Foreign equivalents

This type of large (but under-armed) specialized commerce raider was built by several other countries. The German cruiser SMS Kaiserin Augusta also had a triple-screw design and was nearly as long as the American Columbia-class ships, but had a more general role instead of a specialized commerce raider. The French copied the Columbia-class concept with two large protected cruisers; Guichen of 1897 and Châteaurenault of 1898 before switching to building only armored cruisers for the commerce-raiding role such as the Dupleix class of 1900. Later, Russia acquired a series of oversized protected cruisers such as the Pallada and Bogatyr classes along with Askold and Varyag up until the Russo-Japanese War (1905), although these were given a relatively stronger armament for their size. The British were the most probable target of most of these ships, and invested in various cruiser designs as a counter to the perceived threat.

Acquisition

US Representative Charles A. Boutelle of Maine was the primary advocate of these ships in Congress, and overcame significant opposition to get them built.^[6] William Cramp & Sons of Philadelphia was the sole bidder for Columbia, ordered in fiscal year 1891. Minneapolis was ordered the following year and described as the "most important ship" in that year's program. Bath Iron Works of Bath, Maine was the lowest bidder, but Bath could not build their own engines nor complete the ship in time. So the contract was awarded to Cramp, on condition that they lower their price $55,000 to meet Bath's bid.^[6]

Engineering

The engineering plant needed to meet the designed speed of 22.5 knots (41.7 km/h; 25.9 mph) was unprecedented in the US Navy. Engineer-in-Chief George W. Melville was personally involved in its design.^[6] The designed horsepower of 21,000 ihp (16,000 kW) was nearly double that of the battleship Iowa, and well in excess of the later Brooklyn's 16,000 ihp (12,000 kW).^[7] To achieve this a triple-screw powerplant, the first in the US Navy, was designed. Eight or ten (references vary, possibly 8 in Columbia and 10 in Minneapolis) coal-fired cylindrical boilers supplied steam to three triple-expansion engines.^[5][6] The ships could economically cruise at 15 knots (28 km/h; 17 mph) on the center engine alone.^[6] Both ships exceeded their design speed on trials; Columbia made 22.8 knots (42.2 km/h; 26.2 mph) and Minneapolis made 23.07 knots (42.73 km/h; 26.55 mph).^[5]

Consideration was also given to survivability in the event of battle damage. Each engine was in a separate compartment, and the center screw was 15 ft (4.6 m) aft of the outboard screws, minimizing the chance of more than one screw being disabled by a single hit.^[6] Columbia was built with four funnels while Minneapolis had two; it is possible this, along with the main gun placement on the aft deck, was intended to make the ships resemble their prey from a distance.^[6]

The normal coal allowance was 800 tons. However, the design allowance was 2,130 tons for a globe-girdling range of 25,520 nmi (47,260 km; 29,370 mi) at 10 kn (19 km/h; 12 mph). It seems this proved impractical, as the full load coal allowance is given in the same source as 1,576 tons.^[6]

In July 1895 Columbia made a transatlantic crossing from Southampton to Sandy Hook in 6 days, 23 hours, 49 minutes for an average speed of 18.41 knots.^[5][6] This was without forced draft and was said to be the fastest crossing for a warship to that date. However, the record holder at the time was an ocean liner, the German Hamburg America Line's Fürst Bismarck with a time of 6 days, 10 hours, 32 minutes.^[5]

Protection

The protection system included an armored deck as in other protected cruisers, 4 in (102 mm) on the sloped sides and 2.5 in (64 mm) in the flat middle. The gun shields were 4 in (102 mm), as were the sponsons for the 4-inch guns. The conning tower was 5 in (127 mm).^[3][5] Compared with other US protected cruisers, the armor was not inferior except in relation to the ships' size: the 7,000-ton Columbias had similar armor to 4,000-ton ships such as USS Baltimore.^[8]

Armament

The originally designed main armament for Columbia was four 6 in (152 mm)/40 caliber guns,^[9] two forward and two aft, but during construction the aft pair was replaced by a single 8 in (203 mm)/40 caliber Mark 5 gun.^[6][10] The two 6-inch guns were side by side just forward of the superstructure. Secondary armament included eight 4 in (102 mm)/40 caliber rapid fire (RF) guns in sponsons in the hull,^[11] 12 6-pounder (57 mm (2.2 in)) RF guns,^[12] four 1-pounder (37 mm (1.5 in)) RF guns,^[13] and four Gatling guns.^[6] A field artillery piece on a wheeled carriage was also carried for use by landing parties.^[14] The ships also had four torpedo tubes, 14 in (356 mm) on Columbia for Howell torpedoes and 18 inch (450 mm) on Minneapolis.^[5]

Refits

All torpedo tubes were removed by 1904.^[3] Both ships were out of commission for a long period, Columbia 1907–1915 and Minneapolis 1906–1917. During re-activation refits at the end of these periods the lone 8-inch gun was replaced by a third 6-inch (152 mm)/40 caliber gun.^[3] This was part of a general withdrawal from service of 8-inch Mark 5 guns due to a tendency to burst.^[10] Two 4-inch guns were also removed by 1917, leaving six guns.^[3] One source states that two additional 4-inch guns were removed and two 3-inch (76 mm)/50 caliber anti-aircraft guns were added circa 1918.^[5][15][16]