Failed insulating gaps on 2 rail AtlasO 7.5 turnout frogs.

Hmmmm, what can we do, what can we do?

If I identified a problem that was likely to reoccur, I would take preemptive action, as in widen the rest of them.

Simon

If the dry air is shrinking the wood deck the turnout is fastened to, I could see how it is possible for that gap to close. Thanks for posting this issue, Ed, because I'll be laying some of these high speed turnouts in the near future. I think I will eliminate using a screw in the tie in the center of the turnout and also slide a piece of Kapton insulation film with a drop of glue into that gap.  I used a lot of Kapton film tape in traction motors, when they would get rebuilt, to insulate the heavy copper winding's. It's very strong stuff for how thin it is, so I don't think the pressure will be great enough to force a hole through it, like what may occur with electrical tape. I'll go with two layers if it will fit.   

I feel your pain Ed. We experience the same issue at the club. Usually on the mainline during an open house session. ugh!

There are several hundred insulating gaps on the railroad and it's my practice to epoxy a .020" strip of styrene in the gap just after laying the turnout (typically with Right-O-Way frogs).  Years ago I posted on the forum about failed gaps on AtlasO turnouts, and I thought I fixed all of them - clearly I missed one.

I had this problem with a #5 turnout and removed the points and shaved off of the back end so that they wouldn't short anymore.  If this is a common Atlas issue, I might just do it to all turnouts before I lay them.

Hmm maybe a picture would help to us lesser folk?

Ed, is this the gap you are referring to? I could see if these two rails became a ground by touching the frog, a pick-up roller on an engine would short to ground, but not the actual track shorting itself out.

Keystoned Ed posted:

There are several hundred insulating gaps on the railroad and it's my practice to epoxy a .020" strip of styrene in the gap just after laying the turnout (typically with Right-O-Way frogs).  Years ago I posted on the forum about failed gaps on AtlasO turnouts, and I thought I fixed all of them - clearly I missed one.

Simon

I could be wrong but, I don't think rollers are an issue.  Ed?

Jay

Jay C posted:

I could be wrong but, I don't think rollers are an issue.  Ed?

Jay

Agreed! Have had precious few roller issues with 2 rail track.

Simon

Sorry. I did not see the 2 rail heading. But do see it a possibility of a problem, in three rail, if these rails touched the frog.

 The specific issue I posted about relates to AtlasO 2 rail turnouts of the non power routing variety (so called DCC friendly turnouts).  The problem does not occur with 3 rail frogs as the polarity of the running rails approaching the frog is the same.   Two rail frogs must be insulated from the running rails as their polarity changes depending on the route through the turnout.  Sometimes one can get away with non-powered frogs - providing the distance between frog gaps is shorter than the pickup wheelbase of your locomotive(s).  In the case of 2 rail AtlasO 7.5 turnouts the frog casting is extremely  long.  To avoid stalls I power all my frogs.    (approaches to powering frogs include toggle switch contacts, contacts on the switch motor (e.g. Tortoise), or by a micro switch bearing against the throw bar)  No matter how the 2 rail frog is powered - it must be electrically isolated from the 4 sections of running rails or you get a short. 

To illustrate my circumstance I've attached several photos. The Middle Division staging yard ladder is in a section of the railroad tucked under the approach to Horseshoe curve.  The first photo taken in 2009 shoes the staging yard before the 4 track Pittsburgh Division Horseshoe Curve approach was  was built over it. The second photo shows the area today.  Magnetically held access panels enable acces to the hidden track for maintenance - extremely rare.  During Monday nights operating session we discovered that selecting 3 of the several westbound routes out of staging shorted out the entire power district.  While the operating crew stood around, we finally deduced and verified (with a trusty old Simpson meter) that the culprit was the AtlasO 7.5 turnout to the right in the photo.  The gap between the nearest closure rail and the cast frog had closed creating a short. It was not visually obvious which of the 4 gaps was bad.   Note this turnout had been OK for 8 years.  As previously posted - I opened all the gaps down into the plastic ties with the cut-off wheel.  I'll finish the job by epoxying in slips of plastic between the frog and the approach rails to assure the gaps don'y close again.

While we're talking about AtlasO turnouts - as previously reported by others on the Forum - if you are going to power the frog do not trust the little powering tab extending beyond one of the ties at the frog.  That metal strip along with the cast frog and rails is placed in the mold when the plastic is injected.  That approach to manufacturing the turnout does not provide a rock solid electrical path.   I recommend soldering the frog feeder wire directly to the frog casting.

Indeed - rollers shorting the frog wasn't an issue I was facing!   .  I just changed the title of the thread to narrow it to 2 rail.

Has anyone ever seen a prototype turnout that has guard rail and frog proportions looking anything like those found on these turnouts?  I used them only in hidden areas of the layout  thinking I'd save time building the railroad - never again.  For great appearance and reliable operation I recommend laying your own using Right-O-Way castings.   If you can use a track gauge it's not hard to do.

I'm obviously a closet 2-rail guy as I put plastic insulators in an MTH ScaleTrax turnout (fully insulated 3-rail turnout) to isolate the frog in case the rails shifted. Back to the problem at hand, a big problem with track on wood is thermal shifting. We've had a lot of it at the club over the past several years to the point that my six-axle scale-wheeled locomotives are derailing at different points on the club layout where they used to run through just fine. A check of the spots showed that the track had shifted  (badly in some spots) to the point that the locomotives were actually riding up on the pickup rollers and derailing (don't have that problem in 2-rail mode).   I've been looking at alternate materials like PVC for a pending build.

Suggest you use thin pieces of styrene, with a little glue to hold them in place, to isolate the frog. Just cutting or reopening the gap is not foolproof, as the repeated impact of a train can move the frog over time, a small amount, but just enough to cause a short. The use of styrene positively prevents this.

Hi Ed,  While shooting some turnout photos along the four track main in Marcus Hook,  PA.  I did come across an example of "over long" guard rails.  They were only used on the mainline, not on the diverging stock rail. 

What I find really weird on the Atlas guards is the undersized, I seem to remember, Code .138" height of the Atlas cast guard rails.  I remember asking Atlas why the undersize rail and they said so as not to interfere with uncoupling shoes of PW trucks.  To which I said HUH?

I reminded them this was two rail.  The person said that the shoe allowance apparently was carried over to two rail by the turnout drafting folks.  An apparent bit of disconnection.

In order to have a full ,148" flange protection,  I removed the Atlas guards and replaced them with ROW.  In the process I also trimmed the frog.  That frog is just flat out ugly as built.  The nubs on the ROW guard rails need to be reduced a tad due to the super fat oversized Atlas rail proportions.

Here is an early and before after Atlas photo:

 Yes, look close, both turnouts are Atlas 7.5.

I'm sorry, those stock guard rails make no sense to me.  Great job on improving the frog.  The whole turn out looks much better.

Jay

Tom Tee posted:

Hi Ed,  While shooting some turnout photos along the four track main in Marcus Hook,  PA.  I did come across an example of "over long" guard rails.  They were only used on the mainline, not on the diverging stock rail. 

What I find really weird on the Atlas guards is the undersized, I seem to remember, Code .138" height of the Atlas cast guard rails.  I remember asking Atlas why the undersize rail and they said so as not to interfere with uncoupling shoes of PW trucks.  To which I said HUH?

In my early days of 2 rail, when the Atlas O boom began, I read that Atlas track is made under Lenz license thus it's European profile AND looking.

Seems to explain perfectly the strange sizes (7.5) and the long frogs and guard rails. 

Keystoned Ed posted:

 

 

 

 

It's funny, but even this simple curve looks fantastic to me. I can picture large gatherings of friends running trains, and watching as they crest over the hills and round the curves.

I love looking at this layout. Thanks again for sharing.

The 7.5 and 5 turnout size has something to do with the 4 1/2" center line and multiple 10 inch track lengths making up the Atlas track plan "system".

The Lenz double slip switch tie strip has a perfect snap in fit to the  new Atlas tie strip plus the early '70's tie strip.

Tom. Thanks for posting the photo of your altered Atlas O turnout - a huge improvement.  Also thanks for Joe's comment. That location on the approach to Horseshoe Curve is popular with guests. The track is at 65".    I especially like viewing big O scale steam coming around the super elevated curve at eye level.  

I hope some of the folks on the Forum will be able to come for a visit following the close of the O Scale National Convention Aug 22-26.  We'll have two large O scale layouts ( 1/4 mile apart) in Williamsburg, VA open Sunday afternoon for convention attendees.    We're quite a distance from the Rockville, MD convention site, but if you're traveling south on the I95 corridor were relatively close.