I've been plagued with frequent derailments which occur on 2 code 80 remote switches; one right and one left. Both are positioned after 9" radius curves. When in the switch position my diesels are prone to derail going into the turn. Is this possibly a function of switching, the potential for derailing? Are the curve radii too tight? Are diesel engines prone to derail? Using both atlas and Bachmann engines. Checked track alignments, slow engine speeds, cleaned tracks etc. Any thoughts?
Are these B-mann turnouts or another brand? If B-mann are they E-ZTRAK or older? B-mann does not sell nine and three quarter curves in its E-Z TRAK line, so I am assuming that your track is a different brand, or, if it is B-mann, it is the older track that B-mann no longer sells. Are your turnouts #4, #6 or something else?
You try to avoid putting a turnout immediately after a curve. You try to put a straight section between the curve and the turnout. Unfortunately, many of us do not have the space to do that..
You do not specify what prototypes you are running. If you try to run six axle diesels over those sharp curves, particullarly the modern prototypes, you will get derailments.
In order to give you a helpful answer, we need more information.
Thanks for the reply. All track and turnouts are Atlas Code 80 track. The engines are one Atlas and one Bachmann; the Bachmann is a GP 40 series, the Atlas a GP38. Interesting that the derailment seems to occur as the rear carriage is crossing. The front carriage appears to be making the turn properly. I'm afraid the answer is what you stated about a turnout immediately following a tight curve.
I do not know much about either of those locomotives, as the prototypes are far too late for my era.
The points on some Atlas turnouts do not always align properly, so you might have to check that. Sometimes the plastic frog casting is a bit off, as well.
Those are four axle locomotives, so the nine and three quarter curves should not be a problem. Still, the shorter locomotives tend to have fewer problems on those curves. B-mann sells an NW-2, as does Kato. Atlas sells an SW-1500, an S-2 and a Baldwin yard switcher. B-mann also has an ALCo S-4 and GE 70 and 44 tonners. Those might suit you better. Walthers does sell an SW-8/SW-9/SW-1200, but if you are having derailment problems on the turnouts, those are not for you. Those things do not like Atlas switches as it is.
I am assuming that the locomotives have body mount couplers. Do the cars have body mount or truck mount couplers? If the cars have body mount, that could be another cause of derailment, especially since you mention that it is the aft trucks that derail. Truck mounts on the cars lower the possibility of derailments on sharp curves, but, if the locomotives have body mounts, it still could cause derailments.
Do the locomotives derail when running light or just when coupled to rolling stock?
Do the turnouts have built-in switch machines? The Atlas turnouts that don't come with them are difficult to use until some sort of aftermarket switch controller is installed as they do not stay cleanly pointing in one direction or they other.
-Mark
All switches are remote controlled with switch machines attached. Derailments occur at different speeds, slow or fast, and without any freight cars attached.
Sorry, it's very hard to say what the problem might be without being able to inspect things firsthand. Generally speaking, those locomotives and those turnouts should work just fine together. My best suggestion is that you acquire an NMRA gauge tool and use it to verify that the wheel gauging on the locomotives is correct and that the track gauging is similarly correct. Those are suspects #1 and #2 when it comes to derailments.
-Mark
I assume the gauge tool can be purchased from hobby shops or online dealers? Are the measurement for wheels also available online? I appreciate your help.
They are readily available at hobbyshops and online. Google has many listings.
(http://cdn3.bigcommerce.com/s-hfohoh/products/454/images/1425/NMRAN_250__31092.1432682610.1280.1280.jpg?c=2)
-Mark
Thanks much. The interesting thing I have noticed is that the derailments at turnouts happen more frequently when the diesel is running with the short nose pulling which I am assuming is the usual mode of operation. Why this happens is a mystery since undercarriage trucks and features look the same on either side.