I used a 230 mm or 9" storm water pipe for one of my tunnels and i actually make my own portals out of concrete (cement) using a Jigstones kit.
Rgds ian
One suggestion: Aristo and probably the other manufacturers as well sell prefab face plates for one-track and two-track tunnel entrances. (Here's a link to Aristo's tunnel portals.) That might be a good place to start to determine a minimum dimension for the entrances.
I have several tunnels even a double decker, but what i have doen which would be of interest to you is that i used a 230 mm (9") storm water pipe that was on sale at a plumbing supply place. It is 1.8 m (6')long and i did have a bit of trouble with it initially but its been on for a few uears now. I have a jigstone kit and made tunnel portals out of small concrete (cement) blocks.
My theme is middle Europe pre WW2.and i have all concrete type stuff and it is quite a different look to most.
It's really a simple straight forward process. I have a double track tunnel running under my waterfall and this is how I did it.
First, determine the area you will need to make the tunnel. Do this by laying down your track at the place you have determined the waterfall will be. Assuming you are using a tub with a spillway to act as your waterfall, if you have that handy, set it down on top of the track. If not, go to your nearest garden center or pond supply place and measure out the one you think you'll want to use.
Looking at the footprint of both the track and tub, give yourself at least two feet in all directions and mark it. You may even want to consider making the waterfall side even larger so as to support whatever stones you will be placing beneath the spillway. Dig this area down about four inches and fill with concrete, creating a pad for which your track, tunnel materials, waterfall, stone, lining, and whatever else you may use to create your waterfall. All of these things combined, gets very heavy. A sturdy base is important.
Give the base a week or two to cure and then re-lay the track where you want it. At this point, I highly recommend that you screw the track into the concrete. The length of your tunnel will most likely be short enough that you need not worry about expansion or contraction at this point.
The materials that I used for my tunnel were 12" x 12" x 2" pavers that I got from Home Depot. These were my walls. The width of my tunnel, BTW is 16" due to the double track. I later created portals that reduced the size of the opening. I used concrete construction adhesive on the bottoms sides and tops to glue everything together. For the roof of the tunnel, I used leftover PT 2" x6"'s. to keep the tunnel walls from leaning forward or back, I places 4" to 6" pieces of PT 2" x 2"'s on both sides of the tunnel walls so that it created an interlocking effect. This is an important step and gives your tunnel strength.
Once the glue has set (24 hours is plenty), cover the entire tunnel with the same rubber lining you used on your pond. It's UV protective and waterproof and no water will enter your tunnel.
On the roof of my tunnel, I created cribbing by ripping down PT 5/4 deck boards down to an inch in width and then stacking them lincoln log style making sure to nail/screw the joints together for rigidity.
The only thing you need after that is to make sure that you have enough pond liner to protect the entire hillside that you have just created. Make sure to place the liner as close to the underside of the spillway as possible and that the stones sit on top of the liner. I've included a couple of pics to clarify things.
Mark
Okay, who knows how to post photos in this new format? I have photos that I can add but can't see how to post them.
James http://railway.skeenapacific.ca
Thanks for the answers.
I'm proposing to use 'G' scale 45mm track with the smaller Euro rolling stock, but just in case would make the tunnell able to take the larger US stock.
However as the whole idea is a long term project and next summers starting layout wouldnt include the tunnell area, I'm now wavering with the idea of ignoring it for now. Rebuilding the waterfall for a temporary two year construction and then seeing if my idea remains the same then.
This obviously gives me the chance to experiment and learn with much easier constructions first :)
I must be looking in the wrong places but nowhere have I actually seen things like the actual loco dimensions etc.
Tom Trigg
Hi Bpbill
I am afraid the answer is not going to be very help full .
The loading gauge is determined by your trains IE height width. not knowing what trains you want to run or the scale or not of your trains makes it a bit hard to give a definitive answer.
However don't make the tunnel longer than you can comfortably reach or make sure you have real good hidden access to the tunnel.
Also keep your tunnel straight remember to put track bed and track in the tunnel when you build it.
Do a good job of the track work as it is a potential trouble spot for later
You are wise wanting an oversize bore you never know what is going to come visiting in the way of trains.
Just watch out for bunnies and other critters that might want to make a nice home in your tunnel.
Oh don't forget to put the cess drains each side of the track to drain water out of the tunnel cast them in the concrete tunnel floor along with the track bed.
that's the best I can offer in advice
regards John
Hi
Im currently landscaping part of my garden to change a waterfall. However I would like some time in the future have a garden railroad passing through a tunnell under the waterfall.
What I would like to know is how wide and tall are tunnells expected to be. I will be making it oversize, and probably having some sort of face plate on the entrances. However as the Garden Railroad is a plan for the future I havent as yet any idea on what sort of dimensions I'm looking at.
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