**Expedition 21, 37, 38 also require [[Drum Canister]]s to be equipped. The total number of drums and the number of ships carrying drums must be greater than or equal to a minimum value. | **Expedition 21, 37, 38 also require [[Drum Canister]]s to be equipped. The total number of drums and the number of ships carrying drums must be greater than or equal to a minimum value. |