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Tunnel Portal

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Tunnel Portal
Posted by streetspook on Thursday, July 9, 2015 5:03 PM

Hi all and thanks in advance for the advice and even the good natured ribbing I'm sure I will get. To the point, I have laid a double HO scale (code 83) track where it goes into a mountain. Bought two random stone tunnel portals. One works fine, however at the other end my track is spaced "just a bit outside" the regular width. I need a portal that has an inside dimension of no less than 5.5". Most of these are in the 4.75" range. Any suggestions or can you point me to a manufacturer that makes em a bit bigger. Or, do I get to try my luck at free handing a wooden plank portal? I was really hoping to match the portal that is at the other end. See, I thought I was ahead of the curve by giving myself a little more than the regular width for car clearance so I didn't have to worry about cars tapping each other inside a tunnel. 

Thanks again for the help..

Bill

 

******UPDATE  7-11  **********

Thank you all for your good thoughts and ideas. I just knuckled down and moved one track closer to the other and nailed it in place. It was difficult because of lack of space but I'm pretty sure it's over enough now.

Thanks again

Bill

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Posted by davidmurray on Thursday, July 9, 2015 5:08 PM

Bill:

Have you tried looking for a 3 track tunnel portal.  You could probably cutt out a piece in the centre, and put the edges back together.

My advice is worth what you pay for it.

Dave

David Murray from Oshawa, Ontario Canada
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Posted by streetspook on Thursday, July 9, 2015 5:17 PM

Thanks Dave, I didn't know they made such a creature.  It's off to eBay I go!!

 

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Posted by davidmurray on Thursday, July 9, 2015 5:21 PM

Bill:

I just looked my Walthers catalog:  they don't have a 3 track portals.

Looks like you will need to bodge two doubles to fit, or else scratch build a wide one.

Sorry about the first suggestion, unless eBay works.

Dave

David Murray from Oshawa, Ontario Canada
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Posted by streetspook on Thursday, July 9, 2015 5:25 PM

Nope, I couldn't find one anywhere. I guess I could try and bash two together but at first glance I might need three or four to get it wide enough. It seems the top curves downward relatively quickly from the center, thus not leaving much room to "cutout" a straight portion to plug in the middle.

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Posted by tomikawaTT on Thursday, July 9, 2015 6:18 PM

If you want to try your hand at a fairly easy scratchbuild:

  1. Plot the opening arch on a suitable backing material - pine 1x6, thick styrene or whatever.  This is your base for building up the surface.
  2. For concrete just sand super-smooth, add the equivalent of lintel and other details by laminating sheet and strip stock to the base strate, then prime and paint an appropriate concrete grey, possibly with moss green at the bottom and that soot smudge over each track.
  3. For cut stone, laminate a layer of linoleum to the base (finish side against the base) and carve stonework details into the linoleum with small chisels.  Remember to keep it fairly symmetrical - a commercial product will provide a suitable prototype from which to deviate.  Coloring the stones will be a bit more work after spraying concrete color for the mortared joints.  (This method was popular with John Allen.  I did similar things 'way back when, and will be using similar methods as my scenery needs develop.)

Good luck, and have fun.

Chuck (Modeling Central Japan in September, 1964 - with concrete and cut stone portals)

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Posted by mlehman on Thursday, July 9, 2015 7:09 PM

Carved linoleum is a traditional method for cut and random stone, but the low prices for sheet goods embossed with decent patterns make them a ready alternative. JTT is one brand, with Wee Scapes another, essentially the same stuff only cheaper. I can Wee Scapes at the local art store for about $4/pkg of 2 sheets.

I haven't done any portals with it, but that sounds pretty easy to do.I generally attach it to a backing of wood or foamcore by spraying the back with 3M 77 adhesive and it sticks well.

 

Here's a few pics of structures made with random and cut stone sheeting from the 2 suppliers named above.

Purgatory station

The 9 Lives Cat House

Retaining wall at the Merry Widow Mine

Mike Lehman

Urbana, IL

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Posted by skagitrailbird on Thursday, July 9, 2015 7:20 PM

Bill,

Who is the maker of your tunnel portal? Of what material is it made? How thick is it?

Roger

Roger Johnson
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Posted by Anonymous on Thursday, July 9, 2015 7:25 PM

Bill,

Page 48 of the August 2015 Model Railroader has a short article on how to make a tunnel portal.

Andrew

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Posted by BroadwayLion on Thursday, July 9, 2015 8:44 PM

Cut the portal in half in the middle. Put one half on each side. Disguise the gap with some foliage.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by skagitrailbird on Thursday, July 9, 2015 10:06 PM

Bill,

Another thought: how difficult would it be to re-lay one or both tracks bringing them closer together?

Roger

Roger Johnson
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Posted by Phoebe Vet on Friday, July 10, 2015 8:18 AM

If there is room for a narrow support between the tracks you can make something from two singles.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by streetspook on Friday, July 10, 2015 10:21 AM

Thank you Chuck for the tips. You've given me food for thought. I'll look around at what is available out there and decide how much into the weeds I want to go.

 

Bill

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Posted by streetspook on Friday, July 10, 2015 10:24 AM

Thank you Mike for the pics. Great work there! Hope my feeble attempts at least approach your finish. I'll look into your suggestions. 

 

Bill

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Posted by streetspook on Friday, July 10, 2015 10:25 AM

Andrew, I have that issue, it's been waiting for me to have some quiet time to sit with it. I'll check it out, thanks.

 

Bill

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Posted by streetspook on Friday, July 10, 2015 10:28 AM

Hi Lion, good to hear from you as always. I looked at doing what you suggested but I'm leaning towards trying to find/create a solid one but your idea is definitely in the plan "B" file. Thanks

 

Bill

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Posted by streetspook on Friday, July 10, 2015 10:30 AM

Thanks for the thought Dave. There is room for a very thin support if I don't want to eliminate my safety factor for oversized loads but I'm not sure if that would solve my problem with matching the tops where they come together but I'll give it a ponder.

 

Bill

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Posted by streetspook on Friday, July 10, 2015 10:34 AM

Hi Roger. I gave moving the tracks a quick look and shied away from it at my initial reaction but that may be the way I go if I can't find a reasonable way to make one. I'll text or email you later with the details of what I have.

 

Bill

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Posted by Steven Otte on Friday, July 10, 2015 4:30 PM

If your tracks are too far apart for a standard double portal, then you may be able to do something with the space in between. Try using two single portals, but instead of side by side, stagger them slightly. In between, run a vertical retaining wall parallel to the tracks. I'll do my best to make a simple diagram from type...

- - -_(————
- - (——————

...is that clear enough?

--
Steven Otte, Model Railroader senior associate editor
sotte@kalmbach.com

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Posted by selector on Friday, July 10, 2015 4:32 PM

Here is a W/S double wide concrete portal, but with a plug filling the vertical split halfway through the keystone.  I tried using carved extruded insulation foam board and also a shaped piece of retaining wall of the same plaster, same provider.  Both worked.  I used a light smear of DAP Alex Plus white caulk as an adhesive.

 

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Posted by streetspook on Friday, July 10, 2015 6:02 PM

Thanks, great job on that. I want to try and match what's on the other end of the tunnel which is random cut stone and I think that will give me lots more trouble trying to match up the pieces then flat concrete but it may be the way I go. Thank you.

 

Bill

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Posted by streetspook on Friday, July 10, 2015 6:08 PM

"IS THAT CLEAR?"  "Crystal".   Hi Steve, got it and that may be the solution. I'll have to do some real critical measurements and decide. I really don't have lots of room. I'll try to attach a pic or two, hmmmm. Tried sending pic from my phone to my email. Still waiting on that. If I get them I'll try and add to my post.

 

Bill

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Posted by SouthPenn on Saturday, July 11, 2015 8:52 AM

Buy a retaining wall of random stone from the same manufacturer of the portal. Cut a piece of the retaining wall and install it in the center of the cut in half portal.

South Penn

 

South Penn
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Posted by RogerThat on Saturday, July 11, 2015 4:07 PM

Here is a picture depicting what Steven Otte suggested.

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Posted by richhotrain on Saturday, July 11, 2015 5:12 PM

How about an S scale tunnel portal?

Rich

Alton Junction

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Posted by streetspook on Saturday, July 11, 2015 8:16 PM

Hi South Penn and thanks for the advice. I would probably use that method except I knuckled down and pulled up one set of track, actually I just dislodged it from the glue and shoved it closer to the other set. I think I have enough room. Obviously I will take it real slow with the first run through that tunnel.

Bill

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Posted by streetspook on Saturday, July 11, 2015 8:18 PM

Rich, thanks for that thought. I would look at that as a definite possibility except I just knuckled down and moved one track closer to the other. I'm hoping it was enough. We will see, come the first run through that tunnel.

Bill

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Posted by richhotrain on Sunday, July 12, 2015 4:32 AM

streetspook

Rich, thanks for that thought. I would look at that as a definite possibility except I just knuckled down and moved one track closer to the other. I'm hoping it was enough. We will see, come the first run through that tunnel.

Bill

 

Here is a link to some S scale tunnnel portals at Walthers.

http://www.walthers.com/exec/search?category=&scale=S&manu=&item=&keywords=tunnel+portal&words=restrict&instock=Q&showdisc=Y&split=30&Submit=Search

Rich

Alton Junction

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Posted by zstripe on Sunday, July 12, 2015 7:18 AM

My vote is for Selector's way. I have done it before with random stone.....what ever You decide on...make sure Your tallest rolling stock will fit under the side arch's and long cars on the inside if a curve, will not hit the side arch.

Have Fun! Big Smile

Frank

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Posted by richhotrain on Sunday, July 12, 2015 8:07 AM

zstripe

what ever You decide on...make sure Your tallest rolling stock will fit under the side arch's and long cars on the inside if a curve, will not hit the side arch.

But, of course.   Huh?

Alton Junction

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