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Spacing between turns

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  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Tuesday, September 9, 2014 7:40 AM

Randy, on my old layout with 24" and 22" radius curves, I ran nothing but shorty passenger cars and 40' to 50' freight cars.  But, on the advice of the guys at my LHS, I spaced the two mainline tracks 2.75" apart and bought a pair of 85' box cars to test the spacing, putting one 85' car on each track and rolling them past each other in opposite directions.

I was amazed at how close they came to touching each other even with 2.75" spacing.  They barely cleared each other.

Rich

Alton Junction

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Posted by rrinker on Tuesday, September 9, 2014 7:32 AM

richhotrain
 
rrinker

 You are luckier than I then, Rich - Walthers 85 foot cars managed to bang end of one car into the middle of the adjoining car with 32 and 30" radius and no extra width allowed.

 

 

 

No way!

 

Am I reading your reply correctly?

Where exactly are the 85' cars banging into one another?

On a 32" radius curve???

How far apart are those two tracks?  As I mentioned earlier, my tracks are spaced 2.75" apart on the curves.

Rich

 

 Oh, ok, you have increased the spacing on those curves as I had to. Without the extra spacing - they hit. Not enough to actually shove the other car off the tracks, or get them caught up, but they were hitting enough that I couldn't just leave it to chance. And it was only if the exact middle of a car on the outside met the very end of a car on the inside curve - two trains running exactly parallel to each other, or less than half a car length offset, were fine. Opened the spacing up and it was fine. I think I had drawn it out as 2.5" spacing, and I had to make it 2.75" like yours. Luckily I was second guessing myself and tested it before 'permanently' fastening the inner track. But then, none of the long cars were mine, my stuff is all 40' and shorter, a few early 50' cars thrown in. Even if I do end up running passenger trains, the prototype cars are all 70' or shorter.

                           --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by riogrande5761 on Tuesday, September 9, 2014 7:30 AM

rrinker

 You are luckier than I then, Rich - Walthers 85 foot cars managed to bang end of one car into the middle of the adjoining car with 32 and 30" radius and no extra width allowed.

 Which brings up point 2. Just because the inner radius is 30" and the outer radius is 32", or 22" and 24", doesn;t mean the center to center distance has to be 2". If you shift the start point of the inner curve a bit, the seperation on the curves opens up.

                        --Randy

I agree.  The track planning "Bible", John Armstrongs Track Planning for Realistic Operations, chapter on Standards and Minimums should be required reading.  Two inch centers is only recommended on straight sections of track, usually for yards.  On curves, even relativly broad 30+ inch curves, it is recommended to have greater than 2 inch centers.  I usually go with 2 1/4 inch centers as a minimum, even on broad curves.  More isn't a bad idea.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by riogrande5761 on Tuesday, September 9, 2014 7:04 AM

Howdy Ken,

I remember you from TrainBoard forums - another Rio Grande modeler?  Long time no see.  I still visit that forum now and then but it's pretty slow and since they consolidated the fallen flag sections, it seems even slower.

As for your curves - 2 inch spacing at such tight radius curves will probably result in long cars hitting each other.  Even at my minimum 32-inch curves I use track center spacing at 2 1/4-inches minimum. 

As others have noted, those long steamers will have a lot of over hang on such sharp curves.  I noticed you need to fit a car in with the layout.  I had a 2-car garage in Indiana I built a 16x19' L shaped layout- not sure what size your's is.  That layout was a hollow L and I was able to fit in 30-inch minimum radius curves.

Anyway, if you are stuck with max radius 26 inches, and need three tracks and 2 1/2 inch centers may be sufficient.  That will be 21, 23 1/2 and 26 radius - long equipement may be extreme on those curves but may function.  Heck, even on a 30 inch curve, my autoracks and 89' flat cars look a bit crazy.

Cheers, Jim

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by richhotrain on Tuesday, September 9, 2014 6:47 AM

rrinker

 You are luckier than I then, Rich - Walthers 85 foot cars managed to bang end of one car into the middle of the adjoining car with 32 and 30" radius and no extra width allowed.

 

No way!

Am I reading your reply correctly?

Where exactly are the 85' cars banging into one another?

On a 32" radius curve???

How far apart are those two tracks?  As I mentioned earlier, my tracks are spaced 2.75" apart on the curves.

Rich

Alton Junction

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Posted by rrinker on Tuesday, September 9, 2014 6:41 AM

 You are luckier than I then, Rich - Walthers 85 foot cars managed to bang end of one car into the middle of the adjoining car with 32 and 30" radius and no extra width allowed.

 Which brings up point 2. Just because the inner radius is 30" and the outer radius is 32", or 22" and 24", doesn;t mean the center to center distance has to be 2". If you shift the start point of the inner curve a bit, the seperation on the curves opens up.

                        --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by NeO6874 on Tuesday, September 9, 2014 5:05 AM

thing is, you don't need a "true" 23" (or 26 or 48, or whatever) radius -- just close enough that you're not putting any kinks in the works as you're entering, exiting, or halfway through the curve.

-Dan

Builder of Bowser steam! Railimages Site

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Posted by richhotrain on Tuesday, September 9, 2014 5:03 AM

Ken, I have a double mainline and I space my curves 2.75 inches apart.  And, I use the Ribbonrail Metal Track Alignment gauges to set the curves.

On my current layout the outer radius is 32" and the inner radius is 30".  At one point on the layout, I have a farm siding to the inside of the inner mainline, and the radius is 28".  I can run 85' passenger cars and freight cars with no problems.

On my old layout the outer radius was 24" and the inner radius was 22".   I had no problems there either with 2.75" spacing.

The 5" Ribbonrail gauges are available in 1 inch increments, but the 10" Ribbonrail gauges (my preference) are only available in even numbered 2 inch increments.  I would say that you could use 26" radius on the outer track, 24" radius on the middle track, and 22" radius on the inner track.  If in doubt, then use 23" radius on the middle track, and 20" radius on the inner track.  But, remember, the broader the curve, the better the looks and performance, so try to use 26", 24" and 22" if you feel you can.

Rich

Alton Junction

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Posted by cudaken on Monday, September 8, 2014 10:09 PM

 Thanks for all the answers! I kust checked the the current layout spacing is 3 inches.

 Lets say I use 26 inch as the outer radius an use 2.75 inch spacing. So would the next inner turn be 23.25? I hope to use I think it is called Ribbion Rail guid plates. Pretty sure they come only in whole numbers like 26, 25, 24 and so on. I know how to make a compass with string, but I do not tust my spiking skills to get a ture radius.

 Thanks Again, Ken

I hate Rust

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Posted by bogp40 on Monday, September 8, 2014 4:41 PM

Ken, 2 1/2" will work and still allow for clearances (found to work well on the club layout running all sorts of large equipment- pilot overhangs on articulated clearing long passenger and autoracks).  the 2 3/4" may place the outer radius beyond your allowed space. I would not allow the inner track to be less than the 22".   Even if you need to "bulge" out the area of that outermost track to use a slighty larger radius your equipment will thank you.

It would be a great idea as mentioned to 'tack' down some flex and double check w/ all your "stuff" If you can gain some space by allowing that 'bulgeout" then go w/ the 2 3/4.

Modeling B&O- Chessie  Bob K.  www.ssmrc.org

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Posted by rrinker on Monday, September 8, 2014 12:49 PM

 Definitely tack down some track and try it. Most of your cars should be ok, but those big locos have a lot of overhang, expecially on 24 and 22" radius curves.

 Can't stress enough - test. Test, and test again - all combos of cars and locos that might ever pass one another on those curves. On my old layout, I had 30" on the inside and 32: on the outside, adn originally laid it out to have 2 1/2" of clearance on the curves, 2" on the straights. Full length 80 and 85' passengers cars would sideswipe een on those curves with extra spacing, I had to make it bigger. Luckily I did test before fastening the second track and din;t have to rebuild anything.

  Test! NMRA datasheets and RPs are a good starting point, but test to be sure.

                --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by NeO6874 on Monday, September 8, 2014 7:16 AM

seconding 2.75" between track centers on the curves, and the shove testing.  In addition to that, I find it easiest to check car/locomotive overhang clearance by gently pushing the longest cars (or locomotives, if they're longer) past each other.  If they touch anywhere, then the tracks are too close (so go for say 3" center-center clearance then)

-Dan

Builder of Bowser steam! Railimages Site

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Posted by selector on Sunday, September 7, 2014 6:55 PM

Ken, for your curves and the engines you speak of, try two and three-quarter inches, but between track centers, not between the two closest rails.  Temporary track with a couple of nails only, try that with the engines and longest rolling stock, and then switch them around to the other track and try again.  Sometimes one test doesn't work.  In fact, I would strongly advocate running them in reverse as well, with engines shoving.  Things happen at the couplers when shoving that don't happen when the cars are being trailed through curves and turnouts.

Nice to see you posting again.

-Crandell

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Posted by cudaken on Sunday, September 7, 2014 7:42 AM

 Yep Micheal it is I. Planing to tear down the current layout and start over. Need to come up with a plan where I can get my 68 Road Runner back in the garage and still run the trains.

 I just checked this link.

 http://www.nmra.org/index-nmra-standards-and-recommended-practices

 Is this the right page? Made my eyes bleed.

 Ken

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Posted by Motley on Sunday, September 7, 2014 12:49 AM

Is that CudaKen? Holy cow man, long time no speak, haven't seen you around here in a long time.

So are you building a new layout? Or just laying some new track, re-configuring?

Michael


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Posted by Mark R. on Saturday, September 6, 2014 10:19 PM

You might want to try a test section of a 22 inch radius with some of your bigger engines pulling some cars - that's a pretty tight curve for some of todays big six axle power. You might be able to get the engine around ok, but also verify the coupler swing-out isn't so severe as to start pulling cars coupled to the engine off the track.

A lot of the big six axle engines are recommended to a minimum 24 inch radius.

Mark.

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Posted by cowman on Saturday, September 6, 2014 9:38 PM

If you have some flex track, put a few pieces together and lay out the three curves.  Use the NMRA standards for track spacing to give you clearance and see how it looks to you.  You may find you can use a larger radius or you may find that you don't have enough room to use the radii you are currently thinking of.

Good luck,

Richard

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Posted by Jacktal on Saturday, September 6, 2014 7:48 PM

Check with the NMRA website.They have very well documented charts for all types of rolling stock in any scale.

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Spacing between turns
Posted by cudaken on Saturday, September 6, 2014 7:06 PM

 Little back ground, I am running HO scale, code 100, DCC, bigger engines, mainly 6 wheel trucks and some larger steam like Y6b and a Big Boy. All so run a lot of grain hoppers and 50 foot box cars. Only hav one passenger train and they are the shorter cars and I do not for see adding any at the point.

 I am wanting three sets of track in the same turn. I want 26 in radius on the outside, then 24 inch and 22 inch on the inside. What kind on spacing between the rail ties will I need? Would I be better off going to a small raduis on the center and inside tracks?

 I have around 52 inchs to turn 90 degrees so I need to keep things tight.

 Thanks for the coming ideas.

 Ken

I hate Rust

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