Comprehensive list of causes of derailments

[gdelmoro]

Hi all, 

I know the common causes of derailments but I just found a cause I had never run into. Does a comprehensive list of causes of derailments exist. In other words if you cant find a cause due to the expected reasons try these.

Normal things to check are;

Track gauge

Track level (Longitudal and across)

Mismatched rail code causing bump or drop.

Rail joint not tight.

Track obstructions (on or near) Nails, scenery, buildings bad weld or joint.

Turnouts (not level, improper gauge or wheel clearance at guand rails or frog.

Curve radius too tight

Wheel Gauge or width off

Coupler height (coupler and trip pin)

Here are some things i have found that are less common but still cause derailments;

Trucks are deformed (wheel(s)) don't all sit flat on track.

The Steam loco is connected to the tender by the cable but the bar is disconnected.

A piece of a loco detail or rolling stock has come off and is on track or causing wheels to lift.

Switch machine too close on curve causing loco plow or other body part/detail to hit.

Uncoupler magnet to high or not flat/level

 

Can you add to the list?

[peahrens]

- Kink at rail joint (easy to do with flex track)

- Turnout points not firmly contacting stock rail (both sides)

- Turnout points not shaped right to fit stock rail at top of points

- Poorly adjusted truck movement on rolling stock

- Steam loco lead or trailing trucks not sprung properly

- Steam loco floating / sprung drivers not properly sprung (too strong or weak)

- Diesel loco wheelsets just a tad out of gauge.  The flanges should be centered in the NMRA gauge slots, not just sorta fitting into the slots. 

- I'll second the one on the track level across the rails, including at turnouts, which can readily be a bit twisted.  Part of this is how level you first make your roadbed and, related, how much you choose to glue down the turnout, often avoided for maintenance ease.

- Oh, and running a train into a turnout from the diverging direction with the points thrown wrong.  I've heard this can happen.

[7j43k]

A kink in the track.  One might think that would show up with a gage check.  But maybe not.

Another one I ran into back in the day was when my club had trackwork where they built the main higher than the sidings.  Admirable, actually.  But they had the grade change for the siding happen "inside" the switch.  Very bad.  I jacked up that section of the siding until the track was again fully parallel to the main before starting a grade change.  I'll call this "Grade Change in Track Switch".

And a variant on the above:  Sudden  Grade Changes.  I/we run into that at Free-mo where there's been problems at the ends of modules where the foam shrank and lowered all the track except at the end that sits on plywood.  As I have watched trains cross these problems, I am amazed at how many cars actually make it.

It didn't cause a derailment, but it sure was irritating.  I ran my new Bowser C-628 on a train.  As I say, irritating.  Turns out the snowplows (yes, one at each end--SP) had near-zero* clearance from the rails.  Yup, I'll be a-fixin' that.  Otherwise, a beautiful loco.  So, I'll put this down as "Dragging Equipment".  Also happened on a $500 brass passenger car.

 

Ed

 

*I just measured the clearance:  .005" to .010"

 

PS:  Looks like Paul got some of mine while I was clicky-clacking.

[selector]

Wheels both in gauge, but slipped toward one end of the axle so that, when tracking, neither axle's wheels are directly behind/in front of their counterparts on the next axle;

Axles not seated properly in the trucks' bearing cones;

Sags or humps leading through the points and toward the diverging leg of a turnout;

Frog poorly designed or made allowing wheel drop or improper tracking;

Points rails not sharp enough;

Wrong tire and flange profile for the NMRA-compliant turnout;

Couplers that aren't really compliant or suited for matching;

Couplers that aren't mounted suitably for the curvature radius being used;

...

[DS4-4-1000]

Dirt on the wheels (expecially plastic wheels)

 

[snjroy]

-"S" curve in track

- Steam engine to tender connector that lifts the engine in a curve

- Hanging wires from motor/engine

Also, related to previous comments:

- Lack of weight on leading trucks

- Unbalanced weight on engine

 

Simon 

[SeeYou190]

My former biggest problem:

.

Improperly installed pilot trucks on steam locomotives!

.

This was almost enough to make me go all diesels. Now I only operate Spectrum, PowerHouse, or brass locomotives. These all seem to work well. On many steam locomotives the pilot truck cannot pivot freely, has tension on it, or is just way too light to stay on the rails.

.

On most locomotives there was not a good option for fixing the problem.

.

-Kevin

.

[gdelmoro]

These are great!  I'll wait a couple days and see how many more we get then I'll post a complete list for all.

[Lone Wolf and Santa Fe]

Turnout not reset to proper position. (left switched to siding or spur).
Turnout switch points dance around, not held in place by ground throw or switch machine.
Turnout directly after curve causing a S curve.
Turnouts too tight for longer locomotives or rolling stock.
Loose ballast in a turnout.
Wheel sets not properly set in trucks.
Coupler ‘brake hose’ too low.
Automobiles or livestock on track.

[Lone Wolf and Santa Fe]

Penelope Pitstop tied to the track again.

[MisterBeasley]

Bridge painter falls from bridge, is dragged 500 scale feet by a freight train, and the train derails.  Painter is discovered beneath the locomotive, dusts himself off and continues work on the bridge.

[BRAKIE]

As a rule our models can be quite forgiving but,things they hate that will cause  issues.

 

Sloppy kinky laid track and old BB and Roundhouse cars hastily built with defects overlooked.

Speed..Yup that "S" curve  between switches taken at Marc one or light speed.

Truck mounted couplers.

Trucks to tight won't allow trucks to turn  freely-not sloppy by being to loose.

Long wheel base engines and cars on sharp curves.

 

 

 

[7j43k]

snjroy

 

- Lack of weight on leading trucks

 

 

Hasn't been a problem for me.  I installed two leading and one trailing two-wheel trucks on my logging tanks with no weight or springs.  No derailments.

And, in general, I've not noticed lead truck problems on my steamers.  But mainline steamers have always run on 36" curves and up.  Even my loggers have a min radius of 18".

 

I do wonder if the leading truck problem, at least for two wheel trucks, for long wheelbase locos on sharp turns couldn't be that the lead truck wheels go out of tangent with the rails.

 

Ed

[mobilman44]

Did anyone mention "Excessive Speed"?

I would put that under the sub cat of "operator error".

 

[ROBERT PETRICK]

Whatever is on the list going forward, double it for going backwards. Pushing a string of cars is always tricky, even if everything is near-perfect.

Did anyone mention speed?

Robert 

[IRONROOSTER]

Level to uphill transition too abrupt.

I had no transition at all on my second layout many years ago - took me a while to figure it out.

Paul

[BRAKIE]

ROBERT PETRICK

Whatever is on the list going forward, double it for going backwards. Pushing a string of cars is always tricky, even if everything is near-perfect.

Did anyone mention speed?

Robert 

 

Robert,There shouldn't be any issues in pushing 20,30 or more cars period. I did at the Columbus HO with cars equip with X2F couplers back in the 60s.

Again that falls under not accepting anything less then 100% trouble free operation and contrary to popular beliefs it easy attainable.

[JOHN C TARANTO]

Stiffly sprung diaphragms on passenger cars, operated on sharp radius curves.

[mvlandsw]

   Rail gaps that become too wide due to changing weather conditions.

[gdelmoro]

This list when finished should help a lot of model railroaders that cant figure out what is causing a derailment. I'm also going to add that the cause may not be the site. Often the loco or car derails a good distance before it becomes obvious.

For categories I'm thinking

Operator error: (too fast, loco/tender connection)

Track work: (curves, S-turns, kinks, gauge, transitions, gaps, level)

Turnouts: (Level, points, guard rails, frogs, size)

Rolling Stock: (trucks, wheels, axles, weight, couplers, clearance)

Locomotives: (wheels, number of wheels & configuration, front and rear wheels)

Stuff on track: (parts, figures, ballast, nails, etc.)

 

[Lone Wolf and Santa Fe]

Here is another one:

Long cars being coupled to short cars because they have a different amount of overhang on curves and the longer car will pull the short car off of the track.

[trainnut1250]

 

- Sprung trucks taking an uneven set from track work and not leveling back out.

- Narrow guardrail gaps and tight spacing between frog point and guard rail inside edge.

- Truck swivel impeded by under body details

 

Guy

[gdelmoro]

I'll add - Body mounted couplers on long passenger cars on tight curves.

give me a couple days to put it all together and I'll post the report.

[BroadwayLion]

Cat on the Tracks (any scale)

 

ROAR

[gdelmoro]

BroadwayLion

Cat on the Tracks (any scale)

 

ROAR

 

didn't think of that!

[Lonnie Utah]

https://www.youtube.com/watch?v=HMxJtMoTnx8

[gdelmoro]

Didn’t forget this list. Ive been under the weather... 

[gdelmoro]

OK Here is what was contributed to this post.  Thanks to all!

 

Why Model Trains Derail and Troubleshooting ideas.

 

This information is divided into 3 Categories; Common Causes, Less Common Causes, and You’ve got to be Kidding!

Thanks to the MR Forum members who contributed to this list. Peahrens, 7j43k, Selector, DS4-4-1000, seeYou190, Lone Wolf and Santa Fe, BRAKIE, mobilman44, ROBERT PETRICK, IORNROOSTER, John C Taranto, Trainnut1250

 

 

Common Causes

 

 

Track out of  gauge Track not level (BOTH Ways) along the length and side to side. Note that properly installed track may be super-elevated but this requires detailed attention to Rolling Stock. Mismatched rail code causing height variation. Rail joint too large. Track obstructions (on or near) Nails, scenery, buildings bad weld or joint. Turnouts (not level, improper gauge or wheel clearance at guard rails or frog. Curve radius too tight for locomotive or rolling stock Improper Wheel Gauge Coupler height (coupler and trip pin). Kink at rail joint (easy to do with flex track) Turnout points not firmly contacting stock rail (both sides) Turnout points not shaped right to fit stock rail at top of points Wheels both in gauge, but slipped toward one end of the axle so that, when tracking, neither axle's wheels are directly behind/in front of their counterparts on the next axle; Points rails not sharp enough; Couplers that aren't really compliant or suited for matching; Couplers that aren't mounted suitably for the curvature radius being used "S" curve in track Turnout not reset to proper position. (left switched to siding or spur). Turnout switch points dance around, not held in place by ground throw or switch machine. Turnout directly after curve causing a S curve. Turnouts too tight for longer locomotives or rolling stock. Loose ballast in a turnout. Wheel sets not properly set in trucks. Coupler ‘brake hose’ too low. Sloppy kinky laid track and old BB and Roundhouse cars hastily built with defects overlooked. Speed..Yup that "S" curve  between switches taken at Marc one or light speed. Truck mounted couplers. Trucks to tight won't allow trucks to turn  freely-not sloppy by being to loose. Long wheel base engines and cars on sharp curves. Excessive Speed Everything on these lists going forward, double it for going backwards. Pushing a string even if everything is near-perfect. Stiffly sprung diaphragms on passenger cars, operated on sharp radius curves. Long cars being coupled to short cars because they have a different amount of overhang on curves and the longer car will pull the short car off of the track   Less Common Causes Trucks are deformed wheels don't all sit flat on track. The Steam loco is connected to the tender by the cable but the bar is disconnected. A piece of a loco detail or rolling stock has come off and is on track or causing wheels to lift. Vehicles or livestock on track Switch machine too close on curve causing loco plow or other body part/detail to hit. Un-coupler magnet to high or not flat/level Poorly adjusted truck movement on rolling stock Steam loco lead or trailing trucks not sprung properly Steam loco floating / sprung drivers not properly sprung (too strong or weak) Diesel loco wheelsets just a tad out of gauge.  The flanges should be centered in the NMRA gauge slots, not just sorta fitting into the slots Sudden  Grade Changes  Axles not seated properly in the trucks' bearing cones; Sags or humps leading through the points and toward the diverging leg of a turnout; Frog poorly designed or made allowing wheel drop or improper tracking; Wrong tire and flange profile for the NMRA-compliant turnout Lack of weight on leading trucks Sprung trucks taking an uneven set from track work and not leveling back out. Narrow guardrail gaps and tight spacing between frog point and guard rail inside edge. Truck swivel impeded by under body details     You’ve GOT to be Kidding! Main higher than the sidings. Where the grade change for the siding occurs "inside" the switch.  Very bad Problems at the ends of modules where the foam shrank and lowered all the track except at the end that sits on plywood

Steam engine to tender connector that lifts the engine in a curve Hanging wires from motor/engine Unbalanced weight on engine Improperly installed pilot trucks on steam locomotives! Rail gaps that become too wide due to changing weather conditions

 

[Heartland Division CB&Q]

This is a good list already. 

When installing track. I check for kinks at rail joints both horizontal and vertical. I use a gauge everywhere along the track. 

Next I place a straight edge on the tops of the rails to locate any peaks and valleys . This last step helps make sure rails are on the same plane, and prevents cars from tipping back and forth as they move down the track . 

[dstarr]

Good list, but somehow we missed "Rolling stock too light.  Needs to be weighted up the NMRA standard."  I had a mine branch with a grade and a curve.  The train would go up, but always derailed backing down.  After adding weight to NMRA standard, I could back down and stay on the track.