Watching a good crane operator maneuver a wrecking ball is a little like watching a surgeon; slight hand movements that have big consequences. In this case, one end of the operator’s “scalpel” is a joystick, and the blade is a 10,000-pound hunk of forged steel; pear-shaped instead of spherical, the easier to hoist it out of a hole it just made.
While observing workers from Bolander Demolition deconstruct a double row of grain storage tanks on California Street N.E. on May 10, I was surprised to see the precision involved. Imagine a six-pack of reinforced-concrete beer cans, attached to each other where they touched; these cans are 140 feet high, 50 feet from a public sidewalk to the west, and 100 feet from nine high-tension power lines to the east. No dynamite, please – there’s a row of homes on one side, a working railroad line on the other. These cans have to come down pretty much in their own footprints.
So a firm but delicate touch is called for. The operator slowly moved his Link-Belt LS-148A lattice crawler near the north end of the row, his top boom 30 feet higher than the silo’s roof. He brought the ball to just below the roof edge, placed it against the concrete like a golfer teeing up, and pulled back on the whip line. The ball drew back about 30 feet. When the lower line was loosed, the ball moved like a slow pendulum. The impact made a low thud, and the ground shook a bit. The second blow to the same spot produced a crack and some dust. The third made a breach the size of a tractor tire.
The operator moved the ball about eight feet down from that hole, repeated the three blows, and the breach became a small ravine. As he moved his way down the side of the tank, the skein of rebar was exposed; it was the web holding the wall together. When the ravine got to be about a third of the elevator’s height, the operator raised the ball to its highest point and slowly lowered it inside the cylinder. With back and forth motions of the boom lines, the operator used the ball’s attaching chains to saw through the rebar. He repeated the process on the far side of the cylinder, leaving a jagged obelisk of concrete, which came down with a few taps.
At the same time, another worker in the basket of a mobile hydraulic lift doused the shattered rubble with a fire hose; dust is a nuisance to the neighborhood, and a hazard to the workers. A trencher tore apart a metal shed attached to the south end and loaded the debris into a truck bed. The concrete will be trucked to a St. Paul location where it will be crushed and recycled. Bolander Project Manager Evan Mackey estimates the work will be completed by the end of the month. He guessed the total cleanup as “a few thousand tons.”
The tanks were a later addition (1955) to a grain-milling complex anchored by a six-story structure, now the huge art colony. The building and its additions went up between 1915 and 1920, when Minneapolis was the grain-processing capital of the world. The owners of the site (since 2005) say there are no immediate plans to develop the property, which has long since been under different ownership from what is now the California Building.
Below: Front cover photo and workers were dwarfed by the crumbling tanks. (Photos by Mark Peterson)