Tunnel Construction

[mkblk]

Since I'm getting ready to start construction on the BVRR, I thought I'd resurrect this thread as I'm planning 2 tunnels. As suggested by *** Friedman, I'm limiting the length of each to 4'. The overall length was to be about 10', but by breaking it into 2 four foot tunnels with a two foot trestle between them, I'll be able to reach inside from either end to retrieve whatever disaster may be found within.

In the supplement to GR's, "Beginning Garden Railroading" brochure, a concrete tunnel by Larry and Pam Webb is shown. Is there an article in GR that details this particular type of construction? The current issue of GR shows a massive corrugated pipe type construction that is a little too "wow" for me (how do you reach inside?).

MK

[Michael Smith]

Tunnel Lining. I emailed my local public works department and asked if I could come by and pick up a small piece of 12" diameter water main pipe. PVC cut off the dumbell at the end and I now have a 5' long free tunnel lining.

[d4fal]

My scale is a ride on scale (3 inches to the foot). I require a fairly substantial size tunnel with safe clearances. I still find ideas here that help even me out. Prototype scales are very helpful too.

For a smaller layout, access is key. Tunnels short enough to reach inside will go a long way. Any derailment that happens inside the tunnel would be hard to fix. Having an access portal in mid run might be key, infact neccessary if the tunnel to quite long.

[Anonymous]

QUOTE: Originally posted by d4fal

In my scale, that is a formidable project

What scale do you use?
Scott

[Dick Friedman]

Rule #1: Don't make the tunnel longer than you can reach inside to clean out.
Rule #2: If you MUST build a longer tunnel, make some access hatches, or build a snow shed that partially open.
Now for a suggestion. If the area is dry, redwood 2 by 10's for the sides and top work fine for many years. For a more permanent set up use concrete pavers.

[d4fal]

Depending upon scale, of course, and how big you want this tunnel, the most important part is how the portals look and the functionality of the lining that no one should be able to see anyway. As long as it supports the load above the tunnel, almost anything would do. Temporary tunnels could be mocked up with plywood covered in plastic then overlaid with the dirt covering. Once this is done, and you decided that you like the placement, clearance, etc., you could consider a more permanent structure. In my scale, that is a formidable project, but in G-scale it could be done in pressure treated lumber, and depending upon budget and how long you plan on keeping the tunnel there, you could use a water proof liner and exterior grade plywood. Doubt concrete is really called for in this scale. Seen timber type construction done with treated boards, but that is frowned on in a garden where the treated wood could harm your plants.

[bman36]

Marty,
Did'nt think of it until you mentioned it. Sound would be more realistic given the right conditions. The tunnel I will be finishing this spring will be concrete blocks covered with stone. Hope it sounds good. Later eh...Brian.

[Marty Cozad]

One more thought: When running a sound unit really sounds deep and good in this tunnel, VS a plastic pipe with hollow sound.

[Anonymous]

Thanks for the tips. The first pic is really helpful. The end result looks very good.
Scott

[Anonymous]

Nice Senco Pinner marty, I have one too and strangly enough a dog named Senco, named after the Co.

Carpenter matt

[Marty Cozad]

I make mine in 3 parts, base ,sides,ends. I used CCA wood because its cheap, I coat the inside with mortar so an onboard camera will think its a real tunnel. Then the ends. Heres some links that may help more than words.
http://1stclass.mylargescale.com/NTCGRR/tunnel2%20002.jpg
http://1stclass.mylargescale.com/NTCGRR/newtunnel111.jpg
http://1stclass.mylargescale.com/NTCGRR/newtunnel4%20001.jpg
I need to find the finished photo...
OH be sure to allow for the roadbed height. note the gundersons just fit.
http://1stclass.mylargescale.com/NTCGRR/ditchlight3%20001.jpg
I use 20' dia curves so I placed a one third curve at each end of a 5ft straight section so going into the tunnel it looks black and not just a hole ,yet is easy to vacum leaves out of.

[Anonymous]

To trainmaster, just remember what is going to "live" in your tunnel. From my experience, cats, snails etc its the worst place to keep the rail clean so whatever you finish up using make sure that you can get inside to clean the rails.

[Anonymous]

Thanks for the advice I'll look into it.
Scott

[Anonymous]

In the past issue of Garden railroading, in a feature article, the guy made a stainless steel tunnel liner, but he used thst to go under or through concrete steps. I myself would use some thick wall PVC pipe 8inch or so and lay ballast in the bottom with holes drilled in the bottom side of the pipe smaller than the ballast for drainage and than used rock or wood for your tunnel portholes on the ends. I would paint the inside black as far back as i could as well.


Carpenter matt

[Anonymous]

Well Scott I don't know much about this subject either I was hoping you would, that is why i logged in to this subject.

I have had a few ideas and seen a few things at other peoples layouts. I had ideas of using a 250 mm (10") plastic water pipe, many real rail tunnels are nearly round. I saw an artle in the German Depetch (LGB) magazine and they used "U" shaped concrete moulding, with a matching paving stone on top. They put this all in a trench and filled dirt on top of it after getting the track in first of course. This looked beaut to me but I couldn't get the real guts on iy as i don't understand German.

An important thing seems to be to have an acess chamber in the middle incase of a misshap.

Hope this helps rgs Ian

[Anonymous]

I would like to construct a small tunnel into a dirt mountain on my garden railroad. Unfortunately I don't know what type of lineing i should use.
Scott