Minimum Radius for 4-8-4"

[malibu43]

Hi folks,

This is my first post here and I would probably be considered somewhat of an amature in this hobby. I had a ton of HO stuff when I was a kid with a "permanent" layout set up in the garage. During highschool time/interest in the hobby dropped off, so the layout was dismantled and everything was boxed up and put away in the rafters.

Fastforward ~ 15 years - I am "grown up" (somehow being a grown up means I want to "play with train sets again"...) now and recently brought most of my old HO stuff up to my own house to run around the xmas tree. I have two Athearn Southern Pacific diesel locomotives, a SP switcher, and a SP 2-6-0 (yes, I grew up in centra/southern CA). I've got some frieght rolling stock, and 4 Southern Pacific Daylight passenger cars that get pulled around the tree with my black SP 2-6-0.

It looks nice, but would look WAY nicer if those cars were being pulled by an orange and red 4-8-4! The real thing, #4449, came through my town when I was a kid in '89, and it's been one of my favorites ever since. As I'm a "grown up" now, I could potentially afford to finally buy the HO 4-8-4 that I've wanted since I was 6. But, given that this will realistically be something that probably rarely gets used other than at x-mas time, I can't justify blowing a ton $$$ on it...

I've seen some new SP 4-8-4's out there for $120, which maybe I could spring for. But if I need to swap out my 18" radius EZ track for 22" radius EZ track, that could be another $60 - $80 bucks. Probably too much to spend on something so rarely used... (for me, right now, anyway).

So my big question is - do any of the HO SP 4-8-4's out there run on 18" radius track (which is what I have)? There's a Lionel GS4 4-8-4 I'm watching on ebay, but I would need to know what sort of commitment I'm getting myself into before I pull the trigger!

Thanks!

-Gregg

 

[Cjcrescent]

Hi folks...

So my big question is - do any of the HO SP 4-8-4's out there run on 18" radius track (which is what I have)? There's a Lionel GS4 4-8-4 I'm watching on ebay, but I would need to know what sort of commitment I'm getting myself into before I pull the trigger!

Thanks!

-Gregg

Gregg;

Welcome to the forums! You will learn a lot here. Lots of good folks!

The short answer to your question is yes, there are SP 4-8-4's that will take a 18" radius curve. In fact, the one you're watching on E-bay will, but don't get that one. The mechanisms on those were never very good. They were also made by Bachmann, with the Lionel brand name on them. You can buy the same loco made by Bachmann with a greatly improved the mechanism. They currently come with DCC, DCC & Sound, according to their website. However, they can be obtained from on-line dealers at below retail price and probably without DCC, if you're not into that.

If you're going to go beyond the "train around the Xmas tree", and build a permanent layout, I would suggest that you do look at DCC. If you know nothing about it, its digital command control of your trains. Instead of having to have a complicated wiring system on a layout via DC, DCC allows you to control individual locomotives. The mantra for DCC is, "Control your trains, not your track!" With DCC you can run many locomotives on a single track, with nothing more than two wires going to the track.

If you do know about DCC I apologize for the somewhat long discussion of it. If you would like to learn more about DCC, go to Tony's Train Exchange, DCC primer for beginners at;

http://www.tonystrains.com/tonystips/dccprimer/index.htm

Good Luck, and come back to get more answers from all of us!

 

[Selector]

I don't honestly know the answer, so I can't refute what Carey advises. However, I do have a couple of 4-8-4 steamers, and neither of them, both made by BLI, will work well on curves less than 22". Even then, they don't look very good with their trailing and pilot trucks pivoted so that they can stay between the rails.

However, Bachmann Industries Spectrum engines are their gold standard, and most of their engines are designed to run on 18" radii. Even their standard, or plain Jane "Bachmann" line, (and not their Spectrum), has been the hand-me-down beneficiary of much of the improved mechanisms and details of the higher end Spectrum class in the past couple of years, so at least their running qualities and reliability should be pretty good.

If if were me, I'd get the seller to put it in writing that the engine you eventually buy does run on 18" radius HO track. That way, if you have to ask him to take it back, you'll have recourse. Failing that, determine from the manufacturer's recommendations that it does. Then you'll have recourse to ask them to either fix it or give you a replacement of some kind.

[Edit - I forgot to mention this: Even if a given engine will supposedly run on 18" radius curves in HO, the reality is that there are variables where your new drivers meet your new rails that could seriously impact the veracity of the company's claims. One is variations in assembly from engine-to-engine, and the other is how well and consistently the curved elements conform to the true or 'eased' radius intended. Unfortunately, the closer we get to the minimums in the hobby, particularly as it relates to tracking and derailments and such, the more problems we encounter. IOW, on a pure probability basis, the chances of a derailment on any one curve on any one passage over it are going to be many times higher than if the radius were, say, 10% longer. Or, said slightly differently, the more closely a set of curves is laid to a true radius of 18", and with the wheels all gauged to within 1% variance from the standard in HO, and if the tracks are level across them wherever they are measured for height disparity, and if all of the many rail ends are beveled slightly on their running surfaces (top and inner flange face), your probability of a derailment will be the lowest you can possibly expect. Any deviation from that, plus or minus, doubles and quadruples the chances of a "D'Oh!!!".

Crandell

 

[malibu43]

Thanks for the replys!

A little more searching on the Bachmann GS4 turned up a couple sites that claim 22" radius minimum. I'm not surprised, really. And, Selector, I agree it may look at little funny on the 18" radius anyway. So for the time being, I'll hold off until I have resources and reason to spring for the 22" radius track as well, unless I see a deal that just can't be passed up!

For now, I'll settle for this:

I gotta say, when I think about it now, this is a pretty unique hobby. I've had/have several hobbies, and there aren't a whole lot of them that you can pull stuff out of a box after 15 years (stuff that was years old even before it was boxed), and it's still totally functional and relevent in the hobby after all that time. Try using 15 year old RC stuff, or 15 year old video games along side today's stuff, and it ain't gonna happen.

 

[Selector]

Yes, this hobby is unique in that, if you want to do it well and win some awards, you need to develop some hefty discipline and skills in quite a few crafts or trades. You need to understand electricity, digital control devices, or at least how to get the most out of them, soldering, carpentry, design, scale, modelling in scale, painting, weathering, even seeing critically. I used to 'see' for a living in the armoured corps of the Canadian Armed Forces because I ran tanks and did reconnaissance. Later, I picked up the hobby of Astronomy and learned a different type of seeing. Then I entered this hobby and saw nature a whole nuther way.

You might enjoy your very nice locomotive and train for now, and eventually find that converting the engine to DCC is not that much of a deal. But it will add a whole new dimension to toy railroading.

Designing and erecting a modest, but interesting...AND FUN...layout is a worthy goal. You cut your teeth on the first one, play, enjoy, take some notes about things to change, or things you want to remove or add the next time, and then when you are ready, you design and build a second much better layout.

Crandell

 

[Selector]

Further, as a general rule in this hobby, be generous. Be generous about your time, your space, your willingness to work out details and compromises to achieve as many of your goals and aims as you can, and be generous with your curve radii!

With respect to time, I don't mean be generous to how many hours you spend on your fun, but generous with all temporal commitments. That means your family, too. Many railroad enthusiasts become single-minded, highly focused, and we can slip into being selfish and unavailable. On the other hand, if you are going to do this, do it right, and that means to spend time reading-in and making smart decisions based on acquired understanding. Don't make enemies of your conscience and your family.

Use your space to advantage. None of us gets all we want, but many of us get more than we know how to use. So find a copy, or buy or steal one, of the late John Armstrong's Track Planning for Realistic Operation. It can be purchased from Kalmbach Publishing for a small sum. It is one of the great bibles of model railroading. Once you have read it several times (and that's what it takes the brightest among us...), you will understand that their are sheets of plywood railroads and their are real operational models in exactly the same space, but never shared. Give yourself a good head start by being generous to yourself with the space allotted to you.

Work out a list of must-haves, and then sensibly devote the needed space to them. That especially means the trackage aligned for your engines to actually use to access those functions, too. Your trains need rails to move about, so if you want a turntable, say, how does the engine get to the turntable? And where does it go when it leaves? And John Armstrong would ask you why?

And lastly, as women say you can't have too many shoes, or be too thin, in our hobby you can't have curves that are wide enough. It isn't good enough to plan for tomorrow's purchase if you already have only it in mind. What about the monster steamer announced next year that needs 23" curves? And you have to have one? Would it have been worth spending another hour figuring out how to get 25" curves into your system, now with more necessary changes? Yeah, I'd say so.

Crandell

 

[malibu43]

Thanks for the tips, guys.

For near and medium future, this will continue to be a x-mas time hobby only for me. Too many other real-life things and other hobbies on the radar right now. And that that comment about balancing real-life and hobbies is dead-on. I just can't add another hobby to the already swollen list right now!

Hopefully at some point in my future there is a 6 x 10, or 4 x 8, or some other form of plywood table in a room somewhere where I can work on a real layout (with the LARGEST radius physically possible so I can get my SP Daylight GS4!).

But for now I will lurk around these boards here once in a while just to soak up information and enjoy all the othe excellent layouts folks are putting together!

-Gregg

 

[Armchair]

22" R EZ track

I bought several circles of 22"R BLACK roadbed (steel alloy) on Ebay for about 12 - 15 dollars. Works well for me and should for you. Many will say it is junk not being NS, but it is cheap and do-able.

Armchair

 

[galaxy]

Malibu...
I looked in the Bachmann Trains 2010 Catalog at their DCC OnBoard
4-8-4 SOuthern Pacific Daylight #4446 loco Bachmann part number 50202 {or the#4449 partnumber 50201} for the Bachmann recommended curve radius. They say "performs best on 22" radius or larger". This does not mean it won't handle 18R" curves, but will be best at 22" or larger.

So I would suggest if you want the engine to go with your cars, to go the bucks and get the 22" Nickel silver EZ track you are thinking of.
Unfortunately, everywhere I have looked at online e-tailers, they seem to be out of stock.

One place that does not list in stock or out of stock but has it listed is here:
http://www.trainworldonline.com/cat...]=119&bycategory=91&x=32&y=7&find_section=176

or for the other model {mislabeled as a 2-10-4}:
http://www.trainworldonline.com/cat...]=119&bycategory=91&x=32&y=7&find_section=176

Good luck and merry Christmas!
________
HEALTHY RELATIONSHIP ADVICE DICUSSION

 

[malibu43]

Yeah, the nickel EZ track is all over eBay as well.

Just gonna have to wait until I have $200 burning a hole in my pocket!

 

[Tuna]

My Athearn Genesis UP 844 (4-8-4) calls for 22" radius track.
All the late (1940's) 4-8-4 locomotives with the big drivers (80") have long wheel bases between the first and last drivers, making the minimum radius requirements larger.
Some of the older x-8-x wheel arrangements with smaller drivers have shorter wheelbases and can handle the 18" turns betters. A Mountain 4-8-2 or a Berkshire 2-8-4 with smaller drivers would probably work.

 

[malibu43]

My Athearn Genesis UP 844 (4-8-4) calls for 22" radius track.
All the late (1940's) 4-8-4 locomotives with the big drivers (80") have long wheel bases between the first and last drivers, making the minimum radius requirements larger.
Some of the older x-8-x wheel arrangements with smaller drivers have shorter wheelbases and can handle the 18" turns betters. A Mountain 4-8-2 or a Berkshire 2-8-4 with smaller drivers would probably work.

Thanks for the heads up. At this point I'm thorougly convinced to go with 22" track.

Also, assuming my newly rekindled enthusiasm for the hobby doesn't fizzle out after Christmas, I'm postitive that at the very least, I'm going to treat myself to some 22" radius track and a GS4 as an early x-mas present next year. If an opportunity presents itself before then, it may be earlier!

 

[Tuna]

Thanks for the heads up. At this point I'm thorougly convinced to go with 22" track.

Also, assuming my newly rekindled enthusiasm for the hobby doesn't fizzle out after Christmas, I'm postitive that at the very least, I'm going to treat myself to some 22" radius track and a GS4 as an early x-mas present next year. If an opportunity presents itself before then, it may be earlier!

Since most of my stuff is big steam, I'm using nothing but 22" and bigger track.
Like you, my 'layout' is holiday only and has to be put away by Valentine's Day each year. I'm using Kato Unitrack for my temporary layouts.

 

[bnsf971]

Thanks for the heads up. At this point I'm thorougly convinced to go with 22" track.

Also, assuming my newly rekindled enthusiasm for the hobby doesn't fizzle out after Christmas, I'm postitive that at the very least, I'm going to treat myself to some 22" radius track and a GS4 as an early x-mas present next year. If an opportunity presents itself before then, it may be earlier!

Kato has a Unitrack oval that lists for about $66. It has an oval of track with 22" radius curves, a few sections of straight track, and a terminal track. It can be pricey, but short-term, it's really cheaper than what you're looking at that nobody has anyway. Oh, I use Unitrack on my home layout, and run every kind of steam from Shays to 2-10-4s and big articulateds on it with zero problems.
http://www.katousa.com/HO/Unitrack/boxedsets.html

 

[malibu43]

Kato has a Unitrack oval that lists for about $66. It has an oval of track with 22" radius curves, a few sections of straight track, and a terminal track. It can be pricey, but short-term, it's really cheaper than what you're looking at that nobody has anyway. Oh, I use Unitrack on my home layout, and run every kind of steam from Shays to 2-10-4s and big articulateds on it with zero problems.
http://www.katousa.com/HO/Unitrack/boxedsets.html

Thanks! I'll keep my eyes on that.

FWIW - I found a 22" radius EZ-track circle on ebay in a seller's store for $30. Given that I already have all the straights I need, that will probably be the cheapest way to get me where I want to be.

The same store has a new-in-box Bachmann GS4 for $140 also... so I could combine shipping... hmmmm....

 

[malibu43]

Another quick question - how big would I need to go in terms of locomotives to grow out of the 22" radius track? If I'm buying some new track, I'd like to be able to use this for a loooooooooooooonnnnnnnnggggg time. I could go with 28", but that's getting to the point where it's no longer convenient for running around the xmas tree or in whatever small space I might have available. It seems like a pretty small percentage of stuff out there won't run on 22" radius...

When I had the semi permanent layout in the garage as a kid, I don't what radius we had (it was all flex track laid by eye), but it was probably less than 18". I couldn't run anything with 3 axels on a truck, which ruled out a lot of cool stuff. That's a mistake I don't want to make again!

 

[Selector]

It would be brass or Broadway Limited ten-coupled steamers such as the C&O 2-10-4, as well as it's PRR J1 variant, and longer engines such as the 4-12-2 that BLI should bring to market in the spring. Also, brass anything with more than three coupled drivers, and a lot of those three-coupled, will not work on such tight curves.

The non-brass offerings, for the most part, have been designed to run on 18-22" radii, and this is especially so of the Trix and Marklin engines, although they cost three and five times what the Bachmann and BLI engines cost.

As we have established, pretty much, driver bases with no lateral accommodation engineered into them for tight curves that are about 18 scale HO feet long are going to give you severe migrains in curves below 22". This is so, even for solid 22" curves, with the typical 4-8-4. About the only one I know of that will run well on 18" curves is the Spectrum J Class from the Norfolk & Western. The J is/was a very large and powerful engine, and had the fastest officially recorded speed for steam in the USA, but it had relatively small 70" drivers. There were much faster engines, of course, but no official times that stand. Unofficially, a Pennsy Duplex T1 topped 120 mph on a short segment where the hogger was hard pressed to make up time. I am sure they routinely topped 105 mph when they were clear and behind schedule.

Outside of Great Britain, whose Mallard Class holds the all-time official steam speed record, the Canadian Pacific's Jubilee Class 4-4-4 #3003 topped 112 mph on a high-speed run that was conducted to test a new type of braking system.

Crandell

 

[Tuna]

Depends on what types of locomotives you're thinking about. Articulated steamers like Big Boy, Challenger, SP Cab forward, etc. are designed to handle smaller radius turns. The big single frame steamers with 10 or 12 wheels (2-10-0, 2-10-2, 4-10-2, 4-12-2, etc.) on a single rigid frame will probably require bigger radius turns.

Check out the 'owners' manuals for some of them and see what they call for.

My Big Boys and Challengers take the 22" radius track just fine.

 

[bobwrgt]

The Bachmann, Proto, and IHC 2-10-2's all will run fine on 22in radius. The Piko,Roco,Hornby , Liliput and Fleischmann 2-10-0's will all run on 22in if you are into foreign Steam.
For 4-8-4's and 4-8-2's I have Broadway J's and a M1b, Bachmann heavy and light mountains, Bachmann's Niagra, and Rivarossi 4-8-4's FE that all run fine on 22in radius.
Plenty of choices for large sream.

Bob

 

[trailrider]

Of course you are all talking about modern, r-t-r hogs. IIRC, I saw a review of the 4-12-2 model, and it was not good even on 22" radius. But then UP had similar problems with the 4-12-2 on tight-radius track! Which was probably one reason they went for the Challengers and Big Boys.

I have kitbashed Mantua Pacifics into a 4-8-4 which will run on 18" radius, as well as using Mantua Mikes into 2-10-2's and 2-10-4's that will take 18". The trick there is to use blind drivers on the center three axles and to shim the flanged driver axles down and the center axles up by about .015" so the blind drivers won't catch on the tops of the rails coming out of the curves. Mantua used separate connecting rods between each driver, so you don't have any trouble with the side rods binding as the wheels turn. Mantua used 78" drivers (measured across the tread, NOT the flanges), and the Mikes used 63" drivers. You can still get Mantua Pacifics, but the Mikados are no longer produced.