Some are black white blue even yellow .Is there a reason as to what they carry?
Tank car colors are as a general rule not related to the product they carry.
I dont understand that what it means
He means that there is no color-coded (or pattern) system that tells what product is carried in tank cars.
Sometimes the name is painted on the car, but most often if the contents are hazardous the car is ‘placarded’ with a code number, which can be looked up in this reference (PDF copy)
https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/ERG2016.pdf
While doing some work in Metarie, LA, I was told to watch out for the “candy stripe” tankers.
Found this page with some info about tank cars in general.
About the only cars I’ve encountered, or know of, where the appearance of the car, paint-wise, makes any difference, is the “candy stripe” cars already mentioned (cyanide, by the way) and molten sulphur cars, which often (but not always) have a yellow band around the middle.
I’ve see LP cars in white and black. Nowadays, pretty much everything is black.
Back when the car owners (often chemical companies) were more open to showing off who they were, some had some colorful cars. One frequently modelled car over the years was the orange Hooker Chemical tank cars.
The yellow band in the middle of sulphur cars is there primarly to hide sloppy loading through the top hatch of the car. If the the car was painted all black, it would still be yellow around the loading hatch from overflow.
There are some LPG tank cars that are blue too.
Which was my assumption…
No special color-coding on these, but the wheels are a clue
http://www.railgoat.railfan.net/railwhales/photos/dupx028074_brian_ehni.jpg
There was an alternative I regularly saw ‘parked’ outside Bayway, much smaller double-truck tank cars cheerily painted in blue with white lettering ‘advertising’ the product within. Glad we’ll never go back to that era.