The feasibility study was started yesterday with the drilling of a 6" hole about 75 feet in front of the locomotive. The drill broke into the tunnel at a depth of 36 feet. Today a second hole was drilled over the locomotive. The ground rises between the two holes and the second hole broke through the tunnel at 45 feet and made contact with an object, probably the locomotive, at 55 feet. It is 18 feet from top to bottom in the tunnel. A street runs more or less parallel with the centerline of the tunnel and from the pavement level to the top of the tunnel is about 24 feet.
At both holes the tunnel had water up to the top. The water is about 6 or 7 feet deep with mud beneath, presumably down to the bottom of the tunnel. Pumping was started today and, assuming that the water can be removed faster than it is coming in, on Monday the camera crew should get a good look at the top 6 or 7 feet of the tunnel, maybe a foot or two more if the holes are to one side or the other of the centerline. Perhaps the camera will get an image of the stack and maybe a dome.
Petye Claussen

Do you know how much water you may have to pump assuming the water is not comming in faster than you can pump it out? I guess I am also asking how many feet of tunnel may still exist that you will have to empty to get a look at the locomotive?

John Bohon

The locomotive is 14' 6" to the top of the stack. The tunnel is 18', although it is uncertain whether that is from the floor or the top of the rail. In any event, there would be a minimum clearance of 3 1/2 feet from the top of the stack to the bottom of the tunnel. The water is six to seven feet deep measured downward from the top of the tunnel, so about three feet of the top of the locomotive should be exposed if all the water is pumped out.
The second bore hole should be right on top of the locomotive near the stack, so the camera should identify the stack even if all of the water is not removed. The camera can operate underwater.

Water in the tunnel, huh? Where on this site did I hear that the tunnel was full of water?

Later!
Mr. Ed

I understand that the locomotive is very close to one end of the tunnel, like maybe 200 feet or less. Does that end have the portal that is walled up as depcited in photographs taken shortly after the accident? Is that walled up portal still exposed or has the cut leading to it been filled in since the accident? If the wall is exposed, is it alone holding back all the water in the tunnel?

I can see how the tunnel would fill with water if both ends were sealed. It would act like a dry well collecting seepage from above. I am wondering if the ground elevation at either end of the tunnel would allow it to be drained rather than pumped.

Good luck, and be careful with that drill striking the engine.

RTK

The locomotive is about a city block from the west portal of the tunnel, which is sealed off with cinderblocks that are all that is holding back the water. The tunnel rises to the east for most of its length and then drops at the east end, which is not completely sealed.
As of about noon today about a foot and a half of water had been pumped out of the tunnel. Interestingly, seepage at the west end has increased noticably since the two bore holes were drilled, suggesting that from the west end east to some point, probably a cave in, the chamber is fairly air tight. Additionally, pumping was stopped for about six hours and there was very little change in water level, suggesting little inflow.
The drill probably hit the engine but drilling was stopped immediately so there should be very little drill damage.
Camera work will be done Tuesday at the earliest.

Has a photo of what this locomotive might look like actually been posted?

You know Pete, if you were to knock out the bottom cinderblock, it would save you a lot of pumping..........

dave

Pete,

If you decide to recover the engine, what is the plan? It seems to me that there would be three options:

1) Daylight the tunnel, starting from the west portal.

2) Shore up the tunnel, starting from the west portal.

3) Dig straight down to the engine.

Number three would probably be less work in getting to the engine, but then it would have to be lifted out, whereas with number one or two, you could roll it out.

RTK

Any news?

What's happening? Has work stopped on this project?

Later!
Mr. Ed

Work has stopped. The last I heard they needed to get some permits from the city and bring in a hydrologist to determine if the tunnel would collapse when the water was pumped out. I think this study will take a couple of more weeks. Perhaps Pete Claussen can fill in any details I have missed.

John Bohon

OK, thanks!

Later!
Mr. Ed

I am very interested in learning more about this project. It would be particularly interesting to learn how the hydrologist will determine whether the tunnel will cave in if the water is pumped out, and also, what the consequences of a cave in would be. From what I have read, it sounds like this tunnel bores through relatively unstable soil, and has been in a nearly continuous process of sporadic caving since its inception, occasionally swallowing buildings and other surface features.

RTK

I have been remiss in keeping everybody posted,
After the holes were drilled we found that water was up to the top of the tunnel and, surprisingly, the seepage at the west portal increased substantially. This means one of two things: either that there was negative pressure in the tunnel keeping the water from exiting the west portal at a greater rate or the borings hit an underground stream that began pouring water into the tunnel. The latter is quite unlikely because pvc pipe was pressed into the borings under very substantial pressure and it is unlikely that water was coming in between the soil and the pipe.
So, subject to confirmation, it appears that the tunnel is under negative pressure and that pumping the water out would reduce the risk of collapse ( think of this as a gas can that you try to pour gas out of without opening the little plastic stopper - when you open it the gas pours out. Drilling the holes has the same effect.)
The hydrologist and the city engineering department are going to study this and see if it appears that the water can be pumped out without endangering the tunnel. The city's concern is legitimate - the tunnel is 4000 feet long and goes under quite a few structures, and has had collapses in the past.
The borings showed water in the top third of the tunnel and muck beneath.
Pete Claussen