[AT] Horsepower question

charlie hill charliehill at embarqmail.com
Thu Oct 7 06:17:45 PDT 2010


The one thing I did apparently remember right was from test # 793 for the AC 
H-3 crawler.
"Weighing in at 7395 lbs it made a low gear pull of 7893 lbs at 1.17 mph 
with 6.39% slippage"

Charlie

--------------------------------------------------
From: "charlie hill" <charliehill at embarqmail.com>
Sent: Thursday, October 07, 2010 9:03 AM
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>
Subject: Re: [AT] Horsepower question

> Larry, thanks for the correction.  As usual these days, my memory failed 
> me.
> I should have checked my facts before posting but didn't have time.  At
> least it made for good discussion.  grins.
>
> Charlie
>
> --------------------------------------------------
> From: "Larry Goss" <rlgoss at insightbb.com>
> Sent: Wednesday, October 06, 2010 11:45 PM
> To: "Antique tractor email discussion group" 
> <at at lists.antique-tractor.com>
> Subject: [AT] Horsepower question
>
>> It's hard to "draw rules of thumb" out of the Nebraska tests.  But here
>> goes --- Drawbar pull is generally in the range of 50% to 60% of the
>> weight of the tractor.  Some Caterpillars drop as low as 45%.  Drawbar
>> horsepower is in the range of 50% to 70% of Belt or PTO horsepower.
>> Slippage of the drive wheels varies from 2% to 15% regardless of steel or
>> rubber, but rubber generally runs a bit higher than steel   I don't know
>> that the tests were ever run with the intent of maximizing the balance,
>> traction, weight, etc, the way we do as pullers.  I'm sure the slippage
>> values would be much higher if they did.
>>
>> I found out a few months ago that a one of my wife's close personal and
>> professional friends is the daughter of one of the men who ran the
>> Nebraska tests for years.  I hoped she would be able to tell me stories
>> from Lincoln about those tests.  Unfortunately, she studied music and had
>> no interest in what her father was doing at the University.
>>
>> Larry
>>
>>
>>
>>
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