Re: Nitric Acid Tank Cars
While it’s hard to say without knowing the particulars of the type of steel used for the inner tank of this car……….toggle quoted messageShow quoted text
It could well be the outer shell is another degree of protection against exposure to the weather degrading the main storage tank.
The outer shell will definitely prevent water and ice from degrading the sealing material between the riveted parts of the fabricated inner tank, and greatly reduces the possibility of weather rusting and damaging of the several hundreds of rivets making up the inner tank.
This type of acid might also be very concentrated and perhaps extra containment precaution is worth-while.
Later on….. production changes to different steel alloy sheets, different alloy rivets, sealants, or tougher paint may have made the outer shell unnecessary for newer acid tank cars. Allowing them to look more like the rest of the tank car fleet without that outer shell.
Best to ya,