Chances are, you've ridden so many chairlifts over the years that you rarely take the time to actually consider what utterly amazing feats of engineering they are: towers jutting off precarious moutainsides, a giant motor turning some 20 tons of steel cable, with chairs and people strung below.   

This summer, [R436R, Sugarloaf] is replacing its Spillway Chair, which derailed last December and injured eight people, with the new Skyline Quad chair. 

The resort has been tracking progress of the new chair construction all summer on the Sugarloaf 2020 blog. If you haven't been watching, it's been an amazing show, and much of the heavy lifting is yet to come.

Here are a few highlights.

The 21-ton Skyline haul rope getting dropped: 


And, that's 40,000 pounds of steel cable. What happens if that thing starts rolling?


Building a tower on a mountainside: all the challenges of construction in town, except twice as inaccessible.


The bullwheel.