Tehachapi, BC

[GaryHinshaw]

Quick update - the auxiliary staging yard is now substantially complete:



The tracks are all glued down and power-fed and the Tortoises are installed and functioning well.  The compound ladder feeds 9 stub end tracks, each 14+ feet long (4.5 scale miles of track).  I have not yet installed block detection or single-button route selection yet because I want to get on to the next construction phase before the end of summer, which is to connect this yard to the rest of the layout:



The two tracks curving to the left will make the connections: the front track will connect to south staging (Mojave, the helix under the Loop) and the rear track will cross the garage door and connect to north staging (Bakersfield, along the opposite wall).  The stub track will host a dedicated set of locos for shunting trains between these 3 staging yards.

BTW, I'm very happy with Peco track for this application.  Easy to work with, rugged, and available.  I kind of even like the looks of it in this setting...

[GaryHinshaw]

One quick follow-up comment about the Peco Electrofrog turnouts: I modified mine to make them electrically the same as the hand-laid turnouts elsewhere on the layout.  The main reason I did this is because of the way their power routing works: as far as I can tell, they rely on point to stock rail contact to route power and I wasn't convinced that this was a reliable scheme in the long run.*  Further, because the non-selected route has the same polarity in both rails, you have to be careful where you place feeders and gaps, lest you have shorts.

I circumvented this by cutting a gap between the frog and closure rails to isolate the frog from the rest of the turnout (cut indicated by the oval in the photo below); I then power the frog via the Tortoise using the green feeder.  For the power feeders, I soldered each to both the stock rail and closure rail on their respective sides.  This way they always have the same polarity and a direct power feed.

*I remove the point centering spring for use with the Tortoise.  If you keep the spring and throw them manually or with a solenoid motor, the contact is probably fine as is.



-gfh

[jagged ben]

Are those all Peco turnouts?

I hope you remain happy with them when you have long trains with FVM and BLMA wheels running through the frogs.   I've not been too happy with that interaction.

[ednadolski]

I hope you remain happy with them when you have long trains with FVM and BLMA wheels running through the frogs.   I've not been too happy with that interaction.

What are the issues that you have seen?  wheel drop?

This reminds me too:  Gary, have you used any specific design criteria for vertical curves?

Ed

[GaryHinshaw]

Yes, the issue jb alludes to is wheel drop, and while I'm not happy with it, I have done enough testing to determine that it will not be a problem in this yard.  All of the cars in the background of the first shot above are equipped with narrow tread FVM's or BLMA's and I have been extensively testing the throat with them all along (which is one of the reasons it takes me so long to finish something).  It is definitely the case that the cars rock through there a bit, but I have yet to have a derailment that was caused by that effect, even when pushing a 14' train through it (with mostly truck-mounted couplers still....).  I should add that the throat is on a 0.5% downgrade into flat storage, and that helps a lot when pushing trains in.

[GaryHinshaw]

Ed, my approach to vertical curves has been very laissez-faire.  I have been mostly building the benchwork to print from the xtrakcad plan, including elevations, but I don't actually know how that code handles vertical curves.  My main line of defence is 3/4" plywood subroadbed because it can't curve too much.  The best example I have is at Summit:





The locos in these two shots are just coming out of a +0.5% grade and entering a -2% grade; the backboard behind the track is level.  I have had zero issues with this area despite breaking almost all the rules in the book. The section across the door features all of the following:

* vertical curve within in a super-elevated minimum radius curve,
* vertical curve over a subroadbed splice and benchwork joint
* two turnouts within a vertical curve and over a benchwork joint.
* restricted vertical clearance for nod-under, requiring special Tortoise treatment.
 

[ednadolski]

My main line of defence is 3/4" plywood subroadbed because it can't curve too much. 

IIRC that echoes the SDSoNS track standard

I have had zero issues with this area despite breaking almost all the rules in the book. The section across the door features all of the following:

* vertical curve within in a super-elevated minimum radius curve,
* vertical curve over a subroadbed splice and benchwork joint
* two turnouts within a vertical curve and over a benchwork joint.
* restricted vertical clearance for nod-under, requiring special Tortoise treatment.

Well, rules of course were made to be broken.  Not to mention (not here of course, but all too often for model railroading) to cover up for deficient workmanship and/or design compromises.

Turnouts within a vertical curve should be no greater problem than anywhere else, as long as the curvature isn't excessive and there are no other issues like dangling trip pins (which should be fixed anyways before blaming the vertical curve).   Likewise, splices & joints should not be an issue if they are reasonably well done.


Ed

[GaryHinshaw]

With the storage yard now largely complete, it's time for the next stage of construction, so I broke out the cookie cutter (jig saw) and cut some roadbed for the base of the "vortex."  Here are some raw shots of the progress to date. First, looking under the left side of the Loop shelf:


Second, under the right side:


And along the back wall, right to left:


Normally I build the benchwork frames first, then cut the roadbed.  In this case, because a full helix will rise above this oval and I have some access and storage requirements to accommodate below it, I was having trouble visualizing how to best construct the support structure.  Thus I went ahead and cut the key roadbed elements so I could visualize the benchwork options better.

To remind you what you're looking at, here is the (slightly dated) plan for the lowest level staging:



In the shots above, the straight track across the garage door will connect the storage yard (right in the photos, top in the plan) with the Bakersfield staging yard (left in the photos, bottom in the plan).  The mainline out of Bakersfield takes one loop through the vortex to gain elevation before reaching the food-packing town of Edison (to be directly above the storage yard).

In the photos, but not the plan, you can also see a third inner track.  That will be the main track of the helix which will form Mojave staging going up, and will connect with the storage yard going down and around.  There is also a crossover at this level to connect the helix track to the Bakersfield-Edison main line to enable continuous running. 

Lots of tricky construction yet to come...  Thanks for looking.

[basementcalling]

Lots of tricky construction yet to come...  Thanks for looking.

No, thanks for sharing how you push the envelope.

[ednadolski]

thanks for sharing how you push the envelope.

+1

[GaryHinshaw]

Here's another possible interpretation of the vortex:



[In keeping with the recent Tehachapi/toilet theme.  ]

[ednadolski]

Gee Gary, that's sooo inspiring....   

Ed

[GaryHinshaw]

Perhaps I should clarify...   Mostly it's a tongue-in-cheek comment on the fact that I have designed a complicated configuration of loops under the main loop.  Hopefully my operators won't feel like they're flushing their trains down the toilet every time they enter the Vortex.

Coincidentally, Jim Kelly's column this month (Sep MR) has a story about a train breaking loose from its locos in an enclosed helix on his Tehachapi pike.  At least my helix will be entirely visible and largely accessible.  Not sure how I will make it aesthetically pleasing, but I'll cross that bridge later.

[DKS]

At least my helix will be entirely visible and largely accessible.  Not sure how I will make it aesthetically pleasing, but I'll cross that bridge later.

I don't think it's necessarily a mutually exclusive thing--that a helix that's not entirely visible is also difficult to access. Perhaps just a cloth drape velcroed across the front (or something along those lines) would be relatively aesthetic, yet offer more than adequate accessibility.

[basementcalling]

Perhaps I should clarify...   Mostly it's a tongue-in-cheek comment on the fact that I have designed a complicated configuration of loops under the main loop.  Hopefully my operators won't feel like they're flushing their trains down the toilet every time they enter the Vortex.

Coincidentally, Jim Kelly's column this month (Sep MR) has a story about a train breaking loose from its locos in an enclosed helix on his Tehachapi pike.  At least my helix will be entirely visible and largely accessible.  Not sure how I will make it aesthetically pleasing, but I'll cross that bridge later.

The more hidden it is, the harder it is to access, the more problems it will cause.