Lionel Visionline Big Boy derailing on Atlas 072 curves, what's our next step?

If the area isn't flat, the engine has to go over the hump and maybe hitting.

I have a MTH Allegheny that had to have a steam pipe grounded down to allow for this type of movement.

Put a large straight edge right on the rails (with the power off), to find out how bad any humps are in the trackwork.

You may have to remove that spring detail (if possible) and see if it fixes the issue.

Joe’s got the right ideas, and I’ll add to his suggestions, …..the front engine truck supports the front of the boiler from a spring on the pivot point. if the boiler is sitting down on the truck, this will cause it to derail. ( obviously ) ……the spring and sliding cup washer should ride up against the pivot plate under the boiler. Using a flash light, look to see if the orientation off the spring, the cup washer, & the post they all stand on look to be nice and straight, and the front section of the boiler has spring tension against it. …..this design has been around for a long time, so you can look at your other split frame locomotives for an understanding, and visual comparison……

Pat

My plan would be to use the CAB handheld and run the Big Boy as slow as possible thru the 2 curves, while keeping a finger on the CAB's red emergency stop button, and eyes on the wheels. As soon as I would see any of the wheels starting to derail, I would hit the emergency stop button. You can then examine the front and trailing pilots, and articulated driver sets, to see if you can determine what is causing the derailment to start. If I felt I needed to remove the engine from the track to examine the track better, I would use blue painters tape to mark location of wheels on track along the side of the track, then remove the engine for the examination.

I know this is not a solution, but if you can see mechanically what's happening and post it, then a forum member can probably figure out a solution.

is it this part #47, Pat?

UP Big Boy #4012 Locomotive Only - 6101126001 (lionelsupport.com)

I'm trying to see what it looks like because I've never had one!

I was looking thru Alex M.s post but didn't see any pics of it.

AN INSIDE LOOK AT THE LIONEL VISION LINE BIG BOY, TONS OF PICTURES | O Gauge Railroading On Line Forum (ogaugerr.com)

@Engineer-Joe posted:

is it this part #47, Pat?

UP Big Boy #4012 Locomotive Only - 6101126001 (lionelsupport.com)

I'm trying to see what it looks like because I've never had one!

I was looking thru Alex M.s post but didn't see any pics of it.

AN INSIDE LOOK AT THE LIONEL VISION LINE BIG BOY, TONS OF PICTURES | O Gauge Railroading On Line Forum (ogaugerr.com)

Yep, …they have changed it up a bit, but still does the same job, ….

Pat

The loco specs say it is 32 inches long.  Any chance you have the classic S curve problem even with 30 inches between the end of one curve and the start of the next?  Does it derail on a regular curve of 1/4 or 1/2 circle?  Does it derail only when turning in one particular direction?

@CALNNC posted:

The loco specs say it is 32 inches long.  Any chance you have the classic S curve problem even with 30 inches between the end of one curve and the start of the next?  Does it derail on a regular curve of 1/4 or 1/2 circle?  Does it derail only when turning in one particular direction?

This is is my first suspicion as well, although its the wheel base, not the coupler to coupler distance that matters and 30" is probably enough. Between reverse curves, if you try to pull it in both directions at the same time, especially with the pedestal tender, its going to be a problem. The paint scuffs on the pipes are from the front engine bouncing around.  The long boiler moves up and down as it runs, with the front end basically free to rock up and down on the back set of drivers.  There's nothing you can do about that unless your track work is completely dead flat. It may or may not be from the derailment spot.

I second the suggestion to run it dead slow through there and see if you can identify the exact point where it starts to derail.  If the front end is trying to go one way, and the rear end is still going the other, you may have a situation there where the middle cant change direction and just lifts off. But its also possible that a set of wheels is out of gauge too wide, or a blind center is dropping in the rail and catching the inside edge.

@Boilermaker1 posted:

This is is my first suspicion as well, although its the wheel base, not the coupler to coupler distance that matters and 30" is probably enough. Between reverse curves, if you try to pull it in both directions at the same time, especially with the pedestal tender, its going to be a problem. The paint scuffs on the pipes are from the front engine bouncing around.  The long boiler moves up and down as it runs, with the front end basically free to rock up and down on the back set of drivers.  There's nothing you can do about that unless your track work is completely dead flat. It may or may not be from the derailment spot.

I second the suggestion to run it dead slow through there and see if you can identify the exact point where it starts to derail.  If the front end is trying to go one way, and the rear end is still going the other, you may have a situation there where the middle cant change direction and just lifts off. But its also possible that a set of wheels is out of gauge too wide, or a blind center is dropping in the rail and catching the inside edge.

I agree with Boilermaker1.  I'd like to know if it's the pilot or drivers when running slow speed. I have a Lionmaster challenger that would derail often.  In my case it was the rear pilot and too little spring pressure, now it runs flawlessly.   In addition, I had a railking Erie triplex that derailed only on one switch out of six or so.  Replaced that switch twice only to have the same issue and find one pilot wheel was pressed too far onto the axle by a fraction of an inch.  And as shown in your photo I had an H7 that would occasionally derail but that was due to me asking a bit much of it in less than desired curves.  I mention this because that pivoting steam pipe was limiting boiler articulation.  I know none of these may be your issue but trying to throw everything out there hoping something may be insightful food for thought.

any further info for us?

I watched both videos.

Second one first - the engine should make that left-right twist/jump. Unfortunately (though may not help), could not see what the trailing pilot was doing. I would run the engine through this spot with finger on CAB emergency stop, and with the twist starts to happen, I would do the emergency stop, the look for mechanical interference. The motion seems to be a slow climb with fast drop, indicating to me that mechanical interference is ramp like - slowly ride up on something, the quick drop off. Probably take close up  pics of engine fully on straight track along both sides of engine to use as reference when examining engine stopped on curve mid twist.

My eyes don't catch much in the first video - but I think I see the lead inside front pilot wheel rising off track - shouldn't happen. Again, video doesn't quite have the full engine in view when I think I see the wheel lifting.

Two things come to mind as prep work before digging into my ideas above. 1) Have you made sure that you have removed all packing material/foam pieces from engine and tender? 2) Run engine with no tender through the twist motion area and see if twist still occurs.

Hope some of this may help!

Look closely at 2nd video.  The top yellow pipe has interference with the lower yellow pipe, causing the whole front assembly to ride up off the track. Once the big boy straightens out, the interference is no longer there and the front drops down, and the front drivers can derail.

To me, it looks like there is a spring missing on that lower pipe. See the eyelet on the end of it?  If the spring was there it would stay centered when the loco goes around a turn.

I think this Lionel P/N is missing:  cs-6101434140-p.

Note, I looked for the part on the 1st gen big boy, since Lionel doesn’t yet have the parts diagrams posted yet for the 2nd gen.  It should be the same though, since, AFAIK, there wasn’t any redesign on that part of the model.

Adding pic to show where the spring attaches:

I think you're binding somewhere. But also check the pick up rollers. I have a spot where my 4-12-2 locomotive catches its pick up roller on the middle rail and it jerks like your video. I keep that locomotive off that track for the time being but I will have to find a solution when I screw the track down.

@Crazy Train posted:

Look closely at 2nd video.  The top yellow pipe has interference with the lower yellow pipe, causing the whole front assembly to ride up off the track. Once the big boy straightens out, the interference is no longer there and the front drops down, and the front drivers can derail.

To me, it looks like there is a spring missing on that lower pipe. See the eyelet on the end of it?  If the spring was there it would stay centered when the loco goes around a turn.

Wow, looks like the boiler falls off that pipe and rights itself as it straightens out.

I bet it could do it at random whenever that pipe gets stuck under the other.

All this for a $1 part ....

here's the link that Crazy Train posted above. #56

CHASSIS BREAKDOWN / FRONT / VISION BIG BOY #4017 - 610-1438-500 (lionelsupport.com)

maybe it's just not attached at one end?

So either the track work is viscously off, or the front of the boiler isn’t being supported by the pivot ….one tell tale that we can not see is if the very last set of drivers are up off the rails. This would indicate the front is nose heavy and diving …..but until we hear more from the fellas running it, it’s all a guess….

Pat

Ha -if like me, they r probably still in a turkey coma from Thanksgiving. I’m just coming up for air today

@Crazy Train posted:

Ha -if like me, they r probably still in a turkey coma from Thanksgiving. I’m just coming up for air today

This is where I'm at too. I was supposed to try to fit a speaker baffle in my Big Boy yesterday but that didn't happen at all.

It looks like the front of the front driver is lifting up in the first video. That makes me think something is locked together/binding. But I've been wrong before.

@harmonyards posted:

So either the track work is viscously off, or the front of the boiler isn’t being supported by the pivot ….one tell tale that we can not see is if the very last set of drivers are up off the rails. This would indicate the front is nose heavy and diving …..but until we hear more from the fellas running it, it’s all a guess….

Pat

The rear set of drivers never leaves the rails. Only the front set of drivers derails.

@The TrainBoard posted:

The rear set of drivers never leaves the rails. Only the front set of drivers derails.

You might not ever see the rear engine drivers leave the rails, ….BUT if the nose of the locomotive is top heavy, and sitting down on the front engine at the point of derailment, the tell tale clue would be a slight gap on the rear most axle ( not the trailing truck ) …..it might only be the slightest gap, and not enough to be visible at first glance …..but that might give you a clue as to why she’s plowing into the parts of the front engine…..

Pat

@Crazy Train posted:

Adding pic to show where the spring attaches:

I see where you’re going with this now, ….that could be the culprit!…

Pat

Yep.  Without the spring, that lower pipe is just flapping in the breeze.

After taking the track up and making the curve as good as I can get it, I present three new pieces of evidence. Please let us know what you think!

Is this first clip, I ran the Big Boy at 30 SMPH and it did not derail. You can see the first wheel of the front set of drivers lift off the rail. Also, notice how the front drivers plop back down onto the rails.

In this second clip, I ran the Big Boy at 60 SMPH and it derailed. You can see the last wheel of the front set of drivers is the sole wheel that derails. The first wheel of the front set of drivers no longer derails.

This was the best picture I could get. The spring is there, and attached to the bottom eyelet of the middle bar. I asked someone who has a Big Boy and they said theirs is attached it the same place.

Send it back

What happens if you try to hold the front drivers down as the locomotive rolls along? I wonder if you'll be able to get a feel for what's going on.

Also, what happens if you spin the loco 180* and run it in the opposite direction?

Are there any other 0-72 sections on the layout?

Just a thought.   It appears in your videos that the derail happen right at or immediately after it hits the end of that section of track, where the connectors are.   Maybe just a coincidence

Just a thought -

You can't see both sides of the engine during the twisting event. I would take the engine and place on a table with a slick top, like a glass top table. This would allow me to manually turn the trucks from side in the hope of figuring out where the mechanical interference is occurring.

@The TrainBoard posted:

This was the best picture I could get. The spring is there, and attached to the bottom eyelet of the middle bar. I asked someone who has a Big Boy and they said theirs is attached it the same place.

Yeah, but.....

that yellow paint flaking is the clue!

So I looked at my JLC Big Boy from the early 2000s, assuming mechanically would be very similar to the problem Vision Line Engine. I believe the cylinder I point to in your photo is incorrectly mounted under the boiler.

Here is a pic of my engine making a right hand turn, looking at the right side of the engine. Notice that the steam cylinder pointed to by the Red Arrow and the "Lionel Cylinder" (for making the model function) pointed to by the Yellow Arrow are running parallel, and the Lionel Cylinder end appears to be affixed under the boiler - within blue circle, not coming close to the steam cylinder.

Here are a couple pics of the engine's left side at the same turn position as the right side pic. Notice that the Lionel Cylinder can barely be seen.

So I have to believe that a screw is missing, or some pin is dropped in correct hole, or??? Maybe somebody braver than I handling this big model engine can turn theirs over and get a pic of how the Lionel Cylinder is connected under the boiler.

As it stands now, the locomotive goes around the curve at 60 SMPH without derailing. The front drivers are still leaving the rails, but they come back down without derailing. Take a look at the video and see what you think. Second video is for a closer, better lit look at what is happening and where.

As you can see from the pictures, the curve is perfectly level in both directions. I find it hard to believe that the curve isn't perfect, because we can run ALL of our other locomotives around it without a problem.

Is there any chance the two rail joiners on the outside rail are causing any interference/binding with the drive wheel flanges?  On your second video it looks to me like the 3rd fixed axle on the tender lifts ever so slightly when it is over the rail joiner on the inside rail. Wondering if any lifting or dipping is occurring on the locomotive drive wheels causing the front pilot to lift due to weight shift.

I echo Rob (Sparky) comments about the Atlas rail joiners.

I have used them on my Buco 3 rail brass track, when installing the Atlas remote uncoupling section, and found nearly all of my Buco 0-4-0  and 2-4-0 loco's would "jump" and sometimes derail when going over the transition point, from Buco track to the Atlas uncoupling piece.

Turns out the side flanges of the Atlas rail connectors are slightly higher in profile than my original Buco rail joiners, and protruded ever so slightly out past the rail head, causing the loco wheel flanges to "hit" the tops of the protruding Atlas rail joiners.

I could only use the Atlas rail joiners on the centre rail, and had to substitute them with lower profile Buco rail joiners....and then the world went back to being normal again.

Just a suggestion....check to make sure the Atlas rail joiners are sitting snuggly against the inside edge of both outside rails, and not allowing the driving wheels of the Big Boy loco to catch or pick them as they pass through the curve.  These drivers may be ever so fractionally wider in gauge, and just enough to catch the rail joiners on the entrance to the curves.

Peter.....Buco Australia.

As of today, Dec 3, 2023, this vision line engine still derails on our atlas o 072 curves, no progress and we are at wits end.

@The TrainBoard posted:

As it stands now, the locomotive goes around the curve at 60 SMPH without derailing. The front drivers are still leaving the rails, but they come back down without derailing. Take a look at the video and see what you think. Second video is for a closer, better lit look at what is happening and where.

As you can see from the pictures, the curve is perfectly level in both directions. I find it hard to believe that the curve isn't perfect, because we can run ALL of our other locomotives around it without a problem.

In my opinion, the rail joiners are not the problem. To my eyes, the front set of drivers is lifted off the rail well before the rail joiner location.

Also I see that the front end of the front set of drivers is lifted off the rail the most, the gap off the rail narrowing as you look towards the rear of the front drivers.

I still believe that what I call the Lionel Cylinder is not connected under the boiler correctly. The Lionel Cylinder, as I call it, is indicated by the yellow arrow in the pic below. As I said in an earlier post, my Big Boy is a JLC version from the early 2000s, but is probably very mechanically close to @The TrainBoard Big Boy. I also said that I didn't want to turn my Big Boy upside down to see how the Lionel Cylinder is connected under the boiler.

That said, I did look from the side of the engine through gaps between pilot truck and front drivers, and was able to determine that the end of the Lionel Cylinder under the boiler has a vertical pin in it that goes up into a slot under the boiler. Using tweezers as a probe, I was able to move the Lionel Cylinder end under the boiler from side to side, but was limited by the slot. If the pin was missing, or not engaged in the slot, the Lionel Cylinder could move from side to side limited only by hitting something under the boiler - this could cause the boiler frame to rise up, lifting the front drivers.

@The TrainBoard posted:

Have you tried carefully turning the loco upside down , i.e. putting g it in a cradle or on a soft towel.

Then hold the front driver set parallel to the boiler, as it would be on the track. Then gently turn the drivers back and forth and see what's happening at the attachment points.

@The TrainBoard posted:

The rear set of drivers never leaves the rails. Only the front set of drivers derails.

The rear drivers are rarely a problem, they're fixed to the chassis.  The articulated drivers is usually where the issues surface.

just start by putting the engine on a flat surface and pushing the front drivers from far left to right and back. See if there's anything hitting or interfering with the movement.

I have this same identical BigBoy running on Atlas 072 Curves& have experienced NO problems whatsoever!!  Make sure your Track is fastened down& level ! I don’t think it’s the Engine !!

@Fredstrains posted:

I have this same identical BigBoy running on Atlas 072 Curves& have experienced NO problems whatsoever!!  Make sure your Track is fastened down& level ! I don’t think it’s the Engine !!

Well...?

That says that a good engine can do it. It doesn't say that this engine might not be the actual problem.

Yes, a good hump in the track can cause this issue. Yet, all of his other engines are fine.

I would bet something is hitting the front driver assembly, and it can't swing freely. That's just a big guess from here. That yellow paint flaking is bugging me.

Might have just been assembled incorrectly at the factory, or something is in the wrong placement. Even a missing pressure spring not putting force down on the front drivers. You really have to start from scratch. I would not rule out anything yet.