On the backshift, Roger responded to a motor failure call. It turned out the 40-hp motor had to be replaced. Fortunately, the stockroom had the motor that Roger needed.
Roger and his assistant ran into problems aligning the replacement. The shim kit they were using was the only one on site, and it did not have enough shims for a correct static alignment. Production needed the motor online as soon as possible, so they had to solve this problem.
Roger had some leftover wooden shims he’d used to level a small equipment enclosure before bolting it down. Using these on one foot of the motor, they could achieve the static alignment they needed. With half an hour left on their shift, they restarted the motor and took vibration readings. Perfect. What could possibly go wrong?
With the weight and torque of that motor, those wooden shims will soon compress. This will ruin the alignment, potentially with catastrophic consequences if the shims pop out.
A better solution for ad-hoc shim material would have been sheet metal strips, but anything metal probably would have sufficed for a day or two until proper shims could be obtained.