This is a post I made to MNF a few years ago. It is the only time I have measured a substantial distance on a non-paved surface.
MNF#0653 7Aug2000
Steel Tape Measuring
It is Sunday morning and I am looking at my calculations of last
weekend's measuring for the Sound and Silence 10K. I am mystified at the
results. I used the Jones Counter to double check the sections of this route
that we had to measure by hand. There were three sections: 1247.0 meters,
543.7 meters and 1117.2 meters for a total of 4154.9 meters that would be
used on race day. The 1247.0 m. section is run twice. These three sections
each have different types of gravel surfaces so I was not going to spend the
time to lay out three more calibration courses since I knew we could measure
them more accurately by hand. My checks are as follows:
steel tape: ride 1: ride2:
1247.0 1245.3
543.7 543.1 543.0
1117.2 1116.7 1114.0
I did not included the SCPF for the rides as I wanted a direct
comparison. I would have expected the rides all to be longer but as you can
see they are all just the opposite. I am on my way back out there right now
to remeasure the 543.7 m. leg to satisfy myself that I'm not certifiably
crazy. If this route were completely paved I would have been done two weeks
ago.
Later:
I have to stop second guessing myself. We remeasured the 543.7 meter
leg and got........543.7 meters. So that is what it is. I am going to treat
the steel taped distances as %100 accurate and only apply the SCPF to the
bicycle measured parts.
I wouldn't steel tape that sort of distance again. I would do as Pete has suggested and simply meaure it by bike. It is WAY too much work to hand measure much over a few hundred meters.