Tehachapi Pass in N Scale

Discussion in 'N Scale' started by 3DTrains, Mar 11, 2011.

  1. 3DTrains

    3DTrains TrainBoard Supporter

    Yes, another Tehachapi Pass layout! ;)

    Inspired by the work of Jim Reising on his Oakville Sub, Jamie Schatte's CSX Dixie Line, as well as comments and drawings by Gary Hinshaw, I recently made the decision to switch from my original plan to model the Clinchfield to that of modeling Southern Pacific’s San Joaquin Mountain District through Tehachapi Pass. Besides the inspiration mentioned above, another reason was Intermountain's AC-12s, not to mention the current number of SP/ATSF locos and rolling stock I already own!

    This is a big area to model, and I have no illusions of recreating the entire route scene for scene. What I am after, however, is to capture the look and feel of the Tehachapi Mountains, and use this as a backdrop to the operations of both the Southern Pacific and the Santa Fe as they traverse the serpentine curves throughout the pass during the 1950s.

    Steam was on the wane, especially on the Santa Fe, but Southern Pacific’s AC-12 Cab Forward was still a prominent player in daily operations. Passenger trains were frequent, and there were daily westbound and eastbound mail trains. Citrus and potato packing plants dotted the northern portion of the line, along with long drags of ice reefers and lumber from the North.

    A few doodles I worked up:




    Yes, three decks (mostly double deck though) makes it a monster, so any feedback from the gang here is very much appreciated. The raised floor in some places and 30" minimum aisle width should make the layout a bit easier to fiddle with (a lanky 6'-4" person, I), but perhaps I have gone too far? (Or worse, senility is setting in...)

    Note: Kern Jct. is viewed and operated from the "pit" area near Arvin, and not the aisle to the left on the plan (the text simply fit in the space). Also note that I have not finished the plans for staging, or yet worked out an lift/swing gate to minimize the problems with the duck-under (Mark Dance uses some niffy tricks!). These will come later once the these main plans are further refined.

    Here is a link to my "Givens and Druthers" for the layout, which might clarify some points. Let me know if things still appear to be muddy.

    All I have to do afterward is build the thing...
  2. Bevale

    Bevale TrainBoard Member

    All I have to say is WOW!!!! Three levels including staging top and bottom is a monster for sure! I have no knowledge of the Southern Pacific route, but just following your track along from bottom to top, it looks great! I really like the long stretches of mainline. I can just imagine a consist starting at the bottom and working their way along the (what looks to be almost 300') of mainline to the top.

    If you can figure out a nice clean way to set up the benchwork, I think it would be a beauty to work on. Definitely one for the picture shows!

    Looking forward to seeing where this goes!
  3. subwayaz

    subwayaz TrainBoard Member

    That's one quite interesting layout and with out a doubt would be loads of fun. But sure is one monster of a layout and even in N Scale it will take up quite a bit of room.
    But I hope you decide to build this monster; I sure would be interested in the progress,
    Thanks for sharing so far for sure.
    I say build it!
  4. 3DTrains

    3DTrains TrainBoard Supporter

    Thank you for your comments. :)

    I would think the bench work around the walls will be a snap. The peninsula, however, is another matter. With the 3~4" inches of grade change, as well as my desire to maintain no less than 12" of viewing space o each deck, the structure will no doubt be quite a sight. I'll have to tinker with how the peninsula will go together before making any final commitments. The design elements of the CSX Dixie Line appear to be a good place to start.

    I have another plan, closer to what Gary Hinshaw drew up, and although it too uses multi-deck design (stacks the loop and Woodford over Caliente and Bealville), it only allows for running trains from Bena to Marcel, thereby cutting-off half of the operating potential. I don't mind running mainline-only, but it can get old after a while IMO, and I kinda' like having the Arvin Branch and Summit Switch in the above plan.

    And that loop sure takes up a lot of room! (I suppose I now know where I'll store my FreeMoN modules between shows - for that matter, I can probably store my saws and other tools there too!) Its position, however, is about as good as it gets in allowing access to nearly every square inch. I'll have to tinker with that element again and see if any improvement can be made.

    Give me a box and I'll fill it... :mmad:
  5. JSL

    JSL TrainBoard Member

    Thats going to be one awesome layout. I wish I had the room like you do. I am in the process of building a 3 deck layout with hidden staging. I also based me brackets off of what CSX Jamie did for his layout. Do what pleases you as the builder. I used 3/4 cabinet grade plywood for all my framing, excellent stuff and cheaper her in Canada than 2 sided sanded pine plywood. If you are anywhere in the midwest check out Menards for birch plywood, very nice stuff and good prices... Keep the updates coming. I hope it all comes together like you plan.

  6. jagged ben

    jagged ben TrainBoard Member

    That's one heck of a track plan!

    Don't have time for detailed feedback, but I'll try to give some later on. Tehachapi is my favorite.
  7. jhn_plsn

    jhn_plsn TrainBoard Supporter

    OK Marc, when do we start?

    Wait, but first things first. Did you create a laundry space for the little woman? Priority #1, or else.:ru-wink:

    Looks to me like we will have to add more to the building than originally planned.:tb-err:

    Oh, ya and don't forget the rest of the siding and building prep.:mwacko:

    So this is what the third or fourth plan for this space? At least when we finish preparing the space you can pick your favorite and refine it.:mnerd:
  8. 3DTrains

    3DTrains TrainBoard Supporter

    Workin' on it, but just in case, I'm tinkering with some new plans with the political boundaries redrawn...

    And yes, much concrete to be poured. ;)
  9. jhn_plsn

    jhn_plsn TrainBoard Supporter

    When we drive the first spike after all the building prep a party with all the club members is required. I'll bring the BBQ and some spirits.

    Wait, if I have some spirits first I get to swing the hammer, you get to hold the spike.
  10. jagged ben

    jagged ben TrainBoard Member

    Finally got some more time to spend with this...

    -What resources did you have for prototype research on the era? I'm much more familiar with Tehachapi from the 1970's to the present, but there are a few things where it seems to me there could probably be more prototypical accuracy in the track plan. I'm wondering in particular about Woodford, and a little about the helper pocket in Walong. Asking as much to satisfy my own curiosity about the prototype as to offer further details.

    -Train length. You said 9'-10' in your givens and druthers. (You said minimum but I gather you meant maximum.) I have a feeling this is going to test the limits at 18" radii and 2.5 percent grades, but it might be more doable if you don't hit those limits in the same places. It looks like you've thought pretty carefully about this, but I thought I'd raise these points anyway. One thing you might want to think about is whether your maximum length train is going to be able to cross over itself at Walong. It'd be a bit of a shame if you couldn't do that after building all that layout. Personally my preference would be for slightly more friendly grade and radius specs at the cost of modeling slightly less territory, but of course that's up to you.

    -I think it's a really good idea to be able to do some 'short work' operations on any layout. Kudos for including Arvin and Edison.
  11. ATSF5078

    ATSF5078 TrainBoard Member

    That's a very nice track plan, prety accurate too.
  12. 3DTrains

    3DTrains TrainBoard Supporter

    Hi Ben,

    Actually, minimum train length, as anything shorter (compression aside) looks to me like a local. I was originally shooting for 12~14', but if I can get 9 or 10', then I'll be fine with it (I believe 35 cars is about 50% of the prototype for the period). :)

    Yeah, and I goofed on the sidings (it was pointed out to me that Woodford is backwards, plus I placed some 18" radii where 20" should have been). I'm currently reconstructing the drawings to reflect a better representation of the area. I now have Signor's book, part of which I'm using as reference. I also have a friend at the La Mesa club, and he's been feeding me some useful data, especially around Bena.

    It's funny though that while I think of viewing Tehachapi from the north, my plan is viewed from the south. I've tried every which way to view the other-way around, but so far, no dice - at least not without having severe grades and goofy hide and seek tunnels. Perhaps with a bit more room, but I'll need to knock-down the grades to somewhere in the neighborhood of 1.5%. I'll keep tinkering with it, however.

  13. GaryHinshaw

    GaryHinshaw TrainBoard Member


    Mark Dance alerted me to this thread, and I'm glad he did. You've got quite a plan in the works here! I really like they way you've folded the line to pack everything in while keeping it accessible at all segments. This has a lot of operations potential.

    It's great that you have the Edison and Arvin areas available for switching. My next plan* will definitely incorporate similar features for operational interest. I have a few minimal comments regarding the placement of a few landmarks for your consideration. They are not intended as criticisms, just food for thought. They are minimal in the sense that they try to avoid any significant change to the existing footprints.

    1. Tunnel 2 doesn't work for me where you have it now. I would be tempted to move Tunnel 1, and the curve leading into it, closer to the horseshoe at the end of the aisle, as crudely sketched in the image below. The horseshoe itself would be the exit from 1 that crosses the fill over the drainage and heads up towards 2. I would then move tunnel 2 to the spot where you have the Allard curve now, as shown. This would give you a closer to correct alignment, and the aisle would follow the Caliente-Bodfish road where we all watch trains from. Here is a photo taken from the hill above Tunnel 2 in the direction of the red arrow on the diagram. You could reproduce this cool vista quite nicely!


    2. As much as I love Clear Creek Canyon between Tunnels 3 and 5, this scene seems a bit cramped. Maybe it's the folding of Cliff right over Bealville that makes me think that. An alternative would be to make that horseshoe be Allard into Bealville, as sketched, ending in Tunnel 3. The drawback of my suggestion is that you lose Cliff/Rowan entirely, but you open up Caliente to Tunnel 3 quite a bit. The sightline along the green arrow would give you this vista:


    and the blue arrow would give you this vista:



    Again, I love what you've done. Just wanted to stir it up a bit! ;)


    *My plan had to be scrapped due to a cross-country move. Happily I landed less than a mile from Mark Dance's Columbia & Western, and I'll have a pretty nice garage to accommodate a new plan. Only half as much space as yours, alas...
  14. GaryHinshaw

    GaryHinshaw TrainBoard Member

    Ok, here is one more wacky suggestion. On the upper level, you could reverse the sense of the mid peninsula as shown here. The idea would be to make a short stretch of quasi hidden track (the isolated portion between Marcel and T14) then have it emerge at Tunnel 14 and follow the canyon in the same sense as the prototype. You could also cut off the horseshoe and open up the scenery over the level below.

    The downside of this is that operators would have to double back a bit to stay with their trains.


  15. 3DTrains

    3DTrains TrainBoard Supporter

    Thank you Gary for your illustrations and comments. I like your idea about moving Bealville to the opposite side of the peninsula. However, I'm not certain how to pull off some of the sight lines you mentioned, due to the next deck being only 15" or so above (I'm 6'-4", so the middle deck might not be high enough). I suppose a 3D model would help me "see" what I'm missing.

    Nevertheless, your ideas give better flow than I had thought possible.

    I'm not sure about the reversed tunnel idea, as the back-tracking is twice around the room (to the end and back). I'm wondering though if your idea of removing Rowen/Cliff would allow me to reverse the view from the south, to a more natural northward view?

    I'll work out some figures and see how your ideas mesh. Thanks again! :)
  16. 3DTrains

    3DTrains TrainBoard Supporter

    I just re-read my data sheet and you're absolutely correct (slaps forehead)!
  17. jagged ben

    jagged ben TrainBoard Member

    Just some further comments on grades and radii...

    At our club the longest trains I can run without helpers are about 14', maybe up to 16' if all the rolling stock is in perfect rolling condition and I engineer the weighting of the train correctly. To do this, I must run the train in the right direction around the layout, so that I am going downhill on our ruling grade and radius. Uphill this direction, the ruling grade and radius is our model of Walong, which is modeled with a grade just over 2 percent with about a 24" radius on the main.

    Uphill the other direction, the ruling grade and curve is about 3% and 19 inches, together in the same spot. The longest trains we can run through this reliably are more like 8 feet. 10' is possible if the rolling stock is perfectly managed, or you get lucky.

    These limitations can be overcome with helpers. I occasionally run trains with both head end power and rear DPUs. (So far I have only dared to do this with sets of Kato locos with Digitrax PnP decoders.) I run the forward and rear power as separate consists using the two knobs on a Digitrax throttle. I keep a constant vigilance on the couplers to see where pulling gives way to pushing, and keep this spot a healthy distance from both ends. Doing this I have run trains around 20'. I find that at this point I really lose any and all feeling that my train might not be a prototype length. :)

    Maybe during this run season I'll try to set a new record. I have not done swing helpers yet, but that's only because it's not as prototypical for the railroad my most reliable DCC locos belong to (i.e. BNSF). Probably swing helpers offer the best advantages for running the longest trains. SP used to do swings all the time on Tehachapi and I hope to get enough of my SP locos in top notch order to try this.
  18. 3DTrains

    3DTrains TrainBoard Supporter

    Thanks for the info, Ben. Although the maximum grade is listed at 2.5%, this is only for the loop (@ 24" inside radius), and the rest of the layout can benefit from a reduced grade due to the long run between decks. The grade between levels will be closer to 1~1-1/2% (I'll have to do some checking to be certain).

    Here's a couple of revisions to my original plan, and taking into account the suggestions from Gary and others:

    Lower Level: Not much has changed from the original, except to reflect the tweaks to the alignment from the middle deck above. I also added the spur tracks and helper pocket at Bean and Sand Cut. Illmon also got a minor makeover.


    Middle Level: Here quite a bit has changed, including moving Bealville from one side of the peninsula to the other, as well as the removal of the Rowen/Cliff siding combination. I also fixed the siding at Woodford so that it's now on the correct side of the main. I can't be certain if it was a dead end spur or actually connected to the main in the 1950s, so I'll have to check on that. Tunnels 1 and 2 were also moved per Gary's suggestion, and although Rowen/Cliff are gone, I'm really pleased on how the whole plan is taking shape. Thank you, Gary.


    Since the new plan reflects the use of a lift-out or swing gate, I've reduced the space inside the Caliente Horseshoe to around 24" to allow for more scenery. Also since this is an alcove and not an aisle, it doesn't factor into the minimum aisle figures and should only be used for one operator or for maintenance only (that's my story, and I'm sticking to it). :)
  19. 3DTrains

    3DTrains TrainBoard Supporter

    Here's the upper level revision. Not much has changed, however.


    I'm not fond of Summit being directly over Walong, so I'm going to try an adjust so that at least the end of Summit Switch is above the nod-under at Walong.
  20. jagged ben

    jagged ben TrainBoard Member

    Nice to see things progressing...

    Just one big comment:

    If you're modeling the 1950's, I don't understand why you changed Ilmon to double-track. That area was single track until after the flood in 1983.

    Compare 1971...
    To 1984...

    Here's a picture of the flood damage:

    Hope you saved your first version of Ilmon. ;)

    One small comment about Walong. If you want to be more prototypical, I would move the turnout for the helper pocket some distance away from the turnout for the siding.
    On the real loop they are not right next to each other like that.

    Woodford looks great, now.

    Regarding grades, from what you said in your last reply I think you'll be able to run trains as long as I run on our club layout. Should be pretty spectacular.

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