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Width of an NMRA Standards Gage

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  • Member since
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Posted by 7j43k on Sunday, August 8, 2021 10:22 PM

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?

 

Ed

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Posted by PC101 on Monday, August 9, 2021 12:09 AM

7j43k

 

Interesting how the NMRA gage has widened along with Americans.  Is there a connection?

 

Ed

 

Fatter fingers?

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Posted by Overmod on Monday, August 9, 2021 1:21 AM

Fatter freight cars.

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Posted by gregc on Monday, August 9, 2021 6:05 AM

doesn't the width clearance need to increase as cars get longer on smaller radius curves ?

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Monday, August 9, 2021 6:16 AM

gregc

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.

Sheldon

    

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Posted by richhotrain on Monday, August 9, 2021 6:25 AM

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 take the same approach. I have a pair of 85' boxcars that I use to test clearance on curves. Foolproof!

Rich

Alton Junction

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Posted by Lastspikemike on Monday, August 9, 2021 8:15 AM

SeeYou190

 

 
7j43k
Here'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?

-Kevin

 

Dimension A is the clearance to obstacles Dimension A in the RP 7.3 charts. Should work equally well for curves or straights in terms of measuring the clearance as being at 1 3/32" (Mark V gauge). If you need more clearance than that then of course measuring dimension A with this gauge won't work.

For those easily confused the gauge measures the inside and outside clearance at the same time. ....

Alyth Yard

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Posted by 7j43k on Monday, August 9, 2021 10:37 AM

Overmod

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.

 

 

Ed

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Posted by 7j43k on Monday, August 9, 2021 10:56 AM

 

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

 

 

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Posted by SeeYou190 on Monday, August 9, 2021 12:26 PM

ATLANTIC CENTRAL
Yes, 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.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by Lastspikemike on Monday, August 9, 2021 2:33 PM

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. Assuming use of the widest gauge, the Mark V, then you'd get track centres at 2 3/16". Plenty of spare clearance there. 

Alyth Yard

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Posted by 7j43k on Monday, August 9, 2021 3:05 PM

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. 

 

I'd say it's an even MORE interesting point for anyone UN-succesfullly using 2" track centers for ALL curves.

 

Ed

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Posted by richhotrain on Monday, August 9, 2021 4:21 PM

Curves should be wider than 2" on center. Period.

Rich

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Posted by rrebell on Tuesday, August 10, 2021 8:36 AM

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

 

Wider in the fact that longer cars cars change those dimentions on curves.

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Posted by Lastspikemike on Tuesday, August 10, 2021 9:17 AM

7j43k

 

 
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. 

 

 

 

I'd say it's an even MORE interesting point for anyone UN-succesfullly using 2" track centers for ALL curves.

 

Ed

 

Dont think so.

If you use the Mark V and end up with 2" track centres and no collisions  you have successfully used the gauge.

Alyth Yard

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Posted by Lastspikemike on Tuesday, August 10, 2021 9:19 AM

richhotrain

Curves should be wider than 2" on center. Period.

Rich

 

Peco disagrees. So does NMRA in some ways.

If you use 2" track centres and have no collisions then your categorical statement is categorically incorrect.

I'll let you know in due course.

Alyth Yard

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Posted by 7j43k on Tuesday, August 10, 2021 9:28 AM

Hey, Mike.

Still waiting for your working example of 1.5" track spacing.

 

Ed

 

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Posted by Lastspikemike on Tuesday, August 10, 2021 9:34 AM

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.....

Alyth Yard

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Posted by 7j43k on Tuesday, August 10, 2021 9:44 AM

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.....

 

 

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.

 

Ed

 

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Posted by ATLANTIC CENTRAL on Tuesday, August 10, 2021 9:58 AM

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 

    

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Posted by SeeYou190 on Tuesday, August 10, 2021 10:17 AM

ATLANTIC CENTRAL
First, 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

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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