Unit Train coupler Type Poll - with or without operating couplers

[robert3985]

I run "unit" trains on my layout all the time, if that means I have no intention to break them up and switch the cars.  These include lumber trains, through freights, ballast trains, oil trains from Wyoming headed to Los Angeles, various livestock trains....all a maximum of 9' 5.5" long if they're not priority, and longer if they're priority since they don't need to fit on a center siding.

Without thinking about it too much any more, I am equipping ALL of my cars (with the exception of my passenger equipment) with MT True Scale couplers, properly modified with aftermarket coupler pockets for better functionality and appearance.

Although MT True Scale couplers don't have those distinctive pockets on the sides of the coupler head, they certainly look better than ANY dummy or Magnematic-compatible  coupler presently available, with the possible exception of the Goeman, which I haven't seen in the flesh yet.  From the top, they look prototypical, especially the brown ones with a bit of weathering on them.

Of added benefit of the True Scales is the total elimination of slinky-motion, which is HUGE, especially when switching short strings of cars, as well as the operator involvement with the True Scales, which is operationally more realistic IMHO.

Since even unmodified True Scales will couple with minimum of effort automatically after two or three cars are coupled up, I think they have resigned true non-scale dummy couplers such as Unimates, to the Paleozoic layer of coupler evolution, with no advantages whatsoever.

Yeah, True Scales are really tiny...but so are a lot of things in N-scale.  On the other hand, when one part of them squirts out of my tweezers onto my gray workshop carpet, I haven't had any problems finding it, so that evidently doesn't make their parts as small as other parts I have installed on engines and cars, which simply disappear into the ether, or wormhole their way into that undiscovered room in every home where all the lost stuff resides.

Cheerio!
Bob Gilmore

[Maletrain]

A 72 inch radius curve in N scale is equal to a 6 degree curve on the prototype, so shouldn't be a problem, even for drawbars.  Ten degree mainline curves are considered sharp, but unit trains run around them all the time.

I really wasn't suggesting that 72" radius curves would be a problem for drawbars or the type of actual scale dummy couplers I was suggesting.  I was just pointing out that modelers use curves that are much tighter than what the prototype considers to be "sharp", and that, on models, what I was suggesting might need some tweaking to accommodate our typical curves.

In N scale, even our "broad curves" of something like 20" radius are equivalent to 20° curves, and our tightest 9.75" curves are 44°.  I used the 72" because that is about the largest N scale sectional track curve I had ever heard of, and even that I once read (but can't find it now) would have resulted in a 45 mph speed limit on the prototype in my era.

[johnb]

Ah, back to the 1980's and unimates....I remember that swap when I couldn't afford MTL couplers. 

Upside, little chance of a premature uncoupling, downside,  the only way to uncouple is the old 0-5-0....

Leave it to the modeler to decide.

[jagged ben]

I really wasn't suggesting that 72" radius curves would be a problem for drawbars or the type of actual scale dummy couplers I was suggesting.  I was just pointing out that modelers use curves that are much tighter than what the prototype considers to be "sharp", and that, on models, what I was suggesting might need some tweaking to accommodate our typical curves.

In N scale, even our "broad curves" of something like 20" radius are equivalent to 20° curves, and our tightest 9.75" curves are 44°.  I used the 72" because that is about the largest N scale sectional track curve I had ever heard of, and even that I once read (but can't find it now) would have resulted in a 45 mph speed limit on the prototype in my era.

Tehachapi loop is 575', if I recall correctly, and Williams loop and various horseshoe curves are similar.  Which equates to about 43" in N scale.  Of course the prototypes typically have something like a 25mph speed limit on such curves.  But then, in industrial settings, proto cars can handle curves down to about 200ft or less, depending on exactly which cars are coupled to each other.   And I don't think speed limits are relevant to coupler swing.

All of which is to say, the tradeoff in model coupler box appearance shouldn't become an issue until you've got model curves of less than 2ft, or particularly under 18".  It's high time that the 9.75" standard was abandoned in favor of at least 11".  For a fine-scale type coupler it could probably be higher.

[NtheBasement]

I have two types of coal unit trains: one with a dumper that requires rotary couplers, the other with a dumper that requires uncoupling each and every car.  So any new non-operating option would be of no value to me.  Rotary coupler train: https://www.youtube.com/watch?v=QzmBQ4As_mc

Is the motivation for this to pay less for a coal car, or for reliability?  I've used MTL truck-mounteds for years, super reliable.  But yeah, slinky effect.

Its pretty easy to convert a pair of MTL couplers to a draw bar arrangement (and you get rotary couplers if your drawbar is a fishing swivel).  But there is a big difference between ra eal drawbar and a coupler that requires hand-of-god lifting the car to uncouple.  With true drawbar you won't be removing the string of cars from your layout very often, because railing the string is a royal pita.

[nkalanaga]

"Is the motivation for this to pay less for a coal car, or for reliability?"

Appearance, I think.  Some want true-to-scale couplers rather than oversized (but reliable) operating couplers, yet don't want a drawbarred train that has to be handled as one piece.

Your idea of using fishing swivels as rotary couplers sounds interesting.  I never would have thought of that.

[Atlanticflier]

Does the MT Z scale # 905 mate and work well with N scale couplers ?   Does it have the 'slinky' effect?

[robert3985]

Does the MT Z scale # 905 mate and work well with N scale couplers ?   Does it have the 'slinky' effect?

The MT Z scale #905 works with MT N scale couplers just fine.  I can't confirm that the Magnematic feature works with that combination, but they do couple up easily, and uncouple with a martini straw or RIX uncoupler.  I know this because I was converting everything to the 905's until the True Scale coupler came along, with trains made up of both the 905's and regular N-scale MT's, and I clip off the Magnematic dongle on every coupler.

Unfortunately, the slinky effect curses the MT #905 Z-scale coupler as well.

When using the Kadee N-scale coupler height gauge, I center the 905's shorter Z-scale coupler knuckle with the gauge's N-scale coupler knuckle, as opposed to making the tops of both knuckles even with each other.  This, at least in my case, compensates best for N-scale couplers that may not be exactly the right height.  My Z-scale replacements are all installed at that height and I don't have any problems at all with spontaneous uncouplings, but...my track is carefully installed with no sudden dips or jumps.

When I was active in Ntrak, I also didn't notice any difference in coupling problems between modules using 905's on some of my cars in my trains, even with dips and jumps due to the inevitable alignment problems with joiner tracks.

Cheerio!
Bob Gilmore

[rhwood]

I find assembling trains at shows without operating couplers to add a degree of difficulty I really don't want to deal with.

Randall