Yup. "Gage". That's how it's spelled on my NMRA standards gage.
Anyway.
In the topic "Yard Track Spacing and Radius...", there has been some discussion on how wide the Standards Gage is.
Mike said first that his was 2 3/16" wide.
I said that I felt differently--that it was 2 1/16" wide. I just measured mine again (a MARK IVb) with a micrometer, and it is 2.063 wide. That's 2 1/16".
That's an eighth of an inch difference! For a GAGE!
Very curious, I thinks. I just checked the NMRA Recommended Practice for this dimension, and got 2 X 1.10", or 2.20". THIS is very close to the 2 3/16" reported by Mike and others.
And yet, I'm holding an official NMRA gage that says different.
At least online, it doesn't appear that NMRA keeps historical information about any dimension changes over time.
However, it so happens I have copies from Olden Times. The dimension under discussion was shown as 2 X 1", or 2", in a 1959 copy of Standard S-8.
So, over time, we have a Standard Dimension changing, without notation in the Standards. And/or the Recommended Practices.
To date, I've never used my various NMRA Standards Gages to check this dimension.
I'll note here that the current 2.2" matches the structure clearances noted in both Washington and Oregon railroad clearance standards from the fifties.
I post this topic to explain the differences reported in the other topic, and to reveal a certain fluidity in NMRA standards, generally undiscussed. I should dig out my OLD NMRA gage, buy a new one, and build a display of "NMRA Gages over the years".
Ed
I guess I'm kind of behind the times mine is a Mark II gage and it is 2" wide
mikeGTW Ed I guess I'm kind of behind the times mine is a Mark II gage and it is 2" wide
You're sitting on a FORTUNE, man. DON'T loose that!
No. Wait.
Can I have it for my collection?
When I was building one of my camera cars I made a CAD drawing to scale of my NMRA Gage using my digital caliper.It was very helpful with the design of the car.I was able to keep the camera movement within the needed clearance of my tunnel portals.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.
7j43k Yup. "Gage". That's how it's spelled on my NMRA standards gage. Anyway. In the topic "Yard Track Spacing and Radius...", there has been some discussion on how wide the Standards Gage is. Mike said first that his was 2 3/16" wide. I said that I felt differently--that it was 2 1/16" wide. I just measured mine again (a MARK IVb) with a micrometer, and it is 2.063 wide. That's 2 1/16". That's an eighth of an inch difference! For a GAGE! Very curious, I thinks. I just checked the NMRA Recommended Practice for this dimension, and got 2 X 1.10", or 2.20". THIS is very close to the 2 3/16" reported by Mike and others. And yet, I'm holding an official NMRA gage that says different. At least online, it doesn't appear that NMRA keeps historical information about any dimension changes over time. However, it so happens I have copies from Olden Times. The dimension under discussion was shown as 2 X 1", or 2", in a 1959 copy of Standard S-8. So, over time, we have a Standard Dimension changing, without notation in the Standards. And/or the Recommended Practices. To date, I've never used my various NMRA Standards Gages to check this dimension. I'll note here that the current 2.2" matches the structure clearances noted in both Washington and Oregon railroad clearance standards from the fifties. I post this topic to explain the differences reported in the other topic, and to reveal a certain fluidity in NMRA standards, generally undiscussed. I should dig out my OLD NMRA gage, buy a new one, and build a display of "NMRA Gages over the years". Ed
My old one is smaller, one I just bought from the NMRA last year is bigger.
Sheldon
7j43kYou're sitting on a FORTUNE, man. DON'T loose that! No. Wait. Can I have it for my collection? Ed
I wish $10 on evilbay
As equipment widths on the prototype has changed over the years, the NMRA has changed their standards gage as well. Some of the changes were done to reflect prototype changes, and some were done to reflect NMRA Standards changes. Equipment has gotten somewhat wider over the years. So has the gage.
So it isn't surprising that different variants of the gage have different dimensions (otherwise, why would there be different variants in the first place?).
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
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.
I don't know, but my guess is that as longer rolling stock became more widely used, and modelers developed a robust market for large steamers, it became necessary for 'recommended' clearances to reflect a wider safety margin irrespective of actual prototype dimensions and practices. A responsive governing body will listen to feedback and complaints about a protocol's or a device's deficiencies, and they'll make adjustments so that those things offer more utility to their constituency and membership.
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
Living the dream.
ATLANTIC CENTRALMy old one is smaller, one I just bought from the NMRA last year is bigger. Sheldon
That's what Hersheys and others do with candy bars. A Snickers was 5 cents. They made it bigger and charged 10 cents. Then they made the 10 cent bar smaller again, etc. Expect the next NMRA gage version to be smaller but cost the same, then a larger, more expensive version a few years after that, and so on.
Or, it's like fashion for (wearable) ties: wide ties are in, skinny ties are then in, then wide ties again, etc.
Paul
Modeling HO with a transition era UP bent
Here's the official directions:
https://www.nmra.org/sites/default/files/standards/sandrp/pdf/rp-2_2019.07.07_typo_correctiontrack_gages.pdf
I see there are some videos on the subject, too.
selector I don't know, but my guess is that as longer rolling stock became more widely used, and modelers developed a robust market for large steamers, it became necessary for 'recommended' clearances to reflect a wider safety margin irrespective of actual prototype dimensions and practices.
I don't know, but my guess is that as longer rolling stock became more widely used, and modelers developed a robust market for large steamers, it became necessary for 'recommended' clearances to reflect a wider safety margin irrespective of actual prototype dimensions and practices.
Longer rolling stock isn't involved here, as we're talking about a gage that's designed for straight track. It's the width, only.
Yup, there's a robust market for large steamers. But I doubt that their overall width is significantly greater than "medium" ones. That's a tougher one to nail down though. I just paged through a diagram book for SP&S steam, and the railroad didn't list extreme widths. They must have thought it unimportant.
7j43kHere's the official directions:
Thanks Ed.
It looks like what I thought was correct. The total width of the gage is not used for checking anything.
Am I missing something?
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.
7j43kYou 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 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.
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.
7j43k You use the "total width of the gage" to check for NMRA horizontal clearance on straight track.
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.
dimension A is the distance from track centerline to minimum clearance. 2 X A is for the full width.
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.
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
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 ).
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.
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.
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
That's all well and good Ed, but...
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.
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.
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
Alton Junction
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
That may be, but that isn't going to help with installing curved track.
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.
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......
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.
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?
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.
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.
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........
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.
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
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.
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.
Interesting how the NMRA gage has widened along with Americans. Is there a connection?
7j43k Interesting how the NMRA gage has widened along with Americans. Is there a connection? Ed
Fatter fingers?