Curve track and big boys in "S"?

I'm trying to decide whether to get back into S again after my wife reclaimed a sizeable  part of the basement and my O scale layout.  I would like to be able to run big steam and that of course includes a big boy but I don't know what size curves I need to run on.  Also, what manufacturers make big boys in S?  I have yet to decide on S scale or American Flyer.  I would appreciate any info I can get.

Thanks,  Rick

Original Post

There have been only two big Boys made in S.  One in S Scale brass by Sunset Models (not Sunset 3rd Rail) back in 1983 and one by Lionel/Flyer in 2008 using the (oversized for S) K-Line Big Boy tooling. 

The Sunset Big Boy was a good looking model but ran poorly.  It required a lot of tinkering to get them to run well.   If memory serves it required at least 36" radius curves.

The ex-K-Line Lionel/Flyer Big Boy was built to about 1:60 proportion instead of 1:64 and is noticeably oversized when placed next to properly scaled 1:64 equipment.

A better solution if your tastes lean toward large steam would be the Lionel/Flyer Challenger (2011,) Lionel/Flyer Y3 (2012,) American Models 4-8-4 (2006-present) or Lionel/Flyer 4-8-4 (2016) :

UP 3977 111811 13Y3 122212 02AM 29XX 061111 02LHS 123012 003

The American Models 4-8-4's were available as AC conventional Hirail, DC Hirail or Scale.  Currently only the scale wheel version is available from AM.  The Challenger and Y3 were Lionel Legacy locomotives and the Flyer 4-8-4 can still be found as a FlyerChief (LionChief) controlled.   All of these in their Hirail configurations will negotiate the traditional Flyer R20 curves.




Photos (4)


All things stated by Rusty are correct but, keep in mind that the decision between scale and American Flyer is the tie breaker. I lean much more toward the AF toy train/high rail side of the tracks. I do have the Big Boy and the Challenger, and run on the original AC Gilbert track.  This track has the tighter radii approx. 20". This does give a good deal of cab overhang on curves with the Big Boy and the Challenger, but the tight curves also allow for more layout in a given area. It does come down to what you want more, scale realism or more trains in a limited space. The layout in my basement is only 8 ft. wide at its widest point, most is 6 ft. wide and about 35 ft. long. Using the original AF track and TMCC/Legacy system we have had as many as six people running trains on a play trains session, limited only by the number of hand held remotes available. I enjoy watching other club members running trains, having fun, and enjoying themselves as much or more than operating  trains myself.


Hi Rusty and Ray,  thanks for the info and pics.  I don't think space will be that much of a problem for S.  For O scale the wide radius curves are a problem in the tighter space.  Originally I had about 33' x 25' for O.  Now, I only have about 14' x 23'.

I think I will use AC power and hi-rail wheels with Kadee couplers.  AC power will give me the whistle/horn and bell, I hope, without having to get some kind of DCC system at this time.  To me, the hi-rail wheels really don't show as much in S as they do in O.

Thanks again, guys,  Rick

RICKC posted:

I think I will use AC power and hi-rail wheels with Kadee couplers.  AC power will give me the whistle/horn and bell, I hope, without having to get some kind of DCC system at this time.  To me, the hi-rail wheels really don't show as much in S as they do in O.

Good move.

Even though I'm a "scale guy," approaching S from the Hiral side opens one up to more products.


You will love s gauge. I use Gilbert track and switches which work for both american flyer and american models cars and engines. BUT If I were just starting a new layout I would use one of the other manufacturers for track ......note....I have a lionel american flyer big boy that has had it trucks and tender centipede wheels narrowed for sale if you are interested.......I am a N&W and Clinchfield fan and I no longer have room for western roads on my layout. I like American Models cars very much////// good detail and run very well.   Lots of road names ,,,,,,,, Menards make O gauge buildings That are really neat and will work well gilberts buildings .


Billyjack, thanks for the offer.  I am not really at the point yet to purchase a big boy.  I just wanted to make sure I didn't cut myself short when planning for the correct track requirements.  Don't want to lay 20" radius track if I need 36" radius to handle a big boy.  But, I will keep you in mind.


You might want to consider S track from Gargraves,  I have gotten their 27R wooden tie curves and I love it.  I run a couple of Hudsons with passenger cars and they look great on it.  They also have a 63 and 72 curves.  So those big engines will look and run great on it.  And I believe it is the same height as the regular flyer track.



"Buy another round of track for the boys"

As a former S guy that tried to make a go of it via the scale side of S, I think it would be a very good move to use lower profile Hi-rail track, in the largest radius you can swing, as well as generous switches.  This will result in a layout that essentially accommodate all Hi-rail type equipment currently available, and anything that Lionel, MTH and American Models will come out with. By using Kadee couplers (as you intend to do) and good looking track, it will be hard to tell the difference between Hi-rail and scale.

In fact, it will look more realistic than O 3-rail because there will be no center rail to deal with.

Best of luck!


Here's an attempt at a comparison of AM various radius and Gilbert. Top shot and a frontal shot down the length of the boiler illustrate offset.

Original Gilbert top and frontal.



AM S-42



AM s-48



AM S-54



Whew! Not too scientific but the overhang is more noticeable in person. Go as wide as you can.



Photos (8)

One thing is for sure:

Because the Flyer articulateds have two-point articulation (where both engine sets pivot, like AHM/Rivarrossi used and Athearn uses in HO) overhang is less pronounced that a model locomotive that only has one-point articulation (like the prototype and high end Lionel and MTH O scale articulateds.)

I once owned a brass Sunset S Scale Challenger that could barely negotiate my 33" radius curves with one-point articulation.  The boiler overhang was pretty severe.


RICKC posted:

I see curves listed in S as S-?? and R-??.  What do those letters stand for?  I assume the R means radius but what about the S.  And if I am way off base please correct me.

Thanks,  Rick

R- and S- tend to be interchangeable when dealing with FasTrack or S-Trax.


S gauge track, unlike O gauge is quoted in radius. So original Gilbert track is about R 20. I was putting the S-80 in quotes because I was mimicking the O gauge convention of quoting the diameter. The track radius in the four pictures I posted are R 40 and R 30. Sorry for the confusion.


With S Scale track the "S" designation seems to be used only by AM and it refers to the diameter.  So 24 inch radius AM track is also known as S-48 on their website.

For Lionel (American Flyer) in their current catalog they use the letter "R" to indicate radius and MTH (S Scale S-Trax) on their website simply spells out the word "radius."  No "S" is used in either case.

Add Reply

Likes (0)

OGR Publishing, Inc. PO Box 218, Hilliard, OH 43026 330-757-3020