Minimum curve radii data, O/O27

[Anonymous]

OK, I know this is an open ended question, but here goes;

With regards to engines (any), Minimum curve radius information seems pretty hit or miss and basically hard to come by. Especially for older "no longer cataloged" items. (Ex: the GG1's I'm longing for)

Is there a source/archive/clearinghouse for this type of information ?

I'm guessing I'll just have to dig dig dig before I buy.

Thanks

Fred

Oh and Buckeye, if the French get Cleveland due to this whole Lionel legal mess, we can just round up a few middle school football squads and kick em out [:D]

[Algonquin]

Hi Fred,

I am not aware of a general toy train reference that would provide the minimum radius for all manufacturers equipment from all eras. My best references are to go back to the original catalogs for most modern equipment. This forum is another good source. Post the manufacturer and model number you are interested in and we (other forum members) can check our sources such as old catalogs, magazine product reviews and reference books.

Regards,

Tim Pignatari

[lionelsoni]

Postwar GG1, GP7, RDC, EP5, S2, Anniversary Alco will do O27. Trainmaster, scale Hudson will not (without modification). F3 with vertical motors will, horizontal will not. I get off on making stuff run on O27 that isn't supposed to; and I have a lot of postwar. So, if you have a question about a specific locomotive that I haven't mentioned, I may be able to help.

[waltrapp]

This topic is a bit of a pet peeve of mine.

I run O27 profile track and 30 of my 36 switches are 27". Many curves are also 27" even though I have 42" and 54" but less of these.

I emailed both CTT and OGR and asked why in their reviews they won't mention if a train runs on 27" curves or not - especially when the manufacturer claims 31" minimum. I have 4 MTH engines that are listed as 31" min but they easily handle 27" curves and switches (both Lionel's and K-Line's). I would have never bought the engines if it wasn't for forum members telling me that they would handle 27".

I sent the email about a year ago after reading a review in CTT where they talked and/or showed the engine running on their 'floor special' or whatever they call it. I know that they use Lionel's 27" switches on that layout (Lionel's switches have large motor housing and that's why they're an issue). But yet the review said *minimum curve 31"*. Go figure. To me they should tell it like it is.

Unfortunately I know of no source of this type of information either - not even if you contact the manufacturer and ask, which I've tried!

- walt

[Buckeye Riveter]

QUOTE: Originally posted by FredMc


Oh and Buckeye, if the French get Cleveland due to this whole Lionel legal mess, we can just round up a few middle school football squads and kick em out [:D]

Yes, Fred that would solve the problem with the French. I'm so glad you didn't suggest the OSU Buckeyes. They can't even make fake money. [:D]

[daan]

A lionel F3 with horizontal motors runs on the minimum of maerklin, wich is 75cm. (75 divided by 2.5=30inches) so it will run on 031.
The best thing is to use 031 as minimum if possible. If you make an S-curve, use a piece of straight between it and watch that the cars u use have couplers that are not fixed solid to the boogies. If possible, a slightly bigger radius (045 before a 031 curve) can be used to guide the train into the curve, and besides that gives the visible impression that the curve is wider.
If buying on ebay, I always ask before I buy..

[brianel027]

Fred, Walt and I are riding on the same train (Hi'ya Walt! See ya' in the club car!) when it comes to this topic. I have talked personally with a couple train company people and the reason that they do not always openly advertise an engine's ability to negotiate the 027 curve (and switch boxes) is simply they feel by saying this some folks (especially those into scale) will view the product as a toy.

In the case of MTH product, they do not even make 027 track. Yet they do advertise some product (in particular rolling stock) as making the 027 curves. I was told by someone at MTH that they need to test the product before they state it clears the 027 curves. But since the Railking loco line has moved into more of the "scale" arena, I'm sure the admission of clearing 027 curves relates more to not wanting to lose sales.

Notice in many recent Lionel catalogs that there are locos included in starter sets with 027 track that are then available for separate sale, but with a minimum 031 curve. Huh? If a GP-9 comes with 027 track in a train set, one can assume it does run on 027 track, whether bought in a set or separate sale.

Believe me Fred, there is a great deal of negative feeling when it comes to advertising a product's ability to make the 027 curve. This is because many many modelers equate 027 with "toy" trains and "not scale" and simply cannot accept the fact there are modelers who CHOOSE 027 track due to either space or financial constraints.

Now, it is important to note (as Walt mentioned) that it is the switch box housing on the 027 switches (post MPC era) that is the main culprit here. I have modified and lowered the housing on the manual switches which solves this problem. Also to be noted is that K-Line's new 027 turnout has a new very low housing. Some of the older Lionel switches like the 1024 type, will allow some other products to be run that will not clear the larger switch box housing of the MPC-era trunouts. Our friend Walt has posted some info here in the past year on the new K-Line turnouts... well worth reading so do a search for this.

OKAY, now for the list based on personal experience. These locos will run on 027 curves. On my layout, the switch box housing (along with the excessive base plate) have been removed and severely chopped down. Locos that make the 027 curves but I'm not positive about the turnout housing I'll mark with an *

Lionel and Williams GP7, GP9
Lionel, MTH Railking and Williams NW2
Lionel and Williams Centercab 44-ton Switcher
Lionel and K-Line Alco FA
Lionel 14inch versions U36B, GP20, GP38-2, RS-2, RS3
Lionel Industrial Switcher
K-Line Alco S-2 Switcher and MP-15 Diesel
MTH Railking Bantam Steamers, Dockside Switcher
MTH Railking early diesels Dash9, FP40, SD90Mac etc.* (these are all the pre-1999 diesels with approx. 14-inch lengths... all look a little boxy in proportion except for the 1999 version SD90Mac which is unquestionably the best proportioned of all Railking modern diesels)
Ready-Made-Toys "Beep" Switcher
K-Line 3000 series 4-6-2 Steamer
Most Lionel starter set steamers including docksiders, 0-4-2's, 2-4-2's, 4-4-2's, 4-6-2's.

In general most diesels under 14 inches in length can run on 027 curves, but this is not a solid rule. The K-Line GP38-2 which is close to 14 inches in length, hits the switch housing... the width of the loco must also be considered. 2-3/8 inch to 2-1/2 inch width usually is no problem.

Now some more info: the 2 main causes for rolling stock derailments on 027 track are the varying opening space of the coupler (especially between various manufacturers) and the wobble of the plastic trucks due to the mounting rivet. I remount ALL plastic trucks with rivets and have eliminated derailments almost 100%. Of course we modlers today tend to run longer trains than was done years ago when we were kids and ran trains with 3-6 cars. Another problem is when replacing plastic wheels (from early MPC era Lionel cars) with knock-off replacement die-cast wheels... you need to check the wheel gauge (by eye) and see that both sets of wheels on the same truck have the same gauge. On postwar Lionel cars, be sure the wheels and axles are clean and freshly lubricated so they as free rolling as possible. The least problematic trucks are the Lionel plastic AAR type and Symington plastic trucks, the K-Line Train-19 trucks (which are very nice... K-Line's best) and the Lionel sprung die-cast trucks. The most problematic are the K-Line plastic Symington trucks (due to inconsistant quality and opening space of the knuckle). I have replaced the K-Line plastic knuckle with a Lionel plastic one and this problem is solved. I've also replaced plastic knuckles with K-Line die-cast metal ones (getting the spring in is a pain in the caboose) so I leave the spring out. On 027 "S" curve arrangements, the Industrial Rail trucks derail due to the coupler opening. I again have taken all Industrial Rail cars and filed out the inside space of the coupler opening to cure this problem. The Industrial Rail cars are first rate quality and price, other than this glitch when running on 027 track where you've designed an "S" curve like I have.

Some other observations on personal experience:
The MTH Railking PS-2 hopper will clear 027 switch housing as will the MTH Railking Operating Dump Car. The K-Line Streamliner passengers cars do rub slightly against the Lionel switch housing.

You can also remove the exterior housing on the 027 turnouts and grind down the inside corner where most cars hit, and then fill it in with some plastic putty and give it a touch of brown paint - or even more simply use a piece of brown electrical tape

[spankybird]

I guess its time for me to also pop in here. As Brian will recall, some of my first posting on this forum was about the K-line low profile 027 trunouts. I have them and love them. This does allow me to run many very large engines on 027 track.


K-line low profile 027 turnouts


C-O Allegheny (by MTH Railking)


C-O Allegheny and UP Challenger


Here is a K-line Trainsmaster (scale) going thru the turnouts.

I should point out that the centerline distance between the trucks and the amount of angle turning of the truck will determine what the min. dia track it can run on.

tom

[laz 57]

Fred,
I have also had success with running Lionel deisels on 0-27 track. RS-11, Sd-80MACs, RS3 KCS, run great on my layout. I just run the 0-27 curves in an arc and break it up with a straight or half straight. My NYC Lionmaster J3a Has lots of trouble and an SP 4-4-2 Atlantic has problems too. But my Lionmaster Big Boy can handle them but I prefer to run her on 0-54 because it looks neater.
Laz57

[3railguy]

You don't say if you've built a layout yet so I'll put in my 2 cents for what it's worth.

Assumming tubular track, I like to keep curves to a mininum of 042 with 042 or 072 switches and maybe 027 or 031 switches for spurs. Even if it means sacraficing twists in the design or an additional mainline. Cramming as much track as you can in a layout makes things interesting but too much of a good thing can take away operating fun. Idealy, your curve diameter should be at least 3 times the length of your largest engine. Although many engines and cars will handle 027 or 031 curves, these diameters put too many limitations on running in my opinion. Unless you're running small switch engines and 027 cars, trains look more like trolleys navigating small curves. They cause derailments, trains slow down abruptly, and top heavy steamers without magnetraction are prone to topple over at higher speeds. If you're building a 4 x 8 layout, you can have an outside mainline of 042 with an inside mainline or branchline of 031 or 027. The design won't have much twist to it but it pays back in better running characteristics.

[lionelsoni]

I use John's outside-mainline idea, for visiting equipment. However, I use Marx O34, which has the O27 profile and is not hard to find even though it hasn't been made for many years.

Consider spiral curves. These combine a large radius at each end and a short radius, like O27, in the middle. Example: 22.5 degrees of O54, 45 degrees of O27, 22.5 degrees of O54. Spirals do two things for you: They look much gentler than they really are. And they allow you save space by putting the tangents leading to the curve much closer to a wall, since the ends of the cars and locomotives don't swing very far out until they have already moved away from the wall. You will find that the center section will be about the same distance from the corner of the layout as if the whole curve had the same tight radius.

[waltrapp]

Brianel, as usual, a nice and very thorough discussion.

BTW: I don't recall who convinced me to FINALLY start replacing my Lionel with K-Line but I have started: 12 so far (I can't thank that person enough for giving me that one last pu***o get me over the indecision hump). No more switch chattering problem and and no more concerns about the housing.

As a side note on the Lionel switch motor housing: I have numerous MTH RK box cars and reefers than negotiate the switch motor housing but it's tricky: the car sides are JUST HIGH ENOUGH that they go OVER the housing!. If they sat lower they would not clear. In fact, I bought the MTH RK Heinz striped Pickle car and its sides sit maybe 1/8" lower and it won't clear the housing - even though the car has the same exact dimensions as the 35 other RK reefers/box cars that I have.

I have several older RK tankers and they are all fine too.

Also, I know that length doesn't matter when it comes to cars (careful now!!!). I bought a K-Line PRR caboose and it's trucks would not swing enough to go around 27" curves. Had to take it back.

I can only chime in with these engines. They do handle Lionel's housing OK:
* MTH RK PRR 6-8-6 baby turbine (PS2 version).
* MTH RK SW1500 switchers (PS2 version).
* MTH RK F3s (SF and NYC) but these are 4 to 5 years old. (PS1 version)

As alluded to above, we're going to have to start being careful when referring to Railking. We're going to have to start saying "older RK" or "newer RK". I would bet that the newer RK F3s won't handle Lionel switch housing.

- Walt

[palallin]

You say that like it's a bad thing [;)]

Face it everyone: if it ain't 1:1 sacle AND making money, it's a TOY. . . . [}:)]

Originally posted by brianel027

I have talked personally with a couple train company people and the reason that they do not always openly advertise an engine's ability to negotiate the 027 curve (and switch boxes) is simply they feel by saying this some folks (especially those into scale) will view the product as a toy.[/br]

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