Wait what? They are/were only stacking 2 containers high? When I google on how another big port is doing it, or example Rotterdam, I get a 5 year old video of 5 high stacks and a fully automated system: https://www.youtube.com/watch?v=60Fz5gZRX9c.
As I understand it, the two-high rule never applied to the Port of Long Beach, it applied to various other intermediate container depots throughout the city. These are not owned by the Port, but by various trucking companies, and it is these trucking yards where containers are now allowed to be stacked higher.
This is important because the Port is not receiving empty containers, but trucking companies that have empties on truck chassis need somewhere to put that empty before they can get a new container. Allowing additional buffer for empty container storage may allow the current traffic jam to resolve itself.
What's going on in Long Beach?