Are there any N-scale, DCC-ready locomotives that will operate well on turns of 11-inch radius? I’ve got a round-the-room shelf layout loaded with them, it’s worked fine until now but I’m trying to switch over to DCC and I discover that the DCC locomotive I bought isn’t tolerant of turns that tight. It operates fine by itself but derails any boxcar it’s hauling when the coupler swings to one side at the start of a turn.
Experimenting by buying more and more locomotives until one works isn’t very economical. Can anyone recommend a DCC-ready locomotive that’ll handle 11-inch turns well? Or am I caught between abandoning my DCC plans or else tearing up the whole thing and starting over?
You did not state whether you mean steam or Diesel locos, but, in general, locos with a short wheelbase, like 0-6-0´s, maybe a 4-6-2 in case of a steamer and all 4-axle Diesels should be fine.An 11 ich radius in N scale equals roughly a 20 inch radius in HO scale…
The ability to negotiate sharp curves has actually nothing to do with DCC.
You might try a different coupler that will swing a little more to allow the car it’s pulling to follow it around the curves. I think the length of the coupler shank will effect how well it pulls around curves.
I do realize that it’s the wheelbase, not DCC per se, that is the problem. But browsing my local hobby shop for locos they label DCC-ready shows them all quite a bit larger than my old ones, so I had thought that perhaps they need to be longer to accomodate the decoder. Meanwhile online stores list locomotives by prototype model number and expect you to know what that means; I’m afraid I have no memory for that kind of detail and don’t.
My old locomotives include smaller steam and diesel. Technically I model the famed transition between steam and diesel but I’m really not fussy about period just so long as the locomotive looks like it fits in. So I really model the “transition” between the dawn of railroading and today.[swg]
My GP9 paired up with a 50’ box and 50’ flat had no problems with 9 3/4" curves. MR tested an Athearn FP45 and it they say it went around 9 3/4" no problem. I would for problems with your existing lokes and cars. The swing arc of couplers was mentioned but I would also look at coupler length. A coupler that sticks out further from a car end will have a larger swing arc and may just give the car enough room to go around a curve and not bump into another car end. If that is your problem.
No, cars bumping is not the problem, the problem is that as the locomotive turns left its rear end moves right and drags the coupler on the car behind it in the same direction. Like this:
(Locomotive is blue, wheel truck of boxcar is grey, boxcar itself not shown.)
The locomotive itself navigates the turn with no problems (it’s a Kato EMD SD40-2 according to the box). What I need is more horizontal swing on the coupler relative to the locomotive body, or else a shorter wheel base so the locomotive doesn’t angle so much while the boxcar’s still on the straight.
I’ll see if I can test a GP9 and some of the other specific models people here have suggested at my hobby shop. I’m sure their in-store layout is more reliable on turns but if they have some spare table space we could set out some 11-inch sectional and see what happens.
Okay. The locomotive isn’t the problem. What you have there is a body mounted coupler on the diesel, and a truck mounted coupler on the freight car. Since the body mounted coupler is fixed to the center line of the locomotive, it won’t swing to the same degree as the coupler on the car, which is fixed to the centerline of the track.
The answer, as has been suggested, is to get a coupler with a longer shank, which will have more lateral play than the shorter stock coupler. Either that or get a freight car with a body mounted coupler to couple to the engine so both couplers are aligned.
Of course the better answer is to open up your curves a bit so the trains look and operate better.
Yes, it’s true. Unfortunately that ship has sailed unless I want to tear everything out and start over-- which I’ll do if I have to but not until I’ve tried everything else.
I throw myself on the mercy of the court and plead a bad upbringing: I started in the hobby using z-scale and never quite adjusted my perspective.
My N scale layout has many 9" and 11" curves in the industrial areas and the return loops. I had problems until I weighted the cars properly, and replaced the wheels with Atlas metal wheel sets. Before they would ride up and over the rail and get pulled off the track. Now it does not happen unless there is a bad area on the track that I need to fix.
I think Mr Lee has hit the nail on the head . . . . . you are trying to track a body mounted coupler and a truck mounted coupler and you are coming to griefs. A body mount on the box will probably solve the problem but longer couplers as was suggested may also work.
Eleven inches is just a little stiff for a big loke like an SD40-2–I keep having a vision of a 53’ trailer being turned on a cul-de-sac–and that length is contributing to the problem. What you have encountered is what the late, great John Armstrong labeled “The Coefficient of Lurch.”; your loke, instead of gliding into your curve, is lurching into it. This can be solved through the installation of an easement at your curves. Curves are never fixed in blood; you can modify your trackage by building an easement into those 11" radius curves. It does require some tearing out of existing trackage and the installation of new trackage but it can be done.
By the way, I have installed industrial trackage as short/tight as 9" radius but I restricted motive power on tackage that tight to BB-trucked lokes–11" to me is a more appropriate radius for industrial trackage but even then I would probably avoid CC-trucked units on that tight a radius curve.
Yes, I am considering improving my easements (the existing curves do have them, but they could be made even gentler with only a little pain). There’s only one curve where increasing the easements would be difficult, because it’s hemmed in by spurs on either side. I’d have to move the turnouts outward and accordingly redesign the spurs a bit. The rest of the curves should have room without other changes.
As Lee mentioned, you need to put longer couplers on the larger loco’s. The swing out of the front and rear of the loco is farther from the center line of the track than the coupler can swing. A longer coupler gives you more swing to get back to the centerline of the track, which the truck mounted couplers prefer. Adding weight to your cars, specifically the lead car in the train will help also. For a random SD90 that I have, I keep an over weighted box car around to be the lead car in test trains so that it won’t derail when on my inner test track loop (9 3/4" R).
For reference, a brand new SD70ACe will negotiate kato 9 3/4 radius turns just fine as will most everything I own. They don’t look pretty doing it but I don’t have any problems running them on the test track.
What couplers are you using? What loco’s? If they are older loco’s with Rapido’s, that may be part of the problem. Newer loco’s with knuckle couplers are easier to solve. Microtrains offers long shank replacement couplers for most applications that will improve performance all around.
Actually it’s the opposite, my old locos do fine, it’s the new one (that I bought in preparation to switch to DCC) that has trouble. I’ve figured the problem is its much longer wheelbase. All my locos use knuckle couplers (my N-scale ones, that is).
Long-shank couplers are the easiest solution suggested here-- both in time and money, by several orders of magnitude-- so that’ll be the first thing I try! The middle-term solution will be smaller wheelbase locos. The long-term solution of course is to modify my curves, but I’m putting that off.
If these loco’s are Atlas 6 axle loco’s, then pickup some MTL 1016 couplers to replace the accumates that are on them. The MTL couplers swing freer side to side than the acuumates anyhow. I believe the same should work for newer Bachmann. IM loco’s already have MT couplers on them. If they are Kato, Use the MTL 2001 coupler. Kato did offer long shank couplers of their own and they usually come with the loco. Nobody else really does a long wheelbase 6 axle loco.
The simplest solution is to pick a car or two that will always come first in the train and add a 1/4 oz of weight to them. I think light cars, even with the long shank coupler, will still be a problem.
