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Locos Halting at the Same Spot on the Layout – Why?
Dale asks readers this:
“First, I’m just in the process of building a 10’X 16′ HO layout. I have an BLI Big Boy that, besides causing a short at switches, seems to halt and restart at the same section of track, mostly on curves, but not always. The condition is worse when pulling 26 cars. It also is running at about 1 amp. I’ve cleaned the track over and over, but it does not make a difference. The engine is only about two weeks old. Could the track itself have faults in it? I check it with the voltmeter and it always shows about 13v, sometimes dropping to 10v. I’m using an NCE Power Cab. with incline circuit protection with light emitting fuses. However, my smaller Pacific 4-6-2 does not hesitate even under the same load. Engine trouble? And, how do you prevent shorts at switch frogs? Thanks.”
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18 Responses to Locos Halting at the Same Spot on the Layout – Why?
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Hi I have a 282 that did the same thing you might try to narrow the wheels so it can make the Curve.
As your Pacific has no difficulties, the problem must lie with the big boy – and that is most likely to be the sheer length of the rigid wheelbases, the 8-coupled drivers fore & aft. What is the minimum radius you are using on your railway and what minimum radius is recommended by the manufacturer? If the former is less than the latter, you should not be running the engine on your railway. You may be well advised to check the mechanism for fluff or fibres clogging it up.
Thanks for your response, Sheldon. I’m running on 33″ radius curves.
Sounds fairly generous for H0 gauge; what minimum radius does the manufacturer of your 4-8-8-4 recommend?
First of all this appears to be DCC control. Every section of track should have its own set of drop feeders. Do note rely on rail joiners. Next, how tight is this curve and is it according to recommended standards for your engine. The further apart the wheels are, the wider the curve should be. If it runs well on other curves, are they the same radius as this one? When the engine stops on the spot, is it creating a short across the rail?
i see this is HO, are you using PECO turnouts? There is discussions about wheels shorting at frogs on peco turnouts. i am guessing the distance from the frog to the last rail section coming from the point is very short and the wheel is bridging over. One trick is to put a bit of nail polish on the rail before the frog and see if this isolates the problem. Do one at a time so you can tell when it starts rolling across correctly. Then you have it identified and need a more permanent solution.
Wow, Bob, what a great tip! I’ll try that on my frogs. I’m running on 33″ radius curves and I’m using both Atlas and Peco turnouts. I will eventually power the frogs with Tortoise machines. I have NCE CP6 circuit breakers which glow upon a short. I don’t think I’m getting a short either on the curve or at the turnouts. The amps drop off to near zero. I’m wondering if, at the turnout, the wheels are being lifted up off the rails. The frustrating part is that the stoppages are intermittent, sometimes the engine just runs through perfectly. I noticed that the problem is worse when pulling a large train (26 cars). Could the weight of the load actually lift the tender wheels off the track? Did I mention that the track is not yet secure to the roadbed? Could the problems vanish when the track is solid?
I’ve had 2 BLI locos, 1 an S-3, that did the same thing. I took it to a store that did repairs. Problem was a loose wire internally that prevented the rear wheels from picking up current. up
With that long a wheel base on a Big Boy, There may be a slight bump or dip in the rail at that point that causes the wheels to lift just for a moment. Sight along the rails to see if they are smooth or even use a mirror. The curves could be accentuating an out of gauge condition on the wheels which would also cause the shorts at switches. This may more likely be the problem since you mentioned that it is a new engine. Good luck.
“Thanks for your response, Mike. Because of all-wheel pickup (drivers) it would seem to me that other wheels would compensate if one set is lifted up. I would hope the electrical pickup is not so sensitive to very small track issues. I didn’t mention that I’m running on 33” curves and that I have not yet secured the track to the roadbed. I’m beginning to think that when I glue the track down, that may solve my problem. Thoughts on that?
Are the axles too ridged ? If so you might try & file the inside of one rail.
I made a reverse loop & it was too tight & the file worked
Could it be that with the “HO” gauge track you are creating a short in that the positive and negative do not switch. I have “O” gauge were the center rail is hot all of the time and the outside rails are neutral meaning that I can run a long train changing over rails and the neutral is always constant and the hot is always in the center, thus, a short cannot ac cure as easily.
lt sounds like your track radius is to small try increasing the radius on your turns to so your big
boy runs through the curves easy and does not show any signs of binding.
Thanks for your response, Anthony. I’m running on 33″ radius curves.
Sounds like you’re pouring a gallon into a pint pot my friend. The longer the rigid wheel base the larger the track radius required on the layout. If making the radius bigger is not possible, then try and widen the track gauge on curves (that is what real railways do). Do not play with the back to back on your loco – you could stuff up a very expensive piece of kit. Do you have an NMRA track gauge, if not, get one; they are invaluable for situations such as yours. The National Model Railroad Association Inc is a world wide organisation for model railway (railroad) modelers and membership is a valuable thing. Check them out..
Run your engine slow in the dark.Small sparks will show up if you have a short. Nice for those hard to find shorts that drive you nuts.
Thanks for your tip, David. I do have a gauge, hadn’t thought of using it on this problem. Will check the gauge of the curve. By the way, I didn’t mention that the track is not yet secure to the roadbed. I wonder if that could also be a problem.
If all else fails, and she runs fine every place else on the layout, replace that section of track. Try that and see if that helps. Hang in there.
V=I R and too much resistance in the wires might be lowering the amps or the volts when you pull more cars, the magnets in the motors need to be strong and if the voltage drops it’s going to create like a short in the motor, as it’s getting hotter. The thin gauge copper wire that’s typically used is worthless. You want to take household extension cords and split the wires and use that to power the tracks in farther areas so plenty of copper and no voltage drop far away from the transformer. imo. Copper is only $3 a lb so it’s not the money, it’s the tradition of just using the workable minimum because hobby wire costs a lot. If you split some extension cords you see how thick the copper is and my layout is worthy of being over built in that area, imo.