The Transcontinental PRR

[pwnj]

At the risk of throwing the proverbial thought grenade into the room, have you considered a nolix in lieu of the helix?

TAKE COVER!!! 

[davefoxx]

I think Eric is too far along in the construction, which planned for a helix, to redesign for a nolix without having to tear out a significant portion of the layout.

DFF

[eric220]

Well, the helix is an oval, not a circle, so it's not a true helix.

Two problems with a nolix:

• The way the upper level is oriented, the nolix would come down right above Horseshoe, ruining that scene.
• I can't reorient the upper level without MAJOR redesign at the brewery end.

Basically, unless I want to practically start from scratch, the nolix is a no-go. Given that it's taken me four years to get to this point, starting from scratch is not something I'm willing to entertain at this point.

[DKS]

I was not thinking in terms of a complete around-the-room nolix--obviously that would be disruptive--but rather something that fit within the existing space, such as a dogbone loop that ran from the current helix to Newark and back, along the wall and perhaps hidden behind a removable sky panel...



Then again, not knowing what it might do to the Newark area, it may be just as bad as running over Horseshoe... just a thought...

[glakedylan]

fwiw

with oval helix you have already decided to go with sectional track (Atlas code 55)
with the Kato there will be lots of easement track needed to go fro curve to straight
due to the super-elevation
I doubt that would be cost effective considering the price of kato track

just a thought

regards
Gary

[eric220]

Gary - Kato would be around $300 for the whole helix. Given that there's as much track there as in the mains of either level, I don't consider that cost-prohibitive.

DKS - I'm actually planning something similar for lower staging. For getting between the main levels, I don't think it's going to work as you've shown it. It just interferes too much with the lower level.

[eric220]

Well, after several days of pondering, I think I'm going with sectional. I've thought up an idea for a jig that will align the pieces while they are being soldered. I'll need to invest in a new soldering iron, but hey, I should really do that anyway.

In other news, DKS's proposal for the nolix got me thinking about lower staging. I was intending to build a helix down from the lower level that would be situated under the main helix. I was also planning on building a nolix, spliced in at the other end, to bring trains down from the NW interchange. The idea would be that NW trains going to the interchange would come up the nolix, drop off their cars, run through, and go down the helix back to lower staging, or vice versa. DKS's drawings gave me the idea of just running the nolix along the wall over the yard and connecting lower staging to the lower level through the interchange track. I'd want to work in a turnaround inside the helix, but I've thought about that anyway. I've also given thought to a small (three or so track) staging yard in there to represent the Chicago line and to give the NW interchange train a place to stage.

Drawings later in the day.

[eric220]

Drawings later the next day.



The idea is that the access to lower staging is from the interchange at Morrow on the right.



The track down turns around at the next corner, goes down along the wall at the bottom, makes another turn around under the helix, and connects to the staging throat. Given that this arrangement spits the trains out so that they're pointed up the helix to the upper level, I need a way to turn them around. Hence the new two-track staging yard under the helix. The shorter track is 10 feet long.

[eric220]

The Gandy Dancers came over last night. We had an out of town member stop by, so I wound up with far more people than I had anticipated. Some of the crew were put to work installing tortoises. Another group took the upper level local out for a spin. (Before the group came over, I ran it once to set out the cars.) In its first ops session, the layout performed exactly like you'd expect it to when guests come over. I had a couple of electrical dropouts, several derailments, and the brass shorted at every opportunity. Regardless, the run was a success as a test case. I also ran the camera car, and I was able to route it around the local without significant interference to either. Dispatching this layout should be a lot of fun!

[eric220]

Back to design, here's an elaboration on the nolix up from lower staging idea:



The idea on the right is that the track would be in a slot in the facia so that the train would be visible as it rises from staging.  Not only is it more visually interesting, but it would serve as a warning that something is coming up or down.  There's a total of 380 inches of travel in the track marked in red.  Given that there's 9" separation between staging and the lower level, and the track has to rise a minimum of 2" on the left side (to clear the staging throat) and drop a minimum of 2" on the right side (to clear the mains running overhead), that's plenty of room for a nice, gentle grade.

For orientation, the blue arrow on the right connects to the "Down to Staging" arrow in these images:





Like I said before, this spits out trains from lower staging so that they're headed into the helix, hence the need for the turnaround under the helix.  The alternative to this is a helix down under the main helix, and another helix over the turnaround in the upper right of the staging level to connect to the N&W interchange.

[eric220]

I threw together another layout tour last night.  This time I did something that I've been meaning to do for awhile: I included some photos to give some clue about what I'm envisioning along this plywood prairie of mine.

[davefoxx]

Fun video, Eric.  I enjoy layout tours such as these.  They help give a better understanding of the layout even better than a track plan.  One thought comes to mind, though: thank God I don't have to ballast your mainline.

DFF

[John]

your track is much better than mine .. nice job

[eric220]

thank God I don't have to ballast your mainline.

That's why I employ Gandy Dancers. 

[eric220]

Had the Gandy Dancers over last week.  We cut the first turn for the helix and experimented with installation methods.  In the end, I conceded that there was no practical way to install the turn as one piece, so we cut it in half.  Tonight, I cut biscuit slots and temporarily assembled the thing.



As you can see, this test assembly includes the sectional track that I decided to go with.  I am a little confused by Atlas's marketing.  Both the 20" radius and 18.75" radius "full turn" packets contain six pieces of track, but a 180° turn requires eight pieces.  Evidently I will be sourcing more sectional track than I thought.

Here you can see the back of the turn, which will be hidden from view.



Again, this is a temporary installation, so no CSX jokes.  This was actually a very valuable exercise.  It showed me that trying to connect sectional track in the back of the helix against the wall is a pain in the @$#!  I will need to carefully plan out how the sectional track will be soldered together as it's installed in the final version.

While I was up, I pulled out a Kato Maxi-Stack to test my loading gauge. Here's the deck separation.



There's a close clearance at the end of the first half turn.  This deck is 3/4" plywood, as it is cut out of the helix cap.  That means that at point where the helix crosses under the cap, the material above the helix is 3/4" thick instead of 1/2".  I was very worried about how that was going to work out.  In the end, it was about half a millimeter off.  A couple of twists of the nuts bracing the deck support and,



The cars flow through with no problem, although the visual is a little jarring.  I've actually got some room to back up the point where the grade starts, and I can cut that ledge back a couple of inches, so I should be able to eek out a bit more clearance.