HO timber tunnel portal

[wdcrvr]

I am building an HO layout.  I will have several tunnel portals.  I would like to scratch build them and I want to have timber and/or stone portals.  Is there somewhere I can go for a good source of dimensions or pictures of timber or stone tunnel portals?

thanks

wdcrvr

[jwmurrayjr]

Google "HO timber tunnel portal" and you'll get pics and dimensions.

 

 

[tomikawaTT]

Timber tunnel portals are mid-19th century technology, on railroads that were built on the cheap.  The ones that survive are on railroads that were abandoned years ago (some of which have been reopened as tourist attractions.)  Most on active lines were rebuilt with less flammable materials long ago.

Stone tunnel portals are also 19th century technology, but are more likely to have survived if for no better reason than that stone is more durable than wood.  There are many commercial suppliers of stone portals.  There is also a fairly simple and inexpensive way of creating your own.  Fasten some linoleum to a solid backing, then carve the stonework following the general lines (or possibly, the tiniest details) of a suitable prototype photo.  Unless you are an experienced stonemason, DON'T try to freelance.  In the prototype, little mistakes led to big disasters.

If the tunnel was originally built or rebuilt within the last 100 years, it would probably be poured-in-place concrete.  Concrete is both less costly and more forgiving than stonework.

Two trivia items:

• The general statements I made also apply, though less rigorously, to bridge piers and abutments.  Wood is temporary.  Masonry is forever.  Concrete is cheaper than stone.
• John Allen used the carved linoleum method to create stonework.

Modeling the prototype that I do, I will be carving a half-dozen or so tunnel portals and about three times that many bridge piers in linoleum.  I also expect to use that medium to create the many stone retaining walls typical of Japanese mountain engineering.  Happily, I have several bookshelves full of prototype reference photos.

Chuck (Modeling Central Japan in September, 1964)

[wedudler]

I've built mine following the D&RGW "mud tunnel".

Wolfgang

[Medina1128]

wedudler

I've built mine following the D&RGW "mud tunnel".

Wolfgang

Wolfgang, I don't know if you've ever been to America, but it just amazes me how accurately people in other countries can model American railroads/scenery.

Fantastisch!