Erie-class gunboat

USS Erie (PG-50)
Class overview
Builders:	New York Navy Yard (PG-50) Charleston Navy Yard (PG-51)
Operators:	United States Navy Massachusetts Maritime Academy 1948-1957 (PG-51)
Preceded by:	Asheville-class gunboat
Succeeded by:	PGM-1-class motor gunboat
Built:	1934-1936
In commission:	1936-1945
Planned:	2
Completed:	2
Lost:	1
Retired:	1
General characteristics
Type:	Gunboat
Displacement:	2,000 long tons (2,032 t) (standard) 2,830 long tons (2,875 t) (full load)
Length:	328 ft 6 in (100.13 m) o.a. 308 ft (94 m) p.p.
Beam:	41 ft 3 in (12.57 m)
Draft:	14 ft 10 in (4.52 m) (full load)
Installed power:	2 × Babcock & Wilcox boilers 6,200 shp (4,600 kW)
Propulsion:	2 × Parsons geared single reduction steam turbines 2 × shafts
Speed:	20 kn (37 km/h; 23 mph)
Range:	8,000 nmi (9,200 mi; 15,000 km) at 12 kn (22 km/h; 14 mph)
Complement:	243
Sensors and processing systems:	Mark 3 Radar (mounted atop battery director) ASDIC Sonar
Armament:	4 × 6 in (152 mm)/47 caliber Mark 17 guns 4 × Quadruple 1.1 in (28 mm)/75 cal anti-aircraft guns (4x4) 6 × 20 mm (0.79 in) anti-aircraft guns (refit) 2 × Mark 6 Depth charge racks (each holding 15 depth charges)
Armor:	Side belt (over vital places):3.5 in (89 mm) Deck: 1.25 in (32 mm) Conning Tower: 4 in (100 mm) Gunshields: 1 in (25 mm)
Aircraft carried:	1 × floatplane "Seagull"(original equipment, replaced in refit) 1 × floatplane "Kingfisher"
Aviation facilities:	Derrick

The Erie class gunboats were a class of gunboats built by the United States prior to World War II. The class was designed in 1932, and commissioned into the United States Navy in 1936: Erie (PG-50) and Charleston (PG-51). The Eries had a design speed of 20 kn (37 km/h; 23 mph) and a main armament of four 6-inch (152 mm) guns in single mounts with four 1.1-inch (28 mm) quadruple mount anti-aircraft guns.

In 1930, during the London Naval Conference, Admiral William V. Pratt, successfully argued for an additional class of naval surface combatants that would not be limited in number that could be constructed. Defined as a sloop, per Article VIII(b) of the Treaty. The ships could neither exceed 2,000 long tons (2,000 t) of displacement nor a maximum cruising speed of 20 knots and their armament was limited to up to four guns above 3.1-inch (79 mm) in caliber, but not to exceed 6.1-inch (155 mm) in caliber, and they could not mount torpedo tubes.

It was proposed that the Eries could be used in a number of roles, including: screening the fleet against enemy destroyers and submarines, high-speed mine laying, tactical control of fleet submarines, antiaircraft duty for slower carriers, support of destroyer attacks, anti-submarine warfare during convoy duty, and support of amphibious landing operations. They could also relieve destroyers that were in short demand at the time, the 6-inch guns could be useful against merchant raiders, and with its shallow draft and heavy firepower they could be used to "show the flag" in Central and South American and Far East ports during peace time.