On Feb 14, 2010, at 8:20 AM, STMFC@... wrote:

3b. Re: Kadee Scale Coupler Operational Reliablity
Posted by: "Jim Betz" jimbetz@... oldrockygn
Date: Sat Feb 13, 2010 10:30 am ((PST))

Denny, et al,

While I agree that the standard length of the shanks on
the Kadee product line (and all other mfgrs as well - with the
possible exception of the Sergents) is longer than it should be -
it does mean that we can operate our model trains on track with
significantly more curvature than the prototype. The same can
be said of the width of the coupler box - and that measurement
is directly related to the same thing.

I have never seen a layout that has truly prototypical
curvature standards. And even those that have truly generous
standards (such as "nothing smaller than 36" on the mainline")
still have several areas on the layout that have smaller
curves and lower numbered turnouts. If I remember correctly
a #10 turnout -approaches- the typical smallest radius of the
prototype (and I'm not talking about mainline). Yes, of course,
these are generalizations/standard practices and you can go
out and find examples where the real RRs had more curvature
than these statements. But they are pretty close to what
the real RRs use as their standards (which they may or may
not break depending upon the situation).
On our layouts we 'fudge' even our own standards - not once
in a while but often/always. The phrase "I can make it fit if
I use a #4 turnout here for this industry track" is one I hear
a lot. The other thing you hear are statements such as "we
have 30-inch radius every where on our mainline - except for
the areas at _____ and _____" ... and those statements are made
proudly/as a brag about how generous that particular layout is.
And there is a real reason why the time-saver is based upon
all #4 turnouts.
If I remember correctly I think that an HO layout would
have to adopt s curvature standard of something approaching
that used on O-scale in order to be in the same ball park as
the real RRs.

http://www.youtube.com/watch?v=3IO0XYI8mew - my modular group. The curve the train passes on is 86" radius... 7'2"...and comparing it to main railroads it looks pretty tight. It's pretty sharp for us nowadays. Nothing tighter on the mainline except for the turnouts used to access the yards...which we detest but yards take up enough room without #18 turnouts leading in and out of them.

We use a mix of #5 and #58/158 couplers on our modular layout. If they match up to the Kadee gauge we have very little issue with random uncouplings in 80+ car trains running for 8 hours a day as moving scenery. Cars that uncouple or derail more than twice get lifted and inspected...usually finding a droopy coupler being the cause.



Craig Zeni
Join the Penn Central Railroad HS at www.PCRRHS.org