Closed Frog Turnouts

[Doug G.]

On the old Atlas forum,  I occasionally battled...er I mean...discussed this subject with Rob de Rebel (is he still around?) and I knew I had seen a picture of such an N scale turnout before. I finally found it again (accidently) in an MR article about fine N scale standards in the September 1971 issue:

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I still think this is a superior design, especially for the smaller scales like N. It eliminates one of the worst spots for derailments - the frog. The Lima design could be refined and improved. It could even be made so all the rails are metal (notice the small area of plastic at the frog point on the Lima). Absolutely no break in current continuity or rail path.

Doug

[davefoxx]

One concern might be there are a couple of spots where shorts could occur by errant wheels or wheelsets with narrow backspacing, especially that narrow gap between the closure rails at the frog, or, if both point rails are powered as the same polarity, then the points could become a source for shorts.  I would especially be worried on DCC, because of the higher voltage on the rails at all times and the vulnerability of decoders to shorts.

DFF

[C855B]

OMG, Tru-Scale all over again! It was a line of HO track on milled and pressed wooden roadbed with integrated ties. They had a similar pivoting system that was nothing more than a wood screw into the base. They went out of adjustment with frightening regularity.

[sd45elect2000]

There are real single and double sprung frogs going back years and years. I actually wouldn't mind them .

Randy

[Doug G.]

With today's technologies, the concerns mentioned could easily be addressed and solved. The point rails could be insulated from one another and the pivot made stable.

I don't know about anybody else liking the idea of derailments at frogs being eliminated but I sure would welcome it. Movements through switches being made to be just like traveling on regular track would be wonderful.

Doug

[peteski]

Reliable, yes, but they would not look very realistic.  I seem in the to recall an article in Model Railroader (in recent years)  where someone was scratch-building a similar turnout in H0.

Then there were old PIKO (not Peco) turnouts in the 70s where the points, closure rails and part of the frog were a single metal stamping. The pivot was right near the point of the frog.  Those still worked like conventional-frog but the construction was similar to the one discussed here.

Rob the Rebel - that's a blast from the past. I don't think he is a member here.

[Doug G.]

The gigantic frogs in present turnouts don't look very realistic either.



Doug

[peteski]

The gigantic frogs in present turnouts don't look very realistic either.



Doug

But to me they still look more realistic that a movable frog on a #4 turnout.   The commercially made Code 55 turnouts don't look all that bad. Looks like we will have to agree to disagree. 

[ednadolski]

The gigantic frogs in present turnouts don't look very realistic either.



Doug

That's where the paint & weathering come in....  otherwise it's off to Proto:160   

Ed

[ednadolski]

It eliminates one of the worst spots for derailments - the frog.

Often it is not the frog itself, but out of spec wheelsets, gauge, flangeways, and so on.

Ed

[nkalanaga]

Ed:  You're right.  If everything else is built to the same standards as the frog, there won't be derailments at the frog.  The standards don't have to be based on any known prototype, as long as all of the dimensions are consistent with each other.  The problem is parts that don't match.  Unfortunately N scale has a wide variety of incompatible "standards" all trying to work together.

[garethashenden]

That's where the paint & weathering come in....  otherwise it's off to Proto:160   

Ed

Do it!! https://www.therailwire.net/forum/index.php?topic=33072.msg377678#msg377678

[Blazeman]

Rob de Rebel....appears on Modelers and Kit Forums. He's moved to bigger things now meaning not totally in N.

[randgust]

They are called spring frogs, and they go way back into the 1800's.   

They have also been faulted in several fatal rail accidents over the years and have a specific section in the 49CFR to deal with their maintenance.

It's not a new idea, it is not particularly common, and they are considered to require a lot of additional maintenance and inspection.    If they fail it can be pretty catastrophic.   They do provide a smoother ride, and also a continuous railhead that reduces wheel slip.

I'm working on an article that specifically involved a wreck caused by one, back in 1888.

[peteski]

Randy, sounds like you are talking about real trackwork.  In the N scale version the points and closure rail are a single solid piece and the pivot point of that assembly is around the midway between the tips of the tips of the points and the ends of the closure rails.  There is nothing to spring.

I was comparing it to the high-speed movable frog turnouts.  To me that would be closer to the way the way that model trackwork functions (but still quite a bit different).