Re: How far do we go?


Bill Daniels <billinsf@...>
 

Not a problem for freight (or passenger) cars, Andy, but what do you do for locomotives... especially steam. That gets to be a real problem.


 
Bill Daniels
San Francisco, CA



________________________________
From: Andy Carlson <midcentury@...>
To: STMFC@...
Sent: Wednesday, February 6, 2013 9:30 AM
Subject: [STMFC] Re: How far do we go?


 
Concerning the code 88/110 compatibility with switch work, I suggest looking at the Fast Tracks web site where they have some 3D animation of what happens when a wheel goes through a frog. I took from this the importance of having a sharp frog, to the point of being dangerously sharp!  A freight car wheel tread will go from being supported on the wing rail, and when the wing rail diverges away, the wheel treads outermost edge will contact the point of the frog. Fat wheels, such as the code 110, will be supported farther out on the wing rail before being transferred to the frog point. Narrower wheels, such as the "semi-scale" code 88, will roll off the support of this wing rail sooner. Where a blunt frog point will work with the fat wheels as the wing rail will support it farther along, the narrower wheels will need the full length of the frog to catch the wheel tread. This is where the sharp point of the frog makes a difference, as the tip of the point
extends out just a bit more than a blunt frog, enough to catch the semi-scale wheel tread.

I have been making some switches for several months using the Fast Tracks turnout assembly fixtures, and with careful construction, I don't even hear the metal wheels click upon passing through the frog. I can not see me ever using commercial switches in the future.

Jack Parker showed me many years ago that track work can be made to work flawlessly for both code 88 and code 110 wheel equipped equipment. I ponder the feasibility of having track work which performs flawlessly with a mix of code 88 and P:87 wheels? Fat wheels would need to be excluded.

-Andy Carlson
Ojai CA

--- On Wed, 2/6/13, Mike Brock brockm@...> wrote:

From: Mike Brock brockm@...>
Subject: Re: [STMFC] Re: How far do we go?
To: STMFC@...
Date: Wednesday, February 6, 2013, 9:03 AM

 

Bill Daniels writes:

"But, on the other hand, I do think that the NMRA has really dropped the

ball over the last 50 or so years. They still have a standard for wheels

that NOBODY has made for the last quarter century."

What wheels?

"And the track standards are even worse... my club (Napa, CA in case you are

curious) will not certify cars with "code 88" wheelsets to operate on the

layout unless they have been pushed out to the absolute wide limit...

otherwise they tend to fall in between the points of the turnouts (built to

NMRA standards), which scale out to a foot or more between the point and the

stock rail. A real railroad turnout is, what, 2 to 3 inches at best?"

OK...not arguing, simply trying to understand your statement. "...between

the points of the turnouts, which scale out to a foot or more between the

point and the stock rail. A real railroad turnout is, what, 2 to 3 inches at

best?"

According to Paul Mallery's Trackwork Handbook...4" for PRR in 1915. I can

take another look by checking the Track & Structure Cyc for 1955. But,

falling between the points? Hmmm. I built my own turnouts to NMRA track

standard 3.2 matching wheels built to RP-25 Code 110 and have not yet had

that problem

with so-called Code 88 wheels.

Mike Brock

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