5 ms·

The container in question is SLHU4500470. The first four characters are the owner, the next 6 digits are the unique (per owner) number, and the last digit is a

The container in question is SLHU4500470. The first four characters are the owner, the next 6 digits are the unique (per owner) number, and the last digit is a check digit. Somehow I always assumed there'd be more than 6 digit IDs for these things. I'd guess collisions have happened, but never been caught in the same port before.

Denvercoder9 4y ago
What happens when somebody has more than a million containers? 6 digits doesn't seem enough to guarantee uniqueness.
- cortesoft 4y ago
  You assign a second owner number to the group, probably
- addaon 4y ago
  There's only about six million active containers in the world. If one owner has more than a sixth of them, an easy fix would be to issue them a second owner code, basically extending the six-digit field by a bit.
  - Denvercoder9 4y ago
    > There's only about six million active containers in the world. Huh, that's a lot less than I expected there to be.
    - contravariant 4y ago
      Though that's about 1 per 1000 people, and if you imagine how much stuff you'd end up with using all that a container could carry when constantly in use, I guess about a thousandth of that isn't too weird an amount.
  - elevaet 4y ago
    6 million seems like a underestimate. There are meant to be 54k container ships in the world. That would mean an average of 110 containers per ship, and ignores all of the ones in use on land. Some of those ships can carry 24k containers _each_.
    - walrus01 4y ago
      There are not at all a vast number of 8,000 TEU+ ships however. Small enough that any one ship owning company might have a few dozen at most. Evergreen says it has something like 150 ships.
      - GauntletWizard 4y ago
        Evergreen is still growing, though; They've got several 8,000+ TEU ships set to launch in the next few years. Consolidation is key. I would guess that the next answer is "Evergreen gets multiple Owner codes", because that's a real simple way to stretch it, but...
  - ReactiveJelly 4y ago
    Wikipedia says 20.5 million _in 2012_ https://en.wikipedia.org/wiki/Cargo_container https://en.wikipedia.org/wiki/Cargo_container This was their source. Apparently not updated since that 2012 survey: https://www.csiu.co/resources-and-links/world-container-fleet https://www.csiu.co/resources-and-links/world-container-flee...
  - munk-a 4y ago
    Well, we'd probably just switch over to UUIDs since those things are practically infinite and we've now got a lot of well established infrastructure in place for handling them.
    - fshr 4y ago
      Nope, that many characters would be impractical in daily use. There’s a lot of copying, pasting, reading, and reciting of numbers via email/web/phone/TMS/WMS/etc.
- CodeWriter23 4y ago
  Ahem, 10 million
  - jffry 4y ago
    The 7th digit is a checksum digit, as previously noted. So only 6 "free" digits so a million is correct. You can read more about the container numbering standard here: https://en.wikipedia.org/wiki/ISO_6346 https://en.wikipedia.org/wiki/ISO_6346
    - CodeWriter23 4y ago
      Thanks for the info
- throw0101a 4y ago
  Like IEEE OUIs, one company can have multiple owner prefixes. Maersk has 41: * https://www.bic-code.org/bic-company-search/?searchterm=MAERSK https://www.bic-code.org/bic-company-search/?searchterm=MAER... * https://en.wikipedia.org/wiki/ISO_6346 https://en.wikipedia.org/wiki/ISO_6346
hakfoo 4y ago
I always wondered if this was designed to integrate into the existing railway numbering system. In the US, at least, owner identifiers are pretty consistently 4 characters or less, and individual unit numbers are 6 digits or less (i. e. BNSF 123456).
watchdogtimer 4y ago
I believe the 4th character of a container ID is always a U, so the container owner is the first 3 characters.
- robk 4y ago
  U is code for freight container so yes :)
webmobdev 4y ago
> “I have never seen two containers carrying the same number in my 27 years of career in the shipping sector,” pointed out Mohammed Abdullah Jahir, chief operating officer of Saif Maritime Ltd, adding that such an incident cannot be detected unless the boxes arrive at the same port at the same time. If the port authority conducting the inspection are not diligent, it's easy to miss this.

Denvercoder9 4y ago

What happens when somebody has more than a million containers? 6 digits doesn't seem enough to guarantee uniqueness.

cortesoft 4y ago
You assign a second owner number to the group, probably
addaon 4y ago
There's only about six million active containers in the world. If one owner has more than a sixth of them, an easy fix would be to issue them a second owner code, basically extending the six-digit field by a bit.
- Denvercoder9 4y ago
  > There's only about six million active containers in the world. Huh, that's a lot less than I expected there to be.
  - contravariant 4y ago
    Though that's about 1 per 1000 people, and if you imagine how much stuff you'd end up with using all that a container could carry when constantly in use, I guess about a thousandth of that isn't too weird an amount.
- elevaet 4y ago
  6 million seems like a underestimate. There are meant to be 54k container ships in the world. That would mean an average of 110 containers per ship, and ignores all of the ones in use on land. Some of those ships can carry 24k containers _each_.
  - walrus01 4y ago
    There are not at all a vast number of 8,000 TEU+ ships however. Small enough that any one ship owning company might have a few dozen at most. Evergreen says it has something like 150 ships.
    - GauntletWizard 4y ago
      Evergreen is still growing, though; They've got several 8,000+ TEU ships set to launch in the next few years. Consolidation is key. I would guess that the next answer is "Evergreen gets multiple Owner codes", because that's a real simple way to stretch it, but...
- ReactiveJelly 4y ago
  Wikipedia says 20.5 million _in 2012_ https://en.wikipedia.org/wiki/Cargo_container https://en.wikipedia.org/wiki/Cargo_container This was their source. Apparently not updated since that 2012 survey: https://www.csiu.co/resources-and-links/world-container-fleet https://www.csiu.co/resources-and-links/world-container-flee...
- munk-a 4y ago
  Well, we'd probably just switch over to UUIDs since those things are practically infinite and we've now got a lot of well established infrastructure in place for handling them.
  - fshr 4y ago
    Nope, that many characters would be impractical in daily use. There’s a lot of copying, pasting, reading, and reciting of numbers via email/web/phone/TMS/WMS/etc.
CodeWriter23 4y ago
Ahem, 10 million
- jffry 4y ago
  The 7th digit is a checksum digit, as previously noted. So only 6 "free" digits so a million is correct. You can read more about the container numbering standard here: https://en.wikipedia.org/wiki/ISO_6346 https://en.wikipedia.org/wiki/ISO_6346
  - CodeWriter23 4y ago
    Thanks for the info
throw0101a 4y ago
Like IEEE OUIs, one company can have multiple owner prefixes. Maersk has 41: * https://www.bic-code.org/bic-company-search/?searchterm=MAERSK https://www.bic-code.org/bic-company-search/?searchterm=MAER... * https://en.wikipedia.org/wiki/ISO_6346 https://en.wikipedia.org/wiki/ISO_6346

hakfoo 4y ago

I always wondered if this was designed to integrate into the existing railway numbering system. In the US, at least, owner identifiers are pretty consistently 4 characters or less, and individual unit numbers are 6 digits or less (i. e. BNSF 123456).

watchdogtimer 4y ago

I believe the 4th character of a container ID is always a U, so the container owner is the first 3 characters.

robk 4y ago
U is code for freight container so yes :)

webmobdev 4y ago

> “I have never seen two containers carrying the same number in my 27 years of career in the shipping sector,” pointed out Mohammed Abdullah Jahir, chief operating officer of Saif Maritime Ltd, adding that such an incident cannot be detected unless the boxes arrive at the same port at the same time. If the port authority conducting the inspection are not diligent, it's easy to miss this.