Here is some commentary on this subject from today's MNForum.
CAL COURSE HELP
When you don't have a buddy to help lay out a Calibration Course a
great trick is to use a masonry nail at the hook end of your steel
tape--just make sure to apply enough tension to the measuring tape
when pulling it to mark your pen mark on the piece of masking tape.
Then go back and pull up the nail and carefully align zero on the
measuring tape hook,to where your pen mark is and nail it again for
the next tape length--lather, rinse repeat...
Remember that after you have used the spring gauge to verify correct
tension, tension "by feel" is an acceptable method of determining the
proper amount. Just have a friend help you feel correct tension on
the tape with the spring gauge a few times until you can be really
close without them telling you. You have to pull it pretty taught.
Shaking it out to straighten it is another technique you need to
develop to quickly straighten the tape (kind of like a whip).
It takes a little bit longer but sometimes ya just gotta go solo and
lay out a cal course when you have the time. I did one on my home
street for convenience all by my lonesome--500 meters. When you have
a partner in crime it does go quicker and is less of a pain. There
are a lot of things to remember the 1st time around and a little help
never hurts.
Don't be afraid to start measuring. I think you will find it
rewarding as it is an admirable task to complete for your
running/walking community. We need more measurers out there to help
events adhere to correct distances for races and certify them! After
all--time and distance are the only ways we can compare our
performances: we need to ensure that at least the advertised
distances are consistent--otherwise they are meaningless.
You will have a lot of questions I imagine as you undertake this
project for the first time. Ask questions here--no ? is
stupid--people will help you.
you can also go to
https://measure.infopop.cc/eve/forumsand check out the course measurement bulletin board and post ?'s there.
Matt Sonneborn
nfn03449@naples.net
SOLO CAL COURSE LAYOUT
Here is another option for a solo cal course. It's not fast but it is a lot
more solid then using a kickstand to hold the end of the 100 ft tape.
Calibration Course Layout
11 Nail Solo Method
The original 5 Nail Solo method is very robust and leaves one with a
confident feeling that the measurement is correct. This is because a nail
is holding the other end of the tape and there will be no possible slippage.
This method uses 6 addition nails so that the measuring tape does not have
to be pivoted 180 degrees at each tape length. A second person could reduce
the time required and whose only duty would be to remove the hook from the
nail. Childs play.
My thanks to the originator of the 5 Nail method.
In this method a nail is driven at the start and a second nail driven a
little less than 30 meters up the course. The distance between the two
nails is then determined. This is measured in two parts. The first uses a
30 meter or 100 ft tape with a mark near the end where you know the precise
distance to that mark. The second part uses a metric ruler to measure the
distance from the tape mark to the back of the 2nd nail. This is repeated 9
more times. The total distance is 10 times the know tape distance plus the
sum of the 10 ruler measurements and finally, the temperature correction.
To use this method of course layout you will need a 30 meter/100 foot tape,
a short metric ruler, a heavy hammer, 11 concrete nails and two P-K Nails.
Place a permanent fine mark on the tape at approximately 29.9 meters.
Determine the exact distance of the mark back to the hook in meters. Be
sure to include the hook correction.
Record time and temperature before and after measurement.
Drive the 1st concrete nail at the Start location leaving approximately º
inch exposed.
Place the tape hook over the 1st nail un-reel the measuring tape up the
course.
At a point a 2 to 3 inches beyond the tape mark, drive a 2nd concrete nail
again leaving º in exposed. The exact location should be random and not a
measurement.
Lay the zero point metal metric rule against the back of the 2nd nail Apply
approximately 10 pounds to the measuring tape and record on the Data Sheet
the distance in cm to the tape mark.
Move the measuring tape up the course and drive a 3rd nail as before.
Record the ruler distance.
Repeat in a similar manor until you reach approximately 1000 feet.
Record time and temperature.
Using the Data Sheet calculate the distance from the start nail to the last
nail.
Add the necessary distance, using the 11th nail to make the course exactly
300 meters or 1000 feet.
Drive a Finish P-K nail at that location.
Replace the 1st concrete nail with a P-K nail
Drive home all remaining concrete nail heads flush to the road
Bill Grass
BarbFGrass@aol.com
