Moppy said:
"Strongly suspect" your information is outdated - a lot has changed recenttly - or refers to smaller ports. The big ships can't dock at the US anyway due to their size: they are limited to the Europe-Asia route via Suez or around the Cape of Africa.
24 hours and under is the expected turnaround time for the big ships in a major chinese or european port.
Could be. I have always tracked things more from the rail-side perspective since I like trains more than ships.
There's the listed speed, and then there's the actual. All those containers have to go somewhere, and not every port has an infinite amount of space to put them. The rail terminal for Los Angeles worked for the longest time at max capacity of about 50 or trains per day (each one can handle about 400 containers). But their total through-put had other limitations attached.
Moppy said:
https://www.porttechnology.org/technical_papers/examining_container_vessel_turnaround_times_across_the_world/
> its profile in 2011 has totally changed as it reached the first rank for the number of calls and an average turnaround time of 0.96 days, compared with 5.8 days in both 2006 and 1996.
I didn't download the article, but if his math is correct (and I wonder if the averages also average out how many containers are on the ship. Not every ship moves fully loaded) that's some pretty damn fast turnarounds. Of course for the really big ships (like the triple E that Maersk is working on) they can only go to specific ports that are designed with them in mind. Brand new cranes and more of them would naturally lead to faster unloading times. My "local" port, the Port of Houston, is the busiest on the Gulf coast, but it can't handle that ship. The terminals there have 5 cranes per loading zone. They have been upgrading to take the new Panamax ships, however, so things might be changing here soon.
Moppy said:
Consider also that you aren't unloading the entire ship when it comes in and that containers can sit at the port for a week or more until a truck/lorry picks them up.
edit: Found some actual data for you for different ship sizes. http://ciw.drewry.co.uk/release-week/2015-12/
In table 2 they give the number of cranes needed to turn around 19K TEU ship in 24 hours and it's 8 cranes at 35 crane moves per hour. A quick check on the nearest large ship container port to me ( Felixstowe, UK) gives 50 crane moves per hour and 8+ cranes on an 800 meter (2 ship) berth (although I don't know what kind of cranes those are: all cranes look the same to me).
That's an interesting article! Though your crane moves you cited above is too high, at 50/hr. The tables lists moves by cranes at 25/hour. And this paragraph here
According to the JOC, the terminal with the world’s highest berth productivity (for larger ships) is Khor Fakkan in the UAE which achieved 179 berth moves per hour on average in 2013, which is “only” the equivalent of 4,300 moves in 24 hours.
indicates that the maximum, and the actual are different. Assuming 8 cranes, that's 22 containers per hour. But it doesn't state how many cranes there are, so if you drop it to just 5, that's 35 moves per hour (also cited in one of the tables). Of course this assumes 22hrs continuous operations, with no delays, breakdowns or anything. I suspect the actual numbers are going to be lower somewhat. Still it's pretty damn fast. Not sure ports will ever meet what shipping companies want - but that's been a perennial issue since ships and ports I suppose.
Moppy said:
edit2: Remember a container is two TEU if 40 or 45 foot.
So It only says 'containers exchanged' and the TEU value of those containers equals that of the ship. But not sure what an 'exchanged container' is. It could exchanged between ship and shore (which would be a complete unloadiing) or for a different box, which would be replacing half of the ship's cargo.
Yes, a monster 19,000 TEU ship is "only" carrying 9,000 containers. It's interesting how they ships have gotten wider and container stacks are taller, but the ships have only grown slightly longer.
