The "Ballard Why" is the interface from Hazelton Yard to the layout modules. The Why includes signals for each track going into the yard. Whenever needed, conflicting routes on other tracks are interlocked, power shut off to the conflicting tracks, while trains cross the Why entering the yard.
The mountain line on the upper track has two loops which assault the grade, about 3%, providing yard access for running on the "Hill."
For a look at the Historic Ballard Wye construction project, use the construction button near the top of the page.
The Ballard Wye has been rebuilt. Click the New Ballard Wye link in the menu to follow the construction project.