I’m looking for some advice on a Bachmann EMD 40-2 (HO scale) that was given to me by my young son back around 2005. It has been sitting safely in storage for the last 15 years.
Overall, the locomotive still runs great, but I am having a lot of trouble getting it through #4 turnouts at slow speeds. It results in a short-circuit and derails at least 50% of the time.
Before I give up and turn this sentimental piece into a display-only decoration, I wanted to see if anyone has tips. Is this a known issue with this specific vintage and tight turnouts? Should I look into checking the wheel gauge, cleaning specific pickups, or modifying the turnout frogs?
Any ideas or step-by-step troubleshooting tips would be greatly appreciated!
I’m assuming this is an SD40-2 (each truck has three axles)? If so, it is a fairly large engine to have go through a very tight No. 4 turnout. Sometimes, even an engine that will negotiate a tight 18" radius curve will have trouble with a No. 4 turnout.
It might not hurt to get an NMRA gauge and check the wheelsets. Sometimes, manufacturers make the wheelsets slightly narrow to better handle sharp curves. This could mean the wheels are able to make contact with part of the turnout that is the opposite polarity, causing the shorts. The wheels being out of gauge could also be the cause of the derailments.
Next, what brand of turnout are you using? It might be a different maker’s No. 4 might work better. Long run, building a layout with larger curves and turnouts (like at least 22"-24" minimum radius curves, and No.5 or No.6 turnouts) might allow the engine to run fine.
I’d hate to see you put a perfectly good engine on the shelf if the problem ends up being the track/turnout.
I am using atlas isolated ftogs.
15 years ago life happened and i packed everything up and been moving it all around where ever I went. I am on disability now, so i decided to do a small HO layout i only had to buy glue and few tools i had everything to start back up enough for a small layout,track,ballast etc.
Do you have other engines that run well over your turnouts? Checking the track visually and by running another locomotive over is the first step to figuring out what might be going on. We’ve all had spots on our layout that, for one reason or another, are unreliable.
I have a newer Bachmann SD40-2 that handles 18" curves and atlas snap-switch turnouts (similar to, and probably even tighter than, your no. 4’s) just fine. In terms of inspecting the engine, I agree that using a wheel gauge may be valuable, but if that’s not a tool you have, you could at least put the wheels on the engine up to another piece of rolling stock to do a spot-check. The other thing I would check is whether the trucks rotate freely. If you try to rotate them with your hand and feel undue resistance, remove the locomotive’s shell and check for pinched wires or debris that might be interfering with the movement of the trucks. It’s very possible that congealed lubricant or other grime has built up in an engine that has been sitting for that long, or some component has become brittle.
Both of you guys thank you for the suggests to check.I will be doing that over next couple days. I do have a BLI GE 30-7 CSX 7001 NO sound early 2000s i believe got it used. That gives me trouble as well not as much as 40-2 i think might be 6 axles trucks , my 4 axles rarely give trouble they are both Buchmann.
Sometimes, you can just put the engine on the track and try moving it side to side. If it moves a lot, most likely the wheelsets are out of gauge (too narrow).
BTW…General Motors road switchers are GP (General Purpose) locos with two axle trucks, or SD (Special Duty) units with three axle trucks. As I mentioned, you probably have a Bachmann SD40-2, as Bachmann has modelled that engine but not a GP40-2. Also GE engines use B to indicate two axle trucks, C for three axles. So your GE engine is either a B30-7 or a C30-7. In any case, the letters are part of the name, so help clarify what engine your asking about.
If it’s derailing, that’s almost certainly what’s causing the short. The wheels are touching rails with different polarity when they jump the track.
If the engine can go around curves OK both to left and to right, but derails at the turnout, it’s a pretty good indication it’s the turnout that’s bad, not the engine.
I seem to recall reading somewhere that, even thought the Atlas No.4 is meant to be able to replace an 18" radius section of track, that at it’s sharpest point it’s really more like a 15" radius. That’s VERY sharp, especially for a six-axle diesel.
I’m starting to think the only practical choices are to either put my six‑wheel‑axle diesels on the display shelf or, when finances allow, redesign that section of the layout with turnouts that have a gentler radius. Fortunately, only the track is laid in that area, so changing it later won’t be too painful.
O.K. and is just speculation and is most likely wrong, but here goes. Since you have 3 axle trucks my guess is that the lead axle may be the culprit jumping the frog and touching the opposite side of the frog causing the short. Run the engine through the switch very slowly and see if the lead axle is picking at the point of the frog and consequently riding atop the frog and then touching the opposite rail for the short as well as derailing. You may also try to gently guide the lead axle pushing it with a pencil away from the frog point, to keep it settled down in the flangeway. If you can get that first axle through the frog the two others should follow. Try wiggling the truck as it gets near the frog. With 3 axles you may be experiencing the two rear axles sort of steering the lead axle too close or onto the frog. Turn the engine around, end for end and see what happens. Lack of lateral flexibility might be the culprit. If so, you’ll have to figure out how to keep the lead axle away from the frog point. Check the gauge of the wheels on all three axles. Perhaps a very thin strip of styrene attached to the inside of the guard rail to pull the wheel away from the frog.
If all else fails replace the turnout with a larger one, perhaps a number 6. Did you check the gauge of all the rails in your turnout? One tight spot, especially flangeways, can cause havoc.
So these are just my ideas of what may be happening and may be worth looking at.
You mention that this is an older model. Could your wheel flanges be of the old “pizza cutter” style? Might the flange be too tall and may be bottoming out in the flange way and lifting the wheel high enough to skip over the frog?
Mark B.
A new turnout would only cost about 10% of what a new engine would. If you’ve tried everything else and it still derails, try a larger turnout. Even a No.5 turnout is going to work a lot better than a No.4, and not take up much more space.
In case you don’t know, an Atlas #4 turnout is really a #4 1/2. So for a larger turnout a #6 would be better than a #5.
Also, Atlas #4 turnouts are not the same as Atlas Snap Switches. The Snap Switch has an 18" curve through the diverging leg.
A little vague whether that means an Atlas No.4 or an Atlas No.4 snap switch?
But yes a No.6 would be better than a No.5…but a No.5 would be better than a No.4 or No.4-1/2. It might also fit better than a No.6 if retrofitting it into an existing layout.
Of course it might just be a problem turnout, or a problem of the track not being perfectly level there. I would check those out first. If it’s not that, then try a new turnout and see how it works out. Atlas turnouts aren’t costly, you could even just buy a new No.4 and drop it in and see if works. Shop around and you can get one for $12-15.
