I'm installing the Wather's furnace and have read up on the process to use lime, coke and ore.   But the process also requires oxygen.   What is the source of the oxygen?  Is it produced at the plant or shipped in?   If shipped in, what format - compressed air, liquid?   What types of cars would be used?   My era is 1952 and I have been told that there were few tank type cars then but box cars fitted with internal tanks for shipping were used.   Is this the purpose of the tanks and piping on the kit?