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Tunnel profile clearances

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Tunnel profile clearances
Posted by Anonymous on Wednesday, November 3, 2004 5:49 PM
Hi all,

I went round to a fellows house the other night, and he was proudly showing off his new Bachmann 2-8-0. I thought; wow that's a BIG loco, I hope it will fit through the tunnels I am planning.

The stuff I build is 1:24 New Zealand prototype, and when you put it next to some of the 1:20.3 models around it looks quite small.

Now I want to build a tunnel, and know that if someone comes around with a 1;20.3 loco it's going to fit through it.

Is there an official set of maximum height and width measurements for G scale, that all rolling stock from all manufactures will fit through?
And is it on the net anywhere?

If not there needs to be (and yeh, I'm trying not to start that that scale debate off again [:D]).

Thanks in advance,
Glen Anthony.
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Posted by vsmith on Wednesday, November 3, 2004 8:33 PM
When it comes to the Connie all previous standards are out the window, take your standard LGB 1/22.5 clearances and add 20 %. Thats a big puppy but not as big as an Accucraft K-series. Someone here should be able to give precise dimensions.

   Have fun with your trains

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Posted by Anonymous on Wednesday, November 3, 2004 11:30 PM
Really when I have asked they say 11" from the top of track.
Gut feeling tells me different [%-)]
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Posted by Kiwi Down Under on Thursday, November 4, 2004 1:48 AM
Glen
With all the clearances etc the one I got caught with was the width and a slight curve in the track. Not enough clearance for the overhang parts on the curve.
All clearances were correct, except all was for a straight track into the tunnel..
Never thought of that until I had nearly finished.
If you do NZR coaches to proper scale there going to be rather wide and high for commercialy available locos. I finished up enlarging the HO plans on the photocopier until the plans were in scale with the Bachman wheels. This made them the same height as the Bachman Big Hauler Loco, but a bit of artistic licence (5mm) was needed so that they became the same width.
Tony.

Tony.
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  • From: Rockville, Maryland
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Posted by van buren s l on Thursday, November 4, 2004 6:57 AM
Glen
Glen

Rather than worrying about scale dimensions for your tunnel you may wi***o consider
just measuring the height and width of your friend's loco and adding a few inches all around, particularly if you have curved track on the approaches to the portal.

I had a clearance problem with a truss bridge that I built to scale dimensions a couple of years ago. Last winter, on a whim I built a Baldwin-Westinghouse electric loco. With the trolley pole up the loco couldn't pass through the bridge nor could it go through on the track that ran under the bridge (my layout is a convaluted figure eight). The remedy in volved building a new bridge and about eight feet of trestling to raise the tack up to the new level of the bridge abutment. It will also involve changes to the landscaping which will have to wait until Spring.

Good luck Bob














Glen



r


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  • From: Australia
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Posted by Gary Crawley on Thursday, November 4, 2004 10:40 PM
Glen
When I built my tunnel all I did was look on the net for the specs of most of the Locos I would ever use and add an inch all round.
I have a Bachman Mogul and it fits ok.
BUT the big test was my very large FAT cat who runs and hides in the tunnel, so if she fits anthing will.
Regards
Gary
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Posted by Anonymous on Friday, November 5, 2004 7:51 AM
Hi glen
Nice removable scale tunnle mouths to suit your local loading gauge
with an elephant sized tunnel behind it.
and let visitors know how big the tunnel is so they leave thier giants at home[:D]
regards John
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Posted by Anonymous on Friday, November 5, 2004 9:36 AM
there's nothing like that thud noise when going in to a tunnel ouch!
when visiting rr were they let you run what you brung.
let them look at what you brung to run and ask is it to big to run your RR?
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Posted by Anonymous on Sunday, November 7, 2004 5:43 PM
QUOTE: Originally posted by train-me

there's nothing like that thud noise when going in to a tunnel ouch!


LOL. The thud noise. What about a scrape noise? Friend of mine has a long tunnel make from plastic pipe, so it it should be the same size the whole way through right? Wrong! [}:)] There is more ballast under the track in the middle.

One guys train went in. Loud scraping noise. Came out without the cabbose, which had got wedged in the middle. Tunnel too long to reach from either end, so locos dispatched back in at high speed to ram it back out again. Lucky no damage.

Glen.
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Posted by Anonymous on Sunday, November 7, 2004 6:01 PM
Glen;

It is not like me to quote from the bible or to mention parables but you remember the one about the man and his son taking their donkey to market, ie please yourself and you please every one.

I have just finished my "Vampires Tunnel" and it works wonderfully, looks terrific and was easy to build, i only run LGB at 22.5 : 1 so that is all i allowed for; any one else can worry about their own problems.

I have used 225 mm say 9" storm water pipe and with the portals at each end i have made them out of Jigstones parts that I also bought for my viaduct spans, the whole thing is a working, workmanlike project of which i am proud.

Hpwever if what Vic says is correct and I 'm sure that it is; try adding 20 % to what I have done eg 225 X 1.2 = 270 mm pipe or 11" or you may have to go to 300 mm or a foot. dia. It will be double the price and will look grosse and unecessary if you are not going to go that way tyourself. If your friend wants to give his stuff a run on your tracks let him bring around something to suit your track.

You can only run LGB MTS trains on a lot of my layout, particularly the reversing loops; so I just tell people in advance they can either bring something that will suit the local
conditions or just come yourself and enjoy the companionship.

If you would like to see the tunnel as it is and how it was; send me your email address and i willsend you some pics


Rgds

Ian

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