One of the things I still enjoy about my profession as a journalist is that we get to see and do things not everybody has the opportunity to do. On Wednesday night I watched and photographed the cleaning of a Fort McHenry tunnel tube by a machine called a “Unimog.” Any time a machine is involved in an assignment I’m all over it, and with this involving a couple of unique machines, it was right up my alley, or tube, in this case.
Shown are the two German made “Unimogs” cleaning the ceramic tiles through the left-hand, south-bound tube at the Fort McHenry tunnel. It is a continual process from April through Thanksgiving through all the tunnel tubes. It is a ten-pass process using a 6-foot brush similar to what is used in a car wash. This process takes a week per tunnel. They use approximately 60,000 gallons of water (total) per night, which is then run through the city’s sanitation system. The state has three of these quarter-million dollar machines, which have the ability to be used as a snow plow and grass cutter.
Once the “Unimogs” have gone through, two water spraying trucks follow for rinsing the tile. This is done for appearance plus much better reflective qualities, which will show the brake lights of vehicles around the curve of the tunnel. They use a solution called “soot-be-gone” added to water for their cleaning solution.
So next time you drive through one of the tunnels, and notice the tiles are clean, you will now know the process that does the job.