January 6 - Trenching and Piping

Correction - 
In the last post, I stated that plumbers are half a bubble off. That is not accurate. The correct measure is a quarter bubble off. A quarter bubble off of center indicates a 2% slope to the pipe which is the desired pitch for these drain lines.
Plumbing Facts -
Don says there will be about four hundred feet of pipe buried beneath the floor of the church. Our local landmark, Minnehaha Falls, is about 50 feet high. So if the buried pipe were stood up in one column, it would be about four times as high as the falls. This seems like a lot of pipe to me, but when there are sinks and toilets in about every corner of the building, it is necessary to accommodate drains for all of them. Here Don and Brandon are setting in a twenty foot length of pipe.
When Don made a trial connection to the previous pipe, he checked the pitch with his level. Satisfied with the quarter bubble on his end, he then asked Brandon about the other end. "Screaming", Brandon replied. Screaming? What does that mean, I inquired. "Too steep. We need to pack a little dirt under the pipe to reduce the pitch."
OK, Don, this is a drain line, right? It needs to get the stuff downhill and out of the building, right? Aren't the contents going to be carried down the pipe? How can it be too steep?
Don patiently explained. If the pitch is too great, the liquid will run past too fast and leave the solid matter stranded in the pipe. With drain lines, clean pipes are desired. No islands left behind. With modern one gallon flush toilets the shallower  pitch is more necessary than it was with the three gallon flush of earlier generation toilets.
This conversation reminded me of our first apartment after our marriage. Marilee and I lived in a small apartment upstairs of my grandmother's house. The house originally consisted of a store in front and living quarters behind. As the family grew, so did the house, adding on rooms above and behind. Indoor plumbing was retrofitted in after the sewer system was brought into the neighborhood. Our bathroom had a bathtub sufficiently short that my chin rested on my knees while bathing. The flush system for the toilet consisted of a size large water tank mounted very near the ceiling above the toilet. Pulling a chain released the water which slammed through the toilet bowl with terrific force. This was back in the cloth diaper days and I recall losing a diaper once by having it sucked through the toilet trap with an untimely flush. You did not want to be sitting on the toilet while a flush was in progress, for fear of suffering the same fate as the diaper.
The Mini trackhoe -
I understand the proper name for the digger that Greg used is called a mini trackhoe. While it may be a 'mini' as excavation equipment goes, it was pretty big for use inside the building, especially in the flat ceiling areas where all the digging has occurred to date. The operator has to be careful not to crease the drywall ceiling with the boom while maneuvering the bucket in and out of the trenches.











The picture on the right shows the dirt removed from the long trench
back to the kitchen area. Even a mini trackhoe moves a lot of dirt.

When you need to get back in the corner and there is a trench in the way, just use the machine as a bridge.

 Or when the wall is too close to allow visibility in front, just stand up and lean out of the cab, operating the controls behind your back. Perhaps that is something like riding a bike while sitting backwards on the handle bars.

The cab on this machine can turn in every direction and also do 360 degree revolutions. Don told me that the operators on some jobs he work on said they liked to just spin several revolutions at the end of the day, just to help them unwind a bit.


The Murphy Window - 

 In an earlier post, I noted that there is an extra window. Now I have come to understand that it is actually a Murphy window, according to Bill Sturos. He apparently is a student of Murphy's law which state that anything that can go wrong will, and at the most inopportune time. Bill told someone that as long as we have the window around, it will remain an extra. However, as soon as the window is discarded, Murphy will show up. So, we better keep the window.