Surveyor Tracks

During college, I worked summers as a "rodman", the third (and least skilled) member of a survey crew in the pre-technology era. [Actually, our company did have one electronic distance measuring system, which was as bulky and heavy as it was expensive. I was on one of the few crews that used it, but that is a different story.] Most of our work was construction surveys, mixed in with some pre-design and residential work. As a result, I can "see" plans on the ground when I see the stakes set out by surveyors, the "tracks" that allow you to follow their work.

Back in March, we toured some of the places related to the construction of the new parking ramp, including the apparent locations of the corners of the building. Construction of the storm sewer, a necessary step before above-ground work can begin, is underway and you can see what is used to do that work in the area west of TPP. You might also check out the almost-complete parking lot NW of the SM building, the survey markers related to the pedestrian bridge that should be built in the next few weeks, and the work starting today on the connection to the electrical system (from TPP to the garage).

The first picture shows a collection of "surveyor tracks" laid out in mid July. The picture was taken between the faculty and student lots to the west of TPP, looking south. The same area is shown in the last picture posted in the March blog, which was taken from the health programs entrance looking west. (Click the photos to see them full size.)

The stake labeled "corner?" is the one that was there when we visited in March. It is no longer there, making me wonder if the stake labeled "new?" is where the corner of the building will actually be located. Time will tell.
The others are all related to the new sanitary sewer being installed across the student parking lot during July. That work was done on a line running south from MH140 (manhole number 140) through the tree in the distance marked "alignment". MH150 is just past that tree (which is no longer there as I write this), with new pipe extending south to a point opposite the Student Union. That tree is in the background of the third picture in the March blog, showing the south side of the building. MH150 is just to the SE of the future SE corner of the building (just as MH140 is to the NE of the NE corner). More on MH130 in the third photo.

This second picture is a closeup of two of the stakes in that area. The tall stake with flagging on it is normally a "guard" to help you locate the actual stake and to give you information about the location. The actual location is marked by the rectangular wooden stake (we called it a "hub") at ground level.

The stake in the right half of this photo is the one you see in the previous photo above. The writing translates as centerline (C/L) of sanitary sewer manhole (SSMH) 140. Some writing is crossed out because either the rodman or crew chief made a mistake that was caught later. The stake on the left is an offset (O/S) stake. It is located 30' from the center of the manhole, and the hub has a known elevation (64.31 feet above sea level). There is also a 15' o/s stake. These are used by the contractor to locate the manhole (and its depth) once the centerline stake has been dug up during construction.

Remark added: The notation used is that a sanitary sewer is SSMH, while a storm sewer is SMH. You have to pay attention. The difference between what is flowing inside them is significant.

This last picture is a view looking west from this same location. You can see that MH130 is off at a diagonal from MH140.
In the distance is MH 120, indicating that the pipe will run along the north edge of the parking ramp toward the small holding pond in the background. There is a stake indicating that MH110 will be right at the edge of the pond. (Later work will expand this pond to bring our stormwater system up to current standards and make up for the part taken up by the new building.)

Update added on 10 August: Talked to the contractor today, and he told me that SSMH110 is where this new sanitary sewer line will intercept the existing sewer line. (That area has now been dug up, and pictures of that area will be blogged separately.) The current sewer line flows along the road, under where the building will be. That would interfere with the foundation, so they are diverting it around the east end of the building.

Final note: The numbers for the manholes go up in steps of 10 so that others could be added in between without having to mess up the sequence or renumber all of them. Our practice (at a company in Michigan) was to number them uphill, but they did the opposite in this case. Pipe is laid working uphill, which is what they did here (starting at the outlet end of the detour, west of the union, and working up towards the intercept point by the stormwater pond).