There are no empties in the ports because all the spots to put containers are filled with full ones. In order to get empties back into the ports and onto ships you need to do three things.

1. Get full containers out of ports to make room for empties

2. Bring empties back to port and queue them up

3. Unload a bunch of fulls and reload a bunch of empties onto every ship that comes into port

Right now there's no room to store empties do they're being stored on trailers. Which means there are no trailers to unload full containers onto. So nothing is being unloaded. Deadlock.

I’ve also heard that ships are rushing back to Asia to chase high profits after unloading at US ports before they allow empty containers on the ship.

I think we have mismatched incentives that allow something like Tragedy of the Commons.

There are some systems that don't have a capacity for self-regulation, and this is not solved by believing really hard that if left alone they would. This will need intervention if we don't want to just burn money to let time solve it.

Sorry. I didn’t mean to give off the vibe that I think this solves itself quickly.

I see this as we are quickly approaching deadlock conditions. People are used to restarting a Windows box, but I’m pretty sure that only fixes deadlocks because RAM is (mostly) volatile. The physical containers (whether at ports or lots or warehouses or on ships or on rail cars) don’t disappear after we “restart” any part of the system. Without actively adjusting incentives, this looks like a downward spiral to me.

Given that the described root cause is city port regulations and zoning ordinances, I don't see how such a deeply regulated and forcefully handicapped system is an argument against self-regulation. If anything, the opposite. Yes, the current mess of conflicting piecemeal regulations and dissonant incentives will need additional state intervention and reform to untangle ASAP - but that does not rule out the possibility of a future unencumbered self-regulated alternative potentially working better than the current route of incrementally adding context/dynamism-aware patches to the heavily and archaically regulated status quo.

It doesn't sound like there's a single root cause. Yes, allowing for higher stacking expands the buffer, but proper coordination could have kept the buffer from hitting capacity in the first place, and is necessary to prevent the new, bigger buffer from filling up as well.

As best I can tell, there's a memory leak, and we've "solved" it by doubling our RAM. We need to fix the leak before we hit deadlock again.

There is no 1 root cause.

There is a lack of empty containers in Asia and a glut in the US. There are all sorts of constraints in the US like how high a stack is allowed to be (presumably for safety or sightly reasons). There are too many containers in the US on chassis so there is a shortage of empty chassis available to take to ports. Distribution centers are reporting that truck drivers are dropping off trucks overnight and blocking their loading docks. There are reports that loaded cargo trains are unable to load so they are just blocking critical tracks.

The Twitter thread is from the CEO of FlexPort which is a startup trying to make ports and trust transport more efficient. He is pointing out critical paths in the port nodes of the supply chain graph, but the root causes are many and not necessarily all within his visibility.