Question on identifying diameter of Lionel 027 profile wide radius track

It is stamped with a maker or no?

I know that Lionel made some 042 size curves in 027 profile or height but I have never heard of 054 in 027 profile or height. K-Line made some 042 size switches in 027 profile or height. If it is 042 size curve it needs the same number of curves as regular 027 track to make a circle.

Not sure if anybody else attempted anything else in 027 track.

Lee Fritz

the 027 type track does come in wide diameter, I have 054. the best way is to assemble it and measure across.

Of course you could always put together half a circle and measure it.

Lionel introduced 54 inch diameter curves (027 profile) track in the late 1970s.  16 pieces make a circle.

K line made the following  in 0-27 brown tie track

K 0202   27" curve

K 0212   42" Curve

K 0222   54" Curve

K 0226   72" Curve

and made 027 and 042  manual and remote switches

From the Legacy K line Trains web page.

I printed this in Feb/2011

According to Lionel's website:

6-65113 O-54 curved track sections are 14-1/4" long.

6-65049 O-42 curved track sections are 10-7/8" long.

Assuming this includes pins, which probably makes your track O-42.

Matt Kirsch posted:

According to Lionel's website:

6-65113 O-54 curved track sections are 14-1/4" long.

6-65049 O-42 curved track sections are 10-7/8" long.

Assuming this includes pins, which probably makes your track O-42.

That's not right.  O-72 curved track sections are 14-1/4" long(16 to a circle), O-54 curved track sections are 10-1/4" long(16 to a circle), and O-42 curved track sections actually are 10-7/8" long(12 to a circle).  These measurements are all excluding pins.

this is center rail to center rail 054 track

Thank you for all the replies.

The track is marked Lionel on the ties, and has the 027 profile.
I have not had time to try assembling some of the track.
I will report back when I do.

mytrains posted:

this is center rail to center rail 054 track

 Tubular O-54("O" & O-27) is not 54" center rail to center rail diameter.  it is actually 26.2" radius.

I assembled a loop of my track on the floor.
The track is "054", made by Lionel.
It takes 16 pieces to make a circle.
I measured the diameter of the circle in several places:
   across the outside rails, measured at the outside edge of the rail, the circle is 53-1/4 inches in diameter
   across the ties, measured at the outside edges of the ties, the circle is 53-3/4 inches in diameter.

I measured a section of track, using a metal ruler (so it's the length of a chord from end to end):
   across the outside rail, from end to end, not including any track pins: 10-1/4
   across the inside rail, from end to end, not including any track pins: 9-3/4

Thanks again for the replies to my question.

An interesting discussion.  I happened to be doing some floor layout thinking, either for late this holiday season or next.  Just happened to be dealing with all 3 choices, the O-72, the O-54 (both with the heavier "O" track), and 054 in the lighter track.  All the pieces I measured happened to be the Lionel brand and so stamped, although I do have similar pieces in other brands or other origins (Polk's 072, for example). 

I appear to have had late Lionel to hand, which I would characterize as having a precision of tie placement from one piece to the next; this was also true of Lionel track from the era of the Corporation (so-called postwar) except the tie placement may have been different.  Between, I recall an era where tie placement was erratic from one piece to the next.  What I don't know is whether the 054 radius was always exactly the same;  or for that matter the O-54 radius in the heavier track; I believe I am correct in saying the two weights of 54-diameter track do not have the same actual radius by a significant amount.  As to the O-72 track, the Lionel version was always in the heavier track, and I believe it was always 72" in centerline diameter.

I have in past used Charlies method of assembling a circle and pushing on it in such a way that two equal diameters at a right angle are formed.  The theory here is that the diameter is measured directly, whereas measuring the chord of a single piece of track requires multiplying that dimension by about 5 to get the diameter.  This means that any error in the chord will result in a five-fold error in the diameter.  As an example, my chord measurement on heavy O-72 of 14-1/16" gave a diameter of 72-1/12" (which is 72.083", my calculation below having been 72.086").  Obviously, had I measured the chord as 14-1/32" I would have gotten 72" more exactly.  (It wasn't quite so obvious, as the correct chord was 14-3/64" .)

How exactly is likely? Well, a machinist would detail this type of work most likely in 64ths of an inch, using fractions rather than decimals, to indicate the level of effort desired to be put into accuracy.  So, 'make chord at centerline Center rail 14-2/64".'  (We know the track-making jig at the Lionel factory was set-up on rail centerlines.)  (That's why "O" and 027 have different gauges-- 1.23" and 1.26" inches respectively, IIRC,approximately; it depends on the railhead diameters.*)  So I shoud have used a machinist's steel rule, which would be engraved with 64ths on one edge, and 128ths on the other.  *:  027 is about 4/32, "O" about 5/32, the difference thus about 0.03".

For the two diameters method, I had always worried that in setting up the two to be equal (tensioning  two strings so that one works against the other somewhat) that the arcs between the strings would be bowed outward; or, with opposite effect, the railends could not all be driven tightly together.  So I compared the two methods, using Charlies data for the two diameters method, and a mathematical method based on the measured chord length of the center rail at centerline of rail.  (Note that I do not correct my sloppy measurement of the O-72 chord (see above) as it is illustrative of the shortcomings of the math method.)

As to the 054 (027 profile), however, the difference between the math results and those obtained by Charlies are between 9/16" and 1/2" of diameter, depending on the positioning of the chord on the rail end.  We agree exactly on chord length (10" for me at center rail, corresponding to the average of his 9-3/4" & 10-1/4" for the two outside rails).  His diameter is larger than the math diameter; the reader will have to use the 027 tie length of just under 2" (1-31/32" in my samples late and early) to compare results.  So measuring an actual circle may not be that easy.

The most rapid math formula will use the sine of the half-angle turned by the single section of track, and divide that into the centerline chord of the center rail, to directly obtain the diameter of a circle, centerline of track to centerline of track.  As the sines of angles require a book of tables (or a search page as you read this) I provide three sines below:  (for 11-1/4, 15, and 22-1/2 degrees; for 16, 12, and 8 per circle)

(.19509) 16/circle: O-72: Chord 14-1/16": 14.0625"/.19509=72.086" ...X; better:

(.19509) 16/circle: O-72: Chord 14-1/32":  14.0312"/.19509=71.922" ...X; try again:

(.19509) 16/circle: O-72: Chord 14-3/64":  14.0469"/.19509=72.002" ... That's it.

(.19509) 16/circle: O-54: Chord 10-3/8":  10.3750"/.19509=53.180" or 53-3/16"

(.19509) 16/circle: 054: Chord 10-0/64":  10.0000"/.19509=51.258" or 51-1/4"

Note:  054:  It's 54" over tie ends if every joint has 1/8" of pin showing.

(.25882) 12/circle: S036:

(.38268)   8/circle: O-31 [or 027] ...

Easier to do than to write it out.  At least I know why my "O-54 but O-72 recommended" car didn't like O-54... I didn't have 54" diameter and it had positive stops on the truck swing... you've got to admire the precision of the stops. 

As for actual circles, I am told there are O-72 cars out there that will tolerate nothing in O-72 except exact 72" diameter... does that mean setting 8 diameters, nailing down 4 or 8 sections, taking the other 12 or 8 up, all while ROFLOL?   Remember, some of these guys may be working to a 64th of an inch... .

--Frank   [Note: Edit corrected "chord diameter" to "chord length".]

Interesting discussion here.

To the best of my knowledge, lionel tubular track is measured in diameter from the outer-most part of the track tie, ex, how wide of a table do you need to fit the curve without any overhang.  I would lean toward guessing that the actual diameter/radius of the O27 profile track matches that of the 'standard' "O" track and that the difference in the size of the ties is what causes the 1/4 inch smaller measurement in the o27 track.  

As to cars and engines not running on one brand or another's track, even when it states o72, it is my understanding that the manufacturers use their own track for testing and rating curves, so a brand that measures on center may not quite work on Lionel's slightly smaller curves.  I believe Lionel switched to using the center point of the track for their FastTrack line... though I think the 031 fasttrack is still measured to be the same diameter as tubular 031.

JGL

To the best of my knowledge, lionel tubular track is measured in diameter from the outer-most part of the track tie, ex, how wide of a table do you need to fit the curve without any overhang.

Folks don't always agree on how to measure track, which is the reason I did the measurements more than one way, and tried to describe how each measurement was done.

Oh, Don't get me wrong, you measured just fine.  

All I was meaning by "lionel tubular track is measured from the outer most part of the tie" is that that is how LIONEL measured it when they manufactured the track.  It has nothing to do with how anyone else measures it.  I went on to explain that I think the smaller size of the tie on o27 profile track probably accounts for the 1/4 inch difference in your 53 3/4" measurement and the supposed 54 inches.  Other brands are measured other ways, which I think I mentioned in the original post as well.  

Guess I'm just confused, maybe I wasn't clear about what I was saying in the original post as it seems I'm just repeating things here.  

JGL

JohnGaltLine posted:

Oh, Don't get me wrong, you measured just fine.  

All I was meaning by "lionel tubular track is measured from the outer most part of the tie" is that that is how LIONEL measured it when they manufactured the track...

Except, it seems when it came to Model Builder track and T-Rail track, which is 35.88" actual center rail radius, probably intending on 36"(close enough I would say).

And then there is Super-O, which is 18" center rail radius. This dimension was carried forward to FasTrack.

Great information. I'll be printing this one out.

Sines...angles...? Brings back bad memories of math I thought I would never need to hear again! 

Tom

Rob, I could be wrong, but I don't think most folks count T-rail, super O or Model Builder as TUBULAR track.  In my posts I was repeatedly very specific that I was referring to TUBULAR and not other types of track, and comparing "O" profile to "O27" Profile.  I could be wrong about TUBULAR being the proper designation for the 'normal' track, if so any insight as to it's proper name would be appreciated.   

Guess I need to define my terms better in the future. Sorry for any confusion.  

JGL

JohnGaltLine posted:

...I believe Lionel switched to using the center point of the track for their FastTrack line... though I think the 031 fasttrack is still measured to be the same diameter as tubular 031.

Wouldn't that have been great... but they didn't.  0-31 FasTrack is 31" center rail diameter.

JohnGaltLine posted:

Rob, I could be wrong, but I don't think most folks count T-rail, super O or Model Builder as TUBULAR track...

I could see that, but the Model Builder track(O-72) is the exact same profile as regular "O".

Super "O" & GarGraves is rolled formed sheet like "O" & O-27, but I wouldn't necessarily refer to it as tubular in the sense of picking a track system.

ADCX Rob posted:

JohnGaltLine posted:

...I believe Lionel switched to using the center point of the track for their FastTrack line... though I think the 031 fasttrack is still measured to be the same diameter as tubular 031.

Wouldn't that have been great... but they didn't.  0-31 FasTrack is 31" center rail diameter.

That is a shame.  Could make for some confusing times if it ever happens that a product is rated for O31(fasttrack) and won't work properly on traditional tubular.

I cannot believe Lionel made their O-31 "Fastrack" with a center rail diameter that was anything other than 28.28".  Tell me that is not true!!  What year was this track introduced and who was president of Lionel in that year?

What other reason can there have been to introduce this curvature of  Fastrack, except to persuade those with ancient O-31 layouts to rip up their old track and install the new right into its place?  This will provide support for the new era of track with bells and whistles support.

I have to disagree with Rob on the diameter of the outside tie line being, at the widely advertised "31" inches, the design basis for this O-31 O-profile track.  Nor was the diameter of the outside-end-of-tie line 31" either, despite a hundred Lionel booklets showing this.  It was 28.28" + 2.25" (length of tie), or 30.53".  Actually, for this type of fabrication, they would have worked to the nearest 1/64", IMHO.  So the dimensions would have been in fractions:  28-19/32" + 2-1/4" = 30-35/64".  We mere carpenters would use 28-9/32" + 2-1/4" = 30-17/34".  Well, our tape measures do not have 64's.  But then, carpenters do not make Lionel track.

This diameter can be figured out in one's head while watching TV.  But how is this done so easily, and why is it so?

Tracks with diameter controlled by straight leg of switches:

There are at least three well-known Lionel track choices where this is the case:

027 (027 profile); O-31 ("O" profile); SO (Super O, 36" center rail diameter)

The reason this is so is that the chosen (actually calculated from the customary length of the straight section) diameter will result in a switch which fits in place of one section of straight track, and where the curved path of the switch is also fits in place of one section of curve track.  One further condition establishes the corresponding track center rail diameter:  The curved leg of the switch should end at the point where its center rail intersects a line perpendicular to the straight leg of the switch, drawn from the end of that straight leg.

This means that a following reversed curve section will also fit with its end opposite the end of the next straight section.  Thus on a straightaway a parallel siding track can be constructed without needing to cut a special length of track.  The removal and reversal of pins is a fairly easy process using pliers and illustrated in the Lionel booklets.  Hacksawing a track is not nearly as easy.  So that's why.

As to the how of calculating the diameters required, visualize the common drawing triangles found in the stationery stores:  The 45-degree triangle, and the 30-60 triangle.  Also, recall that the three straight track lengths are (in the same order as the types mentioned):  027-- 8-7/8" (8.875"); O-31-- 10" (10.000"); SO-- 9" (9.000").

Beginning with O-31, place the imaginary 45-degree triangle with its long side as a radius from the end of the center rail of the curved switch leg.  Then a short side of the triangle will be 10.000 inches long and parallel to the straight switch leg.  Then divide this 10.000 by the sine of 45-degrees (.7071) and determine that the long side of the triangle is *14.142" and the radius of the curved section centerline.  (*: Also the square root of 200, or 10 x sq rt 2.)  Thus the centerline diameter of O-31 is 28.284" or 28-19/64".  It will also be evident the the centerline distance to the parallel siding is (14.142" less 10.000" = 4.142") x 2 = 8.284" or 8-19/64",

For 027 curves, the above figures need only be multiplied by the ratio of the lengths of the straight track sections, which is 0.8875 (here is the first need of a calculator).  We will obtain for 027 centerline diameter 25.102" or 25-3/32";  the diameter to the ends of 1-31/32" ties will be 27-1/8" (hence "027").  The centerline distance to the parallel siding is 7.352" or 7-11/32".

It should be clear that the 27-inch and 31-inch circles that these tracks fit within are salesman's shorthand, and not any basis on which the manufactured dimensions of the track are based.  Ovals will more (O-31) or less (027) fit on tables of these widths.

For 36" diameter Super O, the ratio's of the sides of a 30-60 triangle are 1.000 (for the long side), 0.500 (for the short side), and 0.866 (half the square root of 3).  To make the short side correspond to the 9" straight track module, we multiply by 18 to obtain 18" for the long side and 9" for the short side, thus 18" x 2  or 36" for the diameter.  The centerline distance to the parallel siding is four times [(1.000 less .866 = 0.134) x 9" = 1.206] = 4.824" or 4-13/16" ...using a mental shorthand to avoid having to reach for the calculator .  [Super O curves turn 30-deg, or 12 per circle.]

As usual, it takes far longer to write these things out in explanation, than to actually figure the dimensions.  With the sole exception noted (and the 027), I did all this in my head (over again) as I typed.

--Frank

F Maguire posted:

I cannot believe Lionel made their O-31 "Fastrack" with a center rail diameter that was anything other than 28.28".  Tell me that is not true!!  What year was this track introduced and who was president of Lionel in that year?

What other reason can there have been to introduce this curvature of  Fastrack, except to persuade those with ancient O-31 layouts to rip up their old track and install the new right into its place?  This will provide support for the new era of track with bells and whistles support.

I have to disagree with Rob on the diameter of the outside tie line being, at the widely advertised "31" inches, the design basis for this O-31 O-profile track.  Nor was the diameter of the outside-end-of-tie line 31" either, despite a hundred Lionel booklets showing this.  It was 28.28" + 2.25" (length of tie), or 30.53".

I've always used 14.14" for "O", I'm not sure if you might be quoting someone else?

On the FasTrack issue, Lionel certainly went wrong with the O-31. It really should have been made in 14.14" radius, They could have called it Traditional "O"  / FasTrack 28 and published the O-28 actual dimensions with a short blurb/explanation, but the current O31 FasTrack doesn't match anything. The 10" FasTrack sections are a perfect match for the as yet not manufactured Traditional "O" ("FasTrack 28") and would eliminate a LOT of fitter pieces.

Of course, making FasTrack straights in 12.73" lengths would eliminate a lot of fitters, too.