No you don't need a run

No you don't need a run through track on the other side of the turntable. The railroads wouldn't build any kind of safe tracks on the other side of the approach tracks, if they are not needed or used. They keep the cost down as much as possible.

I don't have anything on the other end of the approach tracks on my turntable.

is there always a track aligned on the other end of the bridge?

There's never always anything but generally a turntable would have a run thru track since they tend to cluster facilities around an engine service facility. A turntable out at the end of a branch line might have nowhere to go beyond it and just be used for turning a loco but most of the time the railroad would a have a use for the space beyond the pit so would have some tracks over there. There's lots of vintage photos in books and online so you could look at facilities and try to find one similar to your modeled scene to see how the real railroads handled it. I would not worry about what model railroaders do unless you are modeling a model....DaveB 

Not always

A run through track isn't an "always" thing, but I think perhaps more common than not.  My prototype's Council Bluffs turntable was built by the Rock Island in 1953 simply to turn locomotives, with no associated roundhouse.  Here's a Brad Williams photo of it:

This particular tail track was in place, I believe, to allow a hostler locomotive to pull a longer dead unit or consist up to the turntable (in cases where the dead power plus the hostler unit exceeded the length of the TT), with the hostler unit running beyond the TT and cutting off to allow the other units to be turned, at which point the hostler would shove the other power back down.

The other use I'm aware of for a tail or "whisker" track aligned with the TT approach is in a facility to allow longer locomotives or other equipment (e.g. wreckers) that exceed the length of the TT to operate over it for storage or servicing on the other side.

to allow a hostler locomotive to pull a longer unit

What about the length of the "run through"?

I guess that's what's really my question.  The roundhouse is roughly 90 degrees from the approach track to the turntable because of the way my space is.  There is not room to put the roundhouse "behind" the TT because of the room wall.  The amount of room I need for my coaling and water facilities along the approach tracks is what will govern the length of them and accordingly will govern how close to the wall the turntable gets placed.  So I might have enough room to put a locomotive length run through track but then again I might not. Assuming I don't have room for one long enough to hold a loco then I'm wondering if it would look better to just have a short "run through" track or nothing there at all. I looked at some prototype photos and did not see any examples of shorter tracks....most looked long enough to hold a loco.  I have seen modeled instances of the short tracks though which why I mentioned what other modelers have done. I was assuming maybe they had a prototype

BTW....the turntable, coaling tower and water column is all here...looks great....I'm getting really excited about this project!

Thanks for the advice guys, It's much appreciated!

Michael

In use working example

Here is an overhead of the UP facility in Salina, KS

Too short

I think I'd opt for the too-short tail track rather than none at all.  I've seen the IAIS use the one at Council Bluffs (in the pic I shared above) to tie down MOW equipment.  Doing something like that would help to disguise the length.

I really like that UP Salina facility.  Interesting place.

Been experimeting....

With the TT template and I also got the base of the coal tower out. I had already gotten the roundhouse for my birthday so it's already built and is sitting on a temporary width extension to the layout.  I won't actually build the actual width extension until everything is worked out.  As best as I can tell, it's probably going to be better for the TT to be as close to the wall as I can put it.  It's actually the inside of a curve, but the wall is right behind it.  This means I can go with no  run through or tail track at all or I can go with a very short one, on the order of about three or four inches long. I have to admit that the thought of no track there at all is a bit  weird to me. It just messes with my sense of " how it should be" and I think it might look funny but on the other hand if the track is very short then it bothers me that it wouldn't  have any plausible purpose for being there.  UGHHHH!!  See, even us freelancers are concerned about some stuff being prototypically plausible!!

Regards,

Michael

Weeds

Burying the end of the track in weeds might also help to disguise its length.  Weeds are your friend. 

BTW, speaking of loco length and tracks to hold them...

Anyone know where to find a handy guide to the HO dimensions of various locos and tenders? I can't imagine ever running anything bigger than a Mikado or possibly a Pacific which is why i bought an 90 foot turntable but it would be interesting to know the lengths of various locos.

Michael

Locomotive length sources

Turntable with short stub tracks ...

... from the wiki.   http://upload.wikimedia.org/wikipedia/commons/2/26/Turntable_of_Railroad_001.jpg

The purpose of such tracks I suspect is to allow a bit of track to place some sort of wheel stops on to reduce the chances of inadvertently overshooting the end of the rails.  While I am certain they are not ALWAYS used, I think that if you think that it would seem 'odd' to not include them, you'd have plenty of prototypes that agreed with you.

Thank you!

Nice to see an actual prototype picture of the short tracks. I haven't decided what I'm going to do yet, I'm still experimenting with different arrangements but it's somewhat comforting to know there is a prototype out there for the short stub tracks.

Michael

"there is a prototype out there for the short stub tracks"

Since a locomotive should be balanced on a turntable it would be handy to have short overrun tracks when spotting long locos. As for the photo one would need to know the history of the place, maybe the stub tracks are leftover from and old roundhouse that was there in steam days? Anyone know where that place is? ......DaveB

Left over tracks.....

I did have that thought after studying the picture for awhile.  The thing is though, and I have no idea if this makes any difference, the short stub tracks each seem to have a corresponding track on the other end of the TT.  My eyes may be playing tricks with the angles though.

Michael

Thank you John Armstrong!

Maybe not a prototype example but I found a diagram in "Track Planning for Realistic Operation" that makes me feel a little more comfortable about  the use and purpose of the short stubs if I choose to go that route. Link to the page is here...

http://books.google.com/books?id=TyU6x08dqGkC&pg=PA46&lpg=PA46&dq=short+stub+tracks+around+turntables&source=bl&ots=qXH0KXLc2O&sig=czYQ3rBG_HNHDHSaJj4c_f-qT14&hl=en&sa=X&ei=7p6GUqiiLInRkQfOgoDIBw&sqi=2&ved=0CEwQ6AEwBg#v=onepage&q=short%20stub%20tracks%20around%20turntables&f=false  Figure 4-2....Medium sized engine terminal. If John Armstrong drew them on a diagram then that's good enough for me.

On another note, I wish books like this were available as E-books.  I might never buy the hard copies but would buy and download them for sure if they were available as E - books.

Michael

Books and Stubs

Track Planning for Realistic Operation might be the one hard copy book you should buy. It was invaluable to me during the planning process.

Regarding you turntable/stub track situation... the civil engineers would most certainly have tried to make tracks line up on opposite sides of a turntable (at least the entry tracks) if for no other reason than to minimize turntable rotations. If there isn't sufficient property to do so then so be it, do what they had to do. For alignments that do not have a corresponding track on the other side, a short stub track makes sense to prevent incidents when the locomotive pulls just a wee bit too far onto the turntable. I have pictures of my prototype RR, the AC&Y, showing just such incidents in its early days. Sorry I can't share them right now. They are featured in the upcoming Morning Sun book. Based on later pictures, the AC&Y installed heavy posts across from tracks that had no direct alignment. No doubt this was their inexpensive solution to the problem. You can still see the posts in today's Google images of the turntable remnants.

Decision made....

For better or worse! After much experimenting, I've decided that I just can't afford the cost of real estate that would be required on the other side of the turntable to have a loco length tail track.  There's really not room for a lot of other tracks on that side of the TT even if I allow for a loco length tail track corresponding to the approach track so it's not worth it. I will go with either no track or a couple of short stubs corresponding to the approach tracks. I'll decide which once the TT is in place based on what looks "right" to my eye. I'm about to mark and cut the hole for the TT now so wish me luck. For those that might be interested on how things turn out,  I'll pick up on my  blog now with pics and commentary on how the work goes from here. Once again I thank everyone who has contributed pictures, information and opinions  for their invaluable help and advice!

Regards,

Michael