Pounding a Building to Pieces 



How a huge iron ball was used 

 to demolish a concrete structure 



The iron ball, weighing over half a ton, is suspended on a single fall line. This 

 implement, together with a stiff-leg derrick and a boom is mounted on a convenient 

 movable platform. At right is shown a good sample of the device's handiwork 



POUNDING a reinforced concrete 

 building to pieces with a one- 

 thousand-two-hundred -pound 

 iron ball was the novel method used by a 

 Chicago wrecking company. The build- 

 ing in question was an eight-story struc- 

 ture. It was designed to carry heavy 

 printing machinery, and was unusually 

 strong. 



In order to save labor, the wrecking con- 

 cern conceived the idea of using a cast 

 iron ball, weighing ever half a ton. The 

 wrecking outfit, carrying the ball or 

 "skull crusher" on a single fall line, con- 

 sisted of a stiff-leg derrick and forty foot 

 boom, mounted on a sixteen by twenty- 

 four foot platform on rollers which were 

 built for this particular job to facilitate 

 the steering of the platform between the 

 columns of the building. 



In wrecking a floor the ball was dropped 

 from a height of about forty feet on the 

 central parts of a slab, until the concrete 

 was shattered up to the column capitals 

 or to the edge of the beams, after which 



the reinforcing bars were cut by means 

 of an oxy-acetylene flame. 



The blows of the ball were then directed 

 over the center of the column, where they 

 broke the concrete away from the rods 

 at the base of the columns at the next 

 lower floor for a height of approximately 

 four feet. When as much as possible of 

 the column concrete had been broken off 

 by this method, a wood fire was main- 

 tained around the column base for eight 

 hours. Then water was thrown on the 

 column. This had the effect of cracking 

 the concrete and weakening the column 

 so that when the column reinforcement 

 had been cut with the acetylene torch, a 

 block and tackle attached to the electric 

 hoist easily pulled the standing mass 

 over. Portions of the brick walls not 

 backed by concrete were knocked over 

 by swinging the ball against them. After 

 breaking all but one panel of a floor, the 

 wrecking machine, moving under its 

 own power, on an inclined runway, was 

 lowered to the next floor. 



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