Ship design during the Age of Sail was characterized by a constant struggle to achieve an optimum balance between speed and firepower. As technology and the art of shipbuilding advanced the size of ships increased.
Under the standard rating system for men o’war, ships of the line came in four rates. 1st rates carrying 100-120 guns, 2d rates carrying 90-98 guns, 3rd rates carrying 64-80 guns, and 4th rates carrying 48-60 guns. By the latter half of the 19th century it was obvious that 4th rates and those 3rd rates carrying fewer than 74 guns could no longer hold a place in the line of battle. To compound their weakness as line of battle ships they were too slow to be used as frigates.
Navies were confronted with the dilemma of how to best use these ships as scrapping them before their useful life cycle was ended wasn’t a good option. The solution was to convert them as razees.
A razee was simply a larger warship with a deck removed, or razed, to convert it to a large frigate. The resulting ship would have the strength of construction to carry larger guns and take more punishment than other ships in its class. As a bonus, their increased length made them fast sailers.
This process will be familiar to anyone who wrestled in high school or college. A razee is the guy at the low end of a weight class who could shed 7-10 pounds in a week so he could wrestle at a couple of classes lower than his natural weight.
Take, for instance, Sir Edward Pellew’s famous HMS Indefatigable. Indefatigable started life as a 64-gun 3rd rate that was obsolete upon its launch in 1784. A fact that was recognized by the fact that this new ship was never commissioned. In 1794, Indefatigable was razeed into a 44-gun frigate converting a useless ship of the line into a frigate that could outsail anything it could not outfight.
As technology progressed, razees became more extreme. HMS Majestic was a 74-gun 3rd rate that was razeed into a 58-gun frigate. The US Navy razeed the USS Macedonian, the former 38-gun frigate HMS Macedonian, into a 20-gun sloop. The 50-gun USS Cumberland was razeed into a 24-gun sloop. In these latter two cases not only did the longer hull length and heavier construction overmatch other ships in their class, improvements in technology enabled them to carry the same weight of broadside as they had as larger ships.