0-72 track measurements

Atlas track is measured to the centerline. As I recall, the ties are 9' per prototype for a width of 2 1/4", so that should add 1 1/8" to each side. The outside should be 74 1/4" overall.

Are you asking about the length of different sections of Atlas track?

I apologize for not beng specific. I would like to know how many inches on the outside of one piece of Atlas  0-72 track from outside tie to outside  tie so I can order the correct amount of roadbed.   

I am still not sure what you are asking. Do you want to know the circumference of a circle of Atlas O-72 track; in other words, how much roadbed you need to support a full circle of O-72 track or some fraction of a circle?  Circumference is pi (3.14) x Diameter.

I am looking for the outside measurement on 1 piece of Atlas O gauge 0-72 track from tie to tie to determine how much road bed I will need.

I see -- well, if you are planning on using Atlas track, why not just buy one or two sections on e-Bay and measure them?  I am sure you can find Atlas track sections for sale.

Or you could draw up a scale track plan and measure the total run with a string and go from there on ordering roadbed. Have you already purchased some track?

Not yet.

What kind of roadbed are you going to use?

You can find several sellers of O-72 Atlas track sections on e-Bay -- about $9.00 for one section, used. If you are going to use Atlas O-72 track anyway, you can buy some and take your measurements right from that piece.

Cork

One (1) Atlas O72 Curved Section... the outside rail is longer than (or, protrudes)  beyond the ties.  Following the outside edge of the ties and including the protrusion on both ends... I'm at 14.625".   I would round that up... unless, you are concerned about having 3/8" per section extra as insurance ...I wouldn't recommend going short on cork.

@Dennis-LaRock posted:

One (1) Atlas O72 Curved Section... the outside rail is longer than (or, protrudes)  beyond the ties.  Following the outside edge of the ties and including the protrusion on both ends... I'm at 14.625".   I would round that up... unless, you are concerned about having 3/8" per section extra as insurance ...I wouldn't recommend going short on cork.

Given I have plans, well maybe thoughts, to put up a layout using Atlas O-72 curves, the question asked had me curious. I already bought a layouts worth of used track and have it stored in boxes. I keep buying rolls of 24' Woodside Scenics roadbed for the day when I finally decide to build something other than a seasonal Christmas loop. I just bought 2 more rolls at the Big E train show for $10 each and wondered at the time, "Do I even need these, or should I have saved the $20 for a spaghetti dinner at the Red Rose?"

The response given invoking pi had me reminiscing about my 1st girlfriend in 7th grade. She was cute, but we were never going to marry. My wife came along during my Pythagorean Theorem days in high school. Anyhow, I digress.

I did do the calculation of 3.14 x 72 = 226.08/12 = 18.84 feet of roadbed. I was happy to get the true measurement of one piece (thank you for taking the time) and when multiplying 14.625 x 16 pieces you need 19.50 feet of roadbed for a full circle. Both measurements are less than one roll of Woodland Scenics roadbed so with either calculation I'm ready to remedy any mistakes I make in putting this stuff down...eventually.

Seriously, I actually enjoyed using the formula provided and yelled out to my wife when doing so, "Honey, I just used pi in a calculation!" She responded, "Oh my God, pi reminds me of Jeremy, the 1st guy I dated back in junior high!"

I used Woodland Scenic roadbed as well... somewhere around 10 boxes or so.  You need  a  little extra for switches/crossovers to properly intersect with the divergent paths... it isn't a straight lineal calculation ...a little art/finesse helps.

This whole problem seems to me easily solvable using any one of the methods already discussed: (1) do a scale drawing and use a string, (2) buy some track and measure the different sections (curved and straight), (3) calculate the total length of track from a drawing using pi x D for curved sections and a ruler for straights, and (4) the simplest of all, buy some track and some cork, and when you need more of either one, then buy some more.