Just wondering, if I want to run SD90's and auto decks, what is the smallest radius I can use and have reliability and great looks? I was thinking 36", but it is taking up so much room to turn around! (Keep in mind, I'm coming from N scale!) I thinking of a double deck around the wall layout, and trying to get different ideas to get to the second level. I don't really like the idea of a helix, I'd rather have a hill, or spiral tunnels to get there.
Radius question...
- Thread starter SD90
- Start date
Being around the room you'll be inside the curves so overhang shouldn't be two objectionable. If you're still N gauge 18" R should be OK. Double that for HO. You can also tack down some flex track at various radii to see what looks good. You can also use spiral curves so you equipment eases into the curves.
I'll be in HO scale for sure, I love the dimension sound adds to the hobby, and the added detail on HO scale equipment.
Selector
Well-Known Member
I posted an answer but it hasn't appeared. I'll try again. The looks vs. reliability issue only really has any operational validity as one gets closer to the minimum radius for the rolling stock. Above, say 4 inches higher than the min radius, it's just looks you are going for. I have found that visually the difference between a 30" curve and a 35" curve is minimal unless one stands close and observes from nearly overhead. As a curve is viewed nearer to chest height and further away, the difference between a 30" curve and 46" curve is not going to be noticed. The difference all but disappears as the viewer lowers his view to the height of the rolling stock...IOW directly from the same level at the side.
Walthers Heavyweight passenger cars from the WW II era are wonderful items of rolling stock, but they have stiff diaphragms and need 24" min radius...according to them. I found that the reliability, especially shoving, was almost zero with those cars when subjected to curves below 26" It was those diaphragms; they'd get bunched and run up against one another when the couplers were shoved back into their boxes. Up near 28", though, no problema. It's just that they didn't look great down at that low radius, so I made mine at 33" or better. While they looked great, the reliability in tracking had only gone from something like 99% at or near 28" to 99.9% above that radius, even all the way out to some of my 44" curves.
BTW, I believe the correct term is "auto racks".
Walthers Heavyweight passenger cars from the WW II era are wonderful items of rolling stock, but they have stiff diaphragms and need 24" min radius...according to them. I found that the reliability, especially shoving, was almost zero with those cars when subjected to curves below 26" It was those diaphragms; they'd get bunched and run up against one another when the couplers were shoved back into their boxes. Up near 28", though, no problema. It's just that they didn't look great down at that low radius, so I made mine at 33" or better. While they looked great, the reliability in tracking had only gone from something like 99% at or near 28" to 99.9% above that radius, even all the way out to some of my 44" curves.
BTW, I believe the correct term is "auto racks".
santafewillie
Same Ol' Buzzard
Crandell hit it right on. Unless you are looking from an overhead viewing angle, there's not a lot of difference between 30" and 36". If you can go 36" then that's great, but 30" - 32" will still be reliable. If you are adding a second deck, it will reduce the opportunity for an overhead viewing angle. I run 89' auto racks very reliably on 32". My biggest locos are Dash9-44CW's and SD40-2's, so I can't speak for SD90's.
Regarding helix's and second levels. I also do not like a helix but I may have to use one unless I run each level separately. You say that you are planning on rising 16" (44" - 60"); at a 2% grade, that will take 64 ft of linear track to accomplish. I like the idea of a hidden around the wall grade.
Willie
Regarding helix's and second levels. I also do not like a helix but I may have to use one unless I run each level separately. You say that you are planning on rising 16" (44" - 60"); at a 2% grade, that will take 64 ft of linear track to accomplish. I like the idea of a hidden around the wall grade.
Willie
D&J RailRoad
Professor of HO
I have minimum radius of 48" on the D&J Railroad.
The following video features SD90Macs on the empire.
https://www.youtube.com/watch?v=mh0Rs-qt6DY
The following video features SD90Macs on the empire.
https://www.youtube.com/watch?v=mh0Rs-qt6DY
Your layout empire is amazing! Thanks for the video! What did you take the video with?
D&J RailRoad
Professor of HO
That is a Sony HDR AS20 with Wi-Fi. The Wi-Fi feature allows me to see what the camera is seeing real time using an app on my cell phone. It give me control of the camera while its on the layout so I don't have to catch the train to start recording or stopping the recording. I do that on the touch screen of my phone.
I made the support box for it to ride on the train with some plastic stock and duct tape on the bottom to hold it to the flat car.
I made the support box for it to ride on the train with some plastic stock and duct tape on the bottom to hold it to the flat car.
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I think I've got my plan close to finalized, well as close to finalized as it gets, until I get some trains running!
It will be a point to point, double deck, a combination of around the wall, with one 27' peninsula that has a turn around blob at the end, and a 3 1/2 turn helix to connect the levels. The basement is 32x30, and I should get 350' of mainline. There will be a staging/working yard at each end with 6 sidings/towns/industries between them. Lower deck will be 24" deep 42" high, upper deck will be 14.5" deep and 60" high. I'm going to use 36" radius everywhere to keep everything simple. There should be at least 20 industries in total on the layout, I want to be able to have at least 6 operators during an op session.
It will be a point to point, double deck, a combination of around the wall, with one 27' peninsula that has a turn around blob at the end, and a 3 1/2 turn helix to connect the levels. The basement is 32x30, and I should get 350' of mainline. There will be a staging/working yard at each end with 6 sidings/towns/industries between them. Lower deck will be 24" deep 42" high, upper deck will be 14.5" deep and 60" high. I'm going to use 36" radius everywhere to keep everything simple. There should be at least 20 industries in total on the layout, I want to be able to have at least 6 operators during an op session.
goscrewyourselves
I'm the one
I don't have any SD90's but I do run Kato GE ES44AC's (N Scale) on 15" radius track work with autodecks and intermodal cars and they run fine. If using N Scale, I can't imagine you needing anything larger than maybe 18" or 20" radius. I also run Kato Amtrak Superliners without an issue as well.
If your talking about HO Scale, then I would guess that a 24" radius should be large enough.
When all's said and done though, use the largest radius you have room for.
In HO, 24" is a bit on the sharp side, especially if you are using the newer wide cab diesels and more modern rolling stock. It's the minimum recommended for some longer rolling stock as well and it's always wise to add some onto the minimum to get best performance.
My vote is with the 30 - 32 inch minimum radius curves and if space is really tight, absolute minimum 28 inches. Since SD90 lists a basement space of a relatively generous 32x30 feet, then I'd definitely recommend absolute minimum 32-inches. In addition, I would consider adding what John Armstrong coined as "scenic curves" - which are curves with very broad radius in a few locations where long cars will look nice on. In my small 10x18' layout room, I put in a scenic curve which is 54-inches on one side of the layout to break things up and add scenic interest.
My vote is with the 30 - 32 inch minimum radius curves and if space is really tight, absolute minimum 28 inches. Since SD90 lists a basement space of a relatively generous 32x30 feet, then I'd definitely recommend absolute minimum 32-inches. In addition, I would consider adding what John Armstrong coined as "scenic curves" - which are curves with very broad radius in a few locations where long cars will look nice on. In my small 10x18' layout room, I put in a scenic curve which is 54-inches on one side of the layout to break things up and add scenic interest.
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My latest track plan is a triple deck around the walls layout. I'm going to use the 7'x8' bump out in the basement as a place to put a helix that has one turn to climb to the next level, then an inner 2 turn helix to go back down from level 3 to 1. I think I've got it figured out how to do it! The minimum curve radius should be 42" this way. I never liked seeing trains do a 180 degree curve, especially on an outside curve. This plan will have fairly large radius curves, (90 degree inside curves), long sidings, double track upper level, continuous running and about 450' of mainline.
I didn't know it was against this forum's rules to post on more than one forum.
