than hit our workers.”
The crew works on one wall a night, and cross passages take another night, so each tunnel takes about a week to complete. It’s continuously working, washing each tunnelin a three-week cycle.
Before the wash crew can begin, the lane where it’s working has to be shut down. Signs signaling that a lane closure is ahead are put into place, an arrow board alerting drivers to move over is put into operation, and cones are placed throughout the tunnel.
“It’s like a ballet,” Mr. DeVore said. “The guys do it so often that they know exactly what they’re doing, and they barely have to think about it.”
The wash crew then enters the tunnel, slowly working its way though while avoiding light fixtures and other obstacles.
Once the crew members make it to the end of the tunnel, they have to go all the way around to get back to the other side. In the case of the Fort Pitt Tunnel, the crew drives over the Fort Pitt Bridge to Downtown, then back over the bridge and through the tunnel. They get off at the Banksville Road exit and circle back to Interstate 376 inbound, where they can start the process over again.
The crew will pass through the tunnel at least three times during the night before the job is done. But by the morning rush hour, the only sign of the work should be clean walls.
“If we tried to wash the tunnel at 7 o’clock in the morning it would cause a big problem for people going to work,” Mr. DeVore said. “So when we do it at night, the impact is minor and usually by midnight or so there’s no queue of traffic.”