Talk:ISO 6346

Check digit: special treatment for HCLU?

On 2016-02-25, an anonymous user added (not terribly useful) chinese comments to the Javascript code sample -- and the condition if (con.substr(0, 4) == "HLCU") { sum -= 2; }. This does not match the description of the algorithm above and no equivalent is present in any other code sample. However, I sampled a few container numbers starting with HLCU that I could read on respective containers found via google image search, and indeed the check digit differed by 2 from the expected one calculated by the usual algorithm (e.g. on HLBU... or HLXU... containers; all thse prefixes are for containers operated by Hapag Lloyd), so it seems the HLCU-adjustment is applied in reality.

Does anyone know any documentation on the apparent discrepancy? --217.95.168.92 (talk) 11:13, 6 February 2018 (UTC)

What's the conversion for?

The biggest part of this article is about the conversion algorithm, but it's never introduced. It doesn't appear to be part of the actual number, as depicted here. (The only numerical number with more than 2 digits is the serial number, but that's up to the owner, and unlikely to be connected to any letters.) Is that whole text misplaced? — Sebastian 23:08, 18 March 2016 (UTC)

It seems to be for converting a letter/number coded container to a solely number coded container. Super weird article huh? I can't help but think this informtion is somehow useful though.HappyValleyEditor (talk) 23:13, 18 March 2016 (UTC)

I found it in one of the sources: This whole section is just for computing the check digit. Since Wikipedia is not a manual, and since this one small aspect completely overwhelms the rest of the article, I think it's better to remove it. However, some people obviously put some work into the code samples; it may be worth saving somewhere. I'll ask at Wikibooks if that's something they can use there. — Sebastian 17:10, 21 March 2016 (UTC)

I introduced a shortened version of the Excel formula. Hope it helps someone out there. Greasyham (talk) 18:38, 15 September 2016 (UTC)

Reefer subgroups

The groups and subgroups for reefers are confusing. This article lists:

Group code	Description	Size type
RC	REEFER CONT.(NO FOOD)	22R9
RS	BUILT-IN GEN. F. POWER SPLY OF REEF	22R7
RT	REEFER CONTAINER	22R1

The Swedish version lists:

Group code	Description	Size type
RE	Thermal containers - refrigerated - refrigerated and heated - self powered refrigerated/heated	R0
RT	(None)	R1
RS	(None)	R2, R3

and type codes R4-R9 as spares. The type code table in this article agrees:

Size type	Description
R0	Integral Reefer - Mechanically refrigerated
R1	Integral Reefer - Mechanically refrigerated and heated
R2	Integral Reefer - Self-powered mechanically refrigerated
R3	Integral Reefer - Self-powered mechanically refrigerated and heated

So, questions:

• Are R7 and R9 actually valid size codes? If so, which group(s) do they belong to?
• Which groups do R0, R1, R2 and R3 belong to?
• Are RC and RE both valid group codes? If not, either this or the Swedish article should be corrected.

Waitak (talk) 15:58, 29 March 2016 (UTC)

Size / type codes?

Their meaning is mentioned in the article, but nowhere is explained where one would find them on the container. Are they part of the serial number…? --Rohieb (talk) 21:20, 29 September 2022 (UTC)

Version-Specific Reference for ISO 6346

I was researching the 4510 container type and came across this site, which refers to the older version of the standard (ISO 6346:1984). Since this article focuses on the updated version (ISO 6346:2022), it might be helpful to specify the version in the article's title or content to avoid potential misunderstandings. Bsimjoo (talk) 07:57, 5 December 2024 (UTC)

Restructuring ISO type length/width/height table + automatic unit conversion issues

While editing the page to add the 5 length code for 45ft containers I noticed the combination of the 1st and 2nd character in the same table needlessly confuses things. These are entirely separate, and on account of the tables having to be the same height we end up with duplicated values like 2 and now 5 for the width/height character. Wouldn't this make more sense as two separate tables, one for the first character (length) and one for the second (width+height)

On top of that, this table automatically converts the imperial measurements to metric, but this automatic conversion is misleading. In the PDF of the ISO 6346 it is explicitly stated that the imperial units are the nominal length of the containers, but any metric units are the actual length of the container. This is because a 20ft container is actually slightly shorter (19ft and 10.5 inches) to accommodate twist locks in between so two 20ft containers + a twist lock matches the length of one 40ft container, and thus a 40ft can be stacked on top of two 20ft containers.

The ISO 6346 document states actual lengths for the metric units, while using nominal length for the imperial units. This means the automatic wikipedia unit conversation does not match the ISO 6346 document, and all values in metric are slightly longer than the spec states.

I'm not exactly a hero when it comes to the Wikipedia editor but I'd propose to fix both of these: split the tables and hard code the values instead of auto converting. Happy to give it a shot, but if somebody with more experience with table manipulation wants to give it a go, that would be great. Neovesta (talk) 10:09, 28 August 2026 (UTC)

I also think that the section about container types (the 3rd and 4th characters) needs to be reworked. For example, the main type (General Purpose, Tank, Bulk etc.) and the subtype (Non-mechanical, Mechanical + Internal, Mechanical + External etc.) should be separated instead of being in one cell. Then the cells with the same main type could be grouped together, which would make the table easier to read. (Sadly I don’t understand table syntax, so I can’t show an example here)

Additionally, the table containing the most common size/type codes should be either shortened or removed completely. It takes up a lot of space on the page despite only a few of those (like 22G1 or 45G1) being actively in use, and there being 2 tables below which allow a reader to deduce the specs of any size/type combination. Brawlstarspro (talk) 10:52, 28 August 2026 (UTC)