Doug, sorry my intention was lost in the wording. I meant my response about using my professional set of precision micrometers in model building as a bit toungue-in-cheek.
In reality, for model building, all the precision I will ever need can be achieved with this 6" Mitutoyo dial caliper, and nothing more.
-Kevin
[quote user=“Doughless”]
Lastspikemike
7j43k
Lastspikemike
Here’s a thought: if 2" track centres on tight radius curves can’t work why does Atlas make sectional track in 22" and 24" radii? I note the absence of 20" radius sectional curves but 15" and 18" are made.
Doesn’t Kato make sectional curves in 2" increments?
No.
Ed
You were supposed to look this up.
Kato HO curved sectional track is made in 2 3/8" radius increments, somewhat wider (by 3/16") than the Mark V NMRA gauge size.
If it works for Kato and for Atlas…?
Mike, as you are learning in this hobby, manufacturers make products that are incomplete. The product can do some things, but fails at other things. When judged with the standard that each product should do what the other guy’s does, they all fall short of being competent because they were designed to only do limited applications.
The Atlas sectional track was designed, mainly, to provide train set type of 4 x 8 layouts way back in the day. Their trackplan book ha
Because the topic isn’t really about precision. That’s the topic after hijack. The topic was answered by suggesting live iterations should be how spacing is determined. Whether or not OP even bothers to measure the precise distance beyond the eyeball distance the hands on iterations provided is rather inconsequential to the goal.
But I suppose measurements could provide a supporting role, so he doesn’t have to perform an iteration for each track…provided of course that the radius doesn’t change as he moves inward…DOH!
Maybe he could just add about an 1/8 of an inch to each center line as he moves inward, determined by your pink plastic ruler of course, and call it problem solved.
Yes, that is correct. I do recall that several of their plans look like a electric race car track with lanes rather than a model railroad. Perfectly concentric half circles fitting inside one another with the start of the curves way back on the straights. The only way those curves could be made is with sectional track…and I don’t know that all plans fit on a 4 x 8, so they could have used 24 and 22, but that’s just an assumption at this point.
Still, I would say that thoseplans would work with shorter cars, but thinking they could be run with longer cars that Atlas did not make might be disappointing to the planner.
[quote user=“7j43k”]
Doughless
Sorry, having implicit understanding of that math thing, I know that an answer is not mathematically precise once the inputs start with the word &q
You are starting to splutter. I suggest you take some time to calm down.
Ed
Good call Ed
A bit more of a chance to see things realistically.
My experience of spacing in yards or anything else you need a little spacing of your fingers to get through while you’re fumbling around with your fingers to separate trains.
Realistically HO provides more of that. N sale provides a bit more of a challenge!
I would like to say it’s good to see you here again Ed.
I was sad when you went away for a while[:|][;)]
TF
Thanks, TF.
The place changed for the better, so I came back.
I do think it is interesting to consider whether or not one needs “finger room”. And how much.
IF you can keep your trains on the track (and I know it CAN be done), and IF you don’t need the track to add or remove rolling stock, I can see having narrow track spacing–something I hadn’t given much thought to until this topic. My WAG on spacing here would be 1 3/4". You could pick up one more track after doing 7. Or is it 8?
On t’other hand. If you can’t and/or do (see above), then wider spacing is necessary. Measuring my finger with my trusty plastic pink ruler, I get about 5/8". So I guess, in this case, I’d be interested in a bit over 2", say 2 1/4".
All that’s leaving out the curves, of course. And the brass articulateds–those lovely creatures!!!
Ed
[(-D][(-D]
I know Ed,
I think it’s kind of like the spock thing
If you keep your two fingers on the top of the cars, uncoupling them with the barbecue skerew. You might be okay separating them with N as I do.
[(-D][(-D][(-D]
If you’re lucky as me without derailing them that is!
TF
Looking at an old Atlas track catalogue they do indeed start and end the broader curves about a 1/4 straight past the end of the tangent of the inner radius track, and add that same 1/4 track at the apex of the outer curve. Using 18" inner and 22" outer radius. But only for HO. For N track plans they run the two curves exactly in parallel, constant spacing.
Looking at Armstrong’s book he acknowledges that prototype track spacing scales down to 1 3/4". (13’). He suggests 2 1/8" is enough for 30" radius and progressively wider for tighter curves. He suggests 2" for tangent tracks claiming that it makes our overscale rails look more real. He assumes Code 100 rail I believe. The prototype 13’ doesn’t work on our model curves because our model curves aren’t to proper scale. We should use the minimum spacing we can get away with because it will always look too wide anyway.
He remarks that yard tracks should be wider spaced to allow for fingers. I say don’t plan on using your fingers.
I suggest all this is not necessary and that 2" works for most layouts on mainlines and for curved yard tracks. Then 1 3/4" (or so) works for tangent yard tracks.
You could use 1 1/2" for tangent yard tracks without cars hitting each other. But why would you. Woodland Scenics trackbed is 1 3/4" wide and that provides a useful minimum spacing.
The issue is that as you build multiple yard tracks on a curve, the radius of each ensuing track (as you move inward) gets tighter. So the spacing that works for one pair of tracks won’t work for the next adjacent track. (Remember the overhang discussion)
It seems that you have to continually increase the spacing as the radius gets tighter, eating up valuable benchwork. (My rough guess was a 1/8th inch increase in spacing for each track as you progress.)</
So my new layout will have not one, but two curves in the 25’ long six/seven track freight yard. But the smallest radius will be 36", making the largest one 48". 2" centers will be fine…
Sheldon
My yard will only be four tracks, and I believe the curve on the tightest track will be about 72 inches. It is just for looks.
The reason I want such a broad curve is more a concern for coupler alignment when operating than side clearance. The tracks will be spaced at 2.5"
-Kevin
Why does that not surprise me? Thanks for confirming that reality.
Rich
You need to get better at this or include a flag in these kinds of posts.
I don’t have a problem with freight cars derailing in yards.
I think this is highly unlikely since operation is so slow in these areas.
I do need to develop proficiency with the skewer.
-Kevin
To the OP:
While I am not a big fan of the overall design due to the reasons Dave H pointed out in the other thread, I do think that all the hand wringing and mis-information about track spacing is a bit over the top, but that is just me.
Testing: The spacing on the curves will likely be fine at 2” given how broad they are, but as others have stated, testing is key. I don’t like creating areas on the layout where certain cars and equipment can’t operate – especially in a yard - so I would test with the longest equipment with the most overhang. As others have stated if you are going to run big articulated steam or long passenger cars, thoroughly check clearances with this rolling stock in all directions.
Regarding fixed wheel base articulated steam: I have found that most of the modern plastic articulated steam has double swiveling driver sets (notable exception is the IM Cab Forward). Brass is another story – most of my brass articulateds use the same design as the prototype (fixed rear driver set) – increasing the radius necessary and the overhang….If you plan to run big brass, consider a little extra wiggle room in the curve spacing.
Regarding straight track spacing: Anything closer than 2” makes the yard look like a “parking lot of track” to my eye. Everyone has different aesthetics when it comes to how things look, but I ended up removing track from my yard to keep the rustic feel I was looking for. My thought processes in designing my yard are here:
http://thewilloughbyline.com/willoughby%20text/Willoughby%20Yard%20design.doc.pdf
Any design this complex will have to be laid out and thoroughly tested/vetted bef
Yes, the OP got $1,000,000.00 worth of nonsense in response to a simple two bit question.
-Kevin
As for anyone saying 1.5" track spacing Not if you have a wide vision caboose 
Thanks for the illustrative photo.
Maximum width for railroad cars in normal interchange is 10’ - 8" (taken from various Plate diagrams in use).
10’ - 8" = 128"
128" / 87.1 = 1.470"
1.5" - 1.470" = .030" (approximately 1/32")
A caboose is not in normal interchange service.
Ed