Tunnels

[twhite]

Fergie--I had the same trouble--pianist's forearms, which means they're BIG! On one tunnel, which has about a 45 degree curve, I made the portals removable, camoflauging them with scenery material, so if I have a derailment, I can gently remove the portal and reach in. Unfortunately, the tunnel's in a position where I can't cut access panels. Of course everyone wonders why there's so much brush around the portal, I just tell them the weed train hasn't been feeling up to par, lately.
Tom

[bogp40]

Your NMRA gauge will not allow for side clearance on long equipment, the side overhang may cause interferance with a portal on a curve. Many times portals have to be altered or kitbashed or from scratch in this instance.
Bob K.

[CP5415]

There's going to be a few tunnels on my layout.
As Tom stated, I've been testing the track a lot before the tunnels get built.
From really slow speeds to full throttle, no derailments, including the one curve that's curves around 270 degrees inside a tunnel.
So far the only time I've had problems with derailing, it was the cars fault, not the track.
This does not mean I won't have derailments, but I'm planning for them just in case.
Access panels will be built so that I can access the tunnels without using a fishing rod.

Gordon

[randybc2003]

Check with your cars and locomotives. I once built a door for an enginhouse, and couldnt get my favorite loco throught it. (Woodburning American Standard with Balloon Stack). [banghead] On my latest I said [censored] with dimensions, and sized to clear NMRA standards. Checked it with a track gage, and a husky doublestack. Lots of room, and works just fine, even for guests. [^]

[Fergmiester]

I use to have three but I turned two into "cuts" as I have big forearms that would fetch up on the portals. The remaining one has a guardrail to catcherrant wheels and several holes cut in the shelf, which allows me access to any mishaps.

[retsignalmtr]

i think the NMRA clearance gauge compensates for double stack container cars and auto racks. if the tunnel portal you have is too narrow use a double track portal. i have seen prototype double track tunnels that were singletracked to allow higher cars to fit in the center of the bore with no modifications to the portals.

[twhite]

I've got five major tunnels on my line, and it's pretty impossible to have one without the 'joints' you talk about. The trick is to have the track laid beforehand as carefully as possible. All of my tunnels are on curves, so I made sure that any track-joints in the tunnel were soldered and I ran trains for some time to test the effect of room temperature changes on the track. I laid the curves with a Ribbonrail very slowly and very carefully. And make sure that if your tunnel happens to be on a curve, you test the portals with your LONGEST equipment to make sure of clearances. I mis-calculated on the first portal, and one of my articulateds had an overhang that dinged the portal, meaning I had to tear the portal (and adjacent scenery) out and re-position it. It wasn't fun.
Hope this helps.
Tom [:D]

[locomutt]

What era are you modeling?
For modern day and age,13+feet is normal,but if you are
modeling an earlier time span,it is going to be different.

( today,most semi-trailers are almost 13 ft. tall)

[TRENT B]

I'm my 2nd layout but its the first detailed one I've done. I was convinced that its better to have no joints in a tunnel but some say, " It don't matter."
Also car tunnel for HO. I need a height before a entrance plate is bought cuse limited $. All you pros please give me your wisdom! Thanks!!!