so now that this game is already 6 months old there are quite a lot of people who are very experienced in operating artillery.
They destroy the enemy artillery first and harass the enemy team with their own for the rest of the match. Because cannons and mortars can not be destroyed by any other means all you can do is temporary putting it out of commission by neutralizing the operator. In public matches this means that he will be respawning and trying to claim back his cannon together with his teammates. In other words he will take a one-minute-break from firing the cannon.
It occurred several times that we overran the enemy cannon position and held it for several minutes before we were pushed back by a larger force. After that the cannon was manned again and the same guy kept killing dozens of us until the round ended. This problem is very clearly on the "Highlands" map.
Now, I know that carpenters are supposed to be able to repair ships and craft furniture in the future. While I think that these features can wait I would really like to see carpenters be able to dis- and assemble cannons/mortars. Carpenters should be the only ones with the ability to do this.
Disassembling/sabotaging artillery should take about 20 seconds while repairing should take at least about 60 seconds. Remember that right now when artillery is destroyed it is gone for the rest of the round. I decided to suggest 20 seconds for sabotaging artillery because on many maps the artillery cannons are either right next to the spawn or quite close to it (e.g. Tahir Desert, Arendan River, Desert Ruins). 20 seconds is a lot of time when you keep in mind that the enemies respawn in ten-seconds waves. Right after you killed the cannon operator he will probably spawn and come back directly for the cannon. If the operator does not come back, there is a high risk another enemy who may have heard your shot will see or stumble across you as you sabotage the artillery piece. Knowing that artillery can now be temporarily disabled may force people to be more thoughtful.
On the other side 60 seconds to repair artillery sounds reasonable to me. A public round on Army Battlefield takes about 25 minutes.
Once an artillery piece is disabled you will require a carpenter in order to fix it again. Cannons and mortars can be game chargers like the cannon and the mortar by the tents on Army Siege on Fort Christina.
Sabotaging and repairing artillery should have an own progress bar. Executing these actions should be possible by pressing a button (another than "E"). Carpenters should receive small amount of points for using that ability (something between 25 and 40 points).
Admin parameters should decide whether the carpenter is able to use his abilities or not.
To preventing abuse or griefing, cannons should not be able to get disassembled when they are manned.
Feel free to post feedback.