Former SP LA Division Official Mike Burke went to APL and double stacks went viral.

Early use of the double stacks was for auto parts from Japan and Korea via container. These surprised even yard crews with their extreme weight and poor braking characteristics compared to long pig flats.

Import containers were (are still?) mostly uninspected for weight, and were often overloaded with excess weight loads of steel at over 130,000 pounds, and in at least one case, that broke the back of a standard 86 foot container car. CHP has this problem and in spot inspections in the 90's found over 60% over legal weight.

The Cajon runaway showed that train to be nearly 60% over reported weight. A "piglet", recently promoted, with virtually no "live" train handling experience, did not notice how poorly train handled uphill, went over the summit operating per the "paperwork" and immediately lost control.