I'm definately no expert in this hobby and I have a great deal to learn, but for all you newbies out there like me here's some advise; read, research and plan as much as you can before deciding on a layout or starting a layout. You will save a great deal of time and headaches later on as you can see below
Here's my question:
A few years ago I started building a 4' x 8' layout. I decided on a standard track plan from book, bought the track and turnouts, installed the roadbed and track and found I didn't like the plan. The layout was based on an 18" minimum radius. Now I'm abandoning this layout and designing a new layout based on my prototype (Montana Rail Link), room size and layout and specific industries/scenary I would like to model. What I finding is that my room size and layout is condusive to an 18 minimum radius. Also, I could reuse the turnouts and track I previously purchased. However, I've read that I need a 24" radius to run six axle diesels. Is it still possible to run the six axle diesels on the 18" radius?
Can't be certain of this, but I believe most six axle diesels will track on an 18" radius curve. The real question is will it look right and if you are to run any passenger cars on it will they track. They have a longer overhang and will have trouble coupling to a shorter overhang car. Bob T
Anyone who tells you that six axle diesels won't take an 18" radius curve is either a liar or doesn't know what he's talking about. I run plenty of big six axle jobs on my layout and every curve on it is 18" radius. I run an SD9, SD40, SD40-2's, E6's, E7's, PA's, even a pair of huge SDP40F's. I was even running an AC4400 for a while before I stripped it to rebuild one of the SDP40F's. Sometimes I run my biggest steamer, a 2-10-2.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
Most anything RTR these days is made to work on 18" radius curves, even if it looks silly doing so. However you will have probklems with long cars and locos if the couplers are mounted to the bodies - on sharp curves they will be offset so far to the outside that they can push trailing cars right off the track.
You mentioned building in a 4x8 space - you cannot use 24" radius cuves on a 4 foot wide layout. The 24" radius is measured fromt he center of the track, so the outside edge is more than 24" in radius, which menas more than 4' in diameter. You can use 22" radius curves on a 4' wide layout though. It's close to the edge though.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Some six axle diesels will not run well on 18" radius turns and some will. Best thing to do is refer to the manufacturers manual or data sheet. For instance if you look at the broadway limited site for the SD40-2 you will find that the minimum radius is 18"
http://www.broadway-limited.com/catalog/EMD_SD40_2_HO-1775-1.html
If you look at another of their Six axle engines, the AC6000 you'll find that they say the minimum radius is 22" http://www.broadway-limited.com/catalog/GE_AC6000_HO-1771-1.html
I'm sure they would like to sell the AC6000 to those with 18" turns but don't want an unhappy customer with major overhang and de-railments.
Springfield PA
I don't think you'll have trouble with 6 Axel locos as much as you'll have trouble with full length passenger cars. At least that's what I've found.
But all the guys who say you MUST have at least 24" radius for a realistic "look" apparently have a bigger basement than I do. it is HARD to achieve much in the way of an interesting layout when you decide your min. will be 24" That's why we wind up with 18"... you can do so much more with the layout that way. Sure 24" would look nicer. But it's a trade off, and I opted for the more interesting layout with tighter curves.
jxtrrxI opted for the more interesting layout with tighter curves.
So did I. I have a room that's 8' x 13'. The layout is roughly 8' by 10' and shares the room with a refrigerator, kitchen counter and sink. The heater and computer are under the layout.
I think I would go for at least a minimum of 22'' radius curve, that is what I plan on my layout, while I'm on the subject of my layout would 22'' radius curve work on a 4x8?
demonwolf224would 22'' radius curve work on a 4x8?
Barely! It's gonna be right at the edges.
If appearance is the only concern, it should be possible to use 24" radius curves on the front of the layout and 18" curves for the rear of the layout and still fit on a 4 x 8. The rear curves could be obscured by scenery and buildings, etc.
I've never tried this nor have I even heard of anyone doing it, but I might give it a go on my next layout.
The best recommendation I can offer is to test anything before you commit to it if possible.
- Harry
I'm sure JW didn't mean all of them would, but I think he's right that most of them will. And to most people they look fine and not at all stupid and toy like.
I had a layout with 15" curves (but no six axle engines) and everybody said it looked great.
My layout is intended for fun. I am not trying to duplicate anything in the real world. I also did not do enough research on things before starting and I have redone a couple spots.
I had a couple Atlas snap switches back to back in one spot that essentially made as "S" curve and that kept causing derailments. I have a GP-38 (4 axle) and a SD-50 (6 axle). The GP-38 normally worked fine, but the SD-50 had the issues. I ended up swapping out a few of my couplers with the "long shank" variety and that resolved the issue of the cars transiting that S-curve. Since then, I reconfigured that set of switches to eliminate the S-curve and now use No 4 turnouts there, so it is even better now.
On the regular 18" curves, my SD-50 did not have any troubles even before I swapped the couplers on a few box cars. It was only 2 places that I created "S-Curves" that had issues. In the 2nd location, I had enough room to put in about 10" of straight track to break the S-curve up a little.
I am only talking about the trains staying on track. I am not worried about how realistic they look. My layout is for my son and I to have some fun, not about being prototypical. Thomas the Tank Engine has the most miles on my layout so far.
HO equipment makers will go to any length to allow their product to run on 18" radius, since that is the "train set standard radius", and there are a lot of train set layouts out there. They can sell a lot more units if it can run on 18". In the rare case that the maker says his product needs more than 18" radius, it's best to believe the maker. Most equipment just doesn't say anything about minimum radius, in which case I assume it will work on 18" curves.
In the doubtful cases (whacking long locomotive with no minimum radius) try asking the hobby shop if you can return the unit for credit if it turns out to be too long for your layout.
The sharper the the curve, the more track can be squeezed onto the layout. Was it me, I'd work hard to get 22 or 24 inch minimum radius on the main line so I could run passenger cars and big locomotives. Model railroads are a tradoff. You have to decide what you care about most. You can have a fine layout with 18" curves at the cost of being unable to run long equipment. You can have an equally fine layout that has less track but runs the big stuff. It's a personal decision.
David Starr www.newsnorthwoods.blogspot.com
I've never had a problem running big power on 18" radius.
Then again, I model in N...
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Cat, welcome to the wonderful world of Lack Of Room. Plus there is more to lack of room than you think! I for now have a large room and do have some 24 inch turns. Now 24 + 24 is 48 inch's plus say 4 inch on each side for clearness. That is 56 inches or 4.6 feet. If it is against a wall it is all most impossible to do any modeling, plus if there is going to be a derailment it will be in that conner! Last night a Rio Grand coal train rammed the back of a Santa Fe passenger train! It was a nasty mess, guess where it was, yep at the deep end of the bench. So up I climbed onto the bench to retrieve the cars.
I have been in this hobby for only 3 years at first all I cared about was the train stayed on the track and 18 inch turns where fine with me. Goofy looking was fine if it tracked well. As stated big engines can take 18 inch turns (noted, some will not but if you look it up at the manufactures web site it will be stated what sizes turn it will take) even my PCM Big Boy 4-8-8-4 and Y6b 2-6-6-2 steam engines will make the tight 18 turn I have left.
But, as you do this more the picker you will become. I know I have and stopped running my long tank cars they are 9.25 inches long and do not look right on 22 inch turns.
Now that you think all is lost, take a look at this.
I am in the middle of planing my new layout and it will be a donut design. You have the best of booth worlds.
Ideal withe for modeling is under 36 inches or less, you can do that with this plain.
You can easily have 32 inch turns and run a A line, B Line and even a C line depending on how wide you make the bench. You can get a lot of rails laid in 24 to 36 inches of bench
But you are saying "but Ken, I don't want to craw under the bench and how do I open the door?"
With you being new this may seem like it will be hard to do, but you build a lift out section. There are many ways of doing this but will not be that hard and we will help.
Here is a fine example of a donut layout out, belongs to Selector a member of this great site.
Just food for thought.
Cuda Ken
I hate Rust
You can probably run most six axle diesels on 18" radius curves, but you are pushing the limits real hard. The simple fact is, the wider the radius, the better your trains will run. Trains that derail a lot are no fun.
If you can squeeze out a 5 X 8 or 6 X 8 in the available space, by all means do it. That way you can broaden out the curves to 24"-26". If you are using flex track, I advise you to include spiral easements leading into the curves and the curved portion of your turnouts
John Timm
I'd second going for 22" if you can. I have 22" on my test 4x8' layout, and have found that while passenger cars run without problem, even at that radius they overhang a lot. Enough to spoil the visual effect for me. My Atlas RS11's and GP9s also will not recouple on the curves, as they have normal length couple shanks.
Just food for thought. Ken has a pretty decent looking idea there.
I'm trying to model 1956, not live in it.
ScarpiaJust food for thought. Ken has a pretty decent looking idea there.
Wow. I have really only been doing this for a few months and have already gotten a compliment on an idea. :)
I am not sure if I had read about using the longer shank couplers anywhere or if it was an original idea. When I kept having derailments at that pair of switches I finally noticed how sharply the rear of the SD-50 and it's coupler shifted at the moment the car behind it would get derailed. That's when I thougth a longer shank on the front of the box car or one that had a truck mounted coupler would help it negotiate that turn.
The extra length couple doesn't stand out that much to me. The rest of my rolling stock did not have issues with the S-curves, only the car just behind the SD-50. So, I only really needed to modify the front end of what ever car would be behind the SD-50 (or the coupler on the engine), while the rest could retain the "normal" couplers.
That was the easy solution (compromise) for me until I redid that section of track.
ken_23434Wow. I have really only been doing this for a few months and have already gotten a compliment on an idea. :)
No offense, but I believe he was referring to CudaKen's use of the Heart of Georgia layout plans as a way to work wide curves into a small area.
davidmbedardWhat JW doesn't tell you is that he has had to modify alot of his locos to allow them to squeeze through tight corners.
Hello ??? What scale are we talking about here ?
Not knowing if you're in HO- or N-scale makes it impossible for any of us to properly answer your question. There is a HUGE difference between 18" curves in N-scale and 18" curves in HO.
It seems obvious that people have been talking about HO scale. I don't think there would be much debate about N scale or O scale 6 axle diesels handling 18 inch curves. But I could be wrong.
HarryHotspur It seems obvious that people have been talking about HO scale. I don't think there would be much debate about N scale or O scale 6 axle diesels handling 18 inch curves. But I could be wrong.
Harry,
My question was meant for the OP.
I realise everyone who answered PRESUMED he was modelling in HO; but the OP never says what scale he's modelling. For the sake of clarity, accuracy, and for those new-comers to the hobby who might not know any better, it is important to indicate what scale you're modelling when asking such questions.
I will venture that most six axle (HO-Scale) diesels will operate on 18" radius curves however your posting infers that you are moving from a 4X8 to a room sized layout so I would like to querry why, if you have the room, you would want to operate six axle diesels on that tight a curve. Keep in mind that those six axle diesels are long and on an 18" radius curve there is going to be a lurch factor with the trailing car behind; if you insist on operating six axle diesels and you have room for 24" radius curves by all means USE THEM! Remember, the tighter the curve the shorter the train you are going to be able to operate around it and I don't care how you cut it an SD40-2 looks a little ridiculous lugging around a ping-pong freight!
From the far, far reaches of the wild, wild west I am: rtpoteet
Even if you're not going to use it on the layout when you build it, I would get some Bachmann or Kato snap-together track-with-roadbed of different radiuses and see what will actually fit. I found on my L shaped switching layout that - using 16" wide shelves - I could comfortably fit in Kato 31" radius curves and could probably go a little higher. When I tried it with 12" shelves I could still get the 31" in if I did it just right, but 28" would be a little easier.
Anyway, you might be surprised what will actually fit in your space.
Here are some points to keep in mind when you are planning your new layout.
First, there is an absolute minimum radius for each piece of equipment when it is running solo. This is set by how the running gear interacts with the track geometry. For a diesel locomotive, will the trucks swivel enough to keep all the wheels on the rail without hitting something or causing a bind in the universal joints in the drive train? Will the truck design allow enough side play in the center axle to prevent the flanges from climbing the rail? You can test all these things quite easily, but do test to avoid being sorry. Keep in mind that some allowance should be made for less than perfect trackwork on the actual layout. In my experience nearly any six axle diesel will physically go around an 18" curve.
Then you need to take into account what happens when the locomotive is coupled to it's train as well as what cars are in the train. As the train enters a curve there is an offset at each pair of couplers. This offset can cause real problems and is more often the source of derailments than the fact that the locomotive or car won't "go around" the curve. Interestingly, the use of an easement, or section of track of gradually increasing curvature, really makes a difference here. In fact, an 18" radius eased curve will have less offset problems than will a 24" curve without easements. Easements are a space bargain and allow your equipment to perform optimally with the least space requirement. The length of the easement should be about the length of the longest piece of equipment you plan on operating. You can find more information about easements on the NMRA website. If you are mathematically inclined, you can use the proper formula for the railroad spiral to shape the easement, or you can use a cubic spiral. Most people lay them out by eye or by using a bent stick.
You can use easements with sectional track should you decide to reuse the track you have by purchasing some flex track and using that to make easements when entering and leaving curves.
Two other points to consider. First, avoid reverse or s curves like the plague. Any time two curves come together so as to reverse the curvature, you need to add a length of straight track at least as long as the longest piece of equipment you plan to run between the two curves. If you don't, you are really asking for trouble. Derailments are almost sure to result. S curves can sneak into a track plan in lots of places, such as in the first two turnouts of a classic ladder yard arrangements. First the track jogs to one side and then immediately to the other. Crossovers present the same problem. This is where you want to use number six turnouts as a minimum, or at least test the arrangement before you commit.
Finally, the tighter the curves you use, the shorter the trains you can run, especially if you have grades of any kind on your layout. Heavy trains on sharp curves and heavy grades will pull off the track toward the center of sharp curves. With good track work and broader curves you can run longer trains, if that is a requirement of your modeling preference.
If you do decide to use a larger radius (I would recommend it) you can still use your smaller radius track on secondary track such as industry or branch operations. Just don't install it where it would compromise your overall operating scheme, or where your big power or long equipment would have to negotiate those sharper curves.
Again, if in doubt, test, test, test! You'll be glad you did. Besides, the testing is fun and is definitely part of the hobby.
You don't mention how your room is designed, but you have room for a 4x8 right? Is it possible to build around the walls, so you could actually have a larger than 4x8 layout, and just operate the layout from inside? I did something similar to this when I was renting a duplex many years ago. I started out building with 2 4x8's, and was going to cut one into a 4x6 and a 4x2, then make a sort of "U" shaped layout. I didn't want to attach anything to the wall since I was renting, and I needed to be able to get all the way around the layout for access, or else I might have been tempted to just butt those two 4x8's together to make a 8x8 layout. But shortly after making my original "U" shaped layout, I came up with another idea. I bought some additional lumber, and closed the "U" up on the back side. Also while I was at it, I dropped the level of that wood down, kind of open grid style and made an area for a bridge. By doing this I had doubled my mainline run, made a large open area for a small yard and engine terminal, and had room for several industrial leads, a passing track, and if I'd ever gotten that far, a good bit of scenery. The layout was dismantled shortly after laying all the track, wiring it up and weathering it, but I did get a little run time before I had to tear it apart. Most of my curves on this layout were 22, 24 and 26 inch radius. There may have been a couple broader. One or two of the industrial leads had a smaller radius maybe 18 or 20, but nothing sharper. Also by building this layout as an "open pit" style layout, it forced me to run it from inside, and I could not see the entire mainline in one view, which enhanced the illusion that it actually came from one point and went to another. Also I was able to run longer trains without it look ridiculous (seeing the locomotives chasing their own caboose).
At one time I had considered building a layout on a 4x8 and running only 4 axle locos with 40 and 50 foot cars, but that is terribly limiting especially when you are modelling the 1970's and 1980's. There's just so much great equipment that you have to have for that time period. I don't have to worry about locomotives longer than SD40's and 45's, but a lot of the cars I want to run are pretty long, 70' Greenville woodchip hoppers, propane tank cars, 60' Auto parts cars, etc. I don't model steam, but I could imagine that long steam locos would not look very nice on 18 inch radius.
I started out [many years ago] with a Hornby OO train set that had the standard 18" radius curves. I soon added a second track that used 21" radius curve sections. My "standard" 4X8 soon became 5X10 feet so that the outside track wasn't so close to the edge of the layout. At age 10, I started modelling North American HO. Remembering I never really liked the appearance of my OO passenger cars on those 18", or even the 21" radius curves, I went to 24" minimum curves and started using flex track. Early in that decade, my family moved into a home where I was able to acquire a corner in the basement for my hobby. That is when I moved from the confines of a fixed rectangle 5'X10' layout to a sectional layout, similar to the one described and illustrated here in an earlier posting. My minimum radius became 30" and I've never looked back (umpteen layouts later). So, after all this discussion about 18 versus 24 inch radius curves, everyone is right one way or another in what they have stated. But don't fret too much about this topic today. A lot of you, if not most, will migrate to broader curves eventually I assure you. Have fun on the way.
Cheers, Marty on Vancouver Island
I think Marty is largely correct. I built my original layout with EZ-Track 22" curves, and was I ever glad I had the foresight to purchase the wider turnouts as well. But.................when the time came to seriously consider another layout, my first thought was, "I will not have a curve shallower than 24", and on the mainline nothing less than 28" so that longer passenger cars will look good." I have no regrets, and would love the space and layout where even yard curves were in the order of 28", with mains minimally at 32". Each new layout gets the "gotta do this" treatment of one kind or another, and for many of us who tend to be more rail fan-like, we want the broader mainline running.
Realistically, one has to do with what one has in the way of space, and I am sure there are many happy modellers who enjoy curves a whole lot tighter. I am sure they would like more, and would quickly dispense with a more limiting track plan if they had the chance. I was no different.
-Crandell
From my experience, a six axle power unit WILL run on an 18" radius curve, but watch the length of you cars. Any 86' cars will not take an 18" radius. Even some shorter cars have problems, such as 75', but I don't know about the 60 footers. I have two radii on my layout, a lower "rathole" track that has one section at 15", but the rest of my trracks on the upper level are 24". Even on the 24" I have a problem with 86' equipment-good thing I only bought one to experiment with