ATLANTIC CENTRALFirst, as orginally suggested by several/many so far, simple testing is always a good idea.
Absolutely. I believe strongly in testing before building anything permanent.
-Kevin
Living the dream.
I'm not going to argue, dispute, suggest or disagree with anything or anybody here.
I'm just going to make three simple statements.
First, as orginally suggested by several/many so far, simple testing is always a good idea.
Second, the NMRA has always been very "generous", and thereby conservative in its recomendations for curved track centers. Yet they have always "danced around" the tangent track center issue with scale feet rather than a real life dimension.
Their 14 scale foot recommendation is 1.931"..........
Third, I have used 2" track centers for tangent track since I was introduced to this hobby. As explained earlier it is the defacto industry standard for bridges, crossovers, etc.
I have used 2" track centers on curves, maybe sometimes stretching them out to 2-1/8", ever since I started using 36" radius as my minimum.
I have tested this with locos as big as the Bachmann EM-1 passing 80' Bachmann and Branchline passenger cars with no issues and room to spare.
So for appearance, space and better track civil engineering (yes, I engineer the track location before I install it), I will stay with 2" (or cheat them up just that 1/8") track centers. The NMRA recommended 2-15/32" is just ugly and unnecessary at 36" radius and above.
DISCLAIMER - I don't own a UP BigBoy, brass plastic or diecast, and I have no plans to ever own one. So I think the EM-1 qualifies as a large enough test loco.
Sheldon
Lastspikemike 7j43k Hey, Mike. Still waiting for your working example of 1.5" track spacing. Ed We had to take it apart to move the layout. Sorry, a never to be repeated situation. Wasn't my idea in the first place. Some people just don't know what's impossible and do it anyway. Like the Wright brothers.....
7j43k Hey, Mike. Still waiting for your working example of 1.5" track spacing. Ed
Hey, Mike.
Still waiting for your working example of 1.5" track spacing.
Ed
We had to take it apart to move the layout. Sorry, a never to be repeated situation. Wasn't my idea in the first place. Some people just don't know what's impossible and do it anyway. Like the Wright brothers.....
Strange. After proving the wisdom of this concept at the old layout, it was never repeated. Quite a surprise, I must say.
And so the Wright Brothers went home to their bicycle business.
SeeYou190 Mine is a Mark IV. Does anyone have a link to the instructions for how to use it? I think that would be very helpful. I have a feeling some contributors are are not using the gage the same as others, or maybe we are talking about something the gage is not even intended to be used for. I do not use my gage to check clearances. I use an 86 foot high cube boxcar for that. I space my tracks wider than NMRA recommendations for finger clearance. -Kevin
Mine is a Mark IV.
Does anyone have a link to the instructions for how to use it? I think that would be very helpful. I have a feeling some contributors are are not using the gage the same as others, or maybe we are talking about something the gage is not even intended to be used for.
I do not use my gage to check clearances. I use an 86 foot high cube boxcar for that. I space my tracks wider than NMRA recommendations for finger clearance.
Curves should be wider than 2" on center. Period.
Rich
Alton Junction
Lastspikemike 7j43k RP-2 says in regard to using the Gage as a clearance tool: "This check is valid only for tangent track and curves of very wide radius." RP-7.3 seems to imply that radius would be great than 13', since it shows an increase over the tangent dimension. Ed That's an interesting point for anyone successfully using 2" track centres for all curves.
7j43k RP-2 says in regard to using the Gage as a clearance tool: "This check is valid only for tangent track and curves of very wide radius." RP-7.3 seems to imply that radius would be great than 13', since it shows an increase over the tangent dimension. Ed
RP-2 says in regard to using the Gage as a clearance tool:
"This check is valid only for tangent track and curves of very wide radius."
RP-7.3 seems to imply that radius would be great than 13', since it shows an increase over the tangent dimension.
That's an interesting point for anyone successfully using 2" track centres for all curves.
I'd say it's an even MORE interesting point for anyone UN-succesfullly using 2" track centers for ALL curves.
ATLANTIC CENTRALYes, there is cconsiderable information on this in the NMRA Recommended Practices.
My NMRA data sheet set dates from the 1970s.
Since I model the 1950s, I think that I will be OK with the information that I have.
Overmod Fatter freight cars.
Fatter freight cars.
If you're thinking taller, I'm sure you're correct.
If you're thinking wider, I don't see it. Perhaps you would inform us.
SeeYou190 I do not use my gage to check clearances. I use an 86 foot high cube boxcar for that. I space my tracks wider than NMRA recommendations for finger clearance.
SeeYou190 I think I will stick to using the big Athearn High Cube for clearance checks. It is larger than any other train car I will ever run, so if it is good, all is good.
I think I will stick to using the big Athearn High Cube for clearance checks. It is larger than any other train car I will ever run, so if it is good, all is good.
gregc doesn't the width clearance need to increase as cars get longer on smaller radius curves ?
doesn't the width clearance need to increase as cars get longer on smaller radius curves ?
Yes, there is cconsiderable information on this in the NMRA Recommended Practices. Again, this is not the function of the gage/gauge.
greg - Philadelphia & Reading / Reading
7j43k Interesting how the NMRA gage has widened along with Americans. Is there a connection? Ed
Interesting how the NMRA gage has widened along with Americans. Is there a connection?
Fatter fingers?
Put that MARK (none) gage in a Secure Location. And tell no one.
I joined the NMRA in about 1962, so I assume the gage they sent me was also a MARK (none). I probably ought to specifically name who gets it in my will, so as to avoid nasty knife fights later (we're a rowdy bunch).
Thanks for measuring The Original, and mentioning the width.
7j43k SeeYou190 It looks like what I thought was correct. The total width of the gage is not used for checking anything. Am I missing something? You use the "total width of the gage" to check for NMRA horizontal clearance on straight track. Considering that the width of the MARK V gage mirrors almost exactly the required clearances in Washington and Oregon (and likely elsewhere), it's not totally useless. It's also good for having a place to put all the notches and bumps. That funny little notch on the left is to check platforms. Oh. It turns out the MARK II Standards Gage was issued in the early sixties, to reflect the new RP25 flanges. I doubt the MARK I was marked with a "I". I MIGHT have one somewhere. I MIGHT have lotsa things. Somewhere. Pretty sure I've got a MARK II. Ed
SeeYou190 It looks like what I thought was correct. The total width of the gage is not used for checking anything. Am I missing something?
It looks like what I thought was correct. The total width of the gage is not used for checking anything.
Am I missing something?
You use the "total width of the gage" to check for NMRA horizontal clearance on straight track.
Considering that the width of the MARK V gage mirrors almost exactly the required clearances in Washington and Oregon (and likely elsewhere), it's not totally useless. It's also good for having a place to put all the notches and bumps.
That funny little notch on the left is to check platforms.
Oh. It turns out the MARK II Standards Gage was issued in the early sixties, to reflect the new RP25 flanges. I doubt the MARK I was marked with a "I". I MIGHT have one somewhere. I MIGHT have lotsa things. Somewhere.
Pretty sure I've got a MARK II.
I am holding a first issue (??) and a Mark II GAGE. I'm going to be rich. The NMRA STANDARDS GAGE HO SCALE prior to the ''MARK II'' has no ''MARK I'' or any ''I'' on it.
The ''first issue'' NMRA standard gage is of a softer metal then the MARK II. Both measure 1.996-5'' across there width.
I added two ¼” inserts to these Pike Stuff Tunnel Portals so my articulated locomotives would clear the portals. One ¼” insert on each side of the center bolder to increase the width ½”. Back in 1988 I didn’t have a NMRA gage, when I finally got one it worked out perfect in my tunnel portals.
The inside curve is 34” center the outside is 36¼” center code 83 Atlas Flex. My straight mainline double track has standard 2” center to center spacing. I don’t remember where I got the info to go with 2¼” spacing on my curves but it has worked great for 33 years.I began with 85’ passenger cars and they didn’t have any problems. I switched to Athearn 72’ passenger cars because the 85’ cars looked out of place on my small layout.Mel Modeling the early to mid 1950s SP in HO scale since 1951My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California Aging is not for wimps.
Lastspikemike So you can't fit a hobby industry standard double tunnel entrance over a curved double main line?
So you can't fit a hobby industry standard double tunnel entrance over a curved double main line?
That is not a yes or no question. Some manufacturers do/did allow extra width on double track tunnel portals, some not so much. Different companies have been making different stuff for 70-80 years now, maybe longer. Ther are no tunnel portal design police......
But even if some extra width is given for outboard clearance on curves, the total width is likely to be based on center to center distances only slightly above 2" to allow a proper appearence on straight track at 2" centers.
Again, at 36" radius and above, not really an issue, 2" works.
For me personally, 36" radius is my bare minimum mainline radius, and actually my bare minimum for anything other than urban industrial sidings, so clearances beyond 2" are not an issue for me.
I understand not everyone has that kind of space, or wants to use their space that way. That's fine.
But long before me lots of smart people in this hobby figured out that these standards made sense as a good compromise between prototype practice, good model operation, and realistic model appearence.
Track centers 2" - more on curves if radius is less than 36"
Easements - 1/2" offset, 12" to 18" total length
Curves - 36" radius allows operation of virtually all equipment and looks realistic. Allows operation of working diaphragms comfortably.
Turnouts - #6 or greater for all mainline/yard trackage, #4 for industrial trackage.
Superelevation - optional - 1/32" to 1/16" max.
There is a reason way modular groups use 48" radius.............
A great many of the curves on my new layout will be in the low to mid 40's.......
I'm way happy to build less layout in more space and have broad vistas and reasonably realistic curves. Still selectively compressed........
7j43kThe gage isn't for installing track.
I use Micro-Engineering three point gauges as I install track.
The NMRA "gage" is used for checking and troubleshooting.
richhotrain 7j43k You use the "total width of the gage" to check for NMRA horizontal clearance on straight track. That may be, but that isn't going to help with installing curved track. If the total width of the gauge is used to check for NMRA horizontal clearance on straight track, is that meant to measure the minimum clearance?
7j43k You use the "total width of the gage" to check for NMRA horizontal clearance on straight track.
That may be, but that isn't going to help with installing curved track.
If the total width of the gauge is used to check for NMRA horizontal clearance on straight track, is that meant to measure the minimum clearance?
The gage isn't for installing track.
It's for checking clearances for builings, bridges, scenery, etc. on straight track.
If you want one for a particular radius of curved track, you can build your own out of styrene using the information in RP-7. Since you don't have to include all the notches and bumps of the regular gage, it's not difficult.
ATLANTIC CENTRAL Atlas Custom Line #4, #6, and #8 turnouts all build crossovers with 2" track centers and yard leads with 2" track centers without any cutting or spacer tracks.
Atlas Custom Line #4, #6, and #8 turnouts all build crossovers with 2" track centers and yard leads with 2" track centers without any cutting or spacer tracks.
richhotrain 7j43k You use the "total width of the gage" to check for NMRA horizontal clearance on straight track. That may be, but that isn't going to help with installing curved track. If the total width of the gauge is used to check for NMRA horizontal clearance on straight track, is that meant to measure the minimum clearance? I prefer to set straight track 2" on center, especially on the mainlines because that corresponds to the distance requirement to match up Peco #6 turnouts on crossovers and crossings. I would need to check that distance requirement on Atlas turnouts. Rich
If the total width of the gauge is used to check for NMRA horizontal clearance on straight track, is that meant to measure the minimum clearance? I prefer to set straight track 2" on center, especially on the mainlines because that corresponds to the distance requirement to match up Peco #6 turnouts on crossovers and crossings. I would need to check that distance requirement on Atlas turnouts.
The 12.5 degree crossing is the same angle as the frog of the #4 turnout (which is really a #4.5), the 25 degree crossing is therefor twice the #4 frog angle and the 19 degree crossing is exactly twice the angle of the #6 frog.
The wye frog is twice the #6 frog or 19 degrees for the construction of double track wye diverging routes using the 19 degree crossing, each route having the same diverging "curve/angle" as the #6.
Atlas once published a track plan book that had all these kinds of standard arrangements diagramed, and maybe some of their publications still do, I just don't have any of the newer track plan books from them.
Most of the double track bridges in the industry are designed for 2" track centers, and have been for many decades, or more like over a half century.
Walthers, Shinohara, Tru-Scale back in the day, Bachmann and others all use or used 2" track centers for premade crossovers and double crossovers.
The vast majority of commercial double track tunnel portals throughout the decades have been designed for 2" track centers.
And my Bachmann EM-1 passes my few 80' passenger cars on 36"/38" radius double track curves with no clearance issues. From there my concentric curves only get bigger......
Pruitt 7j43k Mark, Equipment has NOT gotten wider over the years. In 1955, Plate B (the only one shown in my ORER) width was 10'-8". In 2015, all Plates showed a maximum width of 10'-8". I expect the widening of the gage was done for good and thoughtful reasons. But it wasn't done because the prototype got wider. Ed That's all well and good Ed, but... Did you check 1925? 1880? or are you saying that modern equipment is essentially the same width as 1880's equipment? Or 1930's equipment? (Railroading did exist before 1955, you know ).
7j43k Mark, Equipment has NOT gotten wider over the years. In 1955, Plate B (the only one shown in my ORER) width was 10'-8". In 2015, all Plates showed a maximum width of 10'-8". I expect the widening of the gage was done for good and thoughtful reasons. But it wasn't done because the prototype got wider. Ed
Equipment has NOT gotten wider over the years.
In 1955, Plate B (the only one shown in my ORER) width was 10'-8".
In 2015, all Plates showed a maximum width of 10'-8".
I expect the widening of the gage was done for good and thoughtful reasons. But it wasn't done because the prototype got wider.
That's all well and good Ed, but...
Did you check 1925? 1880? or are you saying that modern equipment is essentially the same width as 1880's equipment? Or 1930's equipment? (Railroading did exist before 1955, you know ).
I do know that railroading existed before 1955, Mark. But the NMRA gage was established in the fifties, so I thought it appropriate to start with that era.
My point was that the width standards between when the NMRA Standards Gage was established and today have not changed. And so that is not the reason for widening the gage. If you disagree, I look forward to your thoughts.
Prior to the 1950's, I believe equipment was generally a bit smaller (when boxcars were commonly single-sheathed wood siding on steel frames, or when most cars used truss rods, as examples). Either that or I have a bunch of badly undersized early 20th-Century-to-WWII rolling stock.
As I said, my reference is for the fifties. Earlier equipment was smaller. If you want to visit and work in previous eras, I'll note that the NMRA has an "Old time/Narrow Gaugee Era" standard that should be appropriate.
I appreciate your pointing out oversize standards.
I was talking about AAR Plates. They are the standard for interchange. They may, of course, be ignored by railroads, if they so please.
7j43kMark, Equipment has NOT gotten wider over the years. In 1955, Plate B (the only one shown in my ORER) width was 10'-8". In 2015, all Plates showed a maximum width of 10'-8". I expect the widening of the gage was done for good and thoughtful reasons. But it wasn't done because the prototype got wider. Ed
But I take your point about the more recent decades.
For the modern era, here's how a few of the different prototype railroads define over-width loads.
BNSF:
Machinery & Oversized Shipments | BNSF
Note that a load isn't considered oversized (in width) until the width is more than 11 feet. That's 4" OVER your 10'-8" quote.
UP (same as BNSF): UP: Seven Steps to Shipping Dimensional Loads
Interestingly, CSX over-width size is your stated 10'-8". Dimensional/Clearance - CSX.com.
NS goes even farther. Any dimensional load over 10'-6" requires special attention.
In any case, the standards gage has changed over the years, for usability improvements, changing NMRA track standards, and prototype equipment clearance requirements.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
Thanks Ed. I think I got it now. I appreciate the help and clarifications.
However, I think I will stick to using the big Athearn High Cube for clearance checks. It is larger than any other train car I will ever run, so if it is good, all is good.
SeeYou190 7j43k You use the "total width of the gage" to check for NMRA horizontal clearance on straight track. I missed that part. It must be in one of the detailed RP pages.
I missed that part. It must be in one of the detailed RP pages.
I'm not sure it is. But that is definitely what it is supposed to be.
I wonder why they did not put a lettered measurement on the full width and reference the specific RP like they did for other dimensions. Maybe that is what dimension "A" is, just doubled for both tracks.
I wonder why they did not put a lettered measurement on the full width and reference the specific RP like they did for other dimensions.
Maybe that is what dimension "A" is, just doubled for both tracks.
dimension A is the distance from track centerline to minimum clearance. 2 X A is for the full width.
7j43kYou use the "total width of the gage" to check for NMRA horizontal clearance on straight track.