by Tim Wood
During the 18th century, when wooden warships dominated the high seas, one of the most common naval guns was the mortar. The mortar was a muzzle-loaded cannon with a short barrel. Because the barrel elevation was fixed at a 45 degree angle, the carriage design was simple. All that was needed was a recessed wooden "baulk" that held the breech end of the gun. The trunnions were not used to vary elevation, but to spread the recoil over a greater area. The guns on deck were fixed to fire dead ahead, so the entire vessel had to be turned to aim. Eventually, the base was made to rotate, vastly simplifying and speeding the aiming procedure. Still, by modern standards, mortars were extremely inefficient, difficult to load, and short ranged. A typical broadside of a Royal Navy ship of the late 18th century could be fired only 2-3 times in approximately 5 minutes.