Body mount couplers, what's the big deal?

[hpwrick]

Brakie,   With regard to the preaching and complicated...I couldn't agree more with you.    In this case...however...me thinks the old greay beards, have it nailed down.   Did you ever wonder why the prototypes use body mounted couplers? 

Although, I sound preachie, heck I only went to seminary school for one year...what do you expect?   Now, NOW we have to put up with the scientific minded and engineering types...well...best I leave this alone.       You think I can get preachie...you ain't seen nothing yet.  Wait until they aritculate their thoughts.   LOL

RickH :Why, would you need some scientific study, to tell you what old railroad model heads have been telling us...
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That my old forum friend is a very scary thought! 

I been in this hobby for as long as I care to remember and have found things a lot different then those "old railroad model heads" preach most has complicated the simplicity of the hobby while stating their modeling style as the gospel.

Best to try different methods and find what works best for you.

"Best to"....yep, that's what I been saying for years.  Never take the word of someone else...prove it to yourself.   You set the rules for your railroad and you...not me...determines the standards.
 
Time is getting away from me.  I got to get back to my railroad model projects.

Good to chat with you.

RickH  aka BarstowRick

PS:   Must figure out how to add a signature, avatar and update profile.    I know search, search and search again.   Got you!

[BN1970]

Scott, your conclusions are generally right as long as you are going forward.  If you start to switch with backward moves depending on the length of you're cut of cars (i.e. getting up to 20) you will most likely see more derailments by using truck mounted couplers (again it will depend on wheel flange height on your cars wheels).

I'll add one more item, wheels with crud derail more often than when clean. --Brian

[Zox]

Did you ever wonder why the prototypes use body mounted couplers?

Probably because they don't generally deal with radii under 48 or so inches in N-scale equivalent.

Body-mounted couplers are at their greatest disadvantage when dealing with equipment of wildly-varying length on tight radii--which happens to be where most N-scalers start, hooking together things like auto-parts boxcars and 36-foot hoppers on 9.75"-radius curves.

I've heard it said that even the real railroads occasionally experience this problem, for example needing to insert a 65-foot RPO between 80-foot passenger cars and 40-foot express boxcars to avoid coupler-swing issues.

For full-size railroads, it's an odd situation that happens once in a blue moon. For N-scalers with tight curves, it happens every time they crack the throttle.

[ednadolski]

Did you ever wonder why the prototypes use body mounted couplers?

Probably because they don't generally deal with radii under 48 or so inches in N-scale equivalent.

Also I suspect that on the proto, a truck-mounted coupler would be far more heavy, costly, and prone to failure. 

Ed

[VonRyan]

Well, at least when it comes to couplings you all have prototypical choices as well as semi. With my UK stock, its either NEM's (Rapidos), some etched brass aftermarket "finescale" couplings, or using prototypical three-link chains and couplings hooks as well as buffers (saddly they cannot be sprung in N but that negligible).
Just some of my own insight...

-Cody F.

[hpwrick]

If you are looking for the science behind  why the prototypes use body mounted...it is available.     

The radius of the curves, the tight curves we tend to lean toward all contribute to operational failures such as derails.

If you compare the old heads thinking most of it came from and out of the operational railroad manuals.     They realized the benefits in wide radius curves, body mounted couplers and properly weighted train cars.    There's nothing wrong the old values and they deserve a second look by us.

Ok, I'ma getting preachie again.

Seriously, give it a look see and try it on your layout.   

Don't ignore the pro's mentioned here by others with regards to the benefits of body mounted couplers.    It works for me.

RickH  aka BarstowRick   

[SkipGear]

The reason the prototype use body mount couplers is the trucks are not permemantly attached to the cars. The car bodies just set on the trucks via the bolster pin. If the couplers were attached to the trucks, all that pulling force would be tranmitted through the bolster pin which would probably break or even worse, allow the car body to lift and work its way off the truck.

With body mount couplers, the stress is transmitted directly from one coupler, through the underframe and into the coupler on the other end of the car. It makes a stronger system that can handle more load.

The couplers still buckle and transmit side loads to the trucks when you body mount, it just doesn't torque/twist the truck.

[peteski]

I
If you compare the old heads thinking most of it came from and out of the operational railroad manuals.     They realized the benefits in wide radius curves, body mounted couplers and properly weighted train cars.    There's nothing wrong the old values and deserve a second look by us.

Ok, I'ma getting preachie again.

Preachy?
How about being totally unrealistic?  Rick, I would love you to show me even a single N scale home layout which uses properly scaled curves of the 1:1 railroads. Just one...  You do realize that a mile in N scale is 33', right?  Also a 400' radius curve (fairly tight in 1:1 railroads) would be 30" radius in N scale? Unfortunately N scale modelers have to live with compromises. I'm sure you've heard of selective compression. Most home layouts cannot afford such large curves.   That is why we live with body mounted trucks truck-mounted or long shank couplers.  How can you follow real railroads specs and manuals when your N scale world has to be squeezed into (for example) a 10 by 15 foot room (or even 40 by 23 foot basement?)

[bbussey]

This is true.  Jenkins Curve in Bridgeport CT, which is extremely tight and carries a speed restriction, would scale down to 72" radius in N.

That said, there is no reason why people can't be weened off of 9¾" radius, which contributes to the problem.  That needs to go the way of the Rapido coupler.

[Ian MacMillan]

The reason the prototype use body mount couplers is the trucks are not permemantly attached to the cars. The car bodies just set on the trucks via the bolster pin. If the couplers were attached to the trucks, all that pulling force would be tranmitted through the bolster pin which would probably break or even worse, allow the car body to lift and work its way off the truck.

With body mount couplers, the stress is transmitted directly from one coupler, through the underframe and into the coupler on the other end of the car. It makes a stronger system that can handle more load.

The couplers still buckle and transmit side loads to the trucks when you body mount, it just doesn't torque/twist the truck.

Bingo. On the 24" "model" railroad that I also tinker on some of the early cars were built with truck mounted couplers because of tight corners that were built on the first sections of the railroad. It makes for a major mess when you go to move and pull the trucks out from under two loaded hopper cars, each with about a ton and a half of gravel in them   

[hpwrick]

Preachy? How about being totally unrealistic?  Rick, I would love you to show me even a single N scale home layout which uses properly scaled curves of the 1:1 railroads. Just one...  You do realize that a mile in N scale is 33', right?  Also a 400' radius curve (fairly tight in 1:1 railroads) would be 30" radius in N scale? Unfortunately N scale modelers have to live with compromises. I'm sure you've heard of selective compression. Most home layouts cannot afford such curves.   That is why we live with body mounted trucks or long shank couplers.  How can you follow real railroads specs and manuals when your N scale world has to be squeezed into (for example) a 10 by 15 foot room (or even 40 by 23 foot basement?)

Peteski,

My good friend, good to see you made it here to RailWire.   

Just so we understand, I never did say the curves had to be realistic curves.   I said, "Wider curves are the best curves".   To further claify: It is realistic to install 18" radius curves and 24" radius curves on a layout in a 10'X10' space.   As you said "Selective compression".   Now tell me something I don't know.   

To be more specific about realistic N scale curves.  Accepting your question and challenge, nope I can't show you realistic 1X1 foot scale curves on any home layouts.   None that I'ma aware of at least, not outside of a club layout.   

You and others here might live with "Body mounted trucks or long shank couplers" as you proclaimed.    I certainly.... don't have to.  As I'ma able and capable of doing so... close coupling, body mounted couplers and wider radius curves will always be the name of the game.

Allow me to show you my layout:   

Did I mention housed in a 10'X10' metal shed?

The minimum curvature on the main line is 18" radius with three 24" radius curves.     There is a explanation available with the video/slideshow.   Feel free to give it a read.

Since the photos were taken, quite a number of my freight cars and passenger cars have been converted over to body mounted couplers.    They are superb performers.    Beating out the truck mounted couplers...each and every day of the week.

You mentioned size compression.   Check this out: 

  

Good to chat with you again and I look forward to more friendly exchanges.   

Have fun!

RickH aka BarstowRick

[Brakie]

That said, there is no reason why people can't be weened off of 9¾" radius, which contributes to the problem.  That needs to go the way of the Rapido coupler.

While I fully agree with your assessment I don't see that happening as long as modelers continue to over track small HCD layouts and build 2'x4' layouts.

Why is it modelers design a small layout with mountains and 3% (or steeper) grades that loops  around 2 or 3 times instead of a simpler layout that allows wider curves? 

Some times I think  N Scale worst enemy is it size.

[bbussey]

... The minimum curvature on the main line [on my layout] is 18" radius with three 24" radius curves...

This is what I have planned for my layout as well.  The larger radius the better.  I will be running a lot of varnish, and it just looks so much better traversing larger radius curves with a slight super-elevation.

[Ian MacMillan]

This is what I have planned for my layout as well.  The larger radius the better.  I will be running a lot of varnish, and it just looks so much better traversing larger radius curves with a slight super-elevation.

+1
My old AN had 48" curves and everything looked sweet on them. I'm working on getting a new basement for trains, so hopefully I can get back to that by the end of this year.

[Scottl]

At risk of being an  , I don't think this tangent suggesting we abandon tighter radii curves is viable for most.  Based on what I see here, quite a number of folk have modest spaces and are forced to 9-12" curves.  Even in my medium space, I have a number of 12" radii.  If I needed 48" curves, I'd be modelling HO in a flash     It may look better, and on some switching type or basement layouts be viable.