Trebuchet operators

The trebuchet operators were large, muscular men who worked on the decks of Fire Nation ships, operating the trebuchets. They were not firebenders, but their strength was used to load the trebuchet nets with heavy boulders. They carried large hammers that were used to fire the trebuchets. The hammers also came in handy as weapons. Admiral Zhao was forced to hire a number of mercenaries to operate the trebuchets, since his sudden demand for ships left a few vessels a little short-handed on experienced crew members.

History
When Aang went to ambush one of the ships during the Siege of the North, he first destroyed the trebuchets that the operators were supposed to man. The ship had five trebuchets on it. Aang destroyed the first trebuchet by sending an air blast down from the top of it. The second one was destroyed by putting a hammer in the chain so that it created a hole in the ship once launched. Aang destroyed the third and the fourth by tying the nets of the trebuchets together so that when the trebuchet in the front launched, the one in the back would come smashing into the one in front. Aang was about to destroy the fifth one with a hammer but was stopped by the leader of the trebuchet operators, who swung his hammers around on chains. Aang dodged the leader of the trebuchet operator's hammers for a while until Appa came, picked up the leader, and dropped him into the water. waterbenders then lunged an ice spike through the ship, suspending it in the air, before finally destroying the last trebuchet.