The Transcontinental PRR

[GaryHinshaw]

Forgive me, but I'm a bit lost.  Do Chicago and the N&W have anything to do with each other in your scheme?  And how do either fit into the main PRR ops plan?  Is it ok that Chicago can only be accessed from the east end w/o a back-up move?  Do you have sufficient storage at either end of the PRR main, or are you primarily relying on this N&W yard?  (This is probably covered earlier, but it's been a while...)

Good to see this thread again!

[eric220]

Gary- the only things that Chicago and the N&W have in common is that each is represented by staging and each represents "beyond the basement" destinations. In the first plan, they are represented by two ends of the same yard. In the other two, the N&W is represented in the massive lower staging yard that also serves as storage, and Chicago (or other points west of Ohio and east of Denver) is represented by a smaller holdover yard.

The diverging routes to the Chicago staging represent the divergence of the line to St. Louis and beyond (modeled), and the line to Chicago (staging). I do not plan on modeling any traffic from the west to Chicago. It's simply a way to turn trains that aren't intended to go all the way out to Colorado or California, as well as trains coming up from storage in plans 2 and 3.

[M.C. Fujiwara]

[mrhedley]

A train of MP-54's trundles past a brand new train of MP-85's, which will shortly end the careers of the Ol' Rattlers.

I'm presuming what's between the ties and roadbed is shim stock for super-elevation.  What is it you are using?  What thickness?  Do you know what degree of super-elevation it provides?  And finally were you trying to match prototype angle for the scale radius?

Nice layout.

Ron

[eric220]

I'm presuming what's between the ties and roadbed is shim stock for super-elevation.  What is it you are using?  What thickness?  Do you know what degree of super-elevation it provides?  And finally were you trying to match prototype angle for the scale radius?

Nice layout.

Thanks!  That's strips of masking tape built up to 6 or 7 layers, staggering the end of each layer by about one inch to provide a vertical easement. I have no idea what degree of superelevation it provides, it's just what looked good to me.

[mrhedley]

Thanks for the info.  I'm looking to add super-elevation to the 22" radius curves on my end loops.  I think I'll copy your method since I don't want to mess around with cutting styrene into hundreds of small pieces of trim stock and gluing them to the ties.  The look is what matters, and you've captured it well.  Have you ballasted these sections yet?  I'm curious how ballast takes to regular masking tape?  Doesn't it have some kind of moisture resistant coating? 

[MVW]

Thanks for the info.  I'm looking to add super-elevation to the 22" radius curves on my end loops.  I think I'll copy your method since I don't want to mess around with cutting styrene into hundreds of small pieces of trim stock and gluing them to the ties.  The look is what matters, and you've captured it well.  Have you ballasted these sections yet?  I'm curious how ballast takes to regular masking tape?  Doesn't it have some kind of moisture resistant coating?

I'm also interested in giving this a try, as it certainly seems easy enough. In regards to your question, I wonder if it would be better to put the tape under the roadbed.

Jim

[Lemosteam]

What width masking tape do you use?  Would it be easier to use automotive pinstriping, layered in a similar fashion and better at handling curves? 

[eric220]

I cut strips of tape off of a standard 1" roll. The strips are around 1/8" wide. They flexed pretty freely, and when needed, a tear and minuscule gap was enough to let the tape flatten out. As to ballast, I have no idea. I'm not the first to use this method of superelevation, so hopefully someone can speak to the concern out of experience. In theory, I'd think that the balast would stick to itself enough to bridge that very short distance if it didn't stick to the tape.

[davefoxx]

I used this masking tape method for superelevation on my layout.  It was coated with yellow carpenter's glue when the track went down, which may have provided some water-resistance.  Regardless, I have seen no movement of the track or failure of the masking tape after ballasting.

The tracks in the following picture have superelevation in the distant curves at the far end of this stretch of track, the single track exiting the bottom of this picture, and the mainline track at right (you can see the blue masking tape under the unballasted track at far right).



Hope this helps,
DFF

[Chris333]

I did the same with masking tape. At the ends each layer gets shorter and shorter so the transition is gentle.

[eric220]

I finally have construction progress to report.  I took an extra week off after traveling to the RailBQ, and I've managed to get myself back into the basement.  It began a few days ago with progress in the wrong direction, namely ripping up over a foot of double track main.



It gave me new appreciation for caulk as an adhesive...  This is the entrance to the helix, and I wasn't happy with the somewhat wobbly curves in the existing flex, so I decided to replace it with sectional. You can see the replacement soldered sectional track lying at the edge of the ROW.

This afternoon, I returned and caulked down the first loop of the helix.



The jumpers should be a clue as to my next step.  After testing with a free-rolling boxcar, I ran a BS-10 down the ramp, just to be sure things were working.  Then came the Pennsylvania Limited, pulled by 4935.



It backed down just fine.  Going the other way, it reminded me that it thew its traction tires.  Gonna need to replace those... Apart from traction issues, the first tests were quite successful.  I have to admit, I'm starting to consider a helper district up the helix... It would give those centipedes a job.

[eric220]

Sweet mother of zombie thread.

No construction progress to report yet.  I've been in design mode again.  I'm still thinking about how to connect lower staging to the visible layout.  The basic problem is that it's in the wrong place.  Really, it should be all the way around the room at the end of the layout to represent destinations to the east of Altoona.  I was pondering this problem the other day when a crazy thought popped into my head.  One of the tracks through MG dead-ends in a tunnel, and is really only there for cosmetic reasons.  After going into the tunnel, the mains head up a one-turn helix in order regain the altitude lost from Horseshoe.  After re-emerging, they continue climbing another two inches to reach street level at Newark:



At the point where that cosmetic track disappears, it's five inches below the track level where the tracks pass over lower staging; in other words, it's covered over half of the vertical distance down, with only four inches to go.  Playing around with the available horizontal distances yielded this:



It would mean tearing up part of the existing staging tracks, namely the return loop on the right side of the yard.  If it's not entirely clear, the arrow in the center labeled "Up to MG" is where the staging access would connect to the hidden mainline.  From there it's a steady descent to a point approximately 2" above the staging deck.  Here, the track splits twice.  One track goes into a one and a half turn helix up to the NW interchange (this plan greatly simplifies that track work).  One track continues down grade to the deck (this track is a thin black line in the plan), where it goes into the yard throat on the right.  The last track levels off and goes over the rearmost track in the yard to the helix, where it makes one turn to connect into Five Fingers Maintenance and the yard throat on the left.  This long run is necessitated by the fact that there isn't room to have the ballon track loop back on itself and go back into the left throat.

After working out that there is enough distance and clearance to make this work, I began to consider what it would mean for operations.  For starters, it cuts the run from staging to the main yard about in half.  The only visible part of that run would be over Horseshoe.  Then it hit me: the cosmetic track had just become the main running east out of Altoona!  Now here comes the part where you have to throughly engage your imagination and remember that on my layout, geography and operations are somewhat disconnected.  Let's take a look at the yard:



In simplified schematic form, this is what it looks like:



Mains 1 and 2 West are the eastbound and westbound mains leaving Altoona to the west headed for the layout.  Main East is the single main leaving Altoona to the east headed to staging.  The Coal Branch is a branch line serving a large coal mine.  There are three different routes here, they're just folded together to give the impression of a four-track mainline.  Unfolded and simplified further, the schematic looks somewhat like this:



Operationally, that's how I see it working.  There's an obvious issue with the schematics that a train coming up from staging doesn't have access to the arrival yard without running past the other two yards.  This is easily addressed by the fact that the full crossovers at MG would allow a train coming up from staging to switch over to the appropriate track to line up for the arrival yard.

Reduced to the simplest rationale, this plan:

• Dramatically reduces the run from staging to the yard.
• Eliminates a helix from the plan.
• Reduces the complexity and complications of making the NW interchange live.
• Adds a dedicated runaround track to lower staging (although the act of running around also turns the equipment, for better or worse).
• Allows for increased traffic on The Curve relative to the rest of the lower level.
• Gives all four tracks after MG a purpose.
• Gives the dispatcher a path to send an "eastbound" train out of the yard and into staging without interfering with other mainline operations.

So far, I'm liking this plan.  Thoughts?

[Cajonpassfan]

Holy crapola, lemme sleep on this 
Otto K.

[LIRR]

Isn't it a bit difficult laying track in a helix?