Danube front Damage Ferry

[P.Ako]

Anyone knows how it works? because i place an unit in the hexagon next to the ferry hexagon, and, when they're without movement, i choose the "damage ferry" option, but the program tells me that it's only possible in the hexagons containing a ferry.

Very well, i move them into the ferry, advance turn, i select the units, select the damage ferry order... but the program tells me that it's not possible!!!! i tried both with normal units and with engineers but still can't get those bloody ferries to get blown...

Anyone knows if that feature works in MC? because misteriously, they don't explain that order in the help archive....