Cannons are hazards in the game Dirk Valentine.
Cannons are curved with a round end at their base and a hole at their front. Cannons also have pipes attached to them.
The cannons shoots missiles which will hurt Dirk Valentine if he touches one. They are usually positioned in the walls and sometimes attached to the walls. They are used as the main weapon on the fortress of steam, but are most often seen stationed in the wall outside the fortress. The missile they fire revolves, exploding against the wall. The missile will also hurt Dirk Valentine if it touches him, depleting one health point.
The missile can be destroyed by being shot with the chain cannon. The missiles will not harm enemies, only the player. Cannons only appear outside the Fortress of Steam, never inside. This is probably because having cannons inside would be senseless and probably damage the ship.