<< The sequence leaves off a pivotal event--the design change from
independent support of both walkways to supporting one walkway from another.
I see the "pivotal event" being when the EOR designed the hanger rods to an
excessive length not readily available on the market, this being some 64
feet as I recall. I would call this, "impossibility of design" particularly
when it came to field erection. Even if the "special order" rods had been
procured the options for the connection as designed would have had to been
to upset the diameter of the hangers at the connection points, enabling one
to thread at these point or, alternatively, a 64 foot "All-thread" rod. I
can just see a crew of ironworkers screwing nuts halfway up this apparatus.
Just one more example of the EOR not having knowledge of the commercial
availability of the materials he design with and one more example of
something that looks pretty on paper, but won't work.
I have successfully fabricated and erected multiple layered suspended
catwalks. Simple heavy duty sleeve nuts were used to connect the hangers.
They are still hanging in the barreled roof of Coleman Colliseum at the
University of Alabama today. There again, everybody has 20/20 hindsight and
nothing succeeds like success.