I've had a few layouts in the past but this will be the "THE ONE"! I have been "collecting" track, switches, buildings for this project since 2002.
Sectional benchwork is a big, YES.
I've knocked the layout back to 2 levels...gave up about 8-10ft on the large Viaduct part. I REALLY wanted to do the whole think, but 19.7ft is really big...
Level 1 will be 30" high (office chair) and level 2 am planning to be 50"(high chair on roller skates).
The biggest expense coming up will be lumber. Either 1x4 clear pine or 3/4 plywood stripped down($15-$22/sheet), I've got a woodshop on the 1st floor.
Hopefully I can get back to UBER-ing the spring and make some real money again...
Where do you live? I'm in Lacey, WA just north of Olympia.
I'm several hundred mile south of you, San Diego CA. My N-scale shelf layout is set in Seattle, Washington though. My specific interests are in electric locomotives, and the passenger service out of Seattle Union Station. So the Milwaukee Road, that shared the station with the Union Pacific, is a natural for me. My largely scratch-built model of the station is shown in the photos below. I don't have anything like the amount of space you must have for your very ambitious layout. My shelf layout is attached to two walls of my garage.
Either 1 x 4 pine or 3/4" plywood is going to result in a heavy layout made up of heavy sections. Thinner plywood, and 1 x 3 seems to be very popular now, along with extruded foam insulation board. Some modelers don't use a plywood top at all, but glue the foam board to a simple grid of 1 x 3s.
I use a lot of 1/4" Luan plywood with either a foam center, or 3/4" x 1/4" pine splines glued under the edges as my sub-roadbed. This is very lightweight, but super-rigid and virtually warp proof. Warping might be a concern for you up there. Washington gets plenty of rain and moisture.
My "benchwork" is very unconventional anyway. My layout is a "Bookshelf Model Railroad" design, that I copied from an old article in Model Railroader magazine. The key element is the arches that support the top shelf, as well as the railroad. Using these arches, bolted to the wall, I have an unobstructed view all the way along the railroad, since front supports are not necessary. The arches are strong enough to support my considerable collection of train books & magazines, a TV set, VCR, DVD player and plenty of other stuff.
The original layout in the article was built with 3/4" plywood for the arches and commercial (pressed wood) shelves. It must have weighed a ton!
I went to the other extreme, making my arches of two pieces of 1/4" Luan glued around a foam core. The 2 x 2 in the photo is constructed the same way. My finished 4' long, 16" deep, and 16" high section was light enough for me to lift it with one finger, yet strong enough for me to sit on.
Please post photos of your progress. I'm sure a lot of members will be interested.
Good Luck & Have Fun;
Traction Fan 🙂