Questions on building a new yard

I am thinking of adding a peninsula yard with a turn table to my track plan. How close can tracks be laid for a yard (on straights), and how wide will the yard have to be to utilize a turn table for diesels? Also, anybody have any recommendations for a turn table? Any brands great, or any I should avoid at all costs? Thanks for any help you can provide.

007

I think the late John Armstrong recommended 2-1/4 inches track spacing for straight track (HO). On the East Coast, "classic" era track spacing on the prototype, I believe, was 13 feet (this is something that really ought to be nailed down and published). On the West Coast I believe it was 14 feet. More recently, the railroads have rebuilt things to make both yard and main line spacing wider. So it depends on your location and era, as well as how comfortably you cn squeeze your fingers between cars.

Diesels, of course, at least theoretically don't need a turntable. My own layout, which primarily runs diesels, doesn't have one. Keep in mind that a turntable and roundhouse eat up a great deal of space on a model layout. When you start to look at coaling towers, for instance, even small ones, you begin to see how many tracks you need (usually at least two for the locos to get coal, and a third for hoppers to deliver more coal), and those tracks are at more than minimum spacing. I found, even on a medium-large layout, that a steam-era loco facility was something I didn't fancy as much as many other features.

The minimum is 2.5" for parallel track, I prefer 3" so I can get my clumsy fingers between tracks to re-rail cars and such...

-otto-

A Pennsylvania Railroad booklet entitled "Specifications for the Construction and Maintenance of Track" (pub. 1957) is available in .PDF format at http://prr.railfan.net/documents. In sec. 938 of that book is a table listing track centers. For yards, sidings, etc., centers are to be 13 1/2 ft. For double mainlines, centers are to be 14 ft. (There are also several other configurations.) In HO scale, 13 1/2 ft. works out to 1.86 in., and 14 ft. works out to 1.93 in. (On straightways, there's no reason why you can't follow the prototype, but don't try keeping those narrow centers on curved track or you'll have cars knocking each other off the track.)

snowplough

http://prr.railfan.net/documents

Thanks for the help. I am planning a double track main line, so how much space should I leave on curves?

As for the turntable, while technically I don't need one I was thinking of putting on one the end of a stub yard for drive-in/drive-out use. I have reconfigured my yard so I'm not sure I am going to use one. Still good to know how much space would be necessary.

You can find the NMRA's standards for track centers at http://www.nmra.org/standards/s-8.html.

Basically, if you're running what they call class I engines and rolling stock (which includes everything but the longest articulated engines, passenger cars, etc.), then the minimum track centers for a 23" rad. curve are 2 5/16", for a 26 1/2" rad. curve are 2 3/16", and for a 32" rad. curve are 2 1/8". If you'll be running the very longest equipment (class Ia), then the NMRA warns against having 23" or 26 1/2" rad. curves at all, and lists 2 1/2" track centers for a 32" rad. curve. (It's strange that they don't list a 24" rad. curve, since that is a minimum standard for many people.)

On the straightways, it's up to you where you where you want to fall in the trade-off between prototypical appearance and ease of "0-5-0" switching (= grabbing with your hand). For some reason, few modelers shoot for prototypical track centers, but if your yard space is at a minimum, then why not try it? (Against this, however, is the fact that most turnouts are not manufactured for prototypical track centers, so you will have to trim back the diverging track if you go that route (not hard to do): see http://prr.railfan.net/standards/standa ... =TRACKWORK for prototype plans [.PDF] for a no. 6 crossover at 13' centers.)


snowplough