Bluestem Lady
Passenger
Posts:3
Send Message
 | | 08/23/2008 10:17 AM |
| Hello,
I am in the process of building my layout and have a question about laying track for a s-curve. I'm using two 10' dia. curve pieces and would like to know if you it is best to put a straight piece of track between the two pieces? I will also be laying two other s-curves using 12' dia. curves. If it is essential to have a straight piece, what would be the minimum length? At this point I just have two LGB starter trains, but hope to have a layout that will accommodate most trains people would bring to run. It would be a whole lot easier to make adjustments now than later! Thanks.
Cindy | | | |
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toddalin
Foreman
Posts:462
Send Message
| | 08/23/2008 11:25 AM |
| You can run a 10' diameter S-curve without problem for most equipment. I run my heavyweights though a back-to-back 8' diameter S-curve without problem (typically).
However, it would be better to put a straight section between. While any straight piece will help, a 3' piece of straight will render a very nice looking S-curve with fewer problems.
Do not use a turnout as your straight section unless you put at leat a 6" straight piece piece next to it along the turnout's diverging straight section. Otherwise, as the engine goes through the turn-out then curves away from the turnout, the "talgo" (truck-mounted coupler) will push the heavyweight's talgo toward the curved path resulting in a continual source of derailments!
After trying other fixes for this problem, I eventually had to go back and add the 6" piece of straight beyond the turnout and this totally cured it. | | | |
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Dr G
1st Class Member
Ft Myers Florida
Foreman
Posts:132
Send Message
| | 08/23/2008 3:20 PM |
| Cindy,
Todd is right, you can get away with an s curve if it is large enough, and your rolling stock is small enough (such as LGB starter equipment). A general rule of thumb in track planning is that the straigt section should be at a minimum the length of the longest piece of rolling stock you plan to use, this prevents the end of one car from moving laterally in the opposite direction from the next car. This is what causes derailments. One note on the switch in the straight section--if the diverging route curves the same direction as the curve at the point end of the turnout it will work well. A train comming into or out of the diverging route will just continue in the same curved direction, not reversing the direction of travel. I hope that makes sence.
Matt | |
Matt--FEC Nut
http://www.fecrs.com/ | |
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Bluestem Lady
Passenger
Posts:3
Send Message
| | 08/23/2008 10:12 PM |
| | Thank you Todd and Matt. I appreciate your answers and yes, they make perfect sense to me. I did not plan on using any turnouts in the s-curves, so I'm okay on that point. I'll make the adjustment and add more length in the straight piece of track. Sorry I hadn't replied sooner, my satellite connection has been non-existent most of today. Thanks again. Cindy | | | |
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Dr G
1st Class Member
Ft Myers Florida
Foreman
Posts:132
Send Message
| | 08/23/2008 10:18 PM |
| No satellite connection? Must be Fay's fault.
Have fun with the new layout, and don't forget to post pictures.
Matt | |
Matt--FEC Nut
http://www.fecrs.com/ | |
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Greg Elmassian
1st Class Member
Carlsbad (San Diego), CA
Engineer
Posts:1632
Send Message
| | 08/23/2008 10:31 PM |
| If you run body mounts, you really want the straight section to be the length of your 2 longest cars. Otherwise the cars can still be at a sharp angle when halfway through the S curve.
Regards, Greg | |
Be sure to visit my site, lots of technical tips and modifications, and you can search for topics and key words.
Click here for Greg's web site | |
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kormsen
in the middle of the westparaguayan semi desert
Conductor
Posts:592
Send Message
| | 08/24/2008 5:09 AM |
| with LGB starter trains even R1(four foot dia) s-curves work ... tecnically.
it just does not look very nice, when the coaches or wagons change direction so apruptly.
for one foot long rolling stock even half a foot of straight track between the curves help a lot.
with your planned 10' dia curves a one foot dia straight section between curves should be enough even for wagons of a foot and a half length. | |
 construction site - keep off! | |
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vsmith
1st Class Member
SoCal
Engineer
Posts:1182
Send Message
| | 08/24/2008 9:17 AM |
| Cindy, it depends, S curves are funny things
One thing you havent mentioned is which couplers are you planning on using long term and you mention "visiting trains", well theres the rub, what may work for your trains may derail something a friend brings. If your planning on sticking with the ubiquitous standard LGB hook and loops then you can run pretty much thru anything, but if a vistor has body mounted knuckle couplers they could bind and derail at the S section. On my layout I run very short stock w/ link and pin couplers on the smallest curves R1, and even then found that I needed a striaght transitional section (only 6") to prevent the cars binding and derailing on the two S curves I have.
I would still suggest planning ahead by at the least using a 12" straight section between the S curves sections, this at least minimizes the possibility of visiting trains suffering from a potential negative effects of the S curves.
Good luck and dont forget to post progress pics | |
 Kitbashing, welcome to the Dark Side | |
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Dave F
1st Class Member
Sandy, Utah
Conductor
Posts:773
Send Message
| | 08/24/2008 9:55 AM |
| | As stated above, much depends on the radii of the curves. I have two S curves on my layout. One is comprised of two 5' raidus (10' dia) pieces of track... no problems. things run just fine. The other is comprised of two 2.5' radius (5' dia), it's no end of headaches. I'll be fixing that issue in the next week or so (read that as getting rid of the S) . | |
Dave Fulghum,
CEO/Gandy dancer: Lone Peak & Western Railway.
Member, Utah Garden Railway Society.
www.lonepeakandwestern.bravehost.com | |
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Dean Whipple
1st Class Member
Corona, California
Foreman
Posts:152
Send Message
| | 08/24/2008 4:16 PM |
| | The general rule when using body mounted couplers is that you should have at least a straight section of track equal to the longest piece of rolling stock you plan on running between the 2 curves..... | |
Have fun with your trains
 | |
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Bluestem Lady
Passenger
Posts:3
Send Message
| | 08/24/2008 10:10 PM |
| Hello!
I really appreciate everyone taking time to answer my question. When I built my raised bed, I mis- marked on my layout where my hubby pulled the electric through. I was marking the layout for contouring and realized I was off five feet and I had tracks going right through where the line came up. That is what brought up the 10' diameter s-curve. I had already planned on the two s-curves using 12' dia. track. I redid my layout on paper and can allow 36" straight track on all the s-curves. I think I will proceed with that when I can finally start laying track. I have finished building my tunnel and now trying to build the mountain, stream and pond. I will post pictures when I finish that part, but it will be a couple of weeks since we are leaving on vacation next week.
Cindy
Bluestem and Doga Creek Railroad | | | |
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vsmith
1st Class Member
SoCal
Engineer
Posts:1182
Send Message
| | 08/25/2008 8:18 AM |
| | If you can fit a 36" straight inbetween the s curves, then you shouldn't have any problems at all, good luck with it. | |
Kitbashing, welcome to the Dark Side | |
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cmjdisanto
1st Class Member
Colonial Heights, Virginia
Foreman
Posts:206
Send Message
| | 08/27/2008 6:30 AM |
| In my opinion, sometimes, those pesky "S's" are un avoidable but also offer a sort of character to things. Maybe most look at them as Taboo, yet there are examples of them in real life as well. Like I said just unavoidable.
In our new layout we have a couple. Nothing that uses track smaller than 10 and usually/always a straight of some sort thrown in between.
The pics I provided show the example of our "S" curves. You'll see Martha's Narrow Gauge Euro stuff running on them without issue. I have more modern SD-45's and longer rolling stock in the form of modern tankers from USAT. I can honestly say that I have no issues getting a MU with consist through the layout. Yeah if I don't keep up on maintenance and just run trains with-out checking things I have issues but that can be said for any layout, with or without "S" curves.
So to echo what a couple have mentioned already......you should have no problems. | |
 MLS Member since September 2005 | |
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