Tehachapi, BC

[nscalemike]

Gary,

I've pretty much been MIA all summer due to other demands but I still try and check in on all the layout construction threads when I can.  I am really impressed with your process and also find it very inspiring!  I can see great things shaping up here over the next few months and years,  keep it up!

Mike

[ednadolski]

The copper wire loops remind me of the contour lines on those Topo maps.  Functionally they're pretty much the same (plus you could maybe pick up some UHF signals from space on those too...  )

Gary, do you have enough working room to lay track on that helix?  In the pics it seems kinda snug in a few places.   Likewise, what's your plan for the 5-turn helix - will you build it 'out in the open' and then install it from below?

Also I'm wondering about Bakersfield.  Without a way to turn trains heading in, will you have to swap power by hand?

Ed

[GaryHinshaw]

Good to hear from you Mike.  I hope you'll be able to get back in the fray pretty soon; I miss your updates.

Ed, these loops must be making it easier for you to read my mind.    They are in fact supposed to be topo contours, as that was the best way I could think of to sketch the desired profiles on those boards.  They also help me visualize the final hill shape I'm after.

By coincidence, I was just laying some cork in that helix this morning, and was cursing a bit at how cramped it was. But I think it's turning out fine - the only issue was getting a good sight line so I could see the center line on the roadbed to align the cork to.  When I lay the track itself, I pre-bend it over the printed templates, then lay it in place.  Since the roadbed was cut using the same templates, it pretty much lines right up, so I don't need to phutz with it much in cramped quarters.

I'm planning to build the helix in the open, with it's own supports, then install it in place.  That's one reason for leaving the space open underneath.  The construction details are still hazy to me, but I think I have plenty of options there.  By the way, the plan calls for cross-overs on the straight sections of the helix, to add some flexibility to the staging ops.  Not sure if I'm going with hand laid turnouts in that area though...  (don't tell anyone!)

Bakersfield will have turning capability for sure.  But I don't know yet whether it will be a wye, a single balloon track, or an entire turnback yard, like Jim Resing's.  There is suitable real estate under the Tunnel 2 peninsula, but I haven't nailed that down yet (and it's making me a bit antsy).

Cheers,
Gary

[robert3985]

Gary,

Always a pleasure to see quality and robust benchwork.  I think I enjoy building benchwork almost as much as laying track.  The copper wire idea is very innovative!

I'm going through something similar this week as I use satellite photos, published reference photos and my own extensive photos of the Taggarts twin tunnels and twin bridges area in Weber Canyon on the U.P.

I woulda been further along, but I decided to superelevate my curves AFTER I'd glued the track down!  I don't recommend doing it this way!

Very nice work!

Cheers!
Bob Gilmore

[GaryHinshaw]

Thanks very much Bob.  I enjoy building benchwork too (I guess that's obvious by now), especially when I have the plans in hand.  The contour wires are pretty crude, but they ended up being more useful than I expected, especially for simple but fairly distinctive features like the Loop hill.

In spots where I've glued track down I settled on .02" super-eleveation (~3" difference inner to outer rail) and I'm finding it to be rather subtle;  I might up that a bit going forward.   What do you use? In the above case, did you end up banking the roadbed itself?

Cheers,
Gary

P.S. I'd encourage you to start a layout thread.  I'm still hazy on what modules you have and where you're heading with them.  And from what I've seen, they're very nice!

[ednadolski]

By the way, the plan calls for cross-overs on the straight sections of the helix, to add some flexibility to the staging ops. 

That sounds like the kind of thing that in the long run, you'll be glad to have added it up front.   Just make sure not to introduce any problematic S-curves.  BTW what is the linear run of the full 5 turns? 

There is suitable real estate under the Tunnel 2 peninsula

Aha yes now I see.   Looks like a couple of parallel, dogleg-shape balloon tracks ought to fit.   Something maybe like 4 tracks, with 15" minimum radius and 1.5" spacing (so 15", 16.5", 18", and 19.5" radii).   Somewhat similar to what I had with my old loop setup -- I had 3 tracks, but with 4 tracks you'll definitely want reach-in access from both the inside and outside.  BTW I used the Atlas #7 turnouts with the surface-mount twin-coil switch machines, plus electronic auto-reverse modules, and that worked out OK for me.  If I were building it again I would just include some re-railers, and make sure to leave enough expansion gaps.   Just my $0.02 here...

Ed

[svedblen]

... and I'm finding it to be rather subtle;  I might up that a bit going forward...

Make sure you don't overdo the super-elevation, like I did. Not a pretty sight.



(I know, the roofwalks should probably not be there)

/Lennart

[C855B]

(I know, the roofwalks should probably not be there)

No, you're good. Your power is mid-'60s to late '70s. Roofwalks were acceptable in interchange until 1979.

However, speaking of power... B-B power over Tehachapi in that era was extremely rare. Once per-unit HP topped 2500, it was hard to keep the amps up on the grades and curves without a lot of wheel slip.  So... SP power then was 6-axle, typically SD35 (6900's), SD39 (5300's), U30C (7900's) and SD40 (8400's), with SD9's (3900's) doing the locals and helpers. Into the '70s, use of SD45's (8800-9100's) and U33C's (8700's) became more frequent. When the SD40T-2's (8300's at first, then adding 8200's) were delivered, they were almost exclusively assigned to Tehachapi because of the specialized Locotrol (early DPU) radio control support installed to cover dead zones through the pass.

[svedblen]

However, speaking of power... B-B power over Tehachapi in that era was extremely rare

Thanks for the information Mike. I never really thought about that. I guess I was happy having been able to pick up any SP power at all. I'll store this info a safe place, to be used if I ever do another Tehachapi scene.

Was the Locotrol designed to handle dead zones better than other systems?

/Lennart

[C855B]

Yes. There were radio repeater systems installed in and around the bigger tunnels to relay the signals between the head-end and DPU. The repeaters required a special dual-frequency setup differing from the industry practice at the time. I think I mentioned it elsewhere, but Santa Fe wanted to run standard single-frequency DPUs, and were told "Absolutely not!" by SP since the whole reason for the repeaters was hard, bad experiences with loss of continuity between the ends.

Loss of radio continuity results in the DPU suddenly shutting down to idle. So if the head-end is at full throttle up the grade, it's pulling the entire train PLUS the dead weight of the helpers. You risk busting a knuckle, pulling a drawbar, or, say, if you were circumnavigating the horseshoe at Caliente, stringlining the train.

[GaryHinshaw]

That sounds like the kind of thing that in the long run, you'll be glad to have added it up front.   Just make sure not to introduce any problematic S-curves.  BTW what is the linear run of the full 5 turns? 

The inner track of the helix has 18" radius, and each loop has a run of 12'9", which is a little bit shorter than I might wish (see below*). The crossovers will be #10, so I'm pretty sure the S will be manageable.  Need to test that though.

Aha yes now I see.... If I were building it again I would just include some re-railers, and make sure to leave enough expansion gaps.   Just my $0.02 here...

Your two cents is worth more here in Canada Ed, thanks for the info.  Do you have any photos of your staging scheme?

Make sure you don't overdo the super-elevation, like I did. Not a pretty sight.

Whoa!  That must be close to a foot of SE.  Looks more like Penn Central.     Thanks for the warning!

*On the topic of staging, here is the current concept a bit more schematically:



In the upper plan view the black track is the upper level visible track (the Loop shelf), and the gold is the quasi-hidden south staging, which is shown unfolded schematically below it (5 loops, not all shown).  The idea is that northbound (rightward) trains will be staged sequentially in the helix for the trip over the hill (red & blue trains shown).  There is a RH crossover at the entrance to visible track at A, and there will be a sequence of LH crossovers in the helix at Cn with the idea being that a train further back in the queue can runaround if there is no opposing traffic, which gives the DS some flexibility.  The one minor rub is that, because the loops are quantized, the spacing of the crossovers at Cn is fixed at 12'9".  This means longer trains potentially hog 2 loops, or at least foul the crossover for the next train in line (as the blue train is doing).  One way around this is to pull all leading trains forward until the desired crossover is clear since there is a fair bit of room at B.  (BTW, the maximum train length is expected to be around 13'.  The visible sidings can handle up to 16', but I suspect the locos will balk before the sidings do.)

I also have the ability to add 1 or 2 more staging tracks starting at C2 heading south (left) in the plan.  This is probably a good thing to add.  As always, suggestions appreciated!

-gfh

[jagged ben]

Gary, try this on for size...

-First, let's assume you do add an "additional helix track(s)" where you have the dotted line.  However, this track becomes the Southbound Main.  (This being the outside track of your helix, top track in your schematic, no matter how many tracks you add.)
-From C2 downwards (but not C1), instead of LH crossovers, you have RH crossovers.
-The inside track (bottom in your schematic) remains always the Northbound main.
-The middle track(s) is thus your staging track.  At C2 and below you can bring any train out of the middle staging track onto the northbound main, similar to the way you've already described but with the two tracks switched.  You can also bring a train all the way up the Northbound main from the bottom of the helix without worrying about opposing traffic.
-(You'll need a LH crossover or two from the southbound main to the other two tracks to facilitate southbound trains going to the various options at the bottom of the helix, unless you come up with another arrangment/solution.  Possibly these go on the opposite side of the helix, call that point 'D'.)     

I edited your schematic to show you a picture, which I'm sure is worth all those words.  But I don't have a hosting site handy, so PM with your e-mail if you want me to send the pic to you.

[robert3985]

Thanks very much Bob.  I enjoy building benchwork too (I guess that's obvious by now), especially when I have the plans in hand.  The contour wires are pretty crude, but they ended up being more useful than I expected, especially for simple but fairly distinctive features like the Loop hill.

In spots where I've glued track down I settled on .02" super-eleveation (~3" difference inner to outer rail) and I'm finding it to be rather subtle;  I might up that a bit going forward.   What do you use? In the above case, did you end up banking the roadbed itself?

Cheers,
Gary

P.S. I'd encourage you to start a layout thread.  I'm still hazy on what modules you have and where you're heading with them.  And from what I've seen, they're very nice!

Gary,

In trackage with long sweeping curves, such as Echo Curve I've raised the outside radius ties ends .030".   On S-curves, especially short ones such as on my Emory Center Siding trackage, I superelevate the short curves only .020" by working up to the superelevation by having at least 7 inches in the curve measured on the outside radius rail, with each inch representing a .005" rise from zero to a maximum (on long curves) of .030".  (I considered superelevating every curve an appropriate amount, but decided arbitrarily that it would be too much work and, I believe a less than .020" rise is basically not noticeable.)

In the past, I've just sanded my cork roadbed, and checked the angle with an inclinometer, and this was easy to do on long sweeping curves and went very quickly.  However, the shorter curves were near impossible to get consistent and I decided to use masking tape wedges under the outside radius tie ends for repeatability on all my curves 7" or longer.

My masking tape is .005" thick, and I mark off where to start the rise, which is where the curve starts, and where the superelevation remains constant, and where to start lowering the outer edge back to level. 

I then mark off 1 inch increments from either end of the curve, generally meeting in the middle with an increment that is no longer than two inches long.

Then, I mark each increment...or the space between my 1" marks...with 1, 2, 3, 4, 5, 6....which indicates how many layers of tape to put on the very edge of the larger radius side of the tie ends.

Before I start any superelevation, I make up a bunch of different tape stacks by slicing a 12" length piece of sticky masking tape into 1/8" strips with my drafting straightedge on my drafting table.  I then take a triangle and slice the strips into 3/8" long pieces.  I take these pieces and stack them on a clean scrap piece of pine 1X6 or an equivalent piece of Masonite, and segregate them into stacks with 6, 5, 4, 3, 2 pieces stacked together.  I place single pieces on my pine board too.  On long curves I'll only use two pieces of all of the different height stacks except the 6 piece sets (which is .030" thick) which is the maximum height and is used for a long curve except on the approaches.  This means that I use more 6 layer stacks than the shorter stacks used on the approaches, so...I make more of 'em...a lot more of 'em.

After I've got the wedges in place and the track curvature smooth, I used gap-filling CA to fill the voids between the ties and my cork roadbed between the stacks of masking tape, and watery CA on the inside radius ties, applied to their very ends, and letting capillary action take it as far in as it wants.  I do about a 6" strip at a time, and gently press the track down with a little piece of 1X4 pine on the rails, then spray it with Accelerator while pressing down, and cure it with an old 1200 watt hair dryer set on "hot", which evaporates the Accelerator very quickly.

I don't use solid strips of tape as is more commonly done because I have found that masking tape deteriorates over time and I don't want it to be the major supportive structure between my ties and my roadbed.  In my method, solid gap-filling CA forms the major structure and is very stable and virtually impervious to moisture, alcohol and enamel paints.

This works pretty well for me, but the track isn't really socked down until it gets ballasted since CA doesn't stick to Delrin very well.  If I break off a little section before it's ballasted, it's very easy to just press it into the negative spaces where the ties were again, and use runny CA to fix it.

On flextrack in tunnels (unless they're very short) I don't superelevate more than .020' (four layers of tape) because my tunnel liners are pretty close to prototype scale dimensions (a bit "tight").

I'm of the opinion it's better to be subtle (just a little subtle) with the superelevation rather than over-do it, especially on short curves.

Truth is, the only time the superelevation is obvious is when I'm taking photos...then it shows up very nicely because I'm at more of a track level than when I'm operating.

However, at shows I do have observant onlookers comment favorably about my superelevation, and others ask me why my trains look good running on my modules and what am I doing that's "different".  Gives me a chance to talk to a newbie generally, which I enjoy.

Here's a photo of two brass, much re-worked Overland Centennials (first run) on Echo Curve.


Coincidentally, I have been thinking about starting a layout thread, and I've been documenting my work extensively.  I've got a lot of work to do before the Salt Lake NMRA Show the last weekend in October, and I'll probably start the thread after that.

Cheers!!
Bob Gilmore

[GaryHinshaw]

Thanks Ben & Bob. Ben, PM sent.  Excellent info as always Bob.  Looking forward to seeing more of that Echo scene!!

I'm hoping to get some more track permanently laid this weekend.  TGIF!

-gfh

[svedblen]

That is quite a sofisticated staging scheme, and inside a helix too. Will the helix tracks be visible, directly or through a CCTV system? Or will you rely on occupancy detection?

If it was my layout, nervousness alone would cause derailments 

/Lennart