Coupled Distance between Car Comparison

The Kadee coupler box on the gray car sticks out about 1/8" too far. The flange on the end of the coupler box should be against the end of the car body.  I can't tell about the green car.

@MainLine Steam Very interesting post. Just curious but how did you come up with the 42"? Did you actually measure several versions of the prototype?

@John Sethian John, Mainline Steam (Jim) states "For my comparison I grabbed some unmodified Weaver 3R and 2R cars which were sitting around." I believe those are the original Weaver coupler boxes. That's what they look like to me. I don't remember if that box has a flange in the same exact spot as a Kadee coupler box. Man, I haven't seen those coupler boxes in many years. I used to throw them away in favor of Kadees.

@Hudson J1e posted:

@MainLine Steam Very interesting post. Just curious but how did you come up with the 42"? Did you actually measure several versions of the prototype?

I am going to add another post better explaining the 42".

@John Sethian John, Mainline Steam (Jim) states "For my comparison I grabbed some unmodified Weaver 3R and 2R cars which were sitting around." I believe those are the original Weaver coupler boxes. That's what they look like to me. I don't remember if that box has a flange in the same exact spot as a Kadee coupler box. Man, I haven't seen those coupler boxes in many years. I used to throw them away in favor of Kadees.

Correct Phil, those are the original Weaver coupler boxes not Kadee's.  Weaver coupler boxes do NOT have a flange on them they are just a smooth box.  They do not have any detail on the end to represent a striker plate so the end face has to be assumed to be the striker. Kadee with flange pictured below on a Weaver Hopper.  John while they may appear to stick out too far, they are in the correct location.  That is how Weaver designed and built their couplers and cars.  See my post below.

So when I started this topic was trying to not go into too much detail, but probably should have gone a little deeper.  The 42" is based the following:

A dimension of 15" from the pulling face of the Coupler to the Striker Plate.  This dimension is Standard for FRA compliant couplers over a very long time period.

The extension of the Striker Plate relative to the car End Sills was taken as 6" per end.  While this can vary greatly, this is a reasonable average distance for a Transition Era Boxcar.  I started another topic showing one really good resource for this information.

https://ogrforum.com/...r-diagrams#lastReply

This is representative of a boxcar built in 1937.

https://www.wplives.com/diagra...58/BC20001-20200.php

This is one built in 1947.

https://www.wplives.com/diagra...58/BC20551-20800.php

So 15+6 = 21 per car end = 42 total

I am actively working (volunteer) on the restoration of a 1916 D&H Wooden Caboose.  Took some pictures this morning to back-up the online research.  The Strikers on it extend 4" beyond the Buffer Bars at the end of the platform.  This caboose went through a few mods during its 68 years of service on the D&H.  I plan on posting about this Caboose once the restoration is finished.

Hope this clarifies my earlier posting and is helpful.

There is no standard clearance between cars. With a E-60 coupler and a conventional draft gear the distance may be in the 3 to 4 feet range.  Bur two cars with 15” center of car cushioning have 30” of movement available between the cars plus the two coupler heads. Longer cars have to have longer coupler shanks which results in more space between cars.  Then there was end of car cushioning cars. There were also articulated cars with drawbars between them rather than couplers.  As far as height, vertically the center of the coupler knuckle on an empty car should be 17” above the top of the rail. There are no other standard vertical dimensions except for a few in the safety appliance act.

Seventeen inches above top of rail to C/L of drawbar is too low for standard-gauge US rail cars.  See Code of Federal Regulations, below:

(a) Except on cars specified in paragraph (b) of this section—

(1) On standard gage (56 1/2-inch gage) railroads, the maximum height of drawbars for freight cars (measured perpendicularly from the level of the tops of the rails to the centers of the drawbars) shall be 34 1/2 inches, and the minimum height of drawbars for freight cars on such standard gage railroads (measured in the same manner) shall be 31 1/2 inches.

@David Johnston posted:

There is no standard clearance between cars. With a E-60 coupler and a conventional draft gear the distance may be in the 3 to 4 feet range.  Bur two cars with 15” center of car cushioning have 30” of movement available between the cars plus the two coupler heads. Longer cars have to have longer coupler shanks which results in more space between cars.  Then there was end of car cushioning cars. There were also articulated cars with drawbars between them rather than couplers.  As far as height, vertically the center of the coupler knuckle on an empty car should be 17” above the top of the rail. There are no other standard vertical dimensions except for a few in the safety appliance act.

Agreed, that is why I stated this was specifically for a Transition Era Boxcar.  Although cushion underframes started being used in the late 1920's, they weren't very common until the late 1950's to early 60's.  As I said trying to keep it simple.

@MainLine Steam Thank you very much for doing all that research and for the photos. Obviously, there can be no exact number since there are many types of railcars and any car can be coupled to almost any car but I think your number of 42" is a good enough average number for me.

@Hudson J1e posted:

@MainLine Steam Thank you very much for doing all that research and for the photos. Obviously, there can be no exact number since there are many types of railcars and any car can be coupled to almost any car but I think your number of 42" is a good enough average number for me.

Phil thank you for the words of encouragement.  What I was trying to achieve was a "rule of thumb" for those that model Steam or Transition Era.  I know I am not the only one that does.

Wish I had been born just a few years earlier, so I had Childhood memories of Steam.

@MainLine Steam posted:

Not quite sure where to post because this because it relates to 2R & 3R Scale and Real Trains.

With Scale Modeling my understanding is to try to accurately portray the Prototype.  When I look at a "string of cars" this would mean they are sitting at a reasonable height and properly "spaced".

Depending on "brand", many 3R cars sit higher than the prototype, but most generally accept this if not "excessive".  Also the spacing of 3R is generally too great, but again it is accepted, so the cars can negotiate small radius curves.

But with 2R Scale most seem to expect a tighter standard.

So this got me wondering how close our "scale" trains are to the prototype.  I did some research and found there is no "absolute standard" for prototype equipment for many reasons.  I wanted to keep this simple and decided to just look at a "transition era" boxcar.  The spacing is visually more apparent with box cars than say Tank Cars or Flat Cars.  From what I found a reasonable average Prototype spacing for these cars is about 42".  For my comparison I grabbed some unmodified Weaver 3R and 2R cars which were sitting around.

This is what I found.  (42" prototype = 7/8")

I was actually surprised that the 2R cars were basically "right-on".  I expected them to have some extra space, a 36" Radius Curve (144') would be extremely tight for a prototype curve, only used in very tight quarters for slow speed operation.  Again the spacing for the 3R was oversized, but not really ridiculous.

Anyhow I posted this to share what I found.  Thought some might find this interesting.

in real railroading  the coupler distance from the head to the plate changes quite a bit from manufacturer to manufacturer. If repairs have been done there’s a lot of variables to this, that’s why in passenger cars you have expandable diaphragms because the cars all do not land in the same place. A great topic nevertheless

Craig

PennCentralShops

@ThatGuy posted:

in real railroading  the coupler distance from the head to the plate changes quite a bit from manufacturer to manufacturer. If repairs have been done there’s a lot of variables to this, that’s why in passenger cars you have expandable diaphragms because the cars all do not land in the same place. A great topic nevertheless

Craig

PennCentralShops

Yes Craig it can vary, but prior to cushion underframes, the default dimension for most AAR Type E couplers was about 16 inches.  I originally stated 15 inches but after conducting more research found that 16 was a better number.  However I also found that the striker plate vs end frame dimension when surveying more car diagrams was in the 4" to 7" range (I used 6").  So the 42" still makes sense as a typical average.

https://cs.trains.com/mrr/f/13/t/290146.aspx

As I stated right from the beginning, trying to keep it simple to establish "a rule of thumb". Also to check how close a "typical" model is.

I have gone back and changed lettering to bold in my Original Post, that there is no standard and that this applies to a transition era boxcar.

I do "railfanning", when watching modern equipment roll by there is a lot more variation, and generally larger distances due to cushioned underframes.  Although there NOW are also a lot of freight cars that are articulated.  Freight rolling stock is different than when watching trains 40 years ago.  Let alone 75 years ago (I'm not quite that old).

I just like the way Kadees look.