Tunnels!?

[dukebasketballer`]

Hi guys,

I am in the process of expanding my layout and have plasn to add several tunnels. What is the best way to build a tunel? What are the best materials to use to close in the tunnel?

Thanks

[two tone]

Hi remember rule 1 do not make tunnel more than 2 arms lenth so that you can reach a loco if there is a problem.  2 tunnels can be made by bending strng wire tothe shape you want then cover shape with small mesh chichen wire.  3 Cover this with any thing that will hold the shape IE old bed sheets blankets. 4 To make a hard finish and to shape it talk to your local biulders merchant he will advise you on what to use, remember you do not want a lot of wieght it the construction     Hope this helps

[Anonymous]

As usual i largely disagree with what has been said mainly about the two arms length stuff.

I can speak with some authority as i have 4 tunnels and they are all different, for different reasons. One is 1.9 m (6.3') another is 200 mm (8") and the other is a double decker 2.8 m (9.3') long and i have used 3 different construction methods which suited the situation at the time. The little one is two overlapping holes bored through a concrete (cement) wall. The double decker was a cutting betwen the pool pumphouse and the back fence, that we covered in and the other is most interesting in that i used a 220 mm (9") plastic storm water pipe and i cut a 150 mm (6") section out of one side over its entire length and that become the bottom through which the track passes.

The amount of trouble i have with 3 of them is not worth talking about and if anything gets stuck i send my big Mallet through and it will push just about anything out and in the rare occasion that doesn't work, i use a bit of wood and push it out, even a mop used backwards will do. The other one the storm water one; i did have trouble with but it was my own fault as i didn't do the job properly in the first place.

Rgds Ian  

[ttrigg]

I am in the process of expanding my layout and have plasn to add several tunnels. What is the best way to build a tunel? What are the best materials to use to close in the tunnel? 

David
"What are the best" Man do I ever hate that question!!!!!!!!!!!!  What is best for me could very easily be the worst of all possible choices available to you!!!!!!!

Two Tone says to keep it light.

I'm going to tell you a way to make it VERY heavy and durable.

In my case, the tunnel had to travel under the waterfall box for my Koi pond.  I used 8x8x16 cinder blocks, re-bar, concrete, 2x8x16 cinder block top caps, and about a thousand pounds of rocks and over a dozen bags of mortar, and about 20 boxes of different concrete color powders.  To build the tunnel I laid down two rows of cinder blocks twelve inches apart on a concrete foundation.  I dry stacked a second row of block using a half block at each end to get the normal staggered stack.  The top row of block had 4 notches cut out of one side of each block.  I bent re-bar into a "square U" shape large enough that it would reach from the bottom of one wall, span the gap to the other wall and down to the bottom of it.  I then mixed concrete and filled the slots in the blocks, securing them via the re-bar.  I then spanned the gap between the two "walls" with the cinder block caps, these sit directly on top of the re-bar.  Since I needed to waterproof the tunnel, remember it goes under the water fall box, I then covered everything with several layers of roofing felt (tar paper), then a layer of pond liner membrane.  On top of this I put the waterfall box along with the required PVC pipe.  Then I covered everything with rocks held in place with mortar.  As you can see I needed to go heavy and strong.



Now on the other extreme, get some hardware cloth (very heavy screen wire), some burlap, and some mortar mix.  Build a framework for a mountain by bending, cutting the hardware cloth into a rough shape of a mountain, cut the burlap into strips, soak in the mortar mix and start coating the wire frame with these strips to create a mountain. (Much like is done with paper towels and plaster for indoor layouts.)  Add some color and you have an outdoor version of the paper mache tunnels available from most vendors of the indoor scales.  Light enough it can be carried (by two people) and sturdy enough to withstand some weather (but not high winds.)

Some folks use large diameter plastic pile or chimney flu tiles, flop them onto the ground and cover with dirt.

Now I'm going to ask you, "What is your intent for this tunnel?  Is it just to have some place to drive the train under?  Or will the tunnel be a support for something else within the layout?"

"What is the best way to build a tunel?"  That depends on what you intend to do with it.  Restate you question with a bunch more information describing your needs and desires and what you want it to do, and we should be able to come up with several recommended solutions that will fit your needs.

[Mike Dorsch CJ&M r.r.]

I used 6"x12"x2" pre cast concrete bricks that you can get at Home Depot for around a dollar apiece . Stand them up on a compacted base and mortar them together next to each other . Then use them to form the roof . Then I covered the roof with a landscape fabric and covered it with dirt . Its easy to form around curves or straight sections .

[Anonymous]

Looks GREAT Mike would like to get the engine and the tunnel at a lower shot. You think smaller crushed creet would look ok or higher the effects? Just asking!? Paint it brick red then tint it to older mossy red? Sorry just got to excited about your train there, dang it looks great!

[Mike Dorsch CJ&M r.r.]

Those bricks come in many colors . I just used regular mortar mix . Heres a few photo's I took today of the tunnel .

[ttrigg]

Mike;
In your photo:

It looks to me as if you went that extra step and put in some "timber framing" to "support" the walls of your tunnel.  Looks good, I like it!  If that is timber framing I see, did you put it in while building the tunnel or later?

[Anonymous]

I hate this Tom, but you and i agree once more, there is no best way. Different methods suit different people in different situations.

Do me a favour mate and say something i can disagree with!

On to Tunnel portals, I have a Jigstone kit and as my layout is European between the world wars; i have my tunnel portals made of concrete in a stone pattern, I willpost a photo if i can.

It is the arch span mould pattern modified so its really the same as my viaduct project but used differently.

Rgds Ian 

[Mike Dorsch CJ&M r.r.]

No Tom , actually the bricks come that way . Those are score line groves if you want to break the brick to shorten it . That tunnel is about 5' long and it was real inexpensive to build .

[Anonymous]

A few pictures of my tunnel portals in area 1 under construction a few years ago.

Ian

 

[Anonymous]

Sorry but that is area 3 not area 1 and it is now much more greened with a complete coverage of lawn over the tunnel roof.

You can aslo see my dreaded 4 % gradient with R2 curves under constrction.

Also note club rail 3.69 m in length which i bend myself and cut to size.

Hardly any joins and any shape and size i require.

Rgds Ian

[ttrigg]

Ian:
Is this the infamous 4% twisting turn you constantly state you wish you had never built?



Is that a paved pathway under the bridges?  My wife would never let me get away with something like that.  I'm getting enough verbal abuse from her over a little three inch transgression onto the very corner of the patio where the track turns away from the pond to head out to Vine Arbor.

[dukebasketballer`]

Hey guys,

Thanks for your help and my deepest appologies on the wording of the question. You can tak emy word for it, I will NEVER make the mistake again I really liked the way Mike biult his tunnel with the cement blocks mortered together. That will be the BEST way for me.

Thanks again guys

[Anonymous]

David, what did you think of the portals, i know they are not American more European but i made them myself out of a Jigdstone moulding kit.

Tom yes this over a concrete path, as you know i don't have a backyard as such and this is a courtyard out the back, which we allocated for my railway. I will post a few photos later showing what it looked like before i started, including an idea of tunnel construction. Also photos of the completed thing.

Tom it is not for me to gine marital advice but i had a wife that was hard to get on with and i got myself a new wife; 24 years ago now and it was the best thing i have ever done.

Rgds Ian

[Ray Dunakin]

I also use concrete blocks for my tunnels, although I used Elmer's urethane glue instead of mortar. One thing to bear in mind is that you want good solid ground under your tunnel walls to prevent settling, especially if you will have a sizeable mountain on top of it. Even then you may want to keep the height of your tunnel a little on the high side so that if it does settle over time, your tunnel won't become too low for trains to pass through.

I like to apply textured, tinted cement to the inside of my tunnels, at least near the portals where it shows. This makes it look more like blasted, fractured stone.

I have pics of my tunnels and their construction on my website:

http://albums.photo.epson.com/j/AlbumIndex?u=3009006&a=32116967

[kstrong]

While Ian isn't particularly fond of the "two arms' length" rule to tunnels, I'm here to tell you it's a good rule of thumb. (Or would that be "arm?") Actually, you can go two arms' length plus a foot or two, because all you have to do is be able to reach in and grab the end of the derailed loco or car. Having had the "pleasure" of contorting my body to try to reach inside of one of dad's longer tunnels on more than one occasion, I really don't recommend it for anyone who's--shall we be polite--less than nimble. Yeah, broom handles can work, but I prefer a less destructive method of retrieval.

If you must have a long tunnel, I'd advise against ballast of any kind, and secure the track to a firm subroadbed to keep it from shifting and twisting within the tunnel. You'd also be well advised to block the entrances when not in use to keep leaves and wildlife out. All too many times, I've seen furry and reptilian things scurrying out in advance of the trains.

Getting back to building materials, the cement blocks mentioned above are good. I used a similar technique, using 2' x 2' and 2' x 3' patio pavers for the tunnel on my old railroad. They're set on end into the ground about 10", which keeps them from being pushed inward over time. The top is capped with additional pavers.



Later,

K

[Anonymous]

Well Kev mate, we will agree to disagree on this one. All the best.

Rgds Ian

[kstrong]

Actually, Ian, there's nothing to disagree about. Long tunnels are unavoidable on many railroads. I mentioned my dad's railroad earlier--4 of his 5 tunnels violate the "rule of arm." But in building tunnels or any track where the train is inaccessible, there's an inherent risk. When designing your railroad, you need to take that risk into consideration. If you run collectible pieces, or are all thumbs when it comes to repairs, then keeping your tunnels accessible greatly diminishes your chances of irreparably damaging your prized rolling stock.

It's like building a bridge over a pond. There's an inherent danger of the train getting wet. You can take steps to mitigate the danger (guard rails, etc.) but the only way to completely avoid the danger is to not build the bridge over the pond. When you build a long tunnel, you can take steps to lessen the chance of a derailment, but you cannot completely eliminate it. So long as you're comfortable with the consequences, then there's no issue. If it were my $3,000 locomotive getting pushed out with a broom handle leaving a trail of detail parts and bent valve gear in the process, I'd be seriously rethinking the length of that tunnel.

Later,

K

[Great Western]

Greetings,

             As I have no tunnels on my layout, and at present have none envisaged, I found this a very interesting topic.

  When I started my construction last year I noticed that many advised against tunnels - other then very short ones - for a few reasons i.e. Murphys Law derailments, animals settting up home, and the difficulty of stock retrieval when no longer agile. 

   I see Ians' views and they obviously suit him and maybe he is prepared to risk some possible stock damage, but I go with Kevin regarding that point.

  My No.1 son who lives locally to me was keen to construct a tunnel where the rail line crosses  a pathway which leads on to a lawn.  It seemed a good idea at the time but I realized that it meant steps to negociate, possibly in haste, and therefore a source of injury.

   I haven't discounted the idea of a tunnel entirely but feel that a very short tunnel (not much longer than a standard sized G scale boxcar) could be used as a scenic break and to me that would be permissable. 

     At least in this realm we have very few dangerous reptiles or insects to worry about.    It is interesting that this facet of the  possible problems did not arise  -  I am sure Ian and those in the U.S.A.   could  tell us if this is a problem to them and how they overcome it.

  
 

  
 

[Anonymous]

Yes Kev you do make sense; however i have had my tunnels now for some years and i get few problems and when i do i can rectify them easily by the methods mentioned, with no damage to my rolling stock and i have some very good stuff. (ie a Golden Mountain train pulled by the latest blue crocodile with all the bells and whistles).

I love the tunnels your train disappears and appears elsewhere, very interesting.

The idea of a path is great, you remember all the talk a few months ago about Cyril Freezer the British guru, well he loved to go under paths, then the roof of the tunnel becomes the path or vice versa. I know a great method for tunneling under paths, taught to me by our tame elctrician.

There is an American man; who is respected and revered the world over; who, with his sons jack hammered up his front porch, put in a stainless steel tube for a tunnel, so his trains could run right around his house. What guts, what disregard for his own safety! (wait till his wife finds out)

Rgds Ian  

Rgds Ian

[cutlass12001]

I have 3 tunnels on my garden layout.  The longest one, with a total lenght of just under 5 feet long, was made out of 2 expansion tanks from several old furnaces with the end caps cut out and welded together.  I then coated it with roofing tar to seal and protect and laid it in place.  This one should outlast me.  Then I added two smaller ones made out of terra cotta tile for a large chimney.  This measures 13" x 13" with an inside of 12" x 12".  If I remember right, these were just around 30" long.  I haven't gotten them covered or portals made, but they hold the track just where I want it.  I still have a lot of work to do.  As soon as I can figure out how to add pictures, I will add them to my next reply.

 

[markperr]

One of my tunnels is curved as is the better part of half a ten foot diameter curve.  It's approximately 13 feet in length and has an access hole in the center back.  I've never had a derailment in it but on many an occasion, there have been electrical dead spots after a long period of non-running.  That particular tunnel was made using pink foam insulation covered in chicken wire and mortar.  Were I to do it again, I would use something more formidible.

 My other tunnel is made from 12"x12" concrete paver sides covered by pressure treated lumber, which is in turn covered by EPDM rubber pond liner since the head end of my waterfall into my upper pond begins above the tunnel.  Far sturdier construction.  I have no fears of standing on this tunnel/mountain.

Mark

[mgilger]

David,

My wife made two of the following tunnels.  They are made out of course hobby foam. I'm not sure what you call it.  It's not the pink or blue foam you would by for home insulation, but bought at craft shops. It's held up for 3 years now, with no issues. Before we put it in the ground, she wraped plastic food wrap around it to keep moisture out. Very simple to make.

Regards,

Mark

http://community.webshots.com/user/mvgilger

[Camaro1967]

Hey Dukie, While everyone is arguing about what to make a tunnnel out of, go to your local brickyard, and buy some chimney tiles.  They are about 10 inches square, and you can connect them together,.  Its quick, and works real well.

Paul

Go Terps 

[Saji]

Dukebasketballer,

I found this and just wanted to add some fuel to the fire of questions. I am really just a kid and don't want to impose, but I have a stupid question. In an older volume of the the magazine one man said he used corragaited pipe. But i can't help but guess at how he keeped the track level and how he got it in the pipe. Can someone please clue me in, please

[dukebasketballer`]

Sagi,

 You are not imposing; I too am just a kid. The pipe idea works in certain areas. My problem is that I want to run a double track through the tunnel so I would need some massive pipe. Most people either put a false bottom down low in the pipe or just fill it with dirt. I am now in the construction stages and have decided to use concrete blocks and cement them together.

[pimanjc]

The link is for a post with construction photos for a curved tunnel I built last fall.  The tunnel has a concrete base, block walls, and formed hand cast domed roof.  It uses modified Aristocraft tunnel portals.  Long term plans include the tunnel being almost completely covered with English Ivy.  Tunnel length is about 6ft, with a backside center access port.  The curve is approximately a 9ft diameter.

http://www.trains.com/trccs/forums/989737/ShowPost.aspx

 Picture taken today, during rain storm.

JimC.

[ttrigg]

I am now in the construction stages and have decided to use concrete blocks and cement them together.

David;

Where's the pictures?   

[runawaytrain726]

 one long PVC pipe and cover it with rocks and dirt!

you don't have to listen to me but you can try it and i found it very (suucesful?)!!!

-Steven