Minimum curves for 85' streamline cars


FWIW, when I test my curved track for problems, one of my favorite trials is to run a shoving move of passenger equipment through curves, switches and crossovers. I also test new passenger cars in a similar manner. If the train makes it both ways pulling and shoving, everything is good.
 
Santa Fe 85 footers on 31", 28.5". & 24" Radius

Got my Walthers Santa Fe passenger cars out of my storage trailer to see if there were differences from those PRR classics.

On 31" radius curves
No problems negotiating. Require a minimum of 1" from the CL of the track at the ends of the cars (outer clearance), and at the middle of the cars (inner clearance).

(Those pencil lines outboard of each track are at 1" from the CL of the track itself)
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Santa Fe 85 footers on 31", 28.5". & 24" Radius

On 28.5" radius curves
Appears to require just about the same clearances as those for the 31" radius curves above,...1" on either side of CL

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(this photo would make it appear that the cars require more than the 1" outer clearance, but be aware that it is the angle at which I shot the photo, and prior to my placing those upright angular brackets,.....only 1" minimum required)
 
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Santa Fe 85' footers on 24" radius

Granted it does NOT look very good to run these cars on 24" curves,....but it can occur on many of our 'small layouts', and in a number of spot areas on larger layouts,....staging access lines, freight yards, sidings. etc

Basically it appears as though we need an additional 1/8" on either side,....so 1+1/8" on either side.

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Thanks for doing all the mock ups on this. Makes me feel much better about the radius I chose.
 
Since this subject thread is titled '85' streamline cars', I think perhaps I need to start a new thread for the other long cars and steam locos I measured out??
 
Thanks for doing all the mock ups on this. Makes me feel much better about the radius I chose.

Something to remember when planning curves in yards and engine terminals. The prototype's curves were much tighter in yards, than on high speed main lines. So is the overhang greater. Imagine switching the car shop at Penn Coach Yard, in Philadelphia on Amtrak. All cars - Amfleet or Metroliner Cab cars are 85' long. On the main line one hardly notices any overhang. Yet pulling and shoving the same cars over yard switches, curves and "S" curves results in quite a display of exaggerated overhang, like what one would find with a Rivarossi 85' car on an 18" radius curve.

First criteria on a model railroad is does it work, or is it plausible? Second question, will it clear another train on an adjacent track? Third: Will it clear my scenery, tunnels and other infrastructure. If the answer to all three questions is yes, you're good to go. Esthetics, such as overhang are subjective. If you only have room for 26" radius curves but want to run full length passenger cars or long freight cars, you compromise. The late, Andy Sperandeo, of Model Railroader used to recommend building your benchwork, so that your trains were eye level. This way, the visual effect of the overhang was mitigated.

Boris
 
Long time since I commented on this thread and I had to do a quick re-read to see if I had made this comment about Walthers 85' passenger cars. Walthers estimate of 24" radius only applies to a single car being pushed around that radius, nothing else. But there can be another difficult thing to detect. The stirrups and where they are in relation to a particular car's trucks. I have one which is a postal coach. It has long stirrups, lengthwise, that are right alongside one of the trucks and they are longer 4 wheel trucks as well. Even on quite gentle curves, the truck not only hits the stirrups, it actually locks into it, causing it to derail, but others have also caused derails too.
 
It would be wonderful if all of us had the luxury of running such large radius curves. Unfortunately, we don't. As there are not that many options for shorter passenger cars, we are forced to run at least some of the 85-footers on tighter radius curves. I have been quite successful in operating passenger trains on curves as tight as 18 inches! Yes, it means leaving some gaps between the diaphragms, making sure the trucks clear any steps, etc., in some cases filing the tops a bit, (but at lower track levels it isn't that easy to see such modifications). In some cases, where I have had access to them, running shorter cars between two 85 footers helps.
 
It would be wonderful if all of us had the luxury of running such large radius curves. Unfortunately, we don't. As there are not that many options for shorter passenger cars, we are forced to run at least some of the 85-footers on tighter radius curves. I have been quite successful in operating passenger trains on curves as tight as 18 inches! Yes, it means leaving some gaps between the diaphragms, making sure the trucks clear any steps, etc., in some cases filing the tops a bit, (but at lower track levels it isn't that easy to see such modifications). In some cases, where I have had access to them, running shorter cars between two 85 footers helps.

Modification/adapting is the only way sometimes, if you can accept the compromise. The recent release Walthers Mainline coaches all come with truck mounted couplers on extended arms, minimal detailing, but they do have stirrups
 
Turns out it was in a 20 year old issue of Model Railroader Planning, 1998. I think I have given the source proper acknowledgement. it would be a shame not to share this good but older article.that might be lost in time otherwise. (please excuse my notes and hi=lites)

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Yeah to run on 24” radii usually requires some surgery on the Wally underframe. Passenger trains take up a lot of real estate. If you don’t have the space for the large radius curves there is some nice 60 foot stuff on the market. “Pike sized passenger trains” is a good subject! As Toot said, watch the S curves, and make sure you can back the train reliably. Your track work needs to be up to snuff.
 
I'm one of the guys who runs the 85 foot cars on anything. Here is how you do it. Replace the couplers with Kadee 451 Extended swing gear box and whisker couplers. This will allow the swing for 18 inch curves to be taken by long cars. It might look a bit goofy, but in the end, what really matters is the train runs.

The Aerojet
 
One thing that just came toi mind is a problem we have at out model railroad club. There is one curve that I am guessing that is aboiut a 24 inch radius. There are no problems with long cars such as auto racks, but passenger cars do have a problem. One of the members has a complete Walthers Empire builder and was having derailment problems and it ended up that the diaphragms were causing the derailments. My Walthers cars were having problems there and I found out that the owner of the Empire Builder had to put extended length couplers on all of the cars which took care of the problem.
 
Why I seek to know minimums that might be possible.

Gentleman, please realize that I am trying to build a LOT of railroad into a relatively confined space. This process has me looking for minimums (spaces, curvatures, clearances, etc) that might be utilized.

Sure I would like to just go off and make everything a little bigger so as to not be so concerned about clearances, but I don't necessarily have that luxury,....and often I find that making one thing just a bit bigger, results in having to make an adjoining thing bigger,...and then next the another adjoining thing that much bigger,....and things snowball to the point that it no longer fits in your allowed space.

I do get confused by many of these NMRA specs, and the numerous (and conflicting) postings by many of the forums members.



So I am going to prepare a 'pictorial presentation' of my current clearance issue/question, and post that very soon. What do they say,... “a picture is worth a thousand words”. Hopefully this will more fully define why I felt I needed to revisit this subject.
 
A Picture is Worth a Thousand Words


Just recently I was building a new metal 'bridging deck' that would join my external helix track to my subterranean staging tracks inside the main room of the layout. This bridge supports a 3-way turnout that feeds 3 curved sections of track to the 3 staging areas, and also a rerailer. I had already cut the rectangular hole thru the back wall of the shed. I was replacing my original flat plywood bridge with an alum channel one that would also have 'side fences' on it to protect from derailments falling over the sides of this 'bridge'...
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Per my original plans there are to two 24” radii tracks leading off to either side of that 3-way turnout. I had trimmed off a portion of those 2 fences on either side of the alum channel to allow for sideway clearance for cars traveling on those 2 side routes.



BUT as I looked at these clearances (AND those of the cutout in the wall), I began to question if I had provided enough clearance for those very long auto-racks in addition to the long passenger cars?? That's when I decided to come back to this subject thread and look again at my results, and those references supplied by other participants.





I began to look back thru all of discussions, and charts, and other links,...and get more confused by the multiple answers.


I decided to get out the track, and the cars, and the bridge structure and do a full scale mock-up. So here is my bridge with the side fences trimmed in there first configuration
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Here are two of the large, long cars I would hope to be able to put down in my staging areas
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The question is can they clear the openings I've provided? No questions about height as I've already provided 4"
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My first trail was with the AUTO-MAX pair. I figured that this car had its wheel pivot centers at the very ends of the car which would result it it have the greatest overhang to the inside of the curve.
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The 24' radius track bending off the 3 way (only tested right hand branch). That little bracket sitting out there will come in handy.
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You can see that there is plenty of clearance between the side fences of the deck/bridge and the cars. I forgot to mention that I had already gone ahead and cut an extra 1 inch off of the fences in anticipation of a clearance problem here. It now appears that may not have been necessary, but no matter as I did not require that portion of the fencing.
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Moving along down the curve we can now see the that little bracket right up next to the inner side of the Auto-Max.
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Looks to be 1 1/8” at the very minimum to the centerline of the track.
So if I gave it 1.5” that should be plenty!


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Articulated Auto Racks


Next up that nice pair of Atlas auto racks.
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Again the very bear minimum clearance


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Looks like 1”,...or perhaps 1/16 additional.



Again 1.5” provides plenty of clearance.
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I mentioned before that my original trimming of these fences had me concerned, so I cut off another 1" of their length. They are now 1.5" from the centerline of the tracks, but as you can see in the photos above that might not have been needed.


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Long Modern Passenger Cars


Lets see if my old test proved to be true,...only about 1" overhang to inboard side on 24" radius curve.


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