It seems to me that comparing Chinese ports to American ports is comparing very different things: I would imagine that the vast majority of the traffic at a Chinese port is export traffic while at an American port it’s import traffic.¹ Furthermore, thanks to centralized decision making, the interface between surface traffic and ship in China will inherently be more efficient than the same interface in the U.S. What I’m wondering is how do U.S. ports compare to, say, Europe or Canada where the situation would be more comparable.
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1. In fact, it occurs to me that loading the ship should be faster/more efficient than unloading as there’s not necessarily any reason to do any sorting beyond which ship a container goes on at the export point, while at the import point, there needs to be more direction of getting containers onto individual trucks and trains.
That's not true in my experience. Loading outbound cargo is way more complex, since the stowage plan of the ship dictates where each container goes. Theoretically a lot of containers can be swapped as long as weight is similar, the container type is identical, and the port of discharge is the same. In practice it's still incredibly complex compared to just unloading stuff. While you may need to do less 'digging' on shore, the nitty gritty of the actual operations are way more complex than throwing some boxes ashore.
Import cargo is annoying in that it is mostly random access on pickup. For pickup by train, barge, or feeder ship, a vast minority, you typically don't have cargo manifests until a day or two before pickup at best, so in practice this is also random access-ish. The customs processes are also trickier.
My experience is mostly in Rotterdam and Antwerp, and I'd say the problems in the US probably don't have to do much with automation. Rotterdam and Antwerp have very different automation levels at the biggest container terminals, yet productivity is quite similar.
There is lots of low hanging fruit in optimizing operations, like more collaborative stowage planning, simultaneous unloading and loading operations, and 'modal shifting' from road to rail and water combined with early preannouncement of manifests for trains and barges.
Disclaimer: I'm in the business of consulting and building software for container terminals, so I'll generally be biased towards those solutions.
Unloading can be complex also I would think, in that you have to maintain balance on the ship so it doesn't list or even roll over. You can't just grab the nearest container with your crane.
As a general rule, container ships are unloaded tier-by-tier, breadth-first if you will, not shaft-by-shift (depth-first), so this is not much of a problem in practice.
That does start to change if you want to do simultaneous loading and unloading operations, then you'd want to clear out a vertical shafts first so you can start loading operations as quickly as possible. Which is one of the many reasons dock workers hate that style of operations.
That's a pretty reasonable mental model. The only real requirement during unloading is ship stability, other than that just use max concurrency with all the cranes and equipment to max throughput. Even just on the crane level, you can just keep unloading stuff to shore, and wait until vehicles pick them up. If they are slow, just keep on unloading until they catch up. Chance of stalling ops is close to zero.
Loading operations are much more variable, especially if your yard is not stacked well and you need to 'dig out' specific containers. If you run out of containers underneath your crane, your operations are stalled until the terminal vehicles catch up and bring you new boxes to load.
> Even just on the crane level, you can just keep unloading stuff to shore, and wait until vehicles pick them up. If they are slow, just keep on unloading until they catch up. Chance of stalling ops is close to zero.
It's not done that way, much. When a container is taken off a ship, it's usually placed on something that moves - a truck chassis, a railroad car, or an AGV. If you clutter up the dock with containers, unloading will stall.
Fair enough, I was thinking of terminals one step smaller where reachstackers or straddle carriers directly drive to and from the quay. On bigger terminals it’s a much more interlinked process indeed.
This is a small container port with a two lane access road. Not much traffic. No automation.
Container stacks are only two high, three high at most.
Driver is led through stacks of containers until they find the one they want to pick up. After some yelling, someone driving a stacker removes the container from the top of the one they want, then loads
the desired container onto the truck chassis.
Although there's one container ship at quayside, no loading or unloading seems to be happening.
Yep, that's more my class of customers. The height limitation is probably because of the gantry crane. In my experience having the truck driver follow the reachstacker is kind of uncommon, you'd ideally either tell the truck driver where to go from the gate, or just have the stacker drive across the terminal. This seems like the worst of both worlds. Perhaps a union or regulation thing about minimizing driving around with a reachstacker holding a box?
Fascinating business nonetheless, this is definitely something different than I'm used to over in NL/BE. Thanks for sharing!
> What I’m wondering is how do U.S. ports compare to, say, Europe or Canada where the situation would be more comparable
Did we read the same article? It’s constantly calling out examples in Europe and Japan, with every data source citing global patterns, not limiting itself to China and America.
I wonder if lack of competition is to blame for that.
When you look at Europe each sea faring nation has at least one modern port that can facilitate the largest container ships.
And Unions generally don't operate across borders so a strike can be broken by diverting traffic.
My understanding is that majority of non-raw exports are in shipping containers and those have to be shipped back. So I would expect counts of loaded and offloaded shipping containers to be roughly similar. Interestingly, there are some synergies there - if a truck / train brought a shipping container to the port it's more efficient to put one, potentially empty, back for transport compared to running an empty train / truck.
Notably I am assuming that shipping containers survive a large number of trips and their total number is not growing fast.
China is 63-37 exports to imports. US is 44-56. It's different, but it's not so drastically different that I think it would mean a totally different approach to automation is needed.
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1. In fact, it occurs to me that loading the ship should be faster/more efficient than unloading as there’s not necessarily any reason to do any sorting beyond which ship a container goes on at the export point, while at the import point, there needs to be more direction of getting containers onto individual trucks and trains.