By Larry Scott
The crane was immense - 200 feet high, inching its way across the construction site, with our precious new tower suspended from its massive hook.
The tower was a stainless-steel cylinder about 130 feet tall, 12 feet diameter, and weighing in at just over 70 tons. It would serve as the absorption column in the new nitric acid production facility we were building.
In 1976, as a member of Apache Powder Company’s engineering team, I’d been involved in pouring the vessel’s foundation. It was a stop-sign shaped slab of high-strength concrete roughly 35 feet across, and 30 inches thick. According to my calculations, the foundation contained a full cubic yard of steel in reinforcing rods.
“Maybe we should have checked the spacing on those anchor bolts one more time,” I thought…
For me, the excitement had begun last week when the absorption column arrived by rail. It was supported by massive cradles on two railcars, with a third car between as a spacer. The train crew spotted the cars on a siding about 100 yards from the construction site.
Then three days ago, a caravan of semi trucks arrived with crane parts. The main body of the crane came first, mounted on a multiple-trailer assembly with a semi tractor in front and a steering-cab in back.
The rigs directly behind carried the two crawler tracks, each the full length and width of the flatbed trailer on which it arrived.
Behind them, more trucks pulled up, each hauling a single 40-foot length of lattice boom, the same size as the trailer.
In all, eleven semi trucks arrived that day, with the components needed to assemble the crane.
About the same time, an 80-ton capacity hydro-crane arrived to put the big crane together.
It took three days for the “smaller giant crane” to assemble the “big giant crane.” Finally the assembly process was complete.
The tracks were mounted on the crane body, providing a footprint about 40 feet square. A water-filled counter-weight, the size of a small garage was mounted behind. The main boom stood 200 feet high, with 150 feet of secondary boom behind.
The lift cable was about the size of my wrist. I remember watching two powerful riggers hoist the end of a wire-rope sling over the crane’s hook assembly, which appeared to be about as tall as they were.
On the big day we were to set the tower, I left home, heading for the plant, seven miles away. As I left Benson, I could see the top of the crane, towering above the hills.
The process was a slow, as the crane lifted its load from the railcars so it could be transported, in horizontal position, to the construction site. Everything moved at ‘snail’s pace,’ to avoid any un-controlled ‘swing’ of the load.
At the job site, the load was eased to the ground on timbers, and re-rigged to be stood up. Again a slow and careful process. The crane had to be in position such that when the tower finally cleared the ground, there would be little or no swinging.
Eventually with the tower hung vertically, and the massive machinery began its final approach, inching toward the foundation.
If something didn’t fit… I knew we’d done our work carefully, but it’s hard to not to think about what if…
I remembered setting the anchor bolts - a ring of 16 assemblies, each about five feet long. They were heavy enough that the crew used a crane to position them. Now they were solidly set in concrete.
Eventually the tower was hovering directly above the foundation and workers, looking like ants, eased it into position as the huge winch slowly payed out cable. It settled in place perfectly, and then, with massive hex-nuts safely in place, everyone began to relax.
Three days later, eleven semi trucks - and a hydro-crane pulled through the main gate, leaving a new shape on the skyline.
Most likely, it was the most spectacular crane ‘pick’ in the history of the company. It’s been awhile, but the day still lives, bigger than life, in my memory.
The crane was immense - 200 feet high, inching its way across the construction site, with our precious new tower suspended from its massive hook.
The tower was a stainless-steel cylinder about 130 feet tall, 12 feet diameter, and weighing in at just over 70 tons. It would serve as the absorption column in the new nitric acid production facility we were building.
In 1976, as a member of Apache Powder Company’s engineering team, I’d been involved in pouring the vessel’s foundation. It was a stop-sign shaped slab of high-strength concrete roughly 35 feet across, and 30 inches thick. According to my calculations, the foundation contained a full cubic yard of steel in reinforcing rods.
“Maybe we should have checked the spacing on those anchor bolts one more time,” I thought…
For me, the excitement had begun last week when the absorption column arrived by rail. It was supported by massive cradles on two railcars, with a third car between as a spacer. The train crew spotted the cars on a siding about 100 yards from the construction site.
Then three days ago, a caravan of semi trucks arrived with crane parts. The main body of the crane came first, mounted on a multiple-trailer assembly with a semi tractor in front and a steering-cab in back.
The rigs directly behind carried the two crawler tracks, each the full length and width of the flatbed trailer on which it arrived.
Behind them, more trucks pulled up, each hauling a single 40-foot length of lattice boom, the same size as the trailer.
In all, eleven semi trucks arrived that day, with the components needed to assemble the crane.
About the same time, an 80-ton capacity hydro-crane arrived to put the big crane together.
It took three days for the “smaller giant crane” to assemble the “big giant crane.” Finally the assembly process was complete.
The tracks were mounted on the crane body, providing a footprint about 40 feet square. A water-filled counter-weight, the size of a small garage was mounted behind. The main boom stood 200 feet high, with 150 feet of secondary boom behind.
The lift cable was about the size of my wrist. I remember watching two powerful riggers hoist the end of a wire-rope sling over the crane’s hook assembly, which appeared to be about as tall as they were.
On the big day we were to set the tower, I left home, heading for the plant, seven miles away. As I left Benson, I could see the top of the crane, towering above the hills.
The process was a slow, as the crane lifted its load from the railcars so it could be transported, in horizontal position, to the construction site. Everything moved at ‘snail’s pace,’ to avoid any un-controlled ‘swing’ of the load.
At the job site, the load was eased to the ground on timbers, and re-rigged to be stood up. Again a slow and careful process. The crane had to be in position such that when the tower finally cleared the ground, there would be little or no swinging.
Eventually with the tower hung vertically, and the massive machinery began its final approach, inching toward the foundation.
If something didn’t fit… I knew we’d done our work carefully, but it’s hard to not to think about what if…
I remembered setting the anchor bolts - a ring of 16 assemblies, each about five feet long. They were heavy enough that the crew used a crane to position them. Now they were solidly set in concrete.
Eventually the tower was hovering directly above the foundation and workers, looking like ants, eased it into position as the huge winch slowly payed out cable. It settled in place perfectly, and then, with massive hex-nuts safely in place, everyone began to relax.
Three days later, eleven semi trucks - and a hydro-crane pulled through the main gate, leaving a new shape on the skyline.
Most likely, it was the most spectacular crane ‘pick’ in the history of the company. It’s been awhile, but the day still lives, bigger than life, in my memory.