> It used a combination of pumped brine, and Freon Gas, which is a non-combustible gas, still used today as a refrigerant in air conditioning applications.

Freon (from then) is generally illegal to use today, as it depletes ozone. As a trademark, the name is often applied to newer refrigerants.

this website is a marvel, the fact that there are over 100 year old concrete ships still floating makes me wonder if there are concrete or nonmetallic ships still being constructed today for secondary purposes like carrying garbage or as bridges

There's a (likely apocryphal) story of a Japanese official realizing they'd lost the war when these showed up, as it indicated a level of spare industrial capacity and logistics while Japanese troops were struggling to stay fed at all.

I'm curious how they got the raw material to them. You can't make 5 tons of ice cream a day out of thin air. Were they shipped premixed sugar & milk or did they get straight raw ingredients and mix them onsite? I feel like the refrigeration capabilities are a pretty small part of the supply chain required to actually produce ice cream. Did they get a floating milk tanker to stop by every few days? Were they loaded on shore and just made do with what they had until the next port call?