Fortification and crewed guns

[Hermit]

I apologize if this has already been answered, but I read the game guide and searched the Forum for both "Fortification" and "Bunker" and did not find an answer.
I am buying units for a defense, and see that some bunkers have a "1xx" carry capacity, indicating they can carry crewed weapons. Can these weapons fire from the bunker? Passengers normally cannot fire from transports. I am playing a Long Campaign as U.S., the opponent is China, date is 3/54. I would like to have some AT capability from the heavy bunkers, and the native unit only has light weapons or close assault AT weapons.