I wrote:
"and it would only have to pull the 800 pound capability of the Cub."
Randall reacted!
> Well, that's only (it's) rated capability IN 2ND GEAR.
In Neb. tests, every gear is tried until "maximum pull" is attained . . in
this case and often in the "unweighted" tests, an intermediate gear provides
"maximum pull". Traction is usually the limiting factor, the one mph faster
speed (than 1st gear) allowing the tires to "hook up" better with the test
surface.
I patiently detailed:
I'll explain the test procedure: the 25% miraculous gain in test G dbhp
was achieved by the allowance of unlimited cast iron and/or liquid
tire-fill
weight. . . in some cases, tractor are loaded with ballast weights
approaching the weight of the tractor itself; not practical for daily use
and really tough on the tractor.
Randall figures I made that up!
> "Can't comment on whether they added weights."
Randall misfires:
> but note that adding weights do _not_ (sic) increase drawbar horsepower,
only traction and hence (perhaps) (!) tractive effort.
Sorry you haven't grasped this but adding weight added 25% to the drawbar
horspower in this particular test G. Drawbar horsepower IS the numerical
expression, the measurement of tractive effort with travel speed a factor.
In the Nebraska Tests, it is measured by recording the pull effort on the
tongue of an extremely heavy, towed, wheeled, instrumented load-dynomometer.
Randall "reasoned":
> If it could deliver 8.75 hp in 1st gear with weights, it likely could do
it in 2nd or 3rd without weights.
It is clearly stated in the test:
It delivered 8.75 hp in first with weights, that's it's maximum with
weights.
It delivered 6.75 hp in second without weights, that's it's maximum without
weights.
Randall suspects a conspiracy!
> Also, test H deliberately only loaded the tractor to it's rated load, it
has
> nothing to do with maximum power available.
One more time, test H measured exactly the maximum the tractor could pull
without weights, nothing more, nothing less.
The "Google" search engine found 1780 references to "Nebraska tractor
Tests". Check it out if you'd like to learn more of the official United
States standardized tractor tests.
Tony in Texas
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