Wikipedia:Reference desk/Archives/Science/2019 November 21

= November 21 =

Recharted by DI ?
The articles Stewart Strait and O'Connor Peak (both of which are adapted from USGS antarctic names articles) say these places were "Recharted by DI in 1929" (or 1930). The only antarctic expeditions in that time period were, I think, the British Australian and New Zealand Antarctic Research Expedition and Richard E. Byrd's first antarctic expedition. Neither of these suggest the initials DI. I'm guessing that DI stands for the type of survey ("direct investigation"?). What, or who, is "DI"? -- Finlay McWalter··–·Talk 10:29, 21 November 2019 (UTC)
 * Discovery Investigations?.&mdash;eric 15:28, 21 November 2019 (UTC)
 * W.P. O'Connor, Assistant for survey duties:, O'Connor Peak mentioned.&mdash;eric 15:47, 21 November 2019 (UTC)
 * There are supposedly 4 charts for the surveys of South Georgia and South Shetland Islands, but for some reason records of the 74th Congress are there instead.&mdash;eric 16:26, 21 November 2019 (UTC)

Paint colors for extreme conditions.
I have been working this week on a jobsite where I see a lot of container ships go by. I have noticed that a lot of the containers are a rust red, perhaps based on iron oxide or cuprous oxide. Others look suspiciously like the green of Basic copper carbonate. I don't see a lot of bright primary red, though. I also have seen the same brownish red paint used other places, such a steel bridges.

This got me to thinking; are there some paint colors that are more suitable for a marine environment or are otherwise longer lasting? Do we have an article that covers this? --Guy Macon (talk) 16:29, 21 November 2019 (UTC)
 * Anti-fouling paint? Tigraan Click here to contact me 16:44, 21 November 2019 (UTC)


 * Primer (paint) might be a good place to start. Certain "colors" (i.e. pigments) are better for paint priming or as an undercoat.  Although as such they are typically painted over in another color, but for purely utilitarian purposes such as freight containers there is no need.  Another pigment is the greenish-yellow Zinc chromate used for protecting aluminum alloys.  2606:A000:1126:28D:144E:A9EA:EDD2:AB72 (talk) 16:53, 21 November 2019 (UTC)
 * According to intermodal container, the containers are often made of weathering steel, which forms a stable coating or patina of rust and doesn't require painting. It is also used for bridges, although some bridges (such as the Golden Gate Bridge) are painted an orange-red color.  (Interesting question, I have wondered about this too.) --Amble (talk) 17:45, 21 November 2019 (UTC)
 * According to intermodal container, the containers are often made of weathering steel, which forms a stable coating or patina of rust and doesn't require painting. It is also used for bridges, although some bridges (such as the Golden Gate Bridge) are painted an orange-red color.  (Interesting question, I have wondered about this too.) --Amble (talk) 17:45, 21 November 2019 (UTC)


 * A number of years ago I researched a similar question about the historic use of green paint (or enamel) on locomotives and stationary steam engines. We were restoring a cast iron mount that had red lead primer and a green topcoat which was a mixture of chrome yellow (also a lead paint) and Prussian blue. I couldn't find any mention that a specific color was preferred but I did find some references to weather proofing exposed metal and commonly used pigments. I'd be interested if anyone had additional info about historic weatherproof paint. --mikeu talk 18:18, 21 November 2019 (UTC)


 * I found something related: Lightfastness. Still looking for info on longevity as opposed to fading. I also found a list of container colors here. Note the same lack of bright primary colors that I had noticed. --Guy Macon (talk) 20:20, 21 November 2019 (UTC)


 * This claims that it is company color branding, similar to British Rail corporate liveries. Some examples here. --mikeu talk 22:06, 21 November 2019 (UTC)


 * Certainly different companies use different colors (Maersk is almost always gray, Evergreen is almost always green) but that does not explain why no shipping containers are bright primary red, electric blue or neon green. I have to assume that there are some colors that don't last as long. --Guy Macon (talk) 22:41, 21 November 2019 (UTC)
 * From mikeu's link:
 * —2606:A000:1126:28D:144E:A9EA:EDD2:AB72 (talk) 05:41, 22 November 2019 (UTC)
 * Indeed some of the examples like Container HAMBURG SÜD 01.jpg Container HAMBURG SÜD 01.jpg and File:Hamburg Süd Container Stack.jpg don't seem that far off bright primary red to me. And Hapag-Lloyd container stack train.jpeg Hapag-Lloyd container stack train.jpeg or File:Hapag Lloyd Container 01.jpg seems somewhat bright. As for pink, a quick search find there is Japan's Ocean Network Express/ONE [//www.youtube.com/watch?v=Z02NRg06y5w] BEAGLE & ONE CYGNUS (48941565386).jpg BEAGLE & ONE CYGNUS (48941565386).jpg. Interesting RAL 4003 [//www.bslcontainers.com/about/ral-color-chart/] [//www.budgetshippingcontainers.co.uk/shipping-container-colours/] doesn't seem to be available as a colour from Hempel [//www.bslcontainers.com/about/hempel-paint-color-chart/]. Maybe it's too expensive or too difficult to make, but it's also easily possible there is just too little demand. Edit: I see pink was never mentioned. For some reason I thought it was. Nil Einne (talk) 08:32, 22 November 2019 (UTC)
 * I see the OP also linked to the BSL RAL colour chart. However I wonder if they are confused about what it is. AFAICT, the RAL standard has nothing to do with containers per se. It's just a colour matching system originating in Germany that in the RAL Classic form which is applied to varnish and powder coatings, seems to have become something of a defacto standard. I don't think it has an special connection with containers other than apparently being used to specify the colour for some manufacturers but I get the feeling that also applies in other areas. While I don't see any super bright blues, per List of RAL colors, RAL 6037 and 6038 do exist for green. I'm not sure why they don't show in the BSL link but I'm somewhat confused by their list since they suggest they use Hempel. But Hempel doesn't seem to make all colours they list as options e.g. the RAL 4003 I mentioned earlier. (budgetshippingcontainers.co.uk do have BSL 6037 and 6038, but it sounds like they're targeting the non shipping market.) It's possible RAL 6037 and 6038 are recent additions. While our article and [//www.ral-farben.de/content/about-ral-colours/ral-colours-history.html] seems to imply no revision since 1961, both our article and [//www.ral-farben.de/content/application-help/faqs/faqs-questions-about-ral-classic.html] provides info on how new colours may be added which make me think it's probably been at least complemented since 1961. (By new I don't mean very recent, even if it came in the 1990s I wouldn't be surprised if it still hadn't filtered through to many things.)  Also if I look at the article history, it was created in 2013 from the German Wikipedia [//en.wikipedia.org/w/index.php?title=List_of_RAL_colors&oldid=555779906] and for those 2 colours said "Verwendung in der Schifffahrt zur Verkehrssicherung (Schifffahrtszeichen)" which machine translate suggests "Use in shipping for traffic safety (shipping signs)". Which makes me wonder if possible newness aside, it would be considered unsuitable for a shipping container, perhaps why BSL didn't list it.  Actually this brings up another point which occurred to me. Extremely bright colours can be distracting or used for attention in certain scenarios, potentially discouraging their usage in ordinary situations like shipping container.  P.S. I also think we shouldn't downplay the significance of my "demand" point earlier which also plays into Bus stop's point below. RAL for example requires "overriding public interest and not be subject to passing fashion". If few are demanding the colour because it's seen as bright, garish and distracting, and so not something you'd want to use in many scenarios, even if it can be produced the cost is likely to be significantly higher. It may not be that it has to be expensive, but just that it is. But then even those who may consider it may be put off by the cost and the difficulty of obtained the colour. I can't help wondering if this applied in part to ONE's magenta, but they went ahead anyway because they decided the added cost was worth it for their marketing goals.  Nil Einne (talk) 09:19, 22 November 2019 (UTC)


 * Expense may be a consideration. Pigments vary in cost. It is the coatings industry that is of especial relevance. "The coatings industry is one of the most heavily regulated industries in the world, so producers have been forced to adopt low-solvent and solventless technologies in the past 40 years, and will continue to do so." There are many factors involved in choice of industrial coating. "In general, environmental regulations are becoming more stringent in all regions to limit emissions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs), not only in the industrialized world, but also in developing countries like China. Energy conservation and rising solvent and raw material costs are also contributing factors; raw material costs account for 50–60% of the total production costs for coatings. The coatings industry is one of the larger consumers of solvents, which are mostly derived from petrochemical feedstocks and refinery operations. The coatings industry also uses a considerable quantity of nonpetrochemical feedstocks, such as pigments and additives, which are not very dependent on crude oil and gas prices. The nonpetrochemical portion of the feedstocks is approximately one-third, on a volume basis." Here is some information about considerations that may favor one color shipping container over another. Unrelated but interesting. (16 minute YouTube video) Bus stop (talk) 04:24, 22 November 2019 (UTC)