Engine Keeps Jumping Off Track

rule of thumb if the engine checks out it my be something in your track or table

Out of 10 engines or so this is the only one

c6usa.....Henry ,if  I'm looking at the right engine  ,I  noticed what would be two six wheel trucks  ( each truck having two plastic dummy wheels )    This is a long diesel .   Are the diesels you run that don't  have a problem the same size as this one ?

Do you have lubrication where the trucks ride on the frame ?

If there is a slight dip or rise in the track those dummy wheels can catch on the rails and throw the truck .

If you have some run time on this engine , turn it over and look for any places where the truck might have been rubbing on the frame.

I had a Railking dash-8 ( long engine/ six wheel trucks ) that I slightly filed the two side bumpers in order to give the engine a little more side to side flexing around an O31 rising curve.

Any chance you could post a video?

Dallas: Most of my engines are 6 axle railking. I will look at the wheels and yes I did maintenance on all my engines in December drop of lub every where. gears,axles and rollers are all free.

Ricko: I will post video as well tomorrow

Thanks Henry

one jumps and one stays on the track

Dallas I looked all over the frame and nothing stood out even took the motor and looked at the frame contact points to make sure nothing was rubbing all looks good. I would say its the track but this is the only engine that jumps.  More to follow later I'm done for today

In your video of the engine jumping the track it is definitely happening at a track joint. I've seen something like this on my own layout after laying track. It appears to me that the first outside (right side) wheel flange is catching just enough to ride up and over the top of the rail. That is the side the engine derails on.

The places I saw causing this in my track were usually at a transition on a curve and also between GG and Atlas O.  The Atlas rails are wider than the GG and when on the outside rail of a curve the wheels are naturally pushing on the inside of that rail making the possibility of a jump even greater. A little re-aligning and a few extra screws solved those issues with my engines. I have also the Atlas track clips contribute to this if one gets a bit deformed and is in just the right place.

Why one engine would do this and not another may be due slight differences in the wheel flanges.

It would help if it were possible to step the video frame by frame but you can also try that engine at a slower speed and observe what happens and that joint. I usually run about 5 smph when I first test track I have laid.

I hope this helps.

Did  you check the wheel gauge on the front truck?   From what the video shows , you are  running up a steep grade, going into an S curve and at the track joint into a straight section in the level top of the grade . ( Thats where your front wheel set is coming off)    If the wheel gauge is correct , try  to shim up the out side curve to straight  section to elevate it a little towards the back wall.     I could not tell , from the angle of the video , but it looks  like  the top of the grade  meets the level shelf at the track joint, there the curve and the straight track should be level with each other!

Well, at least it's earned a nickname!...

One of my favorites at bedtime...75 years ago.

Shim the outside of the curve and straight. I had the same problem recently with the Menards F7. I shimmed the offending track section and the problem was solved. Only took less than 1/8".

Looks like the straight out of the curve has dropped a bit.

Start with the simple, before tearing the engine apart.

Bob

If your phone or camera has a slow-motion setting, it's very helpful to see what's really happening VS a train at headway speed. I've used it several time and it's amazing what you can see! I agree with the shim part too, but try a slow-mo video if you can!

Back on the railroad at 7am. Finally got jumper to stay on the track and with a heavy load. Guys you were correct it was the track with a small shim on the outside rail all is good now see the pic below. I guess what got me is the train combo that I have worked for a couple of years with no problems and other trains that I run most of the time are OK over this area.

Endless track: I have a smart phone however I am a dumb owner but now just one more click towards smarter. I found the slow-motion feature this is a awesome tool to have.

Thanks Henry

@c6usa posted:

Back on the railroad at 7am. Finally got jumper to stay on the track and with a heavy load. Guys you were correct it was the track with a small shim on the outside rail all is good now see the pic below. I guess what got me is the train combo that I have worked for a couple of years with no problems and other trains that I run most of the time are OK over this area.

Endless track: I have a smart phone however I am a dumb owner but now just one more click towards smarter. I found the slow-motion feature this is a awesome tool to have.

Thanks Henry

Bob's  ( RSJB18 )  small shim idea did the job......good to have forumites with experience.

Great to see you have the issue taken care of and you are ready for another.

Just be thankful it wasn't derailing and falling off the layout and down... down... down!

Get out your big magnifying glass.  Put a bright light on the track section.

Get as close to the track section/joint as you possibly can.

Put your engine only on the track, and push it by hand as slowly as possible over the suspect section/joint, while watching closely with the glass.

You may have to do this five or ten times, but if it is a back track section/joint, you will eventually see how/where the wheel rides up over the rail.

I think that even putting in a tiny shim under this section may then solve the problem.

The fact that only one loco jumps the track here does mean that it is not a track problem.  I have had the same issues in a couple places on my track, where only one loco derails and the others work fine.

Hope this helps.

Mannyrock

@c6usa posted:

Back on the railroad at 7am. Finally got jumper to stay on the track and with a heavy load. Guys you were correct it was the track with a small shim on the outside rail all is good now see the pic below. I guess what got me is the train combo that I have worked for a couple of years with no problems and other trains that I run most of the time are OK over this area.

Endless track: I have a smart phone however I am a dumb owner but now just one more click towards smarter. I found the slow-motion feature this is a awesome tool to have.

Thanks Henry

Glad that fixed the problem.

Impressive collection of flat cars too!

Bob

@Mannyrock posted:

Get out your big magnifying glass.  Put a bright light on the track section.

Get as close to the track section/joint as you possibly can.

Put your engine only on the track, and push it by hand as slowly as possible over the suspect section/joint, while watching closely with the glass.

You may have to do this five or ten times, but if it is a back track section/joint, you will eventually see how/where the wheel rides up over the rail.

I think that even putting in a tiny shim under this section may then solve the problem.

The fact that only one loco jumps the track here does mean that it is not a track problem.  I have had the same issues in a couple places on my track, where only one loco derails and the others work fine.

Hope this helps.

Mannyrock

After looking at the video in slow motion you can see the wheels starting to move up the rail its clearly not the joint but the rail that's the problem. Here is a still photo

I keep a torpedo level handy for just this reason but I use it to set the plywood sub-roadbed. Then I know the track will be level from side to side.

Glad the shim worked. I created this problem while experimenting with superelevation on my layout. While I liked how interesting it looked when the trains tip while going around curves, in an S curve the truck or in my situation my steam loco would have to actually flex to negotiate the S curve. They don't flex and I ended up creating the same condition you had. I would assume that you had some movement in your layout possibly from the wood expanding / contracting due to humidity. Wood is always moving this way, probably just enough to cause the issue.

@Dan Kenny posted:

While I liked how interesting it looked when the trains tip while going around curves, in an S curve the truck or in my situation my steam loco would have to actually flex to negotiate the S curve. They don't flex and I ended up creating the same condition you had.

Yeah Dan, the need to slightly ' flex ' in this kind of situation is important.

While this is more difficult to achieve with a steamer it can be improved rather easily with one of these long diesels.

  I didn't realize that, in my case, until I compared my offending dash8 with a good one that had more tilting from side to side on the front truck and found the truck bumpers were the difference.         SLIGHT filing on the bumpers on the problem diesel ended the issue. 

The ability of the trucks , slightly more independent of the engine ,to follow the contours of the rails was key.