The pier was gotten off the top of a mountain in northern Georgia not far from Chattanooga, Tn. Tim Puckett had advertised the pier in Astromart, and I decided that this was a possibly great Christmas gift from my wife. We coupled the visit to the Georgia mountain with a visit to my family in Missouri.
In January of 1999, I began serious consideration of just where the pier would be placed. The back yard is has too many trees, so that was out leaving the front yard. The placement of house, garage, trees, and other landscape features produced the best site. Can't say much more than this. The choice was local horizon chosen to give me the best southern view period.
Given the location, the depth of the hole was next considered. At our location outside Washington DC, we don't get extensive freezing, Frost line at the worst case is about 18 inches. I went down two feet and cut out a hole about 18 inches in diameter.
The pier is a 7 inch diameter heavy steel tube that has been welded on a one inch steel plate in the shape of a triangle. a hole for a 1 inch bolt was cut in each vertex of the triangle. The hole is large enough for the bolt plus about 4 degrees of play.
My goal was to mount the pier so that a line drawn through the southern vertex of the triangle passing through the center of the pier would point true north.
This goal was complicated by the simple fact that magnetic north is a good bit off from true north here in the Washington DC suburbs, and since I had an error window of at most plus or minus 2 degrees (because of the size of the holes in the pier), I decided to determine true north with all the precision I could get. To accomplish this, I turned to the The National Geophysical Data Center . This web site, and its supporting staff were very helpful in finding the correct ajustment to make to the compass setting to show true north.
The pier has been placed in my front yard. It's color was originally a bright cheery yellow, which caused a bit of confusion in the sedate suburb or Potomac. Nothing that bright or cheery had been seen in the neighborhood in years. Not since a colorblind neighbor painted his house lemon yellow accented with lime green has such a sight been seen around here. After consulting a soothsayer, I painted the pier a flat black, the result of which was that the pier disappeared into the local landscape, and the local population seemed to seemed a lot more comfortable..
Having set the compass to offset for the correct location of magnetic north, I then took a 100 foot length of cord and tied two stakes, one at each end. I then fixed one stake in the ground about 50 feet to the north of the hole. I then went to the south side of the hole and by eye, set the second stake so that the string would cross the center of the hole. I then used the compass to check for error.
After a bit of trial and error, I positioned the string over the hole such that the string was on the North-South line, and pointed at true north.
I next cut a 2 foot square of half inch plywood and centered the pier on the board. I then marked the center of the holes on the board. I then drilled three one inch holes in the board to accomodate the mounting lugs.
After fitting the lugs into the holes, and checking to make sure that the lugs were square with the board, drew a line from the southern lug through the center point between the othe two indicating the direction of true north. I then set the assembly asside to pour the cement.
I now mixed nine bags of cement, one at a time, and poured it into the hole, being careful not to foul the north-south string. This took a little over 40 minutes to complete the pouring.
When the cement was level with the top of the hole, I took the plywood board with the mounting lugs and placed it atop the cement, pushing the heads of the lug nuts into the cement. I then tested the squareness of the lug nuts to the board one more time using a carpenter square.
I then used a level to make sure that the plywood board was level in every direction. Where it was not, I pushed down on the board in the needed position.
As a final check, I made sure that the north-south line on the board and the north-south string were parallel. That done, I let the cement cure for 2 days.
