Duke's Freighters currently have 2 different designs: The "Cannon Freighter" as shown on the right, and the "Cargo Freighter".
Cannon Freighters have 3 cannons on each side, each side having ammunition of about 4-5 shots. An entire side will fire if a block from the player's machine gets too close. The cannons themselves usually only push the player away. However, the cannons can pop balloons and may blow bombs on the player's machine put of place, causing them to explode.
Cargo Freighters, on the other hand, have no defense at all. They carry wooden cages containing 3-4 rams.