I just started playing Civ3 again since I couldn't resist buying PTW (mostly to get the Celts!).
Anyway I have forgotten if there is a way to transport (aka convoy) food from one city to another (I have a city in the mountains with a ton of gems around but can't sustain a population over 2)
Not by me. I did not care for caravan and managing and protecting them. I do wish we had the total terraforming. I would not object to a empire wide food share mechanism. It would have to be just build a device and it is all handled automatically, like Moo2 freighters.