Sharing convoy routes

[kerog]

So the rules say that unused convoys for one major power (say, the Commonwealth) can be used to ship resources for an allied major power (say, France). But I can't figure out how to make this happen. Can someone explain the process? I had 2 French convoys in the E. Med. that got killed; I'm thinking the two unused British convoys should be able to pipe through the French resources.

Also, it's a bit weird with Italy at war with France but not the Commonwealth. How does a 4-way naval combat work in that situation? German Naval air, Italian convoy, French and British subs.

[paulderynck]

Production planning using the Routing capability will allow the CW convoys to be used, but in certain circumstances, the Italians could elect to search and seize the resources.

As for naval combats - see Multiple States of War in RAC.