## Re: [z_scale] (unknown) Tunnel portal

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• Andy Just remember, tunnel portals over a curved piece of track must be extra wide. Passenger cars on sharp curves overhang the track in both directions. Put
Message 1 of 2 , Aug 9, 2000
Andy

Just remember, tunnel portals over a curved piece of track must be extra
wide. Passenger cars on sharp curves overhang the track in both
directions.

Put your longest car on your sharpest curve and place a block of
something on either side. See how wide it must be for your train to
pass through without hitting. Take your tallest(?) piece of equipment
and that would be the height of the portal.

depends on the length of your trains. Short trains can take fairly
steep grades for a short distance. Grades on curves cause greater drag
than grades on straight track. Connect some track together and
experiment.

Have fun.

Bill
El Toro
• Thanks, Bill K. & Bill H. I found some good-looking Z portals on the Web that measure just under 4 cm high with more than 3/4 of the height taken up by the
Message 2 of 2 , Aug 9, 2000
Thanks, Bill K. & Bill H.

I found some good-looking Z portals on the Web that measure just
under 4 cm high with more than 3/4 of the height taken up by the
opening, so I'll go with the 3cm inside / 4cm outside rule of thumb
for now.

The HO drainage-culvert approach is creative! One scale's plumbing is
another scale's tunnel; I could name my RR the Plumb Line. <grin>
Okay, maybe not, but I'll try your suggestion next time I'm at a
hobby shop.

Good point about the lateral clearance around curves. I'm eagerly
awaiting my "Capitol Limited" Pullman set, and those cars are plenty
long. I've done away with virtually all the small-radius (#8510)
curves in my layout plan, since they just look too small. If I have
to use them, they will be hidden in a tunnel somewhere.

it
> depends on the length of your trains. Short trains can take fairly
> steep grades for a short distance. Grades on curves cause greater
drag
> than grades on straight track. Connect some track together and
> experiment.

What? An excuse to play with my trains? :D I'll tell my girlfriend
it's all in the name of Scientific Research. She'll understand.

To get to the necessary height, my trains will either need to climb a
relatively straight track at a steeper grade, or else climb a more
manageable grade with more curves. So I'll see which slows them down
more.

Jeffrey, good luck with the rest of the trip; hopefully you're home
by now. My one trip to Redding, CA was via Amtrak a couple Decembers
ago. A fun ride from Seattle with some breathtaking mountain scenery,
moonlight on snow. But we underestimated how cold and tired one can
get waiting by the tracks in Redding at about 2:30 in the morning.
I'd never been so happy to see a train in my life!

-- Andy
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