Supply Question: Why Convoys Instead of Infrastructure

[JScott991]

I'm playing Kaiserreich on the latest version of HOI4. I don't think it matters because supply rules are essentially the same as in Vanilla.

As Austria, I am at war with France. I broke through the southern part of our mutual border in the French/Italian Alps and captured Nice and Toulon, but was unable to make headway in the mountains. I was reinforcing my front when I noticed that I was having supply trouble. And I can't figure out what is going on here.

It looks like I am using convoys from my co-belligerent (southern Italy / Naples is not even my ally) to supply my troops in Provence (Toulon), despite having a land border. The infrastructure here is all fine so I am not sure why I'm not using it.

Why am I using convoys in this situation?

What will ultimately happen here is that the French navy will cut the convoy line and the troops in the Nice/Toulon corridor will go out of supply and get crushed. But the troops along the rest of the front are fully supplied because they are using infrastructure.

What can I do about this? I can't figure out any way to manually control supply (or even set a safer Genoa to Toulon convoy).

 

[Simon_9732495]

Why am I using convoys in this situation?

Maybe it's because you get more supply that way. You have 79 in Naples but only 57 in Turin. And it could be that you get the "Control of incoming edge provinces" supply debuff over land, because you don't control all provinces at the border between the Turin and the Toulon supply zone.

What can I do about this? I can't figure out any way to manually control supply (or even set a safer Genoa to Toulon convoy).

You can block sea zones for your convoys. Naval map view (F2) -> Click Seazone -> In the small window click the red icon. (If you have the "Man the Guns" DLC)
If you block the Western Mediterranean Sea you can't get supllies over sea to Toulon. Then you see if supply over land is really worse.

The transfer Genoa - Toulon would not be safer, because the navy stuff is per strategic region. If you get convoy raided in the tyrrhenian sea, it doesn't matter if the convoys go Genoa - Toulon or Naples - Toulon.
(Except that you MAYBE lose a bit more convoys, because the route is longer. But I think that can be ignored.)

 

[HugsAndSnuggles]

Maybe it's because you get more supply that way.

Exactly: Soviet Union supplies forces in Far East via transports, too... until you build 4-5 levels of infrastructure to transport it via land.

 

[JScott991]

Thank you all for the help!

I figured it out. Venice cancelled their military access with me at some point so I stopped being able to use their infrastructure. Once I got that access back, it stopped using convoys.

I do wish the game had more manual control over supply. A land-based nation like Austria shouldn't be sending convoys to their death automatically.