I've worked much of my life in heavy construction. After college I progressively got into more technical fields, but my foundation has always been in
"foundations" and structural steel.
Working in highrise heavy construction I'd seen many things. As a layout Engineer I'd walked the steel much like any iron worker. I'd always
marveled at cranes, especially big ones. Many of the big cranes I'd worked with were big stick, ground based, cranes; Manitowoc 4500's or larger both
on tracks and ring cranes. These cranes had giant counter-weights and several hundred feet of boom. They were delivered in pieces, and taken apart
and sent back home in pieces. I'd seen all those, but one type of crane always fascinated me...a tower crane.
These cranes couldn't lift as much as the mighty Manitowocs, but they were WAY taller. The Manitowocs were mammoths, but the tower cranes were 30-40
stories taller...and they got taller as the buildings got taller. They were amazing.
As an engineer, one of the things which impressed me about tower cranes was how they could erect themselves, going higher and higher. This is where I
focused first. How did they do that? Once you understand the process, it's not all that difficult to see how they work, but I wanted more.
I didn't know it then, but I soon learned tower crane operators are an odd breed. They start up long before the workday starts, and come down long
after the workday is over. They don't hang out with the rest of the construction world, but keep to themselves mostly.
One day I actually met up with one of them, an operator. He was a pretty nice guy. We talked about all kinds of things. I asked him if he ever got
afraid. He said "not really...it's just another day". He said lightning scared him (and others); he'd been hit many times. But the cranes are all
grounded for just such things...but not everything works out as planned. He said he never worried about lightning after his first couple years or so,
but his big fear was big wind and tornados. You see, those two things required the operators to evacuate and come down. If lightning struck the
towers then...they'd be vulnerable. Hmmmm...seems pretty skeery to me!
Anyway, he offered to give me a tour of his crane. I had the OSHA certs for climbing, so I was good to go. The next day I showed up at O-dark-thirty
and we started up. I always thought there must be an elevator, but there isn't. The way up is a half stair, half ladder, gig all the way to the top.
This crane was up about 30 floors...it was a long hike up. The view was commanding; it was spectacular. We were 20 floors above anything. On this
particular day the crane was lifting bunks of steel floor decking. The decking was 16' long and 4' wide, so even in the light morning breeze you
could feel the wind taking the sheets and torqueing the crane around.
In the afternoon the wind started picking up. Nothing major, but just a light breeze. Now you could see the main riser of the crane actually moving
around. The whole crane was flexing. The operator was bullet-proof, he could even anticipate the crane's movements as he swung materials into place
down below. Then the clouds rolled in...
It was December in Minnesota, but the day had been very warm. As the sky darkened, and the sun set, it started to mist. The windshield wipers in the
cab made it relatively easy for the operator to see the landing zones below (he had binoculars as well as radio comms). The radio was playing some
silly song when all of a sudden some alarm went off. It was a buzzer. This guy didn't panic at all, but said "Well, that means we're out of
tolerance for wind"
. By now it was dark. He disengaged the clutch on the swing gears and the crane boom swung around (about 270 degrees) away
from the the wind. As the crane stabilized he casually gathered up his lunch box and weather gear. From there we headed out on the catwalk to the
stairs. Then we started down.
The stair/ladder arrangement which had been a challenge going up had turned into something FAR different going down. The mist which had looked like
rain in the cab had coated all the cold steel rungs with a thin layer of ice. The way the ladder was arranged you couldn't fall more the a floor (or
that was the idea anyway). There was a steel landing where you had to turn around and go through a different hole to get to the next floor, but every
thing was coated in pure ice. The protocol was one person would go down and get out of the way below, and then the next person would start
down...over and over...30 times. On the way down we'd slip off the ladder and hang on for dear life as we smacked our shins into the steel rungs.
Our hands would slip off and you'd have to grab anything you could to keep from falling.
I wasn't afraid of anything back then...and I was terrified. We did make it down finally, and when we got to the ground the operator, Jim, calmly
asked me..."do you remember when you asked me if I was ever scared? ... THAT, was the scariest thing I think I've ever done right there!!"
It took me about 20 minutes to warm up in my truck; that, and to stop shaking from sheer terror!
So tower cranes? Yeah, they are really cool; I'm not sure I'd ever want to run one day in, day out, but I went there once. Maybe it was just a bad
day, but I don't think I want to do that much ever again!!
edit on 12/17/2015 by Flyingclaydisk because: (no reason given)