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Derailments - It Doesn't Take Much to Cause One.

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Derailments - It Doesn't Take Much to Cause One.
Posted by tomikawaTT on Sunday, December 7, 2008 5:14 PM

As regular Forum visitors are aware, I'm something of a fanatic about building derailment-resistant trackwork.  So, imagine my chagrin when several cars I had just purchased derailed when being backed over switchwork that had been in trouble-free (until yesterday) service for almost two years.Shock

Several test runs, in both directions, convinced me that the extremely underweight 4-bay hoppers (intended for kitbashing) would derail at the butt end of one particular switchpoint, on facing point moves only.Grumpy  When I finally got up close and personal with a bright work light, I noticed that there was a tiny blob of solder on the railhead - left behind when that point was soldered to its pivot pin. Sign - Oops  It couldn't have been more than .01" high - just enough to bounce the flange and lift it onto the top of the curved closure rail.Angry

A few seconds of attention with a fine-cut file restored the proper railhead contour.  Now those four-axled feathers seem to roll through without a hitch.Thumbs Up  The next step will be to push the whole string over all of the in-service specialwork to check for other potential problems.Black Eye

The moral of the story?  Just because you haven't had a problem, don't think everything is perfect.  Murphy is alive and well!Evil

Chuck (Modeling Central Japan in September, 1964)

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Posted by SpaceMouse on Sunday, December 7, 2008 5:19 PM

tomikawaTT

 

It's hard to argue with that.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

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Posted by selector on Sunday, December 7, 2008 5:22 PM

...nor to avoid.

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Posted by blownout cylinder on Sunday, December 7, 2008 5:51 PM

A use for feathers--- back them up over points and see if they catch on anything...

Now I got to check back on the wye again...Whistling

Any argument carried far enough will end up in Semantics--Hartz's law of rhetoric Emerald. Leemer and Southern The route of the Sceptre Express Barry

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Posted by cudaken on Sunday, December 7, 2008 8:37 PM

 Chuck good to hear a molder as advances as your self have problems, make me feel a little better.  My new section is the best laid track to date. 24 inch turns, number 6 and 8 turn outs. Big Boy Loves it, same with Y6b, AC 6000, dash 9, Sd 50's, E-6 and E-7's. Tonight I ran one of my BL2's on it, it makes a bumping sound on two of the turn outs, does not derail just bump? Odd thing is I was runnig on the main bench that is not as well done, same sizes turnouts, not a bump to be heard?

            Cuda Ken

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Posted by GraniteRailroader on Tuesday, December 9, 2008 10:29 PM

 Sounds like the natural play in the drivers is allowing it to shift side to side and the "bump" you're hearing is the drivers getting to the limit of their tolerance. Either that, or your locomotive is experiencing the natural pressure pushing it to the outside of a curve and hearing it rebound back as it pushes itself through.

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Posted by tomikawaTT on Tuesday, December 9, 2008 11:04 PM

GraniteRailroader

 Sounds like the natural play in the drivers is allowing it to shift side to side and the "bump" you're hearing is the drivers getting to the limit of their tolerance. Either that, or your locomotive is experiencing the natural pressure pushing it to the outside of a curve and hearing it rebound back as it pushes itself through.

Say WHAT???  The problem children are FOUR-BAY HOPPERS.  The locomotives are nowhere near their tolerances - 610mm curve radius (eased) versus a 'maximum-minimum' tolerable radius of 450mm or less (without easements.)

I have other, longer, bogie stock, cars that have been traversing the same turnout curve with ease for two years - but those cars are ballasted to NMRA recommended weight and have far better quality trucks.

Since I started this thread I've run those (fillintheblanks) over the entire railroad (or at least the part that's finished) and identified two problem cars (flash on the truck mounting pads) and one other track problem (solder too high in a flangeway.)  I've also loaded them with drywall screws - and eliminated their tendency to fly.

Chuck (Modeling Central Japan in September, 1964)

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Posted by GraniteRailroader on Tuesday, December 9, 2008 11:38 PM

Oops. I didn't click the "QUOTE" button when I replied to CudaKen's post!

 

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Posted by twhite on Tuesday, December 9, 2008 11:49 PM

Chuck--

I hear you loud and clear.  My layout is in a partially uninsulated garage ("California Basement") and like you, I've had to be EXTREMELY careful in my track-laying--in my case to overcome some extremes of temperature between seasons.  I like to think that I've done it all and done it well, but Murphy creeps up occasionally, and I end up having to 'temper' some sections that I ordinarily wouldn't think of working.  Oddly enough, never because of my locomotives, but because some piece of rolling stock suddenly decides it doesn't like a particular track-joint.  And when I look at the joint, it might be, like you, just a sliver of solder or a tweak where the rails join.  For instance, I had an Intermountain PFE reefer that just refused to go over a certain piece of track without derailing.  I checked everything until I was bleary in the eyes.  Turned out it was not a wheelset out of gauge or an underweighted car, but the particular way the truck was balanced when it hit the joint.  A few gentle swipes of a file to the track joint and tuning the truck-frame  balance up a little cured it. 

But if Murphy is invited, he'll sure show up, LOL!  Whistling

Tom Smile

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Posted by markpierce on Wednesday, December 10, 2008 1:57 AM

Chuck, my first thought is that the cars-in-question didn't have all-metal wheel sets and the cars are under-weight. Solving those issues, those cars may be OK.  (By the way, did central Japan have four-bay hoppers?  I'm totally ignorant about that.)

Mark

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Posted by selector on Wednesday, December 10, 2008 12:39 PM

Mark, in his post earlier, Chuck mentions that he filled the two problem hoppers with drywall screws, so he seems to be aware that "tonnage" added will do the trick. Big Smile  I have resorted to the same with hoppers that don't seem to want to behave...I add weight to them and they usually settle down.

Most often.

If they want to.

I guess.

-Crandell

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Posted by tomikawaTT on Wednesday, December 10, 2008 2:33 PM

markpierce

Chuck, my first thought is that the cars-in-question didn't have all-metal wheel sets and the cars are under-weight. Solving those issues, those cars may be OK.  (By the way, did central Japan have four-bay hoppers?  I'm totally ignorant about that.)

Mark

Right on both counts!  The big culprit is the lack of weight.  The wheels may be plastic, but the cars will roll if you breathe in their general direction (I thought that track was LEVEL!!!)

Actually, these cars are kitbash fodder - destined to become (after major surgery) seven-axle articulated cars with one bay per carbody.  Nothing like that ever ran in Japan, but the Tomikawa Tani Tetsudo has them.

Chuck (Modeling Central Japan in September, 1964 - with tongue in cheek)

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Posted by jbinkley60 on Wednesday, December 10, 2008 3:13 PM

tomikawaTT

As regular Forum visitors are aware, I'm something of a fanatic about building derailment-resistant trackwork.  So, imagine my chagrin when several cars I had just purchased derailed when being backed over switchwork that had been in trouble-free (until yesterday) service for almost two years.Shock

Several test runs, in both directions, convinced me that the extremely underweight 4-bay hoppers (intended for kitbashing) would derail at the butt end of one particular switchpoint, on facing point moves only.Grumpy  When I finally got up close and personal with a bright work light, I noticed that there was a tiny blob of solder on the railhead - left behind when that point was soldered to its pivot pin. Sign - Oops  It couldn't have been more than .01" high - just enough to bounce the flange and lift it onto the top of the curved closure rail.Angry

A few seconds of attention with a fine-cut file restored the proper railhead contour.  Now those four-axled feathers seem to roll through without a hitch.Thumbs Up  The next step will be to push the whole string over all of the in-service specialwork to check for other potential problems.Black Eye

The moral of the story?  Just because you haven't had a problem, don't think everything is perfect.  Murphy is alive and well!Evil

Chuck (Modeling Central Japan in September, 1964)

I had a similar lesson.  I had a curved incline that had been trouble free in both directions with all rolling stock and locmootives.  That was until I mu'd 2 Atlas Dash 8 Gold units and had the throttle set about 35 and they were going up the incline.  At that point, somewhere along the incline, the front wheel of the lead locomotive would slip over the rail head.  I should mention that this was also inside a mountain.  Coming down the hill or at lower speeds there were no issues.   Anyway, after weeks of hair pulling (and some mountain disassembly) I found that one spot on the curve where the outside rail dipped slightly from the inside rail, even though the overall incline remained perfect.  I shimmed the outside rail to get it even with the nside rail and no more derailments. 

Model railroading works with such a wide variety of rolling stock and locomotives that these things can happen.  I always try to test with as much different rolling stock and locomotives but different trackwork issues cause different results, based upon what you are running across it.

 

 

Engineer Jeff NS Nut
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Posted by markpierce on Wednesday, December 10, 2008 3:35 PM

tomikawaTT
Actually, these cars are kitbash fodder - destined to become (after major surgery) seven-axle articulated cars with one bay per carbody.  Nothing like that ever ran in Japan, but the Tomikawa Tani Tetsudo has them.

Seven-axled articulated cars?!?!  I've got to see a picture of those.

Mark

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Posted by CSXDixieLine on Wednesday, December 10, 2008 10:57 PM

tomikawaTT
Several test runs, in both directions, convinced me that the extremely underweight 4-bay hoppers (intended for kitbashing) would derail at the butt end of one particular switchpoint, on facing point moves only.Grumpy 

First of all, that is THE BEST use of an icon EVER! In fact I am still laughing every time I look at it and imagine you doing the same look as those four hoppers hit the ground!

Secondly, thanks a ton for sharing this information. As a modeler who is just about to start laying track on a large layout for the first time, this type of information is very helpful to store away for future use.

I may have to keep a mirror in the basement so I can remember your post if I ever see Grumpy staring back at me. Jamie

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