PTkills. Everyone was
very lucky.
From
[Link: posttensioncablelocators.com]:
The cables installed are usually pulled so they each have approximately 28,500 lbs. of tension. The released tension will find the path of least resistance. A very loud noise similar to thunder usually occurs if the cables are cut while coring or saw cutting a slab. Experienced saw cutters will know immediately something has happened. Many factors can influence what will actually occur. Some cables just retract back into the slab towards the perimeters of the home. Some cables retract and protrude out of the slab on the side of the house. These types of cable cuts are relatively easy to repair.
Other times the cables pop up above the concrete in several places in a sort of ripple effect along a line towards the perimeter of the home. This obviously destroys the concrete and flooring and can be quite expensive to repair. Injury can occur if someone is standing on top of the cable when it releases.
The main reason to use our services is to avoid the worst case situation when a length of cable whips out of the slab and injures someone. This is a very serious situation, of course. We think it would be negligent for a contractor to cut into a slab suspected of having cables without having them located. Don’t take a chance. Just call us, or some of our friends in the industry.
That was
28,500 pounds of tension.
Researching this answer, I read of a worker 35 feet away from the fixed end of the cable. As the cable was being tensioned it snapped, flew back toward the fixed end, flew 35 feet past it, nailed this guy "in the clavicle," and killed him. A search of "pot tension accident" gives lots of responses, none of which are the first such story I heard, of a cable being cut and snapping some fifty feet outside the building, killing someone. But 35 feet is a damn big expansion of the danger area!
