Engine sizes for track radiuses?

[BRAKIE]

You should be able to use the following steamers:
4-6-0
4-6-2
2-6-2
2-6-0
2-8-0
2-8-2
I do not recommed anything larger.

[Don Gibson]

I think here the tail is wagging the dog

CONSTRUCTION plywood we buy comes in 4 X 8 sheet's.
(HO) TRACK mfgr's design / make track primaily to fit on above 4 X 8's (22"r)
(HO) TOY TRAIN mfgr's design / make their equipment primarily to run on above 22"r.
Those with a 'board' layout can play train's. Old Pr. Blessed are they that run in circles. They shall become known as ' Wheels'.

Now how about the father of HO - 'O' Guage:. It found a home on 8 X 10 plywood sheets made for Table Tennis - or as it was known, 'Ping Pong'.
LIONEL - and competitors - quickly fell into line making track (and equipment) to fit on an 8 X 10 sheet of plywood which became 'O-27' or 27" radius... the HO equivalent of which is 14" or 15" radius curves.

AGAIN the plywood board set the tone and with it the limitation's. Lionel came out with some more serious attempt's at modelling - '0-72'' guage - tried to break the 'board' mentality. It only survives today in clubs and homes of dedicated few. HO brass engines need up to 36"r (half of 72" coincidentally) to navigate safely. So today, where is the line drawn between 'toy' trains, and 'model's'?

Since the word "serious" is offensive to some, how about "more experienced', or dedicated "?- or fill in the blank line. To our Toy tain manufacturer's, we are "customer's". Some of their 'customer's want entry level equipment where cost is king, and their principle motivation is to RUN trains' . Being close to scale is less imprtant than running on 18" radius. To make a pruduct to run on 'toy' curves one has to 'fudge' dimension's, detail, or both. 85' cars become 72', gain oversized wheel opning's, and more. Who NEEDS underbody detail, or radii reducing coupler mounting?

OTHER manufacturer's look for the customer with more sophisticated want's, and is willing to pay them. Expensive plastic model's are replacing the more expensive brass ones, but compromises are being made to sell more product for ROI (Return on Investment). Do we care?

THE ANSWER to 'what engine's will run on 18"r or smaller varies from manufacturer to manufacturer and the market he is aiming for. One man's 4-6-4 - for that matter SD-45 - will, another's won't..In short - It's trial and error. In general - the cheaper ones will, and the expensive one's wont. The prototype's sure wouldn't.

WE will get the say ultimately when we vote with our dollars, and not untill.

[Anonymous]

Athearn SD-2
Atlas SD- 24 & 35
Atlas U30C
Lifelike DL-109 but 22" is better.
Lifelike SD 60M but 24" is better.
There's a couple of Kato's out there( SD70 MAC & 80 MAC)but with the cars may de-rail therefore 24" is recommended.

[tsasala]

Any recommendations on diesel locomotives on 18" curves?

[ARTHILL]

My Broadway Mikado runs fine on 18. I needed to put the rubber wheels on to make my logging style grades. My brass 3 truck shay works great and my brass 2-6-6-2 works. The overhang is a bit much but that is what makes an articulated look goods so I love it.

[Doug Goulbourn]

I remember many, many years ago Linn Wescott suggested measuring the wheel base of an HO steam loco's drivers, multiply by 10 and you would have an approximate minimum radius for that loco. Of course, that was only a rough calculation and actual testing would determine the min. radius. Obviously, articulated locos would be different and "blind" drivers on the loco would affect this performance. I have used this "formula" many times and find it works fairly well. Naturally, even though some locos will negotiate small radius curves, they look out of place doing so and my affect the train it is pulling.

Doug

[Leon Silverman]

In order the satisfy a larger market, most, if not all, "articulated" engines, will negotiate an 18" radius curve. In doing so, however, they will not look protypical. In addition, the overhang will create clearance problems with adjacent structures or track.
I put parenthesis around the word articulated because, while the protype has the rear set of drivers rigidly attached to the engine boiler and allows only the front set of drivers to swing back and forth, the "articulated" models are constructed like diesel locomotives, allowing both sets of "trucks" (the term used by some model manufacturers) to swing freely. The rear steamchest on protype engines is rigidly attached to the frame along with the rear set of drivers, so that it cannot move. The steamchest on the model engines is part of the "truck" and therefore swings out on a curve.
The above recommendations regarding small locomotive are valid. If you run a long train behind a large locomotive through a 180 degree curve, you will have the engine and end of the train moving in opposite directions. If you have to stop or accelerate the train in this location, you run the risk of pulling the midtrain cars off the track. Consequently, you have to restrict yourself to short trains, alonf with short wheelbase engines.

[nfmisso]

QUOTE: Originally posted by stcastle

Okay, I've got a 4x8 layout. The curves are 18" radius. What I want to know is, what size of steam locomotives can I run on that without having frequent problems? The LHS owner told me that an engine with 8 drivers will derail on a curve like that. Is this true, or does anyone else run trains on curves like these? What is the maximum number of drivers? Any help would be appreciated! Thanks!

18" radius is fine for N scale. [:D]

It is very tight for HO. The number of drivers is just one small piece of the equation. How much side to side motion is allowed, and the wheelbase are far more important than the number of drivers.

Bachmann Spectrum 0-6-0T, 2-8-0, 4-6-0, 2-10-0 will work fine.
Bachmann Spectrum 4-8-2 and 2-6-6-2 are borderline.
all of IHC's steamers are fine.
Bowser has specific recommendations for each of thier models: http://www.bowser-trains.com/holocos.php
Life Like's P2K 0-6-0 and 0-8-0 are ok, 2-8-8-2 and 2-8-4 are borderline.

[selector]

I agree generally with the above, but I would add that you should be somewhat sceptical of the manfucaturer's claims. BLI claims that their 4-6-4 will negotiate 18" radii, but that was not my finding. It is much happier on 22" and up.

You might get an 8-drivered loco to go around 18" radii if they were small wheels on the prototype. If they are all flanged, though, you may have a problem. Ideally, at least one of the pairs of drivers should not have flanges if you are constrained to 18" radii.

I don't know how you are fixed for finances, but Life-Like's Heritage 0-6-0 and 0-8-0 are great little engines, but they are not meant for main line steaming, certainly at any speed. Spectrum 2-8-0 might work. Ask your LHS owner if he can demonstrate whichever loco he has on the 18" radii, and see for yourself.

[CP5415]

It all depends on wether you want prototypical or not.

Pretty much everything IHC makes will go around an 18"curve even the 8 wheeled drivers.
My IHC 4-6-2 has had no problems with 18" curves.
I'm not certain a bout Proto or Bachmans offerings.
Rivarossi steamers will make 18" curves
Forget about brass on anything larger than a 4-4-0.
I hope this helps

Gordon

[Anonymous]

According to MR, Jan 2004, The New Riv 4-8-4(FEF-3) can handle 18".
Also P2K Berkshire, MR March 2004.
Riv Allegheny 2-6-6-2, MR Feb 2002.
Athearn Challenger 4-6-6-4, MR Jan 2005
Perfect track layout is required for these babies
I suspect six wheel drivers would almost be problem free.

[ndbprr]

Unless the inside drivers are blind they probably will derail. you might want to look at a Bowswer 2-8-0. Pure Pennsy, will pull the house down and easy to assemble or you can buy it already made. They also have a 4-4-2 passenger engine. Even a six wheel steamer could have problems if the track isn't perfect at 18".

[Anonymous]

Okay, I've got a 4x8 layout. The curves are 18" radius. What I want to know is, what size of steam locomotives can I run on that without having frequent problems? The LHS owner told me that an engine with 8 drivers will derail on a curve like that. Is this true, or does anyone else run trains on curves like these? What is the maximum number of drivers? Any help would be appreciated! Thanks!