# Building a Tunnel, What Size Openings to Allow O Gauge Trains thru?



## LFM

I am looking to build a train tunnel for my nephew and wondering how large the openings need to be to allow a New Lionel O Gauge 3 Rail Trains to pass thru? What is the widest engine or car as to make the openings wide enough as well as tall enough to get them thru?

Any information on size would be helpful. Trying to build something from scratch I know the track is 3.5 inches wide but not sure of the engines and cars being many different ones?

Thanks,
LFM


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## T-Man

Well at least a half inch higher than your tallest car. I saw a surfliner today in O scale it was huge!!.
I have a foam tunnel that cover an 027 corner. This is a worst case since the engine has to swing out of a curve. I will get the dimensions. 4 1/2 wide by 5 7/8 high. Inches.


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## Boston&Maine

Those sound like good dimensions T-Man... The single portal which MTH makes has an opening of 4-1/4" by 5-5/8"...

http://www.mthtrains.com/detail.asp?item=40-9014


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## T-Man

The tunnel is an old foam piece I got at a yard sale for a buck. Part of my instant scenery series!:laugh: Probably made by the company that does carpet grass ( another favorite). 
Anyway the Amtrack was impressive. If you travel through York ( for you outlanders, MAINE not Pen.) stop by to see it.
I also checked a Lionel trestle. 4 1/2 inches rail to rail. The tie closed the gap to 4.


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## LFM

Thanks alot, I had ia layout of 3.75 wide X 5.5 tall. Glad I checked I will make it 4.5 x 6 should not have any issues with future train engines or cars that come out...

Appreciate the prompt replies and information...

Take Care,
LFM


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