A Virginia measurer, Lynwood Wagner, sent this account of how he came to lay out a 1,000 foot calibration course. I enjoyed reading his narrative and hearing how he thought through various problems along the way. He describes a nifty way to get the "feel" of pulling 20 pounds; he refers to a tape holding tool he devised; and (not mentioned here because he's already told me about it) you may notice that he is using another quite special tool. Can you figure out what it is? Here is his account:
Pinecrest Calibration Course Procedure
Measured a 5K in west end of Bristol early amid piles of snow in parking lots. Two of my portable thermometers in a row shot mid teens on pavement which I did not believe. Got out the expensive, big one which said 26 F which is what it felt like and compared well to the 38 F I got in Johnson City earlier calibrating the bike. One of the portables had shot 35.5 F in a puddle of ice water earlier in the week so I was double surprised. Got to the old Pinecrest calibration course with the intention of remeasuring the 1,056’ course from 2002. However, I could not find any of the nails there and there was a muddy construction project near the west / low end.
Deliberated and decided to just do 1,000’ and start farther up (literally as the course is on a 3% slope) the road. Old course was supposed to have been measured 2’ in but road was straight enough I measured in 1’ from the edge. The shoulder was gravel and dirt. Hank showed up as I was finishing my deliberations. Went to a spot as far east as road was still straight and set a nail and washer. Picked a shady piece of pavement and got a reasonable temperature of 36.2 F. Showed Hank what 20 pounds of pull would feel like. I had wrapped a string around a 20 pound dumbbell at the house the night before to recalibrate my brain.
I made a special holder out of a 1/8” steel strap, bolt, nuts and washers to make it possible to hold the zero end of my 200’ tape. This tape is numbered in decimal fractions of feet. Started taping downhill and after the 3rd tape, Hank got my attention and said he had been putting the 1” line on my marks. We went back to the top of the course and started over. After 5 tapings, we reversed places. Slow going as shade made running to mid tape to “kink check” a tedious constant necessity. We did not follow the prescribed procedure but recorded to 1/1000ths of an inch at each old mark. Marking the rough pavement (it feels like that using a fine ball point pen) was tricky and I was a little worried about dislodging my crummy old masking tape off the almost damp pavement. Mainly though I forgot I was supposed to do it that way. Our 5 readings were 200.000’, 200.015’, 199.975’, 199.925’ and 199.990’. That totaled 999.905’ which lead to reporting a final tape length of 199.905’.
Hunted for the old nails again. This time in better light, I found a big nail 2” from a small nail with the big one bent into the pavement at one end of the course. The old certificate did not say there were washers so I guess “those were them” although they were not 2’ in from the roadway like I expected from the certificate map. Hank left after that. I took another temperature in the same area and got 36.7 F. Did calculations and added .252’ to lower end and nailed and painted it.
Rode up the hill and recorded 641,000 at the top nail, 640,062 at first piece of tape and 636,309 at the low, west end nail. That came out well so I started describing the upper and lower nail locations relative to the telephone poles used in 2002. The line from the lower nail to the telephone pole had a guard rail supporting I-beam in the ground right in the way. Decided to reference to the corner of the I-beam. Wrapped a bungee cord tight around it at street level, tucked the zero end of my 100’ tape in and measured to the nail. This worked well so I did the upper end like that too.
I recalibrated on this course from that morning’s ride: 635,000.0, 630,310.5, 625,619.0, 620,929.0 and 616,238.0. I was surprised that the 3% grade did not cause a noticeable directional spread. I had planned to work some on the Bristol Half and Half Half Marathon course that afternoon but was tired and traffic was heavy now. Recalibrated at Liberty Bell in Johnson City and total of 4 rides was only 3 counts fewer than the Pinecrest recal rides.
Lynwood also sent a picture of his holding device, which I will share as soon as I can learn how to do that!