(verbose)
Generally, the most famous twin mounted timepiece was the Halda Speedpilot
with the Heuer rallye set also popular. One timepiece was a stopwatch that
read in 1/100 minutes, rather than seconds. The other was a clock that read
time of day and is not a stopwatch.
If you have two stopwatches mounted on a plate, that would be used for
racing. One is used to measure lap time the other can be used for overall
race time, or so your pit crew can watch the guy in your mirror.
For a rally, you synchronize the time of day clock to the official time of
the rallymaster. The stop watch is basically to keep track of how fast you
are going. If you go 1/2 mile in 60 seconds, you are going 30 miles an
hour. Not exactly rocket science, but try going exactly 1/2 mile in exactly
60 seconds. The navigator is usually a very busy person.
My rally computer <http://www.rally.cc/> would measure distance to 1/1000
of a mile (roughly 5.25 feet), so you get a pretty accurate measurement.
Rallyes are timed to 1/100 minute, and you receive a penalty point for
every 1/100 minute early or late to a checkpoint. It is much easier to do
the math using 1/100 minute over seconds (or 10ths of seconds).
Example - One leg of a rally is 8.449 miles long and the average speed
assigned is 24 MPH. It should take you EXACTLY 2.84 minutes to complete
that leg, but you don't know how long the leg is so you have to stay at the
assigned average speed. The average speed can change in the middle of a leg
as well.
If you come in to the checkpoint at 2.86, you get a 2 point penalty. Top
rallyes rarely assign more than a coupla points to the best participants
over a hundred miles and 10 to 20 checkpoints.
A very accurate stopwatch lets you quickly calculate how fast you are going
so you can stay at the assigned average speed. Any variance has to be made
up before you get to a checkpoint, but you don't know where they are.
If you try this, please add a Stevens Rallye Indicator to complete your
equipment. It is a circular, analog calculator that takes your odometer
error into account for your measurements. Using a Stevens and a Halda will
keep you in a vintage rally class.
(/verbose)
Hope this helps.
Allen Hefner
Former Phila. Region SCCA Rally Steward (retired)
*Current:*
2006 Chebbie
*Former:*
1963 Sunbeam Alpine Series III
1967 Triumph TR4A IRS
1964 VW Type I
1967 VW Type II
1967 Rover 2000TC
1977 MG Midget
On Sat, Dec 29, 2012 at 11:13 PM, Dean Hedin <dlh2001@comcast.net> wrote:
> Explain to me (and others on the list)
>
> How are rally stopwatches used?
> Why are there usually two and why are there two diferent kinds of
> stopwatches?
> ------------------------
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