Shipping container pools and lining

[Dusty pool]

G'Day all pool enthusiasts!
I've been looking into building an in ground shipping container pool. 40ft possibly even putting two together to make 80ft. For under AU $3000, that's a pretty cheap for an 80ft pool shell I understand there's going to be a bit/lot of welding to do and even a ton of marine type epoxy painting.
Another idea was, can they be lined, reneinforced with steel inside and spray concreted? I don't want all the container ribs. I don't want a vinyl liner.
Struggling to find a lot of info online.
Any help would be appreciated

Thanks Ty