Tehachapi, BC

[GaryHinshaw]

Lennart - I understand (and share!) your concern.  I feel somewhat empowered by having witnessed Mark Dance's helix scheme in action.  As long as things are well designed and executed (like Mark's) it can work quite well.  Also, as I learned in the space business, part of good execution is test, test, then test one more time, before you launch.

To answer your other question, yes the helix is designed to be quite visible.  It hangs directly under Tehachapi Loop, down to a level of 42".   Roughly speaking, it will sit where the red rectangle is drawn here:



The "Cn" cross-overs would be roughly where the blue arrows are drawn.  There are no obstructions around the helix (except for all the crap sitting under there...), so it is designed to be quite open.  Also, the spacing between levels is ~3.5", so there should be some finger room if things go awry.  That's the plan anyways. 

-gfh

[jagged ben]

Gary, picture sent to you. 

One quick question:  Why the S-curve at the top of the helix?  Why not just make that tangent track between the two curves on either side?

[GaryHinshaw]

Got it Ben, thanks! I'll be pondering it carefully.  [Sorry I keep calling you Ben. ]

RE the S curve, the reason I designed it that way is because that section has to cross-over the 1-turn helix that carries the lower deck to the upper deck, shown in green here (suppressed in the earlier render):



The clearances are snug and I wanted to minimize the length of the crossover section.  However, I think I will change that in the build.  Here is what the hardware looks like now:



The staging entrance is the dead-end roadbed in the middle, seen crossing over the "green" helix.  I've known all along that I'll need to replace this section of roadbed with thinner stock to clear the lower track.  I'm thinking now that I'll probably just use a pre-fab bridge of some kind (don't really care what it looks like) to connect the staging to the main line.  (The position of the green helix is also why I cant start a 3rd or 4th staging track until C2.) 

Cheers,
Gary

P.S. I want to reiterate how much I appreciate the feedback and advice everyone is giving.

[Scottl]

Gary, your benchwork is really beautiful.  I can't get my head around how you cut out the shapes for the plywood that the track goes on.  Do you have any photographs of how you lay it out on the sheets of plywood?

[ednadolski]

Do you have any photos of your staging scheme?

Afraid not (and it's now long dismantled).   Not that there was ever much worth seeing -- just a couple of teardrop-shaped return loops (and the construction quality was always "temporary at best").

Oh, so you actually have one helix nested inside another, going in opposing gradients (is that right?).  Not sure why I didn't grok that earlier.

Gary, you probably explained this earlier but I can't recall -- what was your reason(s) for going with the oval-shaped helix? (I know you had some lift-outs and access to Edison as some of the constraints.)   Seems to me that if it would fit, a circular helix (with diameter equal to the major axis of the oval) could get you above the 12'9" limitation on a single lap.  Would that maybe be enough to avoid the blue train fouling the crossover?   (tho it would mean having to do curved turnouts for the crossovers)

Ed

[jagged ben]

Seems to me that if it would fit, a circular helix (with diameter equal to the major axis of the oval) could get you above the 12'9" limitation on a single lap.  Would that maybe be enough to avoid the blue train fouling the crossover?   (tho it would mean having to do curved turnouts for the crossovers)

Theoretically he could go with semi-circle on the side without the crossovers, and a semi-oval on the side that does.  IOW, half what you're suggesting and half what he has drawn.

I'd have to think a bit about how trains might handle that, but I think halfway or all the way to a circle would only help.

[Coxy]

Hey Gary,

Nice progress. Coming together really well. How did you convince a cabinetmaker to put your benchwork together for you?
 
And why so stingy with the layout photos?!!  Why use just one to succinctly illustrate your point...when you can post two or three and give us a view of all the adjacent bench and track and stuff? Stop the teasing!!!

I have to say if I was there looking at your layout, and you were showing me something, I'd also be enjoying the chance to look at all the other nearby parts of your layout.

Just  sayin' 

[svedblen]

... Also, as I learned in the space business, part of good execution is test, test, then test one more time, before you launch.

This is taking model railroading to the level of "rocket science". Pls keep us updated.

/Lennart

[Dave Schneider]

Gary, your benchwork is really beautiful.  I can't get my head around how you cut out the shapes for the plywood that the track goes on.  Do you have any photographs of how you lay it out on the sheets of plywood?

+Another on the benchwork. Do you get a monthly wood allowance now that you are a Canadian? Did they teach woodworking at Berkley? What is the secret? It is going to be a shame to cover all that nice wood with scenery.

Best wishes, Dave

[GaryHinshaw]

Lots of good questions and comments that I've been slow to respond to.  Here goes:

Gary, your benchwork is really beautiful.  I can't get my head around how you cut out the shapes for the plywood that the track goes on.  Do you have any photographs of how you lay it out on the sheets of plywood?

Thanks Scott, it's really just textbook cookie-cutter roadbed; but it was definitely aided by the CAD software (XTrackCAD in this case).  With the plan in CAD, I cut & pasted roadbed sections as efficiently as possible onto plywood.  Here is an example of some sections laid out on a 4x8 (the rectangular outline):



Here is a quick grab-shot of that full-size printout sitting on a left-over sheet of 4x8 in the middle of the garage:



I'm keeping the templates around for use in shaping the ME flex track before putting it on the roadbed.  They're getting a bit ravaged though...  This plywood will be used for the lower level roadbed when the time comes.

+Another on the benchwork. Do you get a monthly wood allowance now that you are a Canadian? Did they teach woodworking at Berkley? What is the secret? It is going to be a shame to cover all that nice wood with scenery.

Best wishes, Dave

Thanks Dave.  It's part of the residency exam for new immigrants to BC.    The only real advice I have is the cliche: measure twice, cut once.  That and have a few good tools: chop saw, jigsaw, cordless drill (for screws), and lots of clamps!

Cheers,
Gary

[GaryHinshaw]

Afraid not (and it's now long dismantled).   Not that there was ever much worth seeing -- just a couple of teardrop-shaped return loops (and the construction quality was always "temporary at best").

Ok thanks.  I hope to refine and post my staging plans soon.  Comments will then be solicited!

Oh, so you actually have one helix nested inside another, going in opposing gradients (is that right?).  Not sure why I didn't grok that earlier.

Nested yes, but the outer one is only 1-turn, so barely a helix.  Also, both go up-grade clockwise.  As a quick update, I did manage to get the 1-turn helix corked over the weekend:



I definitely want to have this track laid and tested before installing the staging helix inside it.

Gary, you probably explained this earlier but I can't recall -- what was your reason(s) for going with the oval-shaped helix? (I know you had some lift-outs and access to Edison as some of the constraints.)   Seems to me that if it would fit, a circular helix (with diameter equal to the major axis of the oval) could get you above the 12'9" limitation on a single lap.  Would that maybe be enough to avoid the blue train fouling the crossover?   (tho it would mean having to do curved turnouts for the crossovers)

Ed

Excellent question!  My recollection of this choice is very hazy, but I did specifically want crossovers on each level, and I didn't want them to be curved, so that is at least part of it.  You are correct though that I could accommodate something like a 26-28 inch radius once I get below the 1-turn helix.  I will definitely consider something like that - or jagged ben's semi-circle idea - when I get to that point.  (My short-term goal is to make a closed loop on the upper deck by joining the two ends with a temporary shoo-fly, so the staging helix is still a ways off.)

By the way, jagged ben's idea for the staging schematic was to basically transpose the two tracks below C2 (hope you don't mind me posting this jb):



The difference is such that, if no red train were present, any train in the queue could head north regardless of southbound traffic.  (If the red train were present, running around it would still require no opposing traffic between C1 and A.)  The price you pay for this is that C1-C2 is not a spot in the queue.   The issue of track length between Cn crossovers is still the same, and will be addressed separately.  In addition, I need to get serious about what happens to these tracks at the bottom of the helix, where it joins the lower level...

-gfh

[GaryHinshaw]

One more post on other progress.  The last section that needed attention in order to complete the upper level roadbed was the bridge at the 5th crossing of Tehachapi Creek, immediately below the Loop:

http://www.railpictures.net/viewphoto.php?id=59281&nseq=46

I had planned ahead somewhat by narrowing the roadbed at this spot:



with the intent that I'd hide this with bridge girders.  However, this spine was too wide and too deep to be hidden by the bridge in question, so it has been on my list to deal with it, I just wasn't sure how.   Now that this was the last section of the upper level to get corked, I couldn't put it off any longer!   Since this roadbed is on a (minimum radius) curve and a grade, I was determined to leave some of the plywood in place to maintain strength and alignment, so the only choice was to start cutting it down to size.  After studying proto photos and trying out some girders for size, I got the jigsaw out and narrowed the spine to the width of the track ties.  I also cut a few slots in the bottom of the spine so I could chisel out two plys along the end sections to accommodate the shorter end girders.  Here is the result:



Next, I needed a wider deck to accommodate the ballasted roadbed:

http://www.railpictures.net/viewphoto.php?id=139672&nseq=81

so I cut a piece of .040" styrene to shape, leaving space so I could still glue the cork directly to the plywood: (I chiseled out half a ply of wood to accommodate the styrene cross members so they would sit flush)



Finally, I could lay the "golden" cork that completes the upper deck roadbed!



A few more shots of this area:





I'll finish the bridge off in due time, but at least I have a solid foundation now.

Thanks for looking,
Gary

[Scottl]

Thanks for the pictures and explanation Gary.  Really nice bench work!

[nscalemike]

Gary,

I appreciate the time and effort you put into the bridge issue.  I also appreciate the time and effort you took to share it with us as well!  The old layout had a very similar issue that I thought of doing roughly the same thing but never worked up the courage.  As always, you work is top of the class! 

Mike

[Bendtracker1]

Gary,

I appreciate the time and effort you put into the bridge issue.  I also appreciate the time and effort you took to share it with us as well!    As always, you work is top of the class! 

Mike

+1 Mike.

Gary,
If you ever want a part time job in a cabinet shop, let me know!  Guys with your skill and patience are a scarce commodity now a days!
Nice job on the plywood bridge [and the rest of the bench work]!