There are 10 plus 2* 20FT containers oxygen cylinders needed to be loade everyday since 2020. Workers work as 3 groups as 8 hours a group as 24 hours full a day. 

Containers need to do appointment from day and night as one container needs about 1.5 hours to be full loaded oxygen tanks. 

It's usually loaded in 20ft container because 40ft will be too heavy if full of steamless cylinders.