at some point the 36s were re-rated as 38s. Their "ratings" by number of guns were meant only as an approximation. Ships of this era usually had no permanent battery of guns, as modern navy ships carry. The guns and cannons were designed to be completely portable, and often were exchanged between ships or shore as situations warranted. Each commanding officer generally outfitted armaments to his liking, taking into consideration factors such as the overall tonnage of cargo, complement of personnel on board, and planned routes to be sailed. Consequently, the armaments on ships would change many times during their careers, and records of the changes were not generally kept. Commonly, twelve men and a powder-boy were required to operate each gun. If needed, some men were designated to take stations as boarders, to man the bilge pumps, or to fight fires. Guns were normally manned on the engaged side only; if a ship engaged two opponents, gun crews had to be divided. All of the guns were capable of using several different kinds of projectiles: round shot, chain or bar shot, grape shot, and heated shot. Each gun was mounted on a wooden gun carriage controlled by an arrangement of rope and tackle. The captain ordered the gun crews to either open fire together in a single broadside, or allowed each crew to fire at will as the target came close alongside. The gun captain pulled the lanyard to trip the flintlock which sent a spark into the pan. The ignited powder in the pan sent a flame through the priming tube to set off the powder charge in the gun and hurl its projectile at the enemy. The marine detachment on board provided the naval infantry that manned the fighting tops, armed with muskets to fire down onto the decks of the enemy ship. Frigates The frigates were originally designated by the letters A through F until March 1795, when Secretary of War, Timothy Pickering, prepared a list of ten suggested names for the ships (in addition to those later used, the list also included Defender, Fortitude, Perseverance, Protector, and Liberty). President Washington was responsible for selecting five of the names: Constitution, United States, President, and Congress, each of which represented a principle of the United States Constitution, together with Constellation which derived from the blazon of the Arms of the United States, "13 stars, forming a constellation."