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Trains Derailing Through Turnouts ??

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  • Member since
    February 2018
  • From: Danbury Freight Yard
  • 459 posts
Posted by OldEngineman on Monday, May 4, 2020 9:59 PM

Just wondering, do those Scaletrains engines have "sand pipes" hanging down in front of the lead and behind the trailing trucks?

Could they be interfering with the free movement of the trucks in the turnouts?

Or protruding down far enough to hit parts of the track structure itself?

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Posted by peahrens on Monday, May 4, 2020 12:27 PM

kenben
The "X" I refer to is the plastic insert in the center of the frog where the wheels do rise up becouse of this plastic insert piece. If it weren't the, like a real turnout, it seems there would be no problem. Why is that plastic insert there anyway? The frog is all electrically connected right out of the box. Can I file down some of that plastic?

EDIT:  I made the following comment presuming a plastic frog black part.  If metal, would be tougher, plus you would want to paint the cut black again.  Are you sure you diagnosed this correctly; i.e., it is insufficient frog depth, not flangeway gage or width or excessive wheel flange diameter?

You can use a needle file to deepen the groves between the frog rails and guard rails.  Before you do that, suggest you put the NRMA gage flangeways tabs there (with a flashlight behind it) and attempt to eyeball how much depth clearance exists.  Then compare that with your other PECO turnouts to guestimate whether they will have the same problem.  Don't know whether that is workable. 

https://www.harborfreight.com/12-piece-precision-needle-file-set-4614.html

Additionally, I understand that you can see the loco wheel rise upon entering the frog.  Visually note how much it rises, as a bit more than that would need to be filed away.  

Try these tests with another turnout, uninstalled, to understand whether to expect this problem with others.

BTW, what code are the elctrofrogs?  Code 83?

Paul

Modeling HO with a transition era UP bent

  • Member since
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  • From: Wyoming, where men are men, and sheep are nervous!
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Posted by Pruitt on Monday, May 4, 2020 11:12 AM

After you've checked the wheels out thoroughly (in gauge, flanges are proper contour and properly formed, meaning round and no discontinuities in the bead or the flange) and made sure nothing on the loco is hanging up and forcing the trucks off the rails, focus on the turnout.

Even a high quality product line such as Peco can produce an out-of-spec product on occasion. Perhaps a part did not sit in the assembly jig quite properly and was undetected at the time. It happens. 

Something else about commercial turnouts - none of them conform completely to the NMRA turnout standards. Often flangeways at guardrails are a bit wider than recommended to handle stock with thicker-than-RP25 flanges, for example. So check the guard rail flangeways. You might solve your problem by gluing a thin strip of styrene against the inside face of the guardrail, if the flangeways are too wide. That would be pretty careful work, but it may solve your problem. 

Or you might just replace the turnout and see if that does it. 

  • Member since
    April 2003
  • From: Clinton, MO, US
  • 4,261 posts
Posted by Medina1128 on Monday, May 4, 2020 9:59 AM

I had a couple of locomotives that had derailing issues. It turned out that the gladhands on the Kadee couplers were adjusted too low.

sol
  • Member since
    January 2007
  • 34 posts
Posted by sol on Saturday, May 2, 2020 8:04 PM

Ah ha, now I see what you mean by the plastic X  piece - that is part of the moulding and if your wheels are rising, it means the wheel flanges are too big - normally Code 100 track will take a large range of wheels but Code 75 -  - most modern rolling stock with RP25 wheels works OK but not those with large flanges.

 

Ron

sol
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Posted by sol on Saturday, May 2, 2020 7:59 PM
And if you look underneath, you will see how the rails each side of the frog is wired. Ron
sol
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Posted by sol on Saturday, May 2, 2020 7:56 PM

Peco Electrofrogs  do NOT have a plastic insert in the frog - all metal but Insulfrog turnouts do & they may cause wheels to rise a bit but it has been known that some power bogies will turn enough one way but not the other and then only when moving in one direction.

 

Ron

  • Member since
    January 2018
  • 172 posts
Posted by kenben on Saturday, May 2, 2020 6:40 PM

jjdamnit

 

So the mainline is the diverging (left) side of the turnout?

And, the derailment results in the loco going towards the straight route when the points are thrown to the diverging route?

What turnout control are you using: manual or remote; PECO, Tortise?

After getting the NMRA gage check the flange depth of the wheels. I would be surprised if a Scale Trains unit would not have RP-23 compatible wheels.

As has been mentioned, truck swing or lack there of, might be the problem.

This would show up if you run the suspect loco head-end first or tail-end first over the same track arrangement.

If the derailment only happens when it is "facing" in one direction it's probably the loco.

You mentioned that the loco "lifts up" off the rails...

Could this be happening from some part of the belly of the loco hitting on another part of the turnout?

You could have gotten a faulty turnout; the frog or "X" section as you described, might be not deep enough to allow the flanges to pass over without interruption.

On the NMRA gage there are three track measurement options. One is labeled "Flangeways" with two points protruding from the gage.

The points on the gage should fit into the frog and rest on the top of the frog. If there is a gap the frog is too shallow.

You can take a jeweler's file and file down the frog to gain the needed clearance. Check frequently with gage so you don't remove too much material. 

Do you have another turnout that you could put in its place and see what happens?

 

 

The mainline is the diverging to the left side of this turnout.

The derailments usually do not happen when the turnout is switched to go straight through.

Turnout motors are Tortoise's and Peco electrofrogs.

I only see the wheels making contact with the under body showing some clearance.

The "X" I refer to is the plastic insert in the center of the frog where the wheels do rise up becouse of this plastic insert piece. If it weren't the, like a real turnout, it seems there would be no problem. Why is that plastic insert there anyway? The frog is all electrically connected right out of the box.

Can I file down some of that plastic?

I will be using my NMRA gage to check clearences.

I won't have another turnout to test until my Tortoise order has been delivered.

  • Member since
    February 2008
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Posted by maxman on Saturday, May 2, 2020 1:20 PM

Most likely there is a gage problem between the guard rail and the frog.  This has been discussed here before.

Set the loco on the tracks at the point end.  Throw the turnout for the diverging route.

Grab the front truck by hand and pull the loco through the diverging route while holding the truck lightly away from the curved stock rail.

You will likely see the first axle hit the frog.

Now do the same thing except hold the truck lightly against the curved stock rail.

If the truck passes through without hitting the frog then the guard rail clearance is probably your issue.

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Friday, May 1, 2020 9:52 PM

Don't just look at the turnout, but also the tracks on either side.  A small difference in slope from the approach track could make the locomotive tilt slightly, lifting the front wheels up as it approaches the turnout.

Make sure the entire approach to the turnout is flat.  The turnout itself is not enough.

It takes an iron man to play with a toy iron horse. 

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Posted by jjdamnit on Friday, May 1, 2020 7:24 PM

Hello All,

kenben
Just installed and wired up my first Peco HO #6 electrofrog left turnout. The mainline runs through this turnout when switched to the left trun (SIC) [underline added]. Why are my ScaleTrains 6-axel engines derailing when it hits the frog?

So the mainline is the diverging (left) side of the turnout?

And, the derailment results in the loco going towards the straight route when the points are thrown to the diverging route?

What turnout control are you using: manual or remote; PECO, Tortise?

After getting the NMRA gage check the flange depth of the wheels. I would be surprised if a Scale Trains unit would not have RP-23 compatible wheels.

As has been mentioned, truck swing or lack there of, might be the problem.

This would show up if you run the suspect loco head-end first or tail-end first over the same track arrangement.

If the derailment only happens when it is "facing" in one direction it's probably the loco.

You mentioned that the loco "lifts up" off the rails...

kenben
...making the wheels to come up and off the rail.

Could this be happening from some part of the belly of the loco hitting on another part of the turnout?

I had to shave down the bottom of a Bachmann USRA 0-6-0 gearbox cover because it couldn't clear the re-railers and would derail on straight track. 

You could have gotten a faulty turnout; the frog or "X" section as you described, might be not deep enough to allow the flanges to pass over without interruption.

On the NMRA gage there are three track measurement options. One is labeled "Flangeways" with two points protruding from the gage.

The points on the gage should fit into the frog and rest on the top of the frog. If there is a gap the frog is too shallow.

You can take a jeweler's file and file down the frog to gain the needed clearance. Check frequently with gage so you don't remove too much material. 

Do you have another turnout that you could put in its place and see what happens?

Good luck and keep us informed.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2015
  • From: Shenandoah Valley
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Posted by BigDaddy on Friday, May 1, 2020 6:00 PM

kenben
What appears to be happening is when the leading 3-axel truck enters the frog where the guardrail is (on the left side) and the plastic center area (on the right), the leading truck seems to pull slightly to the right and derails as it goes through the frog. It appears this plastic "X" in the center of the frog is raised up making the wheels to come up and off the rail.

This is the photo Ken sent me

It's a small photo, so it's hard to tell.

I know that Atlas has had problems not with the frog height, but with the material at the base of the frog, which can lift the wheel up.  Althought I think that usually is a bounce rather than a derailment.

Henry

COB Potomac & Northern

Shenandoah Valley

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  • From: Milwaukee WI (Fox Point)
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Posted by dknelson on Friday, May 1, 2020 11:42 AM

Certain Athearn blue box 6 axle engines also seemed to have difficulties with certain turnouts - the SD45 and the FM Trainmaster come to mind.  I think the answer had something to do with that metal strip that was part of Athearn's electrical connection system back then interfering with the sideways movement of the engine's trucks.  

There have always been some combinations of track and trucks/wheels that just did not seem to work, regardless of NMRA standards being met.  

Dave Nelson

  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Friday, May 1, 2020 7:24 AM

 Not Peco, but every loco that had issues with the #6 Atlas turnouts 2 layouts ago ALWAYS was traced to the loco wheels not being properly gauged. Definitely get an NMRA gauge if you don't have one and check these things. Most drive mechanisms these days easily allow the wheels to be adjusted slightly wider or slightly narrower as needed.

                       --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2001
  • From: AU
  • 713 posts
Posted by xdford on Friday, May 1, 2020 5:11 AM

As Crandall points out, (pardon the pun) Peco are very well engineered. From what you are describing however, the problem could be in the movable rail trying to "straighten" itself however microscopically after having been bent and that has been another issue I have had to deal with with extreme conditions in my shed. I think it is due to a very small degree of elastic memory in the rail being bent by machine.  

In short, check the gauge of the track first right the way along the turnout , holding the moving rails with your fingers and very carefully flex that rail outwards but not too far as this is an area where your wheels can be tripped before hitting the frog. This should give you literally that zipteenth difference in gauge that may allow the truck to go through freely!

Hope this helps!

Cheers from Australia

Trevor 

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    January 2018
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Posted by kenben on Friday, May 1, 2020 12:12 AM

The loco is entering from the points and turning left. Going straight it often derails as well. Tested at different speeds and directions. Perfroms a little better coming from the oppsite direction. 

Seems it's happening to my 6-axel Scaletrain locos. Cab forward & cab reverse.

I have the NMRA gage and will check that out.

Turnout is as flat as I could make it. There is no bow in it.

I do have several other Peco EF but are not installed yet. This was the first and I am testing all track and connections for smooth running. Have had to do some filing at a few joiners. These Scaletrains are the only locos where I'm seeing derailing issues.

I will let you know what I find on Friday.

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Posted by selector on Thursday, April 30, 2020 10:58 PM

It's a problem either with the gauge, with the trail, or with the thickness/profile of the wheels that aren't making it through the frog area.  The PECO turnouts are high quality, very reliable, and I have no troulble with any of mine using a wide variety of locomotives from several different importers. If I ever do, I blame the locomotive first.

You can critically check gauge of all axles.  Then, look at the trail.  Like below:

<=)(======)(=>

<)(======)(==>

Both axles the same length, both pairs of wheels in gauge, but the trail....

Also, and it would be the least likely by a country mile, the flange on one wheel might be thicker than the other wheel's.

  • Member since
    December 2001
  • From: AU
  • 713 posts
Posted by xdford on Thursday, April 30, 2020 8:03 PM

Check your loco going in the opposite direction facing both ways. If it is only facing one way and one direction that it derails then check the gauge.

I only have one 6 axle loco as well as a couple of 0-8-0's but heading into a curve, the leading edge of some of the guard rails on Peco turnouts can be a tripping point which can be fixed (in my case) by bending that leading guard rail inwards very slightly or trimming the plastic so that the lead wheel does not pick that corner.  

Hope this helps

Cheers from Australia

Trevor

 

 

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    December 2015
  • From: Shenandoah Valley
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Posted by BigDaddy on Thursday, April 30, 2020 7:28 PM

kenben
(If I knew how to add a photo I would, but haven't figured out how to get it to work) Add Quote to your Post

I sent you a pm, I will post a pic for you.  A 6 axle ought to make it through a #6.

Henry

COB Potomac & Northern

Shenandoah Valley

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    January 2010
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Posted by peahrens on Thursday, April 30, 2020 7:20 PM

Some questions:

https://www.walthers.com/north-american-style-code-83-6-turnout-streamline-left-hand-electrofrog

aa) which way are you describing; e.g., loco entering from points end, turnout set straight ahead (or left)? 

a) do multiple locos do this? cab forward as well as in reverse?

b) do you have a NMRA gage? If so, confirm the depth is ok for flange clearance at the offending spot.  (I had some Atlas crossings where the depth was insufficient for at least one loco, so i filed the groove deeper.)

c) If not all those locos, check that the wheelset gauge is spot on.  I would be shocked if the (RP-25, I presume) wheel flange depth were excessive. 

d) confirm the turnout is nice and flat (not twisted)

e) do you have other Peco EF's that have the same symptoms with this (these) locos? 

Just some ideas.

Paul

Modeling HO with a transition era UP bent

  • Member since
    January 2018
  • 172 posts
Trains Derailing Through Turnouts ??
Posted by kenben on Thursday, April 30, 2020 6:56 PM

Just installed and wired up my first Peco HO #6 electrofrog left turnout. The mainline runs through this turnout when switched to the left trun. Why are my ScaleTrains 6-axel engines derailing when it hits the frog? My Broadway 4-axel switcher runs through the turnout just fine as does my 4-6-2 stream.

What appears to be happening is when the leading 3-axel truck enters the frog where the guardrail is (on the left side) and the plastic center area  (on the right), the leading truck seems to pull slightly to the right and derails as it goes through the frog. It appears this plastic "X" in the center of the frog is raised up making the wheels to come up and off the rail.

(If I knew how to add a photo I would, but haven't figured out how to get it to work)

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