In this case, a heavy steel coil more than four feet in diameter was being hoisted when one of its packing bands broke. The coil unwound like a huge watch spring, struck the hoist operator and severely injured him.

When we visited the accident site, months later, we saw that the coils had sharp edges where they had been cut from larger coils. We wondered if the bands had failed because stresses were concentrated where the bands turned corners.

The failed bands were gone, so we tested 50 bands under like conditions. The apparatus we built pushed against the bands in the same way the sharp edges of the coils would; a hydraulic jack supplied the outward force. The jack was pumped until each band broke; a load cell with a computer readout indicated the force applied during each test.

We learned that the bands broke well below their advertised strength. We also learned that molded plastic or corregated cardboard spacers at the corners increased band strength by about 50%.

The case settled within hours after Dr. Pesuit testified.