American style coupler problem

Re: American style coupler problem

Postby ConducTTor » Mon Jan 02, 2012 10:21 pm

Definitely no straight section there. However, the curves may be shallow enough that it's ok.....well, I guess it IS ok or they wouldn't be using it :)
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Re: American style coupler problem

Postby railtwister » Tue Jan 03, 2012 12:02 pm

I think I saw an illustration of a similar trackplan to the photo in a John Armstrong book on trackplanning. As I recall, the caption was how not to do a turnout on a curve. John suggested it would be better to use a right hand turnout instead of the LH one, and move it up so the curved part of the turnout formed the curve. This also would give extra length to both sidings without taking up any extra yard space.

The rule of thimb for "S" curves is to avoid them if possible, and where you can't avoid them, make the radius as large as possible, and also try to separate the curves by a straight section longer than your longest car, if you can. Otherwise, keep the radius as large as possible, and use NO straight section at all between the curves, because a straight section that is shorter than the car length is worse than none at all.

American style knuckle couplers are more demanding of centered coupler alignment, while the Euro style hook & loop types seem to be more critical regarding vertical alignment. Remember though, that even the prototype couplers need to be properly centered for them to work, sometimes requiring manual adjustment by the brakeman prior to coupling. Almost all model railroads are guilty of using curves that are too small of a radius as compared to the prototype, which makes the problem even worse.

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Re: American style coupler problem

Postby ConducTTor » Tue Jan 03, 2012 12:29 pm

railtwister wrote:try to separate the curves by a straight section longer than your longest car, if you can. Otherwise, keep the radius as large as possible, and use NO straight section at all between the curves, because a straight section that is shorter than the car length is worse than none at all.


Short straight is worse? I can't see why but I'll take your word for it.
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Re: American style coupler problem

Postby TTTerrific » Wed Jan 04, 2012 2:38 am

While I'm certainly no expert on the matter I think that the solution to this problem is to use the prototype practice of "spiral easements." There have been a few articles I've seen years ago in Mod RR mag. Simply, the entry and exit from any specific radi curve is to use a broader radius, and keep pulling it down (radii) until you reach the minimum radius, then coming out the "other side" by reversing the process--opening the radius by degrees until the next tangent (straight) track is reached.

I have a short article from a 1950's Mod RR mag that shows how to create a spiral easement on a model railroad. When properly done, the train "slides" into the curve without the jerking and jumping like it always does when coming off a straight run into an 12", 18", etc. [u]immediate[u] radius. Anyone who broke into this hobby with three-rail Lionel trains knows exactly what I'm talking about.

Still, long cars like 60-80 foot passenger equipment would do well to be equipped with "talgo" mounted couplers--couplers mounted on extensions directly off the truck (coupler NOT mounted to body). Much N scale rolling stock has talgo type trucks/couplers as a matter of course.

According to the modeler who wrote the article I have on spiral easements, when used properly, "S" curves present no problems.
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Re: American style coupler problem

Postby ConducTTor » Wed Jan 04, 2012 4:15 am

My biggest problem with talgo type coupler mounting is it looks terrible on locomotives. Especialy if we're dealing with American prototypes - you'd essentialy destroy the pilot with a big hole in the middle for a swinging coupler. To me the pilots are one of the signatures of American locomotives. And I can't stand the couplers that come out under the pilot and then there is this huge thing (the coupler) sticking out in front.
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Re: American style coupler problem

Postby AstroGoat760 » Tue Jan 10, 2012 9:44 pm

That is something good to know, as I do not think I would have thought of placing a straight section between turnouts until it is too late. Thanks.
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Re: American style coupler problem

Postby railtwister » Wed Jan 11, 2012 8:52 am

AngrySailor302 wrote:That is something good to know, as I do not think I would have thought of placing a straight section between turnouts until it is too late. Thanks.


Hi AngrySailor302,

If at all possible, always try to avoid having turnouts as part of an "S" curve, especially a small radius "S" curve. Turnouts can be troublesome enough if their geometry and dimensions aren't exactly right (no commercially made turnouts meet NMRA standards perfectly that I know of), and adding an "S" curve into the mix is just asking for trouble. I don't know if it's still true since the Tillig takeover, but the Pilz turnouts in HO had a very good reputation here in the US as being very reliable, especially for DCC operation, but I don't know about their TT turnouts. I can tell by just looking at the Tillig TT Bedding Track that they are way too tight in the curved direction to be considered a "scale" turnout (other than for Trolleys & Interurbans), plus I have never checked them closely with an NMRA gauge (not sure there is one in TT!), but the curve radii that we are using on the TT-Tracks modules are pretty sharp as well, so I guess scale appearance is not such a big issue in that particular case.

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Re: American style coupler problem

Postby ConnRiver » Sun Jan 22, 2012 3:39 pm

Say, dileTTante, downtown Vancouver looks model layout clean! Boy. . . .

I'm a fan of the DaVinci's Inquest tv program that was set in Vancouver. I don't recall any scenes in which the city had such large buildings. Was it not shot in Vancouver, do you know?

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Re: American style coupler problem

Postby dileTTante » Sun Jan 22, 2012 4:20 pm

This is off-topic but I'm happy to reply. Da Vinci's inquest was done in Vancouver. I even helped process the film because for many years I worked in the film labs in Vancouver. The reason no large buildings are seen is because the locale for the show is just east of the city centre. Known as the Downtown East Side it is one of the poorest areas in Canada. I live in a neighbourhood called Gastown which is in between the East Side and downtown. Gastown is a tourist spot because it's near the cruise ship terminal and the buildings date from the earliest days of the city. The neighbourhood is also full of drug addicts and other of society's unfortunates. Most city residents avoid the area. However, there is a genuine quality here that I don't find in other parts of the city where people are well off.

Vancouver is much cleaner than other cities. I think the main reason is all the rain. When I first arrived I was told that if you can't see the mountains that's because it's raining. If you can see the mountains that means it's going to rain. It's raining right now.

The train show we talk about is actually held in Burnaby a suburb directly east of the city.
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