Benchwork 3

There have been numerous articles in the modeling press about layout height, and Tony Koester's article in the 2007 Model Railroad Planning magazine discusses the compromises between optimal layout elevation for realistic viewing and ideal height for construction, maintenance or operating crews.

Koester offers an optimal layout elevation formula for consideration: H-28" to H-17" where H = viewer's height in inches. His example of a 6' 0" person (72") is H = 44" to 55". For single deck layouts he recommends a few inches either way of 50" and for multi-deck layouts, a range from 40 inches to 60 inches, depending on the layout and people parameters determined by the owner.

In my analysis i considered several factors: 1) operational visibility while standing both upper and lower decks, 2) reach in capability, and 3) operational visibility while sitting for the lower deck. Assisting me in my consideration was my workbench height - 34 inches based on: 1) chair height, 2) comfort and wrist position while working (carpal tunnel considerations). My modules are approximately 4 inches in height which then places the lower level subroadbed at 38 inches.

The upper level is based on the optimal layout elevation formula modified by the needs of the helix. As sketched, the right of way enters the helix at the rear of the circle and exits the helix at the front. Using Helix Calculator 2.0 I determined that a 21 inch radius, with a 3 inch clearance would be 7 levels (21 inches) and a 2.275% grade (good for my 4 axle locomotives).

That placed the upper level at 59 inches. I'd forgotten about vertical curves coming off the helix but raising the upper level another inch and rotating the heliz 0" elevation start 90 degrees gave me 2 inches in height to achieve the 60 inch upper level height, and an easier vertical curve entering and leaving the helix.

This places the lower L-girder height at 34 inches (zero elevation line) and the compression - studs were level lined. The upper L-girder height was set at 56 inches (22 inches from the lower L-girder).