On the horizon - closer coupling Atlas Accumates?

[bbussey]

What are you talking about??  :  There is no side-force on the wheels if the couplers are body-mounted.  Truck-mounted couplers are why there (was) a need for pizza-cutter flanges.  There is no scenario where truck-mounts are better than body-mounts.

[SkipGear]

Bryan,
 I probably don't want to dive into this but Zox is correct, when the train is being pulled. It is most evident when a short coupled car is coupled to a car with a lot of overhang. Body mounts produce more sideforce on the truck on tighter radius. On large radius, and more important, when backing a train, bodymount's are better for sure, but pulling, talgo trucks are more efficient.

The best example, isn't even between cars but between a steam loco and tender. Mounting the drawbar at the rear of a super power steam loco puts excess leverage and side load on the drivers, often causing the nose of the loco to be derailed. The worst loco to exhibit this is the Walthers/LL Berkshire. Chris has an excellent fix for the problem and that is relocating the drawbar as close to the rear axle as possible. It increased the pulling power and reliability of the loco.

Bodymounts don't decrease the side load, but do decrease torsional load on the truck and this is seen most when backing.

[pfs]

...tankcar...MTL specifically makes a low-mount coupler (#2004) with an offset shank to handle this. 

I didn't know this (#2004)...excellent info...thanks

[bbussey]

Bryan,
 I probably don't want to dive into this but Zox is correct, when the train is being pulled. It is most evident when a short coupled car is coupled to a car with a lot of overhang. Body mounts produce more sideforce on the truck on tighter radius. On large radius, and more important, when backing a train, bodymount's are better for sure, but pulling, talgo trucks are more efficient.

The best example, isn't even between cars but between a steam loco and tender. Mounting the drawbar at the rear of a super power steam loco puts excess leverage and side load on the drivers, often causing the nose of the loco to be derailed. The worst loco to exhibit this is the Walthers/LL Berkshire. Chris has an excellent fix for the problem and that is relocating the drawbar as close to the rear axle as possible. It increased the pulling power and reliability of the loco.

Bodymounts don't decrease the side load, but do decrease torsional load on the truck and this is seen most when backing.

Tony,

Are we referring to small radii curvature that modelers who body-mount would not use?  I agree, with 9¾" radius track I wouldn't want to run body-mounted equipment either.  But on larger radii where longer cars look far better, I think you would agree that body-mounts are superior.  The general statement Zox made that truck-mounts are better is misleading and not accurate.

[Zox]

The general statement Zox made that truck-mounts are better is misleading and not accurate.

So was your "general statement" that body-mounts are better, and for the same reason--neither of us specified under what circumstances our statements were true.

That was the only point I was trying to make--that there are advantages and disadvantages to both styles.

I seem to be on the "wrong" side of every issue these days. (Code 80 rail, DC control, fictionalized prototype, etc.) I might as well add one more heresy to the list.

[John]

i have a fictional prototype  ???

[Zox]

i have a fictional prototype  ???

Oh, that one's not coming from anyone on the Railwire. I just got a little too close to a Tony Koester book recently, that was giving off a "Death To Freelancers" aura.

Okay, so it was more of an "If You're Not Enough of a Man to Run Actual Timetables on a Proto-Replicated Layout (In HO, In the Transition Era), That's Okay, We Still Like You--Now Shut Up and Let Daddy Work" aura. Still not very encouraging. 

[wm3798]

The KBS will soon be proudly hauling around a Laurel Valley gondola, too, Rob.  Represent!

Lee

[Mark5]

i have a fictional prototype  ???

Oh, that one's not coming from anyone on the Railwire. I just got a little too close to a Tony Koester book recently, that was giving off a "Death To Freelancers" aura.

That's kinda funny ...

http://kc.pennsyrr.com/layouts/koester/bibliography.php