Turn Radius

3Bird

3Bird

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11 Dec 2019
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I've been reading a lot about the radius of turns and big locos. We acquired our first big loco recently, and now I'm beginning to get a sense of what people have been talking about! As a complete noob, here is my noob question: As we are planning our garden railway, we envision the trains coming out the back of our barn. The challenge is that the room in the barn is long in the "wrong" direction, necessitating a somewhat sharp turn to move the trains from the indoor yard to the outdoor track. What is the sharpest turn you would recommend?
 
Greg Elmassian

Greg Elmassian

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that's easy, figure out the largest you can fit, and then figure out how to make it 1 foot more in RADIUS.

I'm actually serious, without knowing the locos and the longest rolling stock, no one can give you a number.

List the locos and the longest rolling stock that you WILL have, not just what you have now.

Greg
 
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Bill Barnwell

Bill Barnwell

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Make a reversing loop on the layout and back them in, or back them out of the barn, just a thought
 
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3Bird

3Bird

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that's easy, figure out the largest you can fit, and then figure out how to make it 1 foot more in RADIUS.

I'm actually serious, without knowing the locos and the longest rolling stock, no one can give you a number.

List the locos and the longest rolling stock that you WILL have, not just what you have now.

Greg
Sorry. I meant to say we were looking for best practice for the largest commonly available locos and rolling stock. We certainly don't want to be restricted down the road for something we could have easily addressed up front. At this point our biggest loco is our new-to-us Aristocraft GE U25B . We'll be adding a couple of USA Trains GP9s next probably.
 
3Bird

3Bird

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Make a reversing loop on the layout and back them in, or back them out of the barn, just a thought
Our problem is that the long wall of the room inside the barn is perpendicular to the track exiting the barn. So we need trains to come in and make a turn into the yard that takes advantage of the long wall. Does that make sense?
 
F

Fred Mills

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Draw a plot plan of your situation, giving a few diamentions. This might help us to understand the idea.
You live in the USofA…so where abouts in that fine land, and how should we address you, as a human being...?
Are there any LS railway train clubs near-by, where members could advise you ?
 
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Greg Elmassian

Greg Elmassian

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OK, when you supply information, we can help.

if you never buy a bigger loco, 8' diameter.

10' diameter if you get scale length passenger cars

And you need to leave extra clearance for how far past the rails the loco body will swing.

I would suggest you figure out a way to come straight in the long side, you will eat up a large amount of space in your barn just with the curve, it might be that the useable track on the long side, reduced by the curve is about the same as coming in the shorter side, straight in.

a picture with dimensions as Fred has suggested would help a lot.

Greg
 
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JimmyB

JimmyB

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One of the best pieces of advice from this forum that I received is use the largest radius track you can fit, if you limit the curves on your railway, then you will limit what can be run. It’s called future proofing.
 
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dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
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Our problem is that the long wall of the room inside the barn is perpendicular to the track exiting the barn. So we need trains to come in and make a turn into the yard that takes advantage of the long wall. Does that make sense?
Looking at your issue the only option I can think of is to have the split of tracks (assuming that you want multiple sidings in the Barn) before the turn this would give you the sidings and length you feel that you need. But this will exacerbate your issues with curve diameter as pointed out by Greg and others you would need 8ft and getting larger for the other turns. All very much depends on the size if your barn, a sketch or picture would help.
 
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voodoopenguin

voodoopenguin

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Will the exit from the barn be a custom made hole? If so, is it possible to start the curve outside the barn which will mean you make the hole wider to accommodate the angled track?

Paul
 
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maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
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Will the exit from the barn be a custom made hole? If so, is it possible to start the curve outside the barn which will mean you make the hole wider to accommodate the angled track? Paul
Quite right, nothing stopping you starting the curve before you get to the exit and having the tracks "slewed" as you pass through. You just need to allow a little more on the loading gauge width there. That is essentially what I did when I set up my indoor - outdoor transition but for different reasons. You might try playing around with a transitional curve to get things to fit too. I've done that where there was no alternative, not ideal but it can be a way around.

However, I go with what others say, go as large as you can from the outset. But if you want a "for instance" (dangerous precedent being set here :) ) my Accucraft K-28, big wheelbase, with a rake of their J&S cars, long cars with a bit of an overhang and body mounted couplers, can just about make a 4' radius curve - but it's right on the limit. But it still needs the R5/6' switches minimum.

It's not just a loco's wheelbase one needs to consider when setting a curve radius standard for your line but how your couplings are mounted and the amount the overhangs of cars swing out and push the couplings' movements to their limit. There is a reason that LGB and suchlike have mostly truck mounted couplers , not body, on bogied stock and locos' tenders ;) Max
 
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SophieB

SophieB

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Are you just using your barn as storage? If that's the case then you only need to worry about the minimum radius your trains can physically run through, not whether or not they "look right". Everything my husband and I have can negotiate an 8' diameter curve but some of it looks a bit wonky there and we only actually run it on our 16' track.
 
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3Bird

3Bird

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11 Dec 2019
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Maine, USA
Draw a plot plan of your situation, giving a few diamentions. This might help us to understand the idea.
You live in the USofA…so where abouts in that fine land, and how should we address you, as a human being...?
Are there any LS railway train clubs near-by, where members could advise you ?
I will! I'm trying to take advantage of some freakishly warm weather here in Maine to get some outdoor tasks done, but I'll get back to this tonight!
 
3Bird

3Bird

Registered
11 Dec 2019
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49
Maine, USA
OK, when you supply information, we can help.

if you never buy a bigger loco, 8' diameter.

10' diameter if you get scale length passenger cars

And you need to leave extra clearance for how far past the rails the loco body will swing.

I would suggest you figure out a way to come straight in the long side, you will eat up a large amount of space in your barn just with the curve, it might be that the useable track on the long side, reduced by the curve is about the same as coming in the shorter side, straight in.

a picture with dimensions as Fred has suggested would help a lot.

Greg
Thanks. I'm building the room, so I have some flexibility. I'll get some sketches up later, as I need to get outside and take advantage of these non freezing temps to get some work done.
 
3Bird

3Bird

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11 Dec 2019
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Maine, USA
Will the exit from the barn be a custom made hole? If so, is it possible to start the curve outside the barn which will mean you make the hole wider to accommodate the angled track?

Paul
That's an interesting idea! Yes, it is a custom door for the trains.
 
3Bird

3Bird

Registered
11 Dec 2019
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49
Maine, USA
Quite right, nothing stopping you starting the curve before you get to the exit and having the tracks "slewed" as you pass through. You just need to allow a little more on the loading gauge width there. That is essentially what I did when I set up my indoor - outdoor transition but for different reasons. You might try playing around with a transitional curve to get things to fit too. I've done that where there was no alternative, not ideal but it can be a way around.

However, I go with what others say, go as large as you can from the outset. But if you want a "for instance" (dangerous precedent being set here :) ) my Accucraft K-28, big wheelbase, with a rake of their J&S cars, long cars with a bit of an overhang and body mounted couplers, can just about make a 4' radius curve - but it's right on the limit. But it still needs the R5/6' switches minimum.

It's not just a loco's wheelbase one needs to consider when setting a curve radius standard for your line but how your couplings are mounted and the amount the overhangs of cars swing out and push the couplings' movements to their limit. There is a reason that LGB and suchlike have mostly truck mounted couplers , not body, on bogied stock and locos' tenders ;) Max
A lot of great info there. Thanks!
 
3Bird

3Bird

Registered
11 Dec 2019
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Maine, USA
Are you just using your barn as storage? If that's the case then you only need to worry about the minimum radius your trains can physically run through, not whether or not they "look right". Everything my husband and I have can negotiate an 8' diameter curve but some of it looks a bit wonky there and we only actually run it on our 16' track.
Thanks. The barn is primarily storage, but we'd like to have it be interesting and functional.
 
3Bird

3Bird

Registered
11 Dec 2019
69
3
49
Maine, USA
Draw a plot plan of your situation, giving a few diamentions. This might help us to understand the idea.
You live in the USofA…so where abouts in that fine land, and how should we address you, as a human being...?
Are there any LS railway train clubs near-by, where members could advise you ?
I'm taking advantage of some freakishly warm water to get some outdoor tasks done, but I'll try to get back tonight with a sketch. Oh, and we're in Maine (midcoast if you are familiar with Maine). I believe there is a club down in southern Maine.
 
korm kormsen

korm kormsen

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if the axles of the first and the last driver of a loco are not more than 5 1/2" apart, you can use R1 (LGB counting) that does not look nice, but for a staging area it would be ok.
same goes for coaches and freightcars under 24".

about longer locos and roling stock i have no information.
 
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