How can I conquer Messana in First Punic War BOR scenario?

[Kelte]

Hi all, I'm playing as Carthage and I find some difficulties in conquer Messana, every time I reach a point in which the garrison power goes down to a minimum level (20 points) and then the turn later the garrison power goes up to (120-130 points) as if they recieve supplies from an unknown source, unfortunately I can't stay more time in the province because my supplies aren't unlimited and I have to resupply and redo the siege again with the same results as before like it is an endless besiege.

The sea ports of Messana and Regium are blocked by my naval forces, there is a Consul in Messana and Regium is in roman control but in Messana the units don't recieve supplies, so why they don't capitulate? I have to conquer Regium to be sure that they will capitulate? Thanks

[bob.]

It can be you just have very bad luck. There's a chance every turn that new garrisons will spawn inside a besieged city, even if it is blockaded and besieged. These newly spawned garrisons have full supply.
It's weird, it makes no sense and it can make sieges VERY VERY VERY frustrating especially when you are not a Roman faction and thus have no siege weapons.

So, the answer to your question would be there is basically nothing else you can do apart from besieging Messana for a longer time until they eventually surrender. Remember that instead of going back with your army you can just establish a nice little supply line with your supply carts. And no, Rhegium has no influence.

[Kelte]

Thanks, I didn't know this thing about new garrison spawn in besieged cities.

Actually I have something like 8 supply carts attached to my army but, if I've correctly understand your suggestion, you're saying that I have to detach the carts from the army and with them form a line from nearly provinces with high supplies production, in that way my army will be in supplies without problems, have I correctly understand? Thanks

[bob.]

No, not an actual line line, I worded that a bit badly. Just detaching your supply wagons and moving them back and forth.

Here's how supply works: an army can draw supply from the province it is in and all the provinces surrounding it. So if you besiege Messana as Carthage you will get supplies from the Messana countryside (not the city, for obvious reasons) and from Tauromenium (Catania) and Tyndaris. That is of course assuming you still hold those two.
You will NOT get supply from Syracuse for example because it is not next to it.

So, what you can do is just move your supply wagons to Tauromenium, then they are next to Syracuse which produces a lot of supplies and now your supply wagons can restock. Then once they are full again you move them back to Messana and combine them with your army.