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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Remember that the counterbalancing is not
for a STATIC case but a DYNAMIC case with the mass of the drivers and rods
included and rotating at different speeds. In addition there are first
mode, second mode, third mode and so on, that is, different dynamic loading per
frequency at multiples of the running rpm. Depending on a bunch of
different things, the second, third fourth or other modes might be the most
significant loading comparing a dynamic loading situation to a strictly static
one. In reality, you have the rotating drivers plus the oscillating rods
moving back and forth and going around the driver pin so those loads are part
rotating and part horizontal and vertical loads. Plus the loads from one side
are transmitted to the other side and vice-versa.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thinking about the situation in ‘common
sense’ static balance thinking is pretty far off from what actually
happens in a dynamic situation. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>In physics or vibration
calculations/modeling, this is a complex system requiring some pretty
sophisticated analysis. The <st1:place w:st="on"><st1:City w:st="on">Roanoke</st1:City></st1:place>
engineers would have loved to have had a computer to model what they had to
estimate with a slide rule.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Part of the issue with the RF&P 4-8-4’s
and their poor high speed balancing problems were that the published
state-of-the-art calculation methods didn’t work (1927). The
N&W didn’t do the calculations that way for the A and the J. (The
AT&SF engineers didn’t follow the published methods either for their
high speed locomotives.) <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Gary Rolih<o:p></o:p></span></font></p>
<p class=MsoNormal><st1:City w:st="on"><st1:place w:st="on"><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Cincinnati</span></font></st1:place></st1:City><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'> ( and a Mechanical Engineer)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'> </span></font><o:p></o:p></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
nw-mailing-list-bounces@nwhs.org [mailto:nw-mailing-list-bounces@nwhs.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>NW Mailing List<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, March 25, 2009
3:54 PM<br>
<b><span style='font-weight:bold'>To:</span></b> NW Mailing List<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: Wheel spokes</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Very interesting. I had always assumed that
counterweights were centered exactly opposite the pin holding the rods.
While that appears true for the front and middle A drivers, it is obvious from
the drawing that it is not true for the main driver. Would this be
because the added weight of the main rod throws the balance off-center?</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Sam Putney</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>----- Original Message ----- <o:p></o:p></span></font></p>
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<p class=MsoNormal style='background:#E4E4E4'><b><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-weight:bold'>From:</span></font></b><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:nw-mailing-list@nwhs.org" title="nw-mailing-list@nwhs.org">NW
Mailing List</a> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>To:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:nw-mailing-list@nwhs.org" title="nw-mailing-list@nwhs.org">NW
Mailing List</a> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Sent:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Monday, March 23,
2009 8:20 PM<o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Subject:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Re: Wheel spokes<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Richard,<br>
<br>
I'm surprised no one else has answered this yet. The number is 15. <br>
<br>
You can see drawings of the drivers at the following addresses:<br>
<br>
Front Driving Wheel <a href="http://www.nwhs.org/archivesdb/detail.php?ID=23293"
eudora=autourl>http://www.nwhs.org/archivesdb/detail.php?ID=23293<br>
</a>Intermediate Driving Wheel <a
href="http://www.nwhs.org/archivesdb/detail.php?ID=23187" eudora=autourl>http://www.nwhs.org/archivesdb/detail.php?ID=23187</a><br>
Main Driving Wheel <a href="http://www.nwhs.org/archivesdb/detail.php?ID=23192"
eudora=autourl>http://www.nwhs.org/archivesdb/detail.php?ID=23192</a><br>
<br>
Listing of more Class A wheel drawings is at <a
href="http://www.nwhs.org/archivesdb/listdocs.php?index=rs&id=161&Searchword=wheel"
eudora=autourl>http://www.nwhs.org/archivesdb/listdocs.php?index=rs&id=161&Searchword=wheel</a>
<br>
<br>
Ron Davis<br>
<br>
At 03:15 PM 3/20/2009, you wrote:<br>
<br>
<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'>Hi chaps<br>
Can somebody tell me the exact number of spokes on a Class A driving wheel,
thanks in advance<br>
</span></font> <br>
<font size=2><span style='font-size:10.0pt'>Regards Richard in <st1:country-region
w:st="on"><st1:place w:st="on">UK</st1:place></st1:country-region><br>
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