Best Of Tehachapi Layout research help wanted

[John]

Kiwi Tim



In this example, my bottom level is 40" @ the top of the frame .. and track is about another 1.5 - 2 inches .. the separation between track and bottom of upper level benchwork is around 16-17 inches .. with the upper track around 59 .. you can scrunch the track separation down by another 2 inches, and still get a good separation .. that would be maybe 1 or 2 more loops on the helix .

[kiwi_bnsf]

Hi Ed,

I know you question is directed at Gary... but here goes:

The stub siding on your Loop (not shown on the drawings) might come rather close to the wall.  Doesn't seem like a straight turnout would fit, but IIRC Atlas is releasing a curved turnout with 15"/21" radii that might work.

The access area behind the Loop seems like it could be tight.  Will the backdrop there be against the wall, or close to the track?

There is room for a 16" aisle on the far side of the loop area. The backdrop would be against the wall, and the layout would end 15" in front of the wall. This will look okay viewed from the main aisle (and may even add a sense of depth).

On my plan the idea is to provide a duckunder (or more like a duck-corridor) under the loop on the inner side (ie where the helix and staging turnback levels are slewed to the right). This should allow 40"+ headroom.

Hope this makes sense

Cheers

Tim

[kiwi_bnsf]

Hi John,

Thanks for your post (and the great picture).

One question - is you finished layout going to have three levels or just the two shown in the photo? (Sorry I can't quite tell if you are adding a middle shelf at the back and right sides of your photo)

I'm concerned how I can cram the following levels in:

----------   Summit deck (60")

18" separation

----------   Transition deck (42")

18" separation

---------    Bakersfield deck (24")


A separation of 15" is the minimum I would be happy with (which translates to ~18" when you take into account the thickness of the decks being at least 3" - although I would have to abandon Tortoise switch machines in favour of something smaller).

60" is acceptable for the top deck, but 24" off the floor is too low for my liking. If I raise the lower deck to 36" then the top level will be raised to 72" and my Dad won't be able to see/reach it and it will be at my exact eye height

Maybe I am overly concerned - I will mock it up in cardboard tonight and see if it is okay in the layout room.

Cheers

Tim

[John]

I only have 2 levels of bench work. I do have a line on the lower level that starts a long slow climb (about 35 feet of mainline) to a 4 turn helix under the stairs ..

My benchwork frame is 3" inches thick from top to bottom .. then I have my track a little higher.

I would not do a 3rd deck below 40" except as staging ..

Because my mainline is an inch above the frame, I can put in tortoises on the upper level without any problems.

[GaryHinshaw]

Tim (et al.) - glad you like the general concept - I had fun thinking about it and I'm learning a lot from your schematics too.  I was especially pleased with the way Caliente fits in there, and I had the same idea about the bridge/road crossing forming the duckunder - just like train-watching there.     But I understand that there are numerous clearance issues associated with this around the walls arrangement...  Here are some answers to the questions that have been posed to help you think about it some more.  Since I'm still at work, I'll answer some from memory and will confirm this evening when I have the CAD available.

* The Bakersfield yard was drawn in at 40" and the typical elevation at Cliff siding was 48", so that is tight.  However, it would be quite straightforward to put a turn or two of helix between Bakersfield and Edison to accommodate a larger difference between Bakersfield and Cliff.   It's also quite feasible to increase grades to 2.5% say, and gain some more difference.  The real key is how low you're willing to make the bottom deck, and high high the top.  If you want to mock something up and let me know what your minimum and maximum ranges are, it would be quite simple to mod the drawings to see how it looks and what the grades are like.  [Note added - I see you posted as I'm writing.  Try the mock-up and let me know.  ]

* It is also worth noting that the transition deck can be quite narrow and, since there are only 2 turnouts, you could make those manual, and make the whole deck "slimline". 

* As Ed notes, another turn between Cliff and Summit would increase that separation.  The current elevation at Summit/Mojave is 60" - about 12" above Cliff.  But the grades are just 2% now.

* The access behind the loop is tight, but it would be easy to pull it in to the room a bit more, if desired.  Presumably this is only for photography and "emergencies".  It should also be pretty simple to make the Loop hill a "pop up" for center access.

* I can also try to add some rudimentary fascias or benchwork to this plan to give you a better idea of clearances. 

In the end, I have to agree that compromise is tyranny!  You are trying to pack a lot of ops into this space...  Another possibility is to abandon the separate staging (or accept it at a lower level) and move Bakersfield back to it's original location.

This is only the beginning...

-Gary

[GaryHinshaw]

Ok, I'm home now so I made a few more renders to give you a better sense of the clearances.  First, I checked elevations in the plan I showed earlier and the upper end of Cliff siding is just about 50", so the 3 decks there are 40, 50, 60" respectively.  Pretty tight, but the saving grace is that there's very little going on in the middle deck.  Here is a render with some more elements incorporated: 1) a benchwork frame along the front edge of Summit composed of 1x3 with the top an inch below track level, 2) a 15-car rack train with 3 SD40-2's on the point (just under 10' long) for reference.  The first shot is from above to show the position of the front of the Summit shelf, with the rack train heading around the Loop (a bit hard to see here):



Then a lower level view with the same train leaving Cliff (through Tunnel 7) heading into the helix under the Loop:



The eye level in this shot is just about 60", a bit of a duck for most of us, but not much. 

So: I think this current incarnation is doable, but tight.  Some options:

* Expand the deck spacing.  It would be quite simple to go 35, 50, 65 for this side of the layout by using (more) helix loops under the Loop.

* Push the middle deck closer to the wall.  Limits scenic possibilities, but alleviates clearance concerns.

There's nothing like a mock-up to really tell though, so have at it.  You'll just have to convince your wife that you can't change diapers now because you have important work to do.   

Gary

P.S. John - very helpful shots!  I'm guessing from the ceiling tiles that this bay is 6' wide?  That would be just slightly wider than Tim's bay.  How's human traffic flow in there? 

[ednadolski]

The autorack train looks awesome even in the renderings 

What is the vertical track separation at Tunnel 9?  IIRC my portals were about 2.5" high, and it takes about another inch or so build up the "fill" over the tunnel.  To get that kind of height, you might need to go 2.5% or more on the actual Loop.  (FWIW, prototype scaled would have a separation of nearly 6").

With a steeper Loop, the curves before & after the East Walong switch are an area of maximum stress when running uphill, since most of the train will be on the curve/grade of the Loop.  I'd recommend a generous radii for these, say 18" to 20"  (I think that's already in the drawing, but I can't tell for sure).  Lowering the grade a bit on these curves could also help.

If you're going to use an access pop-up, then it looks like you could rotate the whole Loop a few degrees counterclockwise, and slide the whole Loop a bit further down toward the back wall.  This would put the lower Loop approach track closer to the wall and create a bit more space to stretch out the aforementioned curves.

[GaryHinshaw]

Ed - this program makes it so easy to churn these numbers out.  Ask and you shall receive...

I double-checked the Loop specs and the inner track is 20" radius with a grade of only 1.9% which produces a crossing separation of just 2.5".  Here's a track level shot:



I agree with you that this is about as little as you could get away with.  My recollection from playing with it yesterday was that 2.3% gave a bit over 3" separation, so I would probably go for that as part of an overall deck spreading campaign.  For fun, here's another shot with a better rendition of the loop-o-racks (lengthened to 20 cars now):



I agree that a pop-up hill would allow a bit more freedom of track placement here, but the back-side access is kind of nice.

Tim - you should listen carefully to Ed's words here, since, unlike me, he has actually built and operated a Loop. 

Cheers,
Gary

BTW, I checked the length of the mainline run and came up with 4.3 scale miles.

[ednadolski]

My recollection from playing with it yesterday was that 2.3% gave a bit over 3" separation, so I would probably go for that as part of an overall deck spreading campaign.

These programs are great, they let you try out a lot of ideas very quickly.

How much separation is a matter of what it takes to make it look right to you, so it comes down to preference.  On the prototype the separation is actually quite large -- more that the height of the T9 portal itself:



This is one of those cases where compromise is a given.  I struggled with this myself for a while, and even with a 3.5" rise you can see is still doesn't come close to the prototype:



With less rise than the 3.5", however, it was starting to look to me like a figure-8 train set effect.

One thing I did to increase the rise was to have short sections of 3% grade on a few segments of the Loop.  These give some height but don't seem to impact performance too severely.

[kiwi_bnsf]

Hi Guys,

So I managed to escape downstairs for half an hour last night to get some mockups done...

I tested the three level sections with representative lengths and widths of card taped to the wall to try out different deck heights. It was fun™


Conclusions:

1. Anything above a 60" height for the top deck is not going to work for me. This preference is based on my eye height, my Dad's eye height. I don't want to be looking up at the trains - I want to see over the tops of the cars to the adjacent tracks and be able to easily reach to uncouple manually as required. I'm not happy using steps in the aisle to increase access for normal operations as it will clutter an already narrow aisle.

2. Anything below a 30" height for the lower deck is not going to work for me. This preference is based on being able to sit on an rollaway office chair and get my knees under the front fascia to allow me to reach into Bakersfield yard.

3. I have a preference for at least 12" of backdrop behind a deck. This is so I can allow the transition from scenery to backdrop and then sky. Also some structures on the lower deck are going to be quite tall (yard lighting towers, lights on highway overpass, and cement silos). 18" is even better as when you are sitting operating the lower deck your eye is not distracted so much by the deck above.

4. The narrowest I would be happy having a deck is 12". This preference is based on wanting to avoid the look of long stretches of tangent track parallel to the wall on a narrow shelf with little scenic depth. I want to have room for nice undulating curves and tangent track that runs at a shallow angle to the wall to disrupt the otherwise parallel look of what is essentially a shelf layout.

5. I want to have the decks at least 6" in height (above the supporting woodwork) to allow modeling at least 3" of scenery below track height and 3" above. I want to capture the feel of the line running through cuts and fills as it crosses spurs of hillside, and in and out of tunnels. This is a signature of the Tehachapi line and is not something I think I can compromise without losing the look of the area.


So this process has been really helpful - a double deck layout (in terms of scenicked trackage) is what I'm comfortable with. Triple decking is a deck too far (for me)!

Thanks again for all the time you've put into thinking about this.

Cheers

Tim

[kiwi_bnsf]

Hi Ed,

Wow I am still blown away/inspired every time I see your loop model! I love the subtle details like all the fence posts, the telephone polls, the scrub and trees, the road and access tracks. It really combines to a look that is so clearly in the Tehachapis.

What brand are your signals? Are they Sunrise? The signal bridge looks great

Thanks for your pointers on the grades. I am going down a similar path to you in that I will accept a smaller than prototypical separation above Tunnel 9. I think I will hide this like you have by setting Walong siding back a bit more from the tunnel mouth to get some ground separation (horizontal rather than vertical).

I am also looking at increasing the depth of the loop benchwork to allow wider curves (the width is restricted to ~5' by the walls). So I should end up with at least a 60" by 80" space for the loop (I can extend this with curved fascia extensions at the widest points).

I am going to stick with a stub access aisle behind the loop benchwork as access via a popup in the hill would be very difficult with a helix and staging turn back loop on the decks below (my shoulders are wider than 18"). Also I want to be able to take photos and "railfan" from the opposite side of the loop


Is your loop going to be part of a larger model one day?

Cheers

Tim

[GaryHinshaw]

Good choice Tim.  [By definition, any choice you make is good since it's your layout. ]  As I said in my initial post of the plan, I just threw it out to stimulate some more thinking about the aisle space -- and I wouldn't be at all offended if you didn't go with it.  I myself would not really want a 3-deck layout either, but I am probably extreme in favoring a low track-to-scenery style single-deck plan (with staging below).  If you would like me to flesh out any more of your current plan in 3rd PlanIt to get a sense of grades, sidings, etc., I'd be happy to give it a shot since many aspects of it could be incorporated into my plan too. 

Cheers,
Gary

P.S. As I've told Ed off-line, I think his rendition of the Loop is the best one I've have ever seen, in any scale.

[AlkemScaleModels]

P.S. As I've told Ed off-line, I think his rendition of the Loop is the best one I've have ever seen, in any scale.

Do you include the Le Mesa Club layout in San Diego in your comparison?

[GaryHinshaw]

Do you include the Le Mesa Club layout in San Diego in your comparison?

Good question.  Last time I looked at pictures of La Mesa the Loop was still under construction.  But I just looked back at the link the Ed posted earlier in this thread and it appears that their Loop is more than 50% sceniced now - and it looks good!  I had been used to seeing shots more like this:

http://www.pbase.com/intermodal/image/102907011

Here the land forms are excellent but the texture is too clean - like zip-texturing.  But here I am dishing out criticism of a landmark layout - so next time I post a photo, I'll stand up and take it as good as I give it.   

-Gary

[AlkemScaleModels]

My recollection from playing with it yesterday was that 2.3% gave a bit over 3" separation, so I would probably go for that as part of an overall deck spreading campaign.

These programs are great, they let you try out a lot of ideas very quickly.

How much separation is a matter of what it takes to make it look right to you, so it comes down to preference.  On the prototype the separation is actually quite large -- more that the height of the T9 portal itself:



This is one of those cases where compromise is a given.  I struggled with this myself for a while, and even with a 3.5" rise you can see is still doesn't come close to the prototype:



With less rise than the 3.5", however, it was starting to look to me like a figure-8 train set effect.

One thing I did to increase the rise was to have short sections of 3% grade on a few segments of the Loop.  These give some height but don't seem to impact performance too severely.

That is a good looking scene. Well done!'