LNG Tranport Trailers

[jclsws]

Hello, first time poster here. I am very new to the field of cryogenics. With regerd to the materials of construction for cryogenic transport trailers for liquified natural gas (LNG), why aren't these trailers made from aluminum? I know that aluminum is used for the tanks for other cryogenic trailers such as liquid nitrogen and liquid argon. I have looked through several trailer specifications, and I have seen that the inner vessels are all stainless steel while outer shells are either stainless steel or carbon steel with stainless steel rear heads. None of these specifications mention aluminum inner or outer shells. Does anybody know the reason for this?

Thanks.