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Reasons for Derailments on "Bullet Proof" Track Work

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Reasons for Derailments on "Bullet Proof" Track Work
Posted by richhotrain on Tuesday, December 15, 2020 6:14 AM

OK, yeah, I know, "bullet proof" track work? Am I sure that my track work is bullet proof? Well, let me put it this way. My primary objective when I built my new layout was to be as careful as possible to avoid track work issues, so no humps or valleys, no kinks, soldered 32" radius curves, almost no turnouts on the mainlines. That carefulness has resulted in a mainline with almost no derailments.

Most of my locos, freight cars and passenger cars run flawlessly and consistently. Yet, a few freight and passenger cars derail on occasion, not often but once is too many. Also, a couple of locos that derail, especially in consists.

What I have found in every instance is that a coupler assembly or truck is the cause of a derailment. For the most part, I have been able to correct the problem. But, in a few cases, I continue to struggle to find the cause and to correct it. My temptation is to just toss these few cars. Any thoughts on how to proceed?

Rich

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Posted by rrinker on Tuesday, December 15, 2020 7:49 AM

 What in the coupler appears to be causing the derailments? Trip pin catching? I don't use magnets to uncouple so mine are bent up more than the minimum to clear the Kadee gauge. Lifting the trailing car under load? Might just be a bad coupler, with the pulling face not flat, or a mold part line.

 Wheels all properly gauged? Trucks screwed on too hard? One end should swivel freely, but not rock, the other should be a tiny bit looser so it can rock slightly. Too tight and the truck can't swivel to follow curves, too loose and the car will wobble like the Toonerville Trolley.

                                        --Randy

 


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Posted by richhotrain on Tuesday, December 15, 2020 8:30 AM

rrinker

What in the coupler appears to be causing the derailments? Trip pin catching? I don't use magnets to uncouple so mine are bent up more than the minimum to clear the Kadee gauge. Lifting the trailing car under load? Might just be a bad coupler, with the pulling face not flat, or a mold part line.

Wheels all properly gauged? Trucks screwed on too hard? One end should swivel freely, but not rock, the other should be a tiny bit looser so it can rock slightly. Too tight and the truck can't swivel to follow curves, too loose and the car will wobble like the Toonerville Trolley. 

Randy, thanks for that response.

I am on my way down to the layout, so I will get back to you with a more definitive response to your questions.

But for now, I am not totally sure what in the coupler assembly or installation is causing derailments. I long ago began a practice of clipping the trip bins to avoid entanglements and also to avoid catching the trip bin on obstacles between the rails such as grade crossings. It may be that the coupler is lifting the trailing car under load.

One issue is close coupling on passenger cars where the diaphragms snag each other, but I have pretty much solved that problem by using long center shank couplers, prototypicality be damned.

Regarding the trucks, I will check wheel gauge on offending equipment. I have never heard of the swivel that you mention. I find this comment interesting, "one end should swivel freely, but not rock, the other should be a tiny bit looser so it can rock slightly". I will definitely look into that issue.

Rich

 

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Posted by richhotrain on Tuesday, December 15, 2020 8:32 AM

One issue that I perhaps need to consider is weight. What effect does weight have on derailments?

Rich

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Posted by rrebell on Tuesday, December 15, 2020 9:00 AM

Sometimes it is manufacture error. It can be so slight that most people would never know. BLI has an NW2 that has a problem with the frame, the hole for the truck is slightly off I think (well documented problem but the hole placement is my best guess). Had a truck one time that was slightly off on a boxcar (easy fix) but to see what was causing it you had to look real close to notice the very slight tilt on one side.

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Posted by SeeYou190 on Tuesday, December 15, 2020 11:19 AM

richhotrain
Most of my locos, freight cars and passenger cars run flawlessly and consistently. Yet, a few freight and passenger cars derail on occasion, not often but once is too many. Also, a couple of locos that derail, especially in consists.

On the Scale Rails of Southwest Florida HO scale boxcar layout, there was one turnout where one of the club-owned diesel locomotives would derail frequently.

No other locomotive derailed at this turnout, and the locomotive did not derail anywhere else. No one could figure it out.

I remember the day well when club president, Roger W., through the locomotive into the canal that ran next to the clubhouse.

Problem solved.

richhotrain
What effect does weight have on derailments?

I cannot answer this question other than to say that once I took car weight seriously, I had fewer derailments. Of course other factors were addressed the same time as the weight, so I cannot say what had the greatest impact.

I do not follow the complicated NMRA guidelines... my freight cars are precisely weighted like this:

40 feet and under: 4 ounces

41-59 feet: 5 ounces

60 feet and up: 6 ounces

All cabooses: 5 ounces

-Kevin

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Posted by Water Level Route on Tuesday, December 15, 2020 11:23 AM

Too light of a car can derail much easier than one with some weight to it.  Doesn't even have to be up to NMRA recommendations.  One of my favorite cars when I was but a wee lad had a "weight" in it that was virtually pointless.  It was as light as air, I swear.  It was one of my lightest cars and derailed constantly.  My dad popped it open and melted a bunch of solder on the weight in the car making it much much heavier.  It was like a different car altogether.  Derailments with it virtually vanished.

It was the only change made to the car, so I was convinced.

Mike

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Posted by dknelson on Tuesday, December 15, 2020 2:05 PM

rrebell
Sometimes it is manufacture error. It can be so slight that most people would never know. BLI has an NW2 that has a problem with the frame, the hole for the truck is slightly off I think (well documented problem but the hole placement is my best guess).

Yes the old GSB SD40-2 had endemic tracking problems and one of the Athearn Blue Box SDs did as well, either the SD45 or the SDP40.  The old Athearn Blue Box 40' quad hopper was notorious for needing to be overweighted to run right - just something about the physics.

I thought my benchwork and trackwork was pretty bulletproof too but had issues, some of which were due to learning that some Peco turnouts have gauge and flangeway issues.  Also I bought a small level, circular and about as big around as a half dollar, with the bubble in the center.  I moved it around the track and the benchwork and learned there were all sorts of variations.  Then on a whim I took a larger level to the basement floor and made even more discoveries!   Sometimes perfect bulletproof benchwork and trackwork nonetheless are transmitting upwards oddities about the floor.

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Posted by Bayfield Transfer Railway on Tuesday, December 15, 2020 2:15 PM

If everything is relative, does that mean relativity is an absolute?

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

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Posted by SeeYou190 on Tuesday, December 15, 2020 3:14 PM

A laser level on a tripod is the only way to set up a layout.

I rented one in the past. They are inexpensive enough now that I own one.

-Kevin

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Posted by saronaterry on Tuesday, December 15, 2020 4:33 PM

SeeYou190
I do not follow the complicated NMRA guidelines... my freight cars are precisely weighted like this: 40 feet and under: 4 ounces 41-59 feet: 5 ounces 60 feet and up: 6 ounces All cabooses: 5 ounces

I use this exact same schedule.

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Posted by gmpullman on Tuesday, December 15, 2020 4:51 PM

dknelson
Also I bought a small level, circular and about as big around as a half dollar, with the bubble in the center.  I moved it around the track and the benchwork and learned there were all sorts of variations.

I also used a flat bubble level but I stepped it up a notch and got one of these:

 Digital_level1 by Edmund, on Flickr

It is handy for calculating grades, too:

 Digital_level by Edmund, on Flickr

I was amazed, too, at how many areas had dips and high spots that I couldn't see. Laying a good straight edge on the rail head will also find lows and highs.

SeeYou190
A laser level on a tripod is the only way to set up a layout.

I agree. It is also handy for aligning track around a turntable:

 Laser_RR by Edmund, on Flickr

This little guy is pretty handy around the layout.

 Laser_RRtt by Edmund, on Flickr

I suggested a laser-level in one of the threads here a while back and was pretty much told to go soak my head, phoo-phoo. I backed into the corner and left the REAL modeling up to the experts.

I recently bought a dozen of the Broadway Limited P70 coaches and had some derailment issues. It didn't take long for me to figure out that the trucks were too stiff to give any roll axis movement. Adjusting them required shaving plastic off the bolster because they were designed to "snap" into the pivot hole and the clips were too snug.

Likewise, the Walthers Proto cars require a little work since the trucks ride on the metal pickup "pads" and can inhibit roll axis movement. Sometimes passing a good mill file over the heads of the four screws on the trucks will help.

I've never noticed any derailment problems caused by coupler issues. I run lots of long passenger trains on slightly tighter curves (30" min.) and don't recall any issues.

I trimmed all my trip pins, too, more for appearance rather than any operating issues.

Good Luck, Ed

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Posted by SeeYou190 on Tuesday, December 15, 2020 5:08 PM

gmpullman
I backed into the corner and left the REAL modeling up to the experts.

I will never be a REAL model railroader.

Ed: I think that is the base for the Cornerstone Modern Roundhouse in your picture. If it is, can you let me know the diameter, in approximate inches, of your turntable?

-Kevin

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Posted by richhotrain on Tuesday, December 15, 2020 5:13 PM

I don't think that level track, or the absence therof, is my problem. But, it is good to raise the issue for others who are following this thread.

My problems seem to be coupler related and truck related. That said, I still cannot figure out what the problems are. The derailment problems are limited to just a few locos and passenger cars.

Rich

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Posted by selector on Tuesday, December 15, 2020 5:59 PM

I don't know that 'bullet-proof' is achievable. It may be 99.9% there, but in my limited experience there will be one engine or car that will derail somewhere along the system.  In fact, it's just a fact of life for me that when I get a new type of locomotive, I expect it to act 'homesick'.  It balks at something and refuses to budge past it.  It takes me anywhere from a few minutes to a whole day to figure it out, but often it's the tracks, and not the locomotive. I usually find that the outer rail on a curve dips just enough over four or six inches to allow the lead axle's outer flange to slip sideways and outside the gauge. Or, at the back, there's the opposite, a rise, and that levers the entire frame high on that side, thus causing the same issue for that lead outer flange.

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Posted by BATMAN on Tuesday, December 15, 2020 6:15 PM

I used this little level until I downloaded an APP to my phone that is a level and measures grades.

 

 

Brent

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Posted by wp8thsub on Tuesday, December 15, 2020 7:11 PM

If you're sure about the trackwork, start checking for truck issues. 

  • Truck screws that are too tight.
  • Wheelsets out of gauge or offset so they aren't tracking in the same straight line.
  • Poor interface between the truck and body bolsters preventing a full range of motion.
  • Underbody parts interfering with truck or wheelset movement.
  • Truck sideframes out of alignment (i.e. twisted so that journals are not directly across from each other).
  • Loco axle bearings unable to move freely.

richhotrain
My temptation is to just toss these few cars.

Derailments are rarely caused by the car as a whole.  Replacement of the offending trucks or wheelsets usually cures the problem.  If all else has failed for me, I will often install Kadee HGC trucks. They require filing down the body bolster to create a flat bearing surface, and have an insert that places all responsibility for truck motion on the truck itself.  I've had a few cars that were difficult to tune up that have become reliable thanks to the Kadee trucks.

As for coupler issues, they're usually simple to fix with some judicious filing or use of graphite lubrication.  In only a few cases have I replaced the draft gear.  High quality draft gear from someplace like Moloco might do the trick.

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Posted by Pruitt on Tuesday, December 15, 2020 7:18 PM

richhotrain
...in a few cases, I continue to struggle to find the cause and to correct it. My temptation is to just toss these few cars. Any thoughts on how to proceed?

Rich

With exactly that plan. Or sell them on ebay. After a certain amount of time (in my case a few hours of messing around with the offending car) you reach the point of diminshing returns. It's just better to smash the car (very theraputic!) or drop it in the trash can or sell it - anything to get it out of your hair! Then move on.

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Posted by gmpullman on Tuesday, December 15, 2020 8:41 PM

SeeYou190
Ed: I think that is the base for the Cornerstone Modern Roundhouse in your picture. If it is, can you let me know the diameter, in approximate inches, of your turntable?

I'll take some measurements shortly, Kevin. New thread started in Layouts & Layout building.

Thank you, Ed

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Posted by richhotrain on Tuesday, December 15, 2020 10:57 PM

selector

I don't know that 'bullet-proof' is achievable. It may be 99.9% there, but in my limited experience there will be one engine or car that will derail somewhere along the system.  In fact, it's just a fact of life for me that when I get a new type of locomotive, I expect it to act 'homesick'.  It balks at something and refuses to budge past it.  It takes me anywhere from a few minutes to a whole day to figure it out, but often it's the tracks, and not the locomotive. I usually find that the outer rail on a curve dips just enough over four or six inches to allow the lead axle's outer flange to slip sideways and outside the gauge. Or, at the back, there's the opposite, a rise, and that levers the entire frame high on that side, thus causing the same issue for that lead outer flange. 

Yeah, I have to confess that you are right. But like the parable of the lost sheep,I have to find that one loco, that one car, that derails and fix it.

Rich

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Posted by richhotrain on Tuesday, December 15, 2020 11:06 PM

Pruitt
 
richhotrain
...in a few cases, I continue to struggle to find the cause and to correct it. My temptation is to just toss these few cars. Any thoughts on how to proceed?

Rich 

With exactly that plan. Or sell them on ebay. After a certain amount of time (in my case a few hours of messing around with the offending car) you reach the point of diminshing returns. It's just better to smash the car (very theraputic!) or drop it in the trash can or sell it - anything to get it out of your hair! Then move on. 

BowBowBow

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Posted by selector on Wednesday, December 16, 2020 1:29 AM

One other thing not mentioned, and I dunno if it's comparatively rare or if it happens more than most of us realize:

The flanges all have to run line-astern when they enter a turnout and get near the guards.  They may be in gauge, but they don't really line up if you eyeball them from the back...or the front, whichever.

If you invert the loco, and press all the axles in any one truck to the side, you should find that the flanges are very closely in line.  Graphically:

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

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

Both axles are the same length, and both wheelsets ARE in gauge, but.....well....

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Posted by "JaBear" on Wednesday, December 16, 2020 3:16 AM
I can’t add to all the good tips you’ve already received Rich.
Running exhibition layouts (when there were such things as Train Shows) required bullet proof equipment and I made it a point that none of my stuff was removed due to poor running qualities, in fact I quite like fettling rolling stock.That said I do have one box car that will only run in one direction, don’t ask me why!!
 
What to do with a recalcitrant piece of rolling stock…
 
 
Unfortunately Photobucketitius has struck not only on this past thread but is worse on other similar threads. 
Cheers, the Bear.  Smile

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Posted by Southgate 2 on Wednesday, December 16, 2020 3:30 AM

 

 

[/quote]

SeeYou190

 

 
 

 

No other locomotive derailed at this turnout, and the locomotive did not derail anywhere else. No one could figure it out.

I remember the day well when club president, Roger W., through the locomotive into the canal that ran next to the clubhouse.

Problem solved.

-Kevin

 

I couldnt't tell ya how many times I've resorted to this kind of method to solve any number of operational problems. (Spaced out over many years though)

As mentioned further down, smashing a delinquent piece of equipment CAN be very theraputic. But only after all other known possibled cures have been tried. Dead Dan

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Posted by richhotrain on Wednesday, December 16, 2020 6:05 AM

I cannot tell you how much that thought appeals to me.

Rich

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Posted by richhotrain on Wednesday, December 16, 2020 6:26 AM

I can’t add to all the good tips you’ve already received Rich.
Running exhibition layouts (when there were such things as Train Shows) required bullet proof equipment and I made it a point that none of my stuff was removed due to poor running qualities, in fact I quite like fettling rolling stock.That said I do have one box car that will only run in one direction, don’t ask me why!!
 
What to do with a recalcitrant piece of rolling stock…
 
 
Unfortunately Photobucketitius has struck not only on this past thread but is worse on other similar threads. 
Cheers, the Bear.  Smile
 

Bear, I quite agree. More than once, I have reversed a problematic freight car or passenger car only to achieve immediate success. This tells me that it is likely a truck that is the culprit.

Rich

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Posted by SeeYou190 on Wednesday, December 16, 2020 10:04 AM

There was an answer in MR Clinic years ago to a question about a layout where one freight car derailed in the same place constantly.

The answer was that the greater likelihood was that the root problem was in the freight car rather than the trackage.

I remember that well, because it was printed at the same time we were having problems with that one locomotive on the Scale Rails of Southwest Florida HO scale boxcar layout, and it did not help at all!

We checked that turnout with the NMRA gauge over and over again... nothing we could detect.

-Kevin

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Posted by richhotrain on Wednesday, December 16, 2020 12:16 PM

CASE STUDY: I have two identical Life Like PA/PB consists. One runs perfectly around the entire layout either as a consist, just the PA loco, or the PA/PB pullings a 7-car passenger consist. However the other PA/PB consist cannot make it around the layout in one spot. Every other loco that I own own, steamer, 4-wheel diesel, 6-wheel diesel, has absolutely no problem. So, correct me if I am wrong, but the problem has to be the front truck which is the one that derails. Where do I go from here?

Rich

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Posted by ATLANTIC CENTRAL on Wednesday, December 16, 2020 12:35 PM

richhotrain

CASE STUDY: I have two identical Life Like PA/PB consists. One runs perfectly around the entire layout either as a consist, just the PA loco, or the PA/PB pullings a 7-car passenger consist. However the other PA/PB consist cannot make it around the layout in one spot. Every other loco that I own own, steamer, 4-wheel diesel, 6-wheel diesel, has absolutely no problem. So, correct me if I am wrong, but the problem has to be the front truck which is the one that derails. Where do I go from here?

Rich

 

Check the wheel gauge.

Check for smooth lateral motion of all the axles, three axle trucks need lateral motion.

Remove the shell. Set the loco on a smooth hard surface, steer the trucks feeling for any binding or limitation that seems not right.

Also check that all the wheels are setting on the hard surface.

Flip the loco upside down in your hand. Steer each truck from side to side, tilting it side to side and front to back as uneven track might do. You are looking for any kind of bind or limitation that seems within the required range of motion.

Run the loco with the shell off, watch the gear towers for unusual movement as it goes thru the offending area of track.

Check to make sure drive shafts are not bottoming out in their sockets when the truck turns or moves. A socket may not be all the way on its shaft.

Sheldon 

    

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Posted by snjroy on Wednesday, December 16, 2020 1:54 PM

There was a past effort to do an inventory of causes of derailments :

http://cs.trains.com/mrr/f/88/p/264737/3012077.aspx

Simon

 

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