Tunnel Portal Inside Width

[Anonymous]

How wide is your typical double track tunnel portal in the opening? My double track mainline has 2 1/2" centers since I have several spots along the line where I need to place ground throws between the tracks, thus 2 1/2 instead of 2". Are the typical portals wide enough for this or do I need to bring my parallel tracks closer as I approach the tunnel entrance? The widths shown in the various catalogs are outside diamentions as far as I can tell.

Thanks

Joe

[cwclark]

if you are running two trains into a tunnel your best bet is to position the portal over STRAIGHT track..tunnels in curves are hard to do because the cars swing out as they turn through the track radius...I have shaved tunnel portals out before to get them to work but a lot of times I've had to scratch build the portals to accommodate the trains in a curve...use an NMRA gauge to see if you will have enough clearance to position the tunnel where you want it to go..deminsions?..I have no idea....Chuck[:D]

[rexhea]

I have a single track tunnel portal in a curve. I checked it with an 85' passenger car and all seemed great. So I continued to complete the installation and scenery. Then one evening I backed my 4-6-6-2 up and ----quick stop! All this time it had been dragging the side of the tunnel portal going in the forward direction. [:I] I had to get out my selection of hobby knives and go to work chiseling away until there was enough clearance.

To make me feel even worse, I remembered reading and being warned not to put a tunnel portal in a curve.

REX

[jwmurrayjr]

QUOTE: My double track mainline has 2 1/2" centers since I have several spots along the line where I need to place ground throws between the tracks...

You can also place your ground throws on the opposite side of the track by reversing the throw bar on some switches or using a wire link under the track (I use the wire link.).
This may also be "handier" to manipulate.

[cacole]

A regular double track tunnel portal will probably be too narrow for what you want. There are several possible options, including the use of two single-track portals trimmed down on one edge so they can be butted together in the center, or buying two double-track portals and splicing them together in the center to extend their width.

[Anonymous]

Thanks for the advice guys. Think I'll go with the wire reverse link on my switches and can the tunnel. Have no place to start other than a curve. I'm using plan #39 in the 101 plans book (Denver Northwestern) on a 5x10 foam board table. After all of my track has been laid, run and tested I will begin my elevations using the cookie cutter method. Originally thought about reversing the plan's elevations with a tunnel on the branchline side but now maybe I'll use trestles. More dramatic.

I'm doing the layout in DC (gasp!) since I am in possession of several (around 7) vintage brass steam locos passed down from my Dad. They are dated 1954 thru 1961 (according to the paperwork in the boxes). Problem is to find a way to get them running again. They have been in the Great Service Yard in the Sky for a while. They do not run, just sit on the track and look at you waiting [:D] Suggestions other than the Kalmbach Care and Maintenance book?

Again, thanks for your help on this little problem. Hope to hear fron y'all soon!

Joe

[cwclark]

you can scratch build a tunnel very easily...build a 3 sided jig with strip wood on a scrap piece of plywood, take some card stock and shape it on the open side of the jig to create the tunnel...hammer some nails against the card stock into the plywood so it doesn't sag, and pour plaster of paris into the mold you created....let it dry and gingerly remove the cardstock, nails and the stripwood...works like a charm if you let the plaster dry a couple of days...sometimes a tunnel in a curve is unavoidable so scratchbuilding one will work just fine....that way you can get the deminsions you need for it to work...Chuck[:D]

[bogp40]

Don't givr up on DCC yet, it sounds like those old brass pieces are already in for some work even repowering- at that time the motor can be isolated and add a decoder. Sounds like they have a lot of sentemental value so alterations are of no consequense.
Bob