I watched a new show on the History channel, Mankind, last night, and got a new piece of info on the use of crossbow by the Qin army. I remember that we argued back and forth a lot about the advantage and disadvantage of crossbow a while back. And it seems to me the biggest disadvantage of crossbow is its slow rate of fire and potential damage to the equipment when the bow had to be pre-drawn to save time before going into a battle. Well, on this new show, the weapons experts explained that the Qin army actually used a 3-men team to operate crossbows. So each team had a stringer whose job was to pull the string back, a loader who loaded the arrow onto the bow and a shooter who only pulled the trigger. And instead of one bow, the team operated 3 bows at the same time. So the stringer always had a bow to pull the string, the loader always had a bow in his hands to load the arrow and the shooter always had a bow in his hands to shoot. So there was no slowing down whatsoever. In fact, the shooting was much faster than a typical archer who has to load the arrow onto the bow, pull the string and shoot all by himself. The 3-men team also rotates since shooting a crossbow was no longer a specialized skill and anyone can do it with minimal training. So the stringer would become the shooter and the loader becomes the stringer and so on. This way, they tired much slower than typical archers who, again, had to do all the things by himself. Another thing is the formation. Instead of standing still, the 3-men team constantly march forward. The stringer moved forward immediately after he handed the drawn bow to the loader and the loader moved forward once he loaded the bow and gave the bow to the shooter. Then the shooter stepped up and shot the bow. So the whole formation constantly moved forward and advanced while shooting nonstop. One more thing that made the use of crossbow so effective in Qin was the mass-production of exchangeable parts, which made maintenance so easy.