<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML xmlns="http://www.w3.org/TR/REC-html40" xmlns:v =
"urn:schemas-microsoft-com:vml" xmlns:o =
"urn:schemas-microsoft-com:office:office" xmlns:w =
"urn:schemas-microsoft-com:office:word" xmlns:st1 =
"urn:schemas-microsoft-com:office:smarttags"><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.16809" name=GENERATOR><!--[if !mso]>
<STYLE>v\:* {
BEHAVIOR: url(#default#VML)
}
o\:* {
BEHAVIOR: url(#default#VML)
}
w\:* {
BEHAVIOR: url(#default#VML)
}
.shape {
BEHAVIOR: url(#default#VML)
}
</STYLE>
<![endif]--><o:SmartTagType name="country-region"
namespaceuri="urn:schemas-microsoft-com:office:smarttags"></o:SmartTagType><o:SmartTagType
name="City"
namespaceuri="urn:schemas-microsoft-com:office:smarttags"></o:SmartTagType><o:SmartTagType
name="place"
namespaceuri="urn:schemas-microsoft-com:office:smarttags"></o:SmartTagType><!--[if !mso]>
<STYLE>
st1\:*{behavior:url(#default#ieooui) }
</STYLE>
<![endif]-->
<STYLE>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:blue;
text-decoration:underline;}
p
{mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman";}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</STYLE>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></HEAD>
<BODY lang=EN-US vLink=blue link=blue bgColor=white>
<DIV><FONT face=Arial size=2>Thanks, Gary.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I realize that in counterbalancing drivers you're
trying to come up with a fixed or static solution for a dynamic problem that is
changing constantly (I guess that's redundant) and you have to come up with the
best compromise possible to enable the locomotive to reach a top desired speed
while not doing damage to the track, the moving components of the loco drive
system and the fixe<FONT face="Times New Roman" size=3>d parts of the
locomotive--frame, cylinders, etc. And it has to stay on the track!
I just had never noticed counterweights that didn't at least appear to be
centered directly across the axle from the rod pins. I'm know there's
a good engineering reason why weights are put where they are and my bias toward
the centered location is just an observational bias not a reasoned one. I
took enough engineering before becoming an English major that I could probably
follow the vectors, polar moments, etc. that would explain the forces leading to
the location decisions. And if not, I could just nod.</FONT></FONT></DIV>
<DIV> </DIV>
<DIV>Sam</DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=nw-mailing-list@nwhs.org href="mailto:nw-mailing-list@nwhs.org">NW
Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=nw-mailing-list@nwhs.org
href="mailto:nw-mailing-list@nwhs.org">'NW Mailing List'</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, March 25, 2009 8:06
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Balancing, Counterbalancing and
Dynamics</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Gary
Rolih<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><st1:City w:st="on"><st1:place w:st="on"><FONT face=Arial
color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Cincinnati</SPAN></FONT></st1:place></st1:City><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> ( and a Mechanical
Engineer)<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" color=navy size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: navy"> </SPAN></FONT><o:p></o:p></P></DIV></DIV>
<DIV>
<DIV class=MsoNormal style="TEXT-ALIGN: center" align=center><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR tabIndex=-1 align=center width="100%" SIZE=2>
</SPAN></FONT></DIV>
<P class=MsoNormal><B><FONT face=Tahoma size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</SPAN></FONT></B><FONT
face=Tahoma size=2><SPAN style="FONT-SIZE: 10pt; 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 face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<DIV>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; 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></DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Sam
Putney</SPAN></FONT><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P></DIV>
<BLOCKQUOTE
style="BORDER-RIGHT: medium none; PADDING-RIGHT: 0in; BORDER-TOP: medium none; PADDING-LEFT: 4pt; PADDING-BOTTOM: 0in; MARGIN: 5pt 0in 5pt 3.75pt; BORDER-LEFT: black 1.5pt solid; PADDING-TOP: 0in; BORDER-BOTTOM: medium none">
<DIV>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">----- Original Message -----
<o:p></o:p></SPAN></FONT></P></DIV>
<DIV style="font-color: black">
<P class=MsoNormal style="BACKGROUND: #e4e4e4"><B><FONT face=Arial
size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">From:</SPAN></FONT></B><FONT
face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <A
title=nw-mailing-list@nwhs.org href="mailto:nw-mailing-list@nwhs.org">NW
Mailing List</A> <o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><B><FONT face=Arial size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">To:</SPAN></FONT></B><FONT
face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <A
title=nw-mailing-list@nwhs.org href="mailto:nw-mailing-list@nwhs.org">NW
Mailing List</A> <o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><B><FONT face=Arial size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">Sent:</SPAN></FONT></B><FONT
face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> Monday,
March 23, 2009 8:20 PM<o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><B><FONT face=Arial size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">Subject:</SPAN></FONT></B><FONT
face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> Re:
Wheel spokes<o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P></DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">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 face="Times New Roman" size=2><SPAN
style="FONT-SIZE: 10pt">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: 10pt">Regards Richard in <st1:country-region
w:st="on"><st1:place
w:st="on">UK</st1:place></st1:country-region><BR></SPAN></FONT>________________________________________<BR>NW-Mailing-List@nwhs.org<BR>To
change your subscription go to<BR><A
href="http://list.nwhs.org/mailman/options/nw-mailing-list"
eudora="autourl">http://list.nwhs.org/mailman/options/nw-mailing-list</A><BR>Browse
the NW-Mailing-List archives at<BR><A
href="http://list.nwhs.org/pipermail/nw-mailing-list/"
eudora="autourl">http://list.nwhs.org/pipermail/nw-mailing-list/</A><o:p></o:p></P>
<DIV class=MsoNormal style="TEXT-ALIGN: center" align=center><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR align=center width="100%" SIZE=2>
</SPAN></FONT></DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">________________________________________<BR>NW-Mailing-List@nwhs.org<BR>To
change your subscription go
to<BR>http://list.nwhs.org/mailman/options/nw-mailing-list<BR>Browse the
NW-Mailing-List archives
at<BR>http://list.nwhs.org/pipermail/nw-mailing-list/<o:p></o:p></SPAN></FONT></P></BLOCKQUOTE></DIV>
<P>
<HR>
<P></P>________________________________________<BR>NW-Mailing-List@nwhs.org<BR>To
change your subscription go
to<BR>http://list.nwhs.org/mailman/options/nw-mailing-list<BR>Browse the
NW-Mailing-List archives
at<BR>http://list.nwhs.org/pipermail/nw-mailing-list/</BLOCKQUOTE></BODY></HTML>