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Running 24" radius car on 18" radius track?

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Running 24" radius car on 18" radius track?
Posted by pugdogg55 on Friday, October 18, 2019 10:31 PM

I was looking into getting a few passenger cars for my layout. The issue is most of the ones I'm looking at have a reccomended turn radius of 24" and all my turns run at 18". I know this is quite a leap in the degree of the turn, but would the cars still run on my 18" radius curve or would they struggle through it or derail (or possibly have coupler problems?)?

Thanks in advance to any answers I could get!

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Posted by "JaBear" on Friday, October 18, 2019 10:42 PM
I would suggest that it would be easier to push a chain uphill!!
It’s a Bold statement but while anything can be remedied or made to work, especially if you like a challenge; it may not be worth your investment in time and money.
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Posted by hon30critter on Saturday, October 19, 2019 12:32 AM

pugdogg55,

You likely have two issues:

One is the distance between the cars when coupled with their existing couplers. If you run the cars on a curve tighter than 24" the corners of the cars or the diaphrams will hit each other which will push the cars off of the rails. The solution would be to lengthen the coupler shanks, but that will leave quite a gap between the cars when they are running on straight track. You may or may not find that acceptable.

The second is the ability of the trucks to pivot far enough to match the curves. They may or may not be capable of doing that as is, but if they are not you will have to modify either the trucks or the underside of the car, or both, to provide sufficient clearance for the trucks to pivot far enough to match the curves.

I believe that there are shorter passenger cars available but I'm not sure if they are still being made or if you will have to look for older cars. Maybe somebody can advise us on what might work.

Dave

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Posted by Medina1128 on Saturday, October 19, 2019 12:56 AM

hon30critter
I believe that there are shorter passenger cars available but I'm not sure if they are still being made or if you will have to look for older cars. Maybe somebody can advise us on what might work.

I found some "shorty" 60' passenger cars made by Rivarossi on eBay, and they look right on tight curves. That's why I designed my layout with 26" radius minimum.

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Posted by IRONROOSTER on Saturday, October 19, 2019 1:49 AM

Replace the trucks with trucks with mounted couplers (also known as talgo trucks).

Athearn (and maybe others) make passenger ones.

Note you may have some issues backing these up, but they will allow cars around too tight curves.  You may also have to remove some under body detail to allow the coupler swing.

Good luck

Paul

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Posted by mobilman44 on Saturday, October 19, 2019 4:54 AM

Speaking from the provervial "experience", running proto length passenger cars on 18 inch curves is just an excercise in frustration.  Can you get them to work?  Of course you can........with butchering the cars or otherwise altering them. 

The thing is, they look very toylike in their running around those curves, and I doubt that is what you would want to see.

However, Athearn's old "Blue Box" passenger cars - being somewhat short - will work beautifully on 18 inch curves and look half way good.  While these are out of production, you will find a plethora of them on Ebay.

 

ENJOY  !

 

Mobilman44

 

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Posted by ATLANTIC CENTRAL on Saturday, October 19, 2019 5:50 AM

mobilman44

Speaking from the provervial "experience", running proto length passenger cars on 18 inch curves is just an excercise in frustration.  Can you get them to work?  Of course you can........with butchering the cars or otherwise altering them. 

The thing is, they look very toylike in their running around those curves, and I doubt that is what you would want to see.

However, Athearn's old "Blue Box" passenger cars - being somewhat short - will work beautifully on 18 inch curves and look half way good.  While these are out of production, you will find a plethora of them on Ebay.

 

 

Actually they are not completely out of production.

Athearn still runs batches from time to time of these, now RTR under their Roundhouse brand, and prior to that in the Ready to Roll line. 

So both blue box kit and RTR versions can be found, depending on the desired road name.

Sheldon

    

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Posted by Harrison on Saturday, October 19, 2019 7:36 AM

mobilman44

Speaking from the provervial "experience", running proto length passenger cars on 18 inch curves is just an excercise in frustration.  Can you get them to work?  Of course you can........with butchering the cars or otherwise altering them. 

The thing is, they look very toylike in their running around those curves, and I doubt that is what you would want to see.

However, Athearn's old "Blue Box" passenger cars - being somewhat short - will work beautifully on 18 inch curves and look half way good.  While these are out of production, you will find a plethora of them on Ebay.

 

 

I find that I can get the BB cars to run on 18", just got a few at a train show for $6 a piece.

Harrison

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Posted by SPSOT fan on Saturday, October 19, 2019 7:46 AM

I can tell you right away that you can not run cars on radii less than what the manufacturer says you can. From experience I can tell you that I have have issues running 28” cars on a 30” curve, the diaframes still hit and derailed the cars (I suspect either the diaframes where sticky or the track kinked).

What era does the OP model. Is you model and earlier era you could look into Athearn Overton/Overland cars. They are quite short and certainly could run on 18” curves and look fine. Only issue is they are very much old time!

Otherwise, as others have said, look for shortly cars and be prepared to make modifications!

Regards, Isaac

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Posted by richhotrain on Saturday, October 19, 2019 8:02 AM

SPSOT fan

I can tell you right away that you can not run cars on radii less than what the manufacturer says you can. 

Sure you can. It's just that often they don't look very realistic doing so.

Rich

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Posted by ATLANTIC CENTRAL on Saturday, October 19, 2019 8:33 AM

A few more thoughts.....

Not all "prototype" passenger cars were are 80' or 85' long. So there is not blanket "proto length".

Many heavyweight coaches were only 75' +/-, even some streamlined cars were only in that range.

The Athearn and ConCor cars are 72', pretty close to many prototypes.

Sheldon

    

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Posted by RR_Mel on Saturday, October 19, 2019 9:34 AM

I have dozens of Athearn 72’ passenger cars both streamline and heavy weight and all work on 18” radius.  My entire yard consists of all #4 turnouts many S curves and I can pull or push them (no diaphragms) through my yard turnouts without problems.
 
I haven’t found a diaphragm that works without problems so I only have them on my over weighted Athearn Heavy Weight cars.  They don’t do well through the S curves in my yard.  I store them on a hidden siding not in my yard.
 
 
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Posted by ATLANTIC CENTRAL on Saturday, October 19, 2019 10:26 AM

RR_Mel

I have dozens of Athearn 72’ passenger cars both streamline and heavy weight and all work on 18” radius.  My entire yard consists of all #4 turnouts many S curves and I can pull or push them (no diaphragms) through my yard turnouts without problems.
 
I haven’t found a diaphragm that works without problems so I only have them on my over weighted Athearn Heavy Weight cars.  They don’t do well through the S curves in my yard.  I store them on a hidden siding not in my yard.
 
 
Mel
 
 
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I'm beginning to realize that aging is not for wimps.
 
 

Mel, the reality is no diaphragm is going to work on curves that sharp. You need near prototype interaction of car ends, which means 28" to 32" curves at minimum.

Sheldon

    

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Posted by RR_Mel on Saturday, October 19, 2019 10:48 AM

ATLANTIC CENTRAL

 

Mel, the reality is no diaphragm is going to work on curves that sharp. You need near prototype interaction of car ends, which means 28" to 32" curves at minimum.

Sheldon

 

You’re correct Sheldon
 
My tightest radius on my mainline is 28” and my 72’ SP Lark Heavy Weights with Walthers diaphragms work great in that environment (pulled by a Cab Forward), no problems at all!  I park it on a hidden siding when not in use. 
 
My streamline 72’ SP Daylights don’t have diaphragms and will negotiate #4 turnouts and 18” radius easily, I guess because of the Athearn Talgo trucks.
 
 
Mel
 
 
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Posted by Eilif on Saturday, October 19, 2019 11:33 AM

One more vote for sticking with radius-appropriate passenger cars.

Athearns are available in Heavyweight and Streamliners in a variety of liveries.  As others have said, they are quite common used online and at train shows. I think they are among the sturdiest, best looking and best running of the shorties.  

Con Cor also makes short cars designed for 18" curves.  Their 72' line is designed for 18". 

If you like Harriman-style coaches, Model Power had short Harriman coaches that will easily navigate 18" and would probably even do 15".  They are pretty common used and the really good news is that now Lionel is just about to re-release them and they will come standard with metal knuckle couplers and wheels.  Right now they're mostly vintage armed forces recruiting liveries, but I bet more traditional passenger liveries will follow.

Lastly, check out IHC, They aren't as smooth or quite as nice as the above, but they were available in a huge number of liveries and IIRC, there are 8 different types of cars.  They are also OOP, but widely avaiable used.

The limits of 18" are why I decided to go with a Ping Pong table instead of an 4x8 for my first layout.  I want superliner passenger cars (Con Cor superliners require 22")  to be able to run on both the inner and outer loops.  Its' tough to get bigger than an 18" inner loop on an 4x8 sheet but on a 9x5 Ping Pong table the inner loop can be over 22"!

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Posted by dknelson on Saturday, October 19, 2019 8:33 PM

richhotrain

 SPSOT fan

I can tell you right away that you can not run cars on radii less than what the manufacturer says you can. 

Sure you can. It's just that often they don't look very realistic doing so.

Rich 

Disagree.  It is not always a matter of mere appearances.  If the trucks or couplers interefere with the steps, then snipping off the steps is often the only way to make it work.  Highly detailed airbrake and steam line systems can be another interference point.  There might be other mechanical or practical engineering issues as well, including derailments -- AHM's and Athearn's 6 wheel passenger trucks for example were deliberately designed to be loosey goosey around tight curves,  while those on Walthers passenger cars, less so, and those on brass, or Central Valley, hardly at all.  

 

 

There isn't much incentive for a manufacturer to be overly conservative in its recommended minimum radius.  Sometimes you get lucky and a 20" minimum radius car or locomotive can run on smoothly laid 18" radius.  But 24" to 18"?  That's a huge difference.   

Dave Nelson

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Posted by MisterBeasley on Saturday, October 19, 2019 9:49 PM

I have 4 Rivarossi cars, about 65 or 70 footers, that say they run at 18 inch curves.  That is correct, but they do NOT work on 17 3/4 inch curves.  These cars have body-mounted couplers with swinging coupler box mounts.

I also have a set of ancient Tyco streamliners that have Talgo couplers.  They easily navigate 18 inch curves,, but they are probably 50 years old and were built to more forgiving standards.

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Posted by jjdamnit on Sunday, October 20, 2019 7:42 PM

Hello All,

The "main line" on my pike consists of an oval comprised of asymmetrical curves made up of 18- and 15-inch radius sectional track.

Despite this being a coal-branch loop the Royal Gorge excursion train makes an occasional appearance. (The advantage of a freelance pike to suspend reality.)

The turnouts are Atlas Snap Switches with one Atlas Mark IV #6 and a PECO curved turnout.

Eighty-five-foot passenger cars can negotiate the "main line" curves and the Snap Switches but look ridiculous to the point of comical when running. 

The passenger cars have body-mounted articulating or "swing" couplers. I do not use diaphragms.

Stock couplers were replaced with long shank couplers in the articulating draft gear boxes. This gives the necessary clearance on the tight curves and turnouts but the overswing is completely non-prototypical. 

When this train makes an appearance special orders of clearance have to be observed to allow the longer cars to pass safely.

I've also tried running six-axle SDs. They can negotiate the curves and turnouts but look ridiculous. That's why I stick with GPs. 

Yes, you might be able to get away with less than manufacturers recommended practices but it won't look right and, as others have posted, you run the risk of more headaches. 

Of course, I wish I could run longer cars and road diesel, but until "She Who Must Be Obeyed" says I can expand beyond a 4'x8' pike I have to accept my lot in life. 

Hope this helps.

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Posted by xboxtravis7992 on Sunday, October 20, 2019 10:48 PM

pugdogg55, the real question might be what you intend to depict on your layout. Heavyweight, streamlined, and modern intercity passenger cars of course are not appropriate for such sharp curves. But mining, logging and other odd railroads ran specialized equipment that was shorter for use on sharp curves.

I picked one of my local examples, the long gone Salt Lake and Mercur railroad a standard gauge mining railroad. According to UtahRails.Net the maximum grade was 4.2%, and the maximum curves were 42*. Translating that to HO scale, we would have a 19.2 inch radius, not to far off from the standard 18" trainset radius.

The equipment the railroad ran all reflected that, Shay locomotives and short boxcars/ore cars. The passenger equipment was similarly short: 

So this would be an absolutely appropriate prototype to run short passenger cars fit for 18" curves. It would require some scratchbuilding though with the cars, although I think a few HO Shays and other geared locomotives like Heislers and Climax engines are available on market.

Of course if your beholden to modern passenger cars of heavyweights, it might be best to look instead for a layout design with much larger curves. 

Edit: if you want a preserved example of such a steep and sharp mining railroad, look no further than the V&T especially on the grade and curves out of Gold Hill: https://youtu.be/XMBdgRrtwRY?t=90 

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Posted by SeeYou190 on Monday, October 21, 2019 6:37 AM

mobilman44
Running proto length passenger cars on 18 inch curves is just an excercise in frustration. They look very toylike in their running around those curves. Athearn's old "Blue Box" passenger cars will work beautifully on 18 inch curves and look half way good.

.

I agree with all of these statements 100%.

.

You really can't beat Athearn passenger cars if you want to run passenger equipment on 18" radius curves.

.

-Kevin

.

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Posted by Eilif on Monday, October 21, 2019 7:07 AM

One more related thought for the OP.   Even besides the way they look in the curves, I think that shorter cars just look better even on the straits of a smaller (with 18" curves I assume yours is compact) layout.  Generally everything on a smaller layout is compressed anyway and having cars that are similarly compressed looks good to the eye.   Plus, you can put more cars on your consist without wrapping halfway around the layout.  I feel that long full-length cars on a small layout dominate the scene and not necesarily in a good way.  

I'm building on a 9x5 in the modern era and yet -though there are some exceptions- I'm generally sticking to 50' freight for this reason.

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Posted by riogrande5761 on Monday, October 21, 2019 8:13 AM

If the OP is planning to run Walthers 85' passenger cars that are listed to have minimum radius of 24 inches, some have commented they need considerably broader curves to operate reliably.  If that is the case, the I would think 18 inch curves are out of the question.

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Posted by mobilman44 on Monday, October 21, 2019 8:35 AM

I have two long streamliners (ATSF & IC) using the Walthers passenger cars.  They are beautiful but "RTR" as advertised is not necessarily true.

My layout is 28 inch minimum curves on the mains with one 26 inch.  Each of the 16 Walthers cars needed a complete check up before they would run the way I like.  Most were simply a matter of oiling the axle ends (as Walthers states) and changing out the couplers.  

For most of the cars this worked ok, but there was some rubbing of the diagphrams - so I put in a long shank KD as needed.

However, four of the cars needed some cutting and judicious trimming to get the trucks to turn freely.  Two of those four cars needed minor surgery to do this, the other two needed minimal cutting.  None of this work is noticeable track side.

FYI, all of the above has been covered many times in past posts.

Have to add........while I really like the Walthers cars, I find it notable that the streamline and heavyweight Athearn passenger car trains I used to have gave me as much or more fun.  Gee, out of the box those Athearn cars almost always ran beautifully!  And the price - even for those now on Ebay - was and is very affordable.

ENJOY  !

 

Mobilman44

 

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Posted by wjstix on Monday, October 21, 2019 4:33 PM

As someone mentioned, AHM/Rivarossi heavyweight and streamline cars were all full-length, and all were made to operate on 18" radius curves. Shopping around online or at railroad flea markets will usually turn up quite a few, usually at quite a bit less than Walthers or other more recent cars. Some AHM/Rivarossi cars came with interiors.

(Just to clarify, above isn't referring to the later Rivarossi / Walthers 60' cars...although all four of them were based on actual 60' long prototype cars, so were not shortened versions of longer cars.)

Athearn heavyweight RPO, Baggage, and Coach cars are all full-length, since their prototypes were cars that were in the 63-72' range. Also, if used as a business car, the heavyweight observation car would be correct length also, since many of them were around 70' long.

Stix
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Posted by kasskaboose on Monday, October 21, 2019 8:18 PM

Why put yourself through that misery?  Even many freight cars can't handle that tight a curve. Is there any possible way of giving yourself a broader curve?  I'd recommend altering the layout.

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