| Beginning in 1872 the Navy categorized its ships in four rates, 1st through 4th, which were based on displacement tonnage. Analysis of the 2nd and 3rd Rates showed that each contained two lines of development, one larger and one smaller, and this totally unofficial subdivision is used here. The break for 3rd Rates was at around 1400 tons, with none below about 700 tons. |
| Note: Four of these ships were authorized as new construction on 10 February 1873. The fifth, Nipsic (2), was officially the steam sloop Nipsic (1) of 1863 "rebuilt." Adams, Enterprise, and Essex were built by leading private contractors working in navy yards. Intended for general overseas cruising, primarily under sail, these gunboats had a greater beam and draft and fuller lines than their Civil War predecessors, and their new compound engines were more economical to operate than the Civil War machinery. |
| Note: Because of political pressure these gunboats were built with iron hulls. They were somewhat smaller than the wooden-hulled Adams class and originally had broadside armaments of one 9" gun per side instead of two, along with the single 11" pivot gun and single 60-pdr rifled chase gun that were in both classes. |
| Note: On 3 March 1885 Congress authorized the Secretary of the Navy to "place the steamer Thetis for use in the Navy, as a surveying vessel or otherwise." At the same time Congress directed that Bear, also acquired for the Greely Relief Expedition, be transferred to the Treasury Department for use as a revenue cutter in the waters of Alaska. |
| Note: On 2 March 1889 Congress authorized "two steel cruisers or gun-boats of the most approved type, of 800 to 1,200 tons displacement" (Machias and Castine). The last in the series that began with Yorktown (large 3rd Rate) and Petrel (4th Rate), they were initially referred to as Cruisers Nos. 12-13, indicating the ambiguity in their design. They were larger and faster than Petrel and therefore closer to cruisers in concept, but their primary armament was made up of relatively light 4-inch guns. They were originally designed on a displacement limited by law to 800-1400 tons and were to carry eight 4" guns, two at the ends, two under the forecastle deck, two amidships and two under the poop, with a speed of 14 knots. They proved to be overgunned and top-heavy and had to be lengthened 14 feet [and ballasted] after trials. |
| Note: On 3 March 1893 Congress authorized "three light-draft protected gunboats of about 1,200 tons displacement each" (Nashville, Wilmington, and Helena) for service in the Far East. Congress cited the Act of 3 March 1886 which required the use of steel. One of them (Nashville) had a full length flush deck for more enclosed volume, probably to carry troops. |
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USS Nashville (Gunboat No. 7, 1895-1921) North Atlantic Station, 1897-1898. Photo No. NH 63415 Source: U.S. Naval History and Heritage Command |
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| Note: FY 1894. On 3 March 1893 Congress authorized "three light-draft protected gunboats of about 1,200 tons displacement each." Two of them (Wilmington and Helena) were the first specialized China gunboats. They had a limited draft of 9 feet, which would allow them to operate in river mouths but not upriver, twin screws, and large rudders for maneuverability in narrow waters. Their tall military masts provided a commanding view over the 50-foot banks and dikes of the Yangtse. Unlike Nashville they had shallow hulls with substantial forecastles extending about three quarters of their length, providing internal volume not only for crews but also for refugees and special landing parties. The stern was cut away, reducing bouyancy to improve water flow over the propellers, particularly in shallow water. |
| Note: FY 1895: 6 gunboats. All had composite hulls (steel above the waterline, wood below). The Navy invited bids on two variants (alternative approaches to balancing speed and endurance), a single screw gunboat with full sail power (barkentine rig) and a twin screw steamer with steadying sails only. Both had to make 12 knots. The non-sail variant carried 120 more tons of coal, while the sail variant had to be longer to carry the sails. The four barkentines were built on the east coast and the two steamers by Union Iron Works on the west coast. The fourth barkentine, Princeton (Gunboat No. 13), was still building in 1897. |
| Note: FY 1895. These are the twin screw steamers with steadying sails mentioned above. |