Car & locomotive height

[mark.hinds]

Note on most recent edit:  I have rewritten this post (May 9th) to emphasize my 2 major suggestions.  These were (1) to consider setting personal car height standards, and (2) to accurately measure models against these standards.  This first portion should not be controversial.   The more controversial part follows the image, and consists of my 1980s-era personal car height standards.   

A systematic approach to the car height issue would be to establish personal measured “standards” for equipment height, instead of just doing it “by eye”.  For each type of equipment, the standard could either be the scale height, or some other height which the modeler feels is a more practical compromise, given personal preferences. 

To facilitate checking model car height against one’s standard, one may want to create a jig.  Here’s an image of a jig which I made.  Its main advantage is that it allows a more precise measurement from railhead to the top center of the end of the car, independent of viewing angle.  One first adjusts the height of the bar relative to the rail head at that end of the tool, using a scale ruler.  Then one tightens up the clamp.  The bar in the image happens to be set for 14’ (for F7s).    This jig can also be used to check for car sideways lean, by putting a small machinist’s square vertically along side the car on the “shelf” and sighting from one end of the jig. 



The following is an example of the type of height standards compromise which a particular modeler might decide on.  It derives from my experience back in the 1980s, when I last did significant work on my layout (which has been in a state of suspended animation since).  This issue almost certainly needs to be revisited by me, in light of currently available N-scale products and improved modeling standards. 

Anyway, back then I had decided that some equipment was so off that adjustment to actual dimensions was impractical (personal decision here).  For example, the steel ice reefer shells I was modifying to represent R-40-20s (above image) could only be lowered so much before they started looking worse.  This was because the model car body width was excessive when compared with the width of the MT trucks I use, thus making the body overhang the trucks when viewed from above and to the side, thus making the ground clearance of the car look inadequate when viewed from that angle.  So, I settled on reducing the height to 14’ instead of to the actual 13.5’. 

Based on similar reasoning, here were some of my actual prototype / standard modeled heights.  The models would have been adjusted to match the 2nd number.  Note that in all cases the models were originally even higher, as produced by the manufacturer:

EMD F7 diesel    14’ / 14’
PS-1 box car   15’ / 15.5’
R-40-20 reefer   13.5’ / 14’
R-40-25 reefer   13.7’ / 14.2’

MH 

[bbussey]

Is the reefer in the photo the R-40-20 you are referring to?  That model appears to be the old Atlas/RivaRossi or MiniTrix bodyshell from the early 1970s, which might not have a correct width.

You also reference MTL trucks, most of which have the offset bolster hole (I think only the trucks with the medium extended coupler arm have a properly centered bolster hole), so that's also a factor in the aesthetics of how the model appears on the trucks.  Rather than unilaterally compromising on the car height, one could experiment with the various truck frames that exist from multiple manufacturers to see how the model looks.  Since lowering a model nearly always dictates body-mounted couplers, being "locked into" MTL trucks is not a given.

[mark.hinds]

Is the reefer in the photo the R-40-20 you are referring to?  That model appears to be the old Atlas/RivaRossi or MiniTrix bodyshell from the early 1970s, which might not have a correct width.

You also reference MTL trucks, most of which have the offset bolster hole (I think only the trucks with the medium extended coupler arm have a properly centered bolster hole), so that's also a factor in the aesthetics of how the model appears on the trucks.  Rather than unilaterally compromising on the car height, one could experiment with the various truck frames that exist from multiple manufacturers to see how the model looks.  Since lowering a model nearly always dictates body-mounted couplers, being "locked into" MTL trucks is not a given.

I also share your concerns about compromise with scale, but remember, anything I do here moves the models closer to scale height than if I had left them alone.  In other words, the “standards” result in either the car being left at its original height, or in being moved closer to its scale height.  I would never make a car worse.  It just is that in some cases, I might judge it to be more practical to accept an imperfect height than no car at all.  

The shell (kitbashed to represent an R-40-20) was sold by Roco back in the 1970s.  It did not have the correct width, but back then available 40-foot steel reefer models were limited (no Intermountain or Micro-Trains).  If I use that shell, I am stuck with 14’ I think.  I also own a large number of IM 40-foot steel reefer kits (R-40-23), whose height I have not yet checked.  

I’m not sure what you mean by “offset bolster hole”, but the hole in this case is laterally symmetric on both the car floor and the truck, so the overhang issue is equally visible from both sides.  The only other solution I can see here is major surgery on the shell to narrow it (too much work), or use a different shell (wastes the shells, of which I have about 15).   For various operational reasons, I am committed to MT trucks and wheel sets.  However, others may not be.  

MH

[sirenwerks]

...The only other solution I can see here is major surgery on the shell to narrow it (too much work), or use a different shell (wastes the shells, of which I have about 15)....

MH

Use the car sides with IM kit ends and roof, which are the right width.

[mark.hinds]

Use the car sides with IM kit ends and roof, which are the right width.

That's something to consider.  Does IM sell reefer parts separately, or does one need to cut up entire shells?

With respect to my "standards", I also need to revisit why I didn't lower the MT PS-1s all the way.  (My "standards" were made back in the early 1980s, and my incomplete layout has been in a state of suspended animation for the last 25 years or so).  If it was the "pizza cutters" hitting the floor, I will probably replace them with the new MT "standard" medium flange wheel sets anyway.  Alternatively, I could grind out depressions in the bottom of the car floor to clear the flanges.

MH

[sirenwerks]

Mark,

It's been a couple years, but I have purchased parts via phone from IM. The reefers and box cars are still sold as kits, as are other body types.

[bbussey]

... I’m not sure what you mean by “offset bolster hole”, but the hole in this case is laterally symmetric on both the car floor and the truck, so the overhang issue is equally visible from both sides.  The only other solution I can see here is major surgery on the shell to narrow it (too much work), or use a different shell (wastes the shells, of which I have about 15).   For various operational reasons, I am committed to MT trucks and wheel sets.  However, others may not be.  

Not sideways.  If you're using standard MTL Bettendorf trucks with coupler, as in your photo, the hole for the bolster pin in the truck frame is offset.

Again - if you are using truck-mounted couplers, you are compromised on how much you can lower the cars.  Using body-mounted couplers, MTL or otherwise, affords you greater flexibility in adjusting the car height.

[bbussey]

... With respect to my "standards", I also need to revisit why I didn't lower the MT PS-1s all the way.  (My "standards" were made back in the early 1980s, and my incomplete layout has been in a state of suspended animation for the last 25 years or so).  If it was the "pizza cutters" hitting the floor, I will probably replace them with the new MT "standard" medium flange wheel sets anyway.  Alternatively, I could grind out depressions in the bottom of the car floor to clear the flanges.

Here is the MTL PS-1 lowered simply by adding with BLMA trucks and body-mounted MTL couplers, with no underframe modifications.

[mark.hinds]

Not sideways.  If you're using standard MTL Bettendorf trucks with coupler, as in your photo, the hole for the bolster pin in the truck frame is offset.

Hmm; I don't see this on mine.  I even just now measured one with a caliper, and the truck's bolster hole is centered to within 1/100 of an inch side-to-side.  Something that small I am not going to notice.  

You may be right about body-mount.  For now, I am postponing that decision, but I may have to revisit if I decide to further reduce any of my standard heights.  Based on what I have read, it would require me to body-mount all my cars in order to avoid operational problems, so it would be a lot of work.  

MH

[mark.hinds]

Here is the MTL PS-1 lowered simply by adding with BLMA trucks and body-mounted MTL couplers, with no underframe modifications.
<image removed>

Nice weathering.  How high is the car now (in scale feet)?  Should be 15' from railhead to top of roofwalk, if I remember correctly. 

MH

[Mark5]

With respect to my "standards", I also need to revisit why I didn't lower the MT PS-1s all the way.  (My "standards" were made back in the early 1980s, and my incomplete layout has been in a state of suspended animation for the last 25 years or so).  If it was the "pizza cutters" hitting the floor, I will probably replace them with the new MT "standard" medium flange wheel sets anyway.  Alternatively, I could grind out depressions in the bottom of the car floor to clear the flanges.

MH

I can relate to suspended animation, I took down my last layout in 1978 when I was off to college ... only in the past 10 years have I even begun to mess with model railroading again (except for a few isolated models that I built during my "wilderness years").

I would definately lose the pizza cutters, it'll make lowering many cars much more pleasant! 

Mark

[SkipGear]

Hmm; I don't see this on mine.  I even just now measured one with a caliper, and the truck's bolster hole is centered to within 1/100 of an inch side-to-side.  Something that small I am not going to notice. 

You may be right about body-mount.  For now, I am postponing that decision, but I may have to revisit if I decide to further reduce any of my standard heights.  Based on what I have read, it would require me to body-mount all my cars in order to avoid operational problems, so it would be a lot of work. 

MH

It's not a side to side issue. The bolster hole center is offest .015" to the rear of the truck. This causes the truck to be pushed out to the ends of the car and not line up with the bolster and ride pads. The offset to the center causes the proportions to look off just as much as an overly wide body.

[bbussey]

Hmm; I don't see this on mine.  I even just now measured one with a caliper, and the truck's bolster hole is centered to within 1/100 of an inch side-to-side.  Something that small I am not going to notice. 

See Tony's post.

You may be right about body-mount.  For now, I am postponing that decision, but I may have to revisit if I decide to further reduce any of my standard heights.  Based on what I have read, it would require me to body-mount all my cars in order to avoid operational problems, so it would be a lot of work. 

Mixing truck-mounted and body-mouted is only an issue if you pushing long consists through curves with tight radii.  You would not have a problem in normal operations.  Body-mounted is superior to truck-mounted for a large number of operational reasons, not just for aesthetics.

Nice weathering.  How high is the car now (in scale feet)?  Should be 15' from railhead to top of roofwalk, if I remember correctly. 

The dimi data EXH is 13'3".  The model measures out to a scale height of 13'5".  So the car is a tad high, but I'm not going to quibble over .0125" when all I had to do was slap on a new set of trucks.

[mark.hinds]

It's not a side to side issue. The bolster hole center is offest .015" to the rear of the truck. This causes the truck to be pushed out to the ends of the car and not line up with the bolster and ride pads. The offset to the center causes the proportions to look off just as much as an overly wide body.

(Looks at MT PS-1 model...)  Damn; you guys are right about the longitudinal offset on the truck's mounting hole.  Now that's annoying...

<content removed>
The dimi data EXH is 13'3".  The model measures out to a scale height of 13'5".  So the car is a tad high, but I'm not going to quibble over .0125" when all I had to do was slap on a new set of trucks.

If overall scale height of the model is 13' - 5", you don't need to worry about it being too high.  According to my sources, the PS-1 was 14' - 11.75" (essentially 15') from the top of the rail to the top of the car's roofwalk.  (From plans in Mainline Modeler, December 1982, page 69). 

MH

[wcfn100]

The dimi data EXH is 13'3".  The model measures out to a scale height of 13'5".  So the car is a tad high, but I'm not going to quibble over .0125" when all I had to do was slap on a new set of trucks.

Bryan, you've written a couple times about the 'EXH' dimi data and I have to say I'm a little confused.  For the most part there are four external measurements that are part of a box car's diminsional data.

For a PS-1 it could be something like...

EXW  10-4     H 13-7

EW   9-4         H 14-5


These numbers represent the Extreme Width of the car and the height at which it occurs, and also the width at the eaves and the height it occurs.  

There's nothing about the overall height of the car (which in this case is 15'-1").  ???

So how are you using what's written on the car to figure the proper height?

Jason