Over a year ago I was asked to be part of an inspection team, to walk/boat through the 12′ tunnel that connects the Loch Raven Reservoir to the Montebello Filters. This tunnel was built between 1875 and 1881. In the early years it was inspected quite often. In the 1960s it was decided, after a parallel tunnel was built in the late 1930s, to reverse the flow in this old tunnel to supply drinking water to Towson via the Cromwell Pumping Station. The old tunnel was last inspected in 1984. For that info you can see my post linked here: https://rep5355.com/2016/04/06/tunnel-inspection/
In preparation for the inspection, I did all the necessary training – Red Cross/CPR, Confined Space, etc. Then we were told that it was too unsafe to send anyone in the tunnel. Totally bummed!
So now they have finally gotten around to inspecting the tunnel with a remote operated vehicle. It has been a long week starting last Friday. First order of business was to clear the site for the contractor to bring in his equipment.
Area cleared and the phragmites sprayed.
Next, construction mats were placed across the phrag roots – which is very soft. (And the equipment very heavy) These boards did the trick.
The equipment was unloaded. This is the inspection vehicle. It is about 14′ long and weighs 1500 pounds.
This is the tether. The sub is connected to this. It is 7 miles long, but only needs to go 5-1/2 miles.
The sub will enter at the top right. This is looking down the shaft towards the tunnel.
Here she goes.
Because this is a pipe that is in use, with drinking water, everything that enters the water was sprayed with a chlorine solution.
The control center. All this information on all these screens will be made into a report for the City to decide if the tunnel is still usable. The interesting one is bottom center. If you watch that and there is a change in the circle, say a rise in the bottom, that means the sub is going over a rock fall. You then look at the camera display and you can actually see it.
In my previous tunnel inspection post is a photo where the balancing shaft enters the tunnel at Cromwell. It is mostly smooth. Unlike this entry point – it looks like someone busted thru the top of the tunnel with a sledge hammer.
The sub was moving at a nice pace – looked like the Enterprise going at warp speed! Not sure what those particulates are just yet. Probably just some stirred up lime deposits.
And when I got bored, I went looking for nature. There are 3 young bucks…
A couple babies.
An Eastern-eyed Click Beetle
Bunches of other bugs.
And our night time visitor looking for food.