Fort Upgrades?

[colonel hurst]

When upgrading a pre-war fort such as Donelson/Henry or Island 10, does it still take 4 artillery units and a supply wagon? Also, what are the advantages to doing so? Lastly, does it matter what type of artillery units are used to build a fort, are 6 lb. units effectively the same as 20 lb. units?

[enf91]

I don't think it's possible to upgrade those forts. Manually built forts have to be built in cities.
>>Artillery types are irrelevant.

[blackbird]

>>Artillery types are irrelevant.

The one exception is that those fixed emplacement fortress guns can not be used. Use the 6 pounder guns since they are the cheapest and since they are used up and disappear, you can request them again in the reinforcement panel.