Thoughts on initial construction

It's almost time to start the benchwork. I've put a lot of thought and planning into this. As with any project, I'm sure things will be adjusted during construction. Here's what I'm planning.

Basic benchwork:

• 1" square steel tubing for the frame of the benchwork. 
• The peninsulas will be built first and attached to one wall. Strength and stability are my top priority. All pieces will be welded together. I will reinforce as necessary. 
• One of my guiding principles is that I don't want any floor to ceiling connections. The railroad is designed for open space above the backdrop. 
• A key challenge in designing the peninsulas is the fact that they must support 3 levels. 1) Lower Staging, 2) Main level, 3) Upper level on the small peninsula and a small staging yard on the large (Taylor Yard) peninsula.
• I'm planning on a square steel pad on the bottom of each let about 2"x2". And then attach to the floor with caulk. Worst case if I'm not able to establish the rigidity that I'm looking for, I'll attach the legs to the floor. 
• I will build the helices in conjunction with the lower staging level.

I will need to build the railroad from the bottom up. In doing so, I need to determine the best way to support the levels above. For that, the main frame of the peninsula will be ladder like construction. Once the lower staging benchwork frame is complete, I will attach legs that support both the lower level and connect to support the main level. The legs will be inset somewhere between 9" and 12". I used the same inset on the Exeter Branch and I've never had issues with operators kicking the legs.

Supporting the upper staging level above the Taylor Yard peninsula will be vertical posts on the centerline. Since the staging is only 12" wide, I don't see an issue. 

For the smaller peninsula I'm still working on my approach. I want to keep the posts between the main and upper levels as invisible as possible. Again, not wanting to have something connecting up to the ceiling. 

Peninsula construction is really the foundation. The benchwork that is attached to the walls will be pretty simple in comparison. 

For the sub-roadbed my plan is to have wood risers from the steel benchwork and plywood for the track. I'm going to use Homabed under the main track and sidings. And, potentially masonite spline on the upper level. 

Helix construction will be made from masonite. Likely 3/16". I will cut sections that are 1/3 of a circle. Next will be to laminate 2 pieces together using wood glue. The pieces will be offset by 1/2. As laminated material will be stronger, this will allow me to keep sections thin. I'll use all thread rods to maintain the separation. My calculations have the grade around 1.45%

I continue to refine my benchwork design as I prepare to start construction.