Talk about spring cleaning.
Your cluttered basement and spotty windows are child's play compared to what Maryland Transportation Authority workers are tackling this month: They're scrubbing the 9 miles of tunnels that run under the Baltimore Harbor, from top to bottom and side to side.
The Fort McHenry and Harbor tunnels are filthy. They have not been cleaned since August, when drought restrictions took effect. Since then, car exhaust, diesel smoke and road grime have turned the white tile walls a dingy brown and dimmed the bright ceiling lights.
"I've been doing this for 15 years, and I've never seen it like this," said Willie Barrett, foreman of a wash crew that was cleaning Bore 3 Thursday night. (That's the left tunnel on northbound Interstate 95.)
Besides the water restrictions brought on by last year's drought, crews were hampered by a cold, snowy winter. The tunnels can't be cleaned when the temperature is below freezing, or when snow is caked on the walls near the entrances, which happened this winter.
In the months since the last cleaning - the longest the 17-year-old Fort McHenry has gone without a scrubbing - about 24 million vehicles have passed through the four tubes, leaving a layer of oil and grime.
This is what the Unimog was made for. To clean the tunnels, the transportation authority uses three $250,000 Mercedes-made machines that each require two operators. The machines carry a 250-gallon vat of cleaning solution on the front end and a 7-foot-long blue brush at the rear.
The brush can be manipulated to reach high and clean the ceiling or stretch out to the side to clean the walls. It is soft enough to clean the lights and tough enough to agitate the dirt clinging to the walls.
"It's like an inside-out car wash," said authority spokeswoman Lori Vidil. Cleaning a single tube takes about 60,000 gallons of water, 360 gallons of cleaner and a week's time. The work is done only at night, when a tube can be closed and not disrupt traffic.
"You can wash anything with it," Barrett, the foreman, said of the Unimog. "I've had truck drivers pull me over and say, `Hey, can you wash my truck?' But we can't do that."
The wash crew mixes 15 gallons of a pink, heavy-duty cleaner/degreaser called GP-66 - made by state prisoners - with 200 gallons of water. The solution is pumped into the brush as it spins furiously against the tunnel walls. The Unimog travels slowly, no more than 5 mph, so the walls get a thorough scrubbing.
Following the Unimog are usually two rinse trucks, each carrying 2,500 gallons of water. As the cold water is sprayed onto the walls, the dirt breaks loose and cascades down the white tile in brown rivulets.
"The crud doesn't all come off the first time," said Barrett, explaining why two rinses are needed. "One rinse leaves lines on the walls, and we don't like leaving lines on the walls."
The thousands of gallons of dirty water trickle down to the lowest point in the 1 1/2 -mile tunnel and are filtered by the transportation authority before being pumped into the city sewer system.
"Usually Bores 1 and 4 are the dirtiest. They're the truck tunnels," said Frank Hartman, a maintenance supervisor, referring to the two outer tubes favored by truck drivers. "We'll scrub them twice because they're so hard to get clean."
It's about more than just good looks (though that certainly is a consideration). When the white tile walls are sparkling clean, brake lights reflect off them. This is especially important in the Fort McHenry Tunnel, said to be the only curved tunnel in the country. Drivers need to know if traffic is stopping around the bend.
It doesn't help matters that there's a coal plant next to the northern entrance of the Fort McHenry Tunnel, and when the wind is from the west, coal dust gets blown across the tunnel opening. "We'll get a black cloud over the toll plaza and sometimes the fans will suck it right into the tunnel," Hartman said.
(The tunnels have fresh air vents throughout, and when traffic moves slowly, air can be pumped in at up to 80 mph.)
When the weather is decent, the four tubes of the Fort McHenry Tunnel and two tubes of the Harbor Tunnel usually get cleaned every six weeks. So it's been a long time for them both, and they were showing it. State Transportation Secretary Robert L. Flanagan noticed several months ago when he took office and has been pushing to get the job done.
"It's good customer service," Flanagan said. "We want clean tunnels that people are happy to drive through. We want them to be proud of Baltimore and proud of their state. We're here to serve the public, and it oftentimes is making the effort on smaller things that really makes the difference for people."
The wash crew will soon finish with the Fort McHenry Tunnel and move on to the older Harbor Tunnel, which has seen about 14 million vehicles pass through since its last scrub.
"They say the Harbor's real dirty," Barrett said. For him, it's just another chance to do a good job. "Our work speaks for itself. People will call up and say the tunnel looks real nice," he said.