The Steam warship classification system used during the 19th century was a classification scheme for the comparison of steam warships, including

steam frigate Steam frigates (including screw frigates) and the smaller steam corvettes, steam sloops, steam gunboats and steam schooners, were steam-powered warships that were not meant to stand in the line of battle. There were some exceptions like for exam ...

s and

steam sloop Steam frigates (including screw frigates) and the smaller steam corvettes, steam sloops, steam gunboats and steam schooners, were steam-powered warships that were not meant to stand in the line of battle. There were some exceptions like for exam ...

s. The system originally classified steam warships according to the thrown weight of their broadsides, then rated them by tonnage, using separate standards for

ironclad An ironclad is a steam engine, steam-propelled warship protected by Wrought iron, iron or steel iron armor, armor plates, constructed from 1859 to the early 1890s. The ironclad was developed as a result of the vulnerability of wooden warships ...

and non-ironclad ships, with allowances for sailing ships still in commission. It was used in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

, officially and unofficially. The

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

adopted the system by 1875.

Ratings

First system (Civil War-at least 1870)

(Weights given are representative)

Second system (by 1875)

{, class="wikitable" , - !align="center", Type !align="center", Tonnage (non-ironclad) !align="center", Tonnage (ironclad) , - , align="center", First Rate
(also sailing

ships-of-the-line A ship of the line was a type of naval warship constructed during the Age of Sail from the 17th century to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which depended on the two colum ...

) , align="center", 4000 + {{Cite book, isbn=, title=A Naval Encyclopædia: Comprising A Dictionary of Nautical Words and Phrases; Biographical Notices, and Records of Naval Officers; Special Articles of Naval Art and Science, url=https://archive.org/details/bub_gb_IPvxNqDjeXYC, last=, first=, authorlink=, publisher=L. R. Hamersly & co., year=1881 , align="center", 8000 + , - , align="center", Second Rate
(also

sailing frigate A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied somewhat. The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and ...

s) , align="center", 2000 - 4000 , align="center", 2000 - 8000 , - , align="center", Third Rate
(also sailing sloops of war) , align="center", 900 - 2000 , align="center", 1200 - 2000 , - , align="center", Fourth Rate
(also

dispatch vessel Dispatch boats were small boats, and sometimes large ships, tasked to carry military dispatches from ship to ship or from ship to shore or, in some cases from shore to shore. Dispatch boats were employed when other means of transmitting a message w ...

s and

store ship Combat stores ships, or storeships, were originally a designation given to ships in the Age of Sail and immediately afterward that navies used to stow supplies and other goods for naval purposes. Today, the United States Navy and the Royal Navy ...

s) , align="center", 0 - 800 , align="center", 0 - 800

References

Steamships