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Turnout measure

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  • Member since
    August 2017
  • 55 posts
Turnout measure
Posted by Scandinavian on Wednesday, July 14, 2021 3:30 PM

Hi guys,

I have converted to 1:48 O-scale and have a question regarding the turnout #5 size. Does anyone know the correct "lead" lenght (point of switch - point of frog), i'm handlaying all of the track and turnouts.

I have a printed paper mock up but i don't know if it is to the actual scale.

Thank you !
Peter

 

 

 

  • Member since
    August 2011
  • From: A Comfy Cave, New Zealand
  • 6,250 posts
Posted by "JaBear" on Wednesday, July 14, 2021 4:09 PM
Gidday Peter, I’m not an “O” gauger and am only contemplating hand laying HO turnouts, but I notice that the Fast Tracks printable track templates have a scale, top right, page one.
 
 
Hope this helps.
Cheers, the Bear.Smile

"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."

  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Wednesday, July 14, 2021 5:35 PM

NMRA RP-12 has these dimensions.  It's available on-line:

 

https://www.nmra.org/index-nmra-standards-and-recommended-practices

 

Ed

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, July 14, 2021 5:40 PM

you may be interested in Variations in Turnout Dimensions i wrote when trying to better understand turnout dimensions

the table below reports prototype lead lengths, "frog distance", 47.1 ft for a #5, which scales to 11.775" for 1/48

greg - Philadelphia & Reading / Reading

  • Member since
    August 2017
  • 55 posts
Posted by Scandinavian on Thursday, July 15, 2021 2:57 AM

Guys, thanks for the info !

I have printed the Fast Tracks papers but in 3 pieces and glued together, so i was not sure of the correct lenght. And my frog was not the same as in the printout, so... why not get the correct measure to begin with and then the rest will fall into place.

From gregc's information the length is: 0.299085 meters (299mm)

Problem solved, sweet!

Thanks! Thumbs Up
Peter

  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Thursday, July 15, 2021 9:39 AM

Very nice article, Greg!

The length for an NMRA specced switch is .2688 meters, for comparison.

 

Ed

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Thursday, July 15, 2021 9:43 AM

Scandinavian
From gregc's information the length is: 0.299085 meters (299mm)

That 0.000085 of a meter is only about three one-thousandths of an inch, less than a human hair.

Is that kind of precision nesessary for turnout length?

I am never going to measure it.

Laugh

-Kevin

Living the dream.

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