HO locos that work on 15" curves (you might be amazed)

Model Railroader General Discussion (Model Railroader)
1

I commented about my loco testing on the other two posts about small radius curves and logging locos. I expanded my test sessions and couldn’t believe how many of my HO locos do not derail running through a 15" radius curve, even at full speed.

The S curve test track consists of 3 feet Atlas straight track to build up speed, then one 18" radius Atlas curved snap track, then a reversed 15" Atlas curved snap track, then 2 feet of straight.

Here’s a list of all the locos that wouldn’t derail on this setup after several passes, even at full throttle:

Bachmann Spectrum 3 truck Shay

Bachmann Spectrum Baldwin 10 wheeler 4-6-0

Bachmann Spectrum Decapod 2-10-0

Proto 2000 SW8 (no surprise)

Proto 2000 FA1-FB1, lashed up

Atlas Classic RS-3

Proto 2000 E8/9 six axle (!)

Athearn Genesis Mikado 2-8-2

Rivarossi Berkshire 2-8-4

IHC Santa Fe 2-10-2

The Berk and Santa Fe slow down a bit running through the 15R and of course they look silly but they would not derail!

This test might prove useful to owners of larger locos where a small section of the layout has to be 15R to fit.

50’ cars and passenger cars look laughable on a 15" curve but they do make it through.

Hope you all find this useful and ENJOY YOUR FOURTH!

Rob

2

On this test, was anything coupled to the locomotives? And if so, what?

Sometimes the loco by itself is indeed fine, but everything coupled to it is not…

3

I believe a 2 or 3 sections of 15 inch radius track would be more telling.

The E units don’t really surprise me much, because each truck obviously had no limitations - not hitting any underframe components. But I doubt full size passenger cars would do as well.

4

No Rick, just the locos, with tender if steam, I didn’t think 40’ freight cars would pose a problem. I’ll try it. -Rob

5

I only own one 15R track section. I created the S for a more tortuous test. Also my Athearn BB passenger cars roll through fine, they have the separate trucks too like the E8s. Those 10 driver locos really surprised me, despite them binding, but like I said they made it through.

6

I’ve got an SD9 that can’t make 18 inch curves all by itself. I had to redo some track to get Rivarossi short coaches over them.

I had a bit of tighter radius turn, but that jet led to an engine house for trolleys.

7

My tightest curves are Atlas #4 Custom Line Turnouts and all of my current locomotive roster will clear them easily with the exception of my two Bowser 4-8-4s, they are a no go! I had a Bowser Big Boy for almost 50 years that wouldn’t negotiate the #4 turnouts.

The Bachmann GS4 4-8-4s just clear a #4 at a creep, locomotive only. When I bought my first Bachmann GS4 (non pancake motor, maybe a Plus) the specs said 18” radius but when I got my DCC Spectrum GS4 it said 20” radius, the frames are identical as are the wheel size and it barely clears a #4 towing my Athearn 72’ passenger cars at a creep.

I agree with your findings on the 15” radius, the rest of my locomotives will easily clear my #4 turnouts pushing or pulling my over weight cars.

Mel

My Model Railroad
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8

Rick, I coupled three 40 foot freight cars to my longest steam loco and ran the train through the test, slow then fast. All the cars behaved. -Rob

9

Good to know, might be handy in unseen areas. On my old layout all unseen was 18" but tried to use larger elsewhere.

10

I’ve operated the following on a 15” oval:

GG1 doubleheader

2-8-0

Bachmann ES44AC and SD70ACe

E60

Athearn RTR SD50 and Dash 9

Genesis Challenger (really slow)

F7’s

Sharknoses

GP38-2/GP40

And am SD40-2 to finish it off.

11

Just a thought, but if I only had room for 15’ radius curves, I would sell off my HO scale stuff and move into N scale where everything would be less problematic.

Rich

12

Rich,The problem with your theory there are those that believes N is to small or it for running long trains through scenery and you can’t switch cars etc.

You should start ignoring the so called experts and see how versatile this hobby really is… How about a 0-6-0T or 2-6-0 and 36 or 40 foot cars? A BB SW7 and 40’ cars will work. Any logging type locomotive will work with 36 or 40 foot cars… A 44,45 or 70 Tonner will work with 40’ cars. How about a SW1 and 40’ cars? There are several more small engines and cars on the list that would work.

13

if you only had room for 15" curves (like John Allen’s original layout) wouldn’t it make sense to have smaller locomotives and trains? Is an IHC Santa Fe 2-10-2 really going to look right on a small layout?

14

Larry, it is not a theory. It is all about confronting reality.

I am quite sure that I could set up a small HO scale layout with 12" radius curves. But what would I run on it? And, what would it look like?

At some point, you just have to be realistic and accept the laws of physics. If you want to run a model railroad and have is look good and be problem free, but you just don’t have the space to at least install 18" radius curves, then just maybe it is time to consider N scale. You say it is too small, but the truth of the matter is that N scale is not that small. You can see it, you can run it, you can be happy with it. I speak from experience.

I currently run HO scale because I have the space to do so. I would love to return to my days of yesteryear and build an S scale layout, but I would have to make too many compromises to please me. So, I stick with HO scale because I have the space.

So, it’s not a theory, it is a reality. OK, the OP claims he can run even mid-size HO scale steamers on 15"

15

Rich,See? You’re still looking in the box…Some city buildings and some trolley cars and Bingo! You can use those 12’" curves.

At some point, you just have to be realistic and accept the laws of physics. If you want to run a model railroad and have is look good and be problem free, but you just don’t have the space to at least install 18" radius curves, then just maybe it is time to consider N scale. You say it is too small, but the truth of the matter is that N scale is not that small. You can see it, you can run it, you can be happy with it. I speak from experience.

Really? How about those engines and cars I mention that works on 15" curves? I know abot N Scale seeing I spent the majority of my hobby in N not HO and that dates back to '68.

16

Larry, all I am saying is that not everyone wants to run a trolley or 0-4-0 switcher.

If you can only manage 15" radius in the available space but you want to model modern equipment, say the 1950s or later, then consider N scale.

Rich

17

Rich,Reread what I mention… A Athearn BB SW7 and 40’ cars wil go around 15" curves. As for your 50 era a aging 2-6-0 on a branch line. In modern times even a short line will require 22" or better curves but,we are discussing equipment that can use 15" curves.

N Scale has far more possibilities then just running modern trains through screnery and around sweeping curves. A lot of N Scalers still use 9 3/4" curves or 11" curves.

BTW. I still read N Scale Railroading and N Scale magazines.

18

My point exactly!

Rich

19

Good advice, Rich, but ah, the challenge of making the most of an HO layout in a small space is what intrigues me. I enjoy tackling the near-impossible just to see if it will work. -Rob (OP)

20

I agree Greg, the Santa Fe looked ridiculous but I included longer steam in my test just to see if it would work. I was challenging manufacturer’s specs of 18" radius minimum to see if there were exceptions and most of the locos on my list ran through a 15 no problem and didn’t look so bad. The drivers on the longer steam like the Santa Fe and Berk binded up. The Mikado, Decapod and 10 Wheeler rolled smoothly through. -Rob