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fighting ships of the world

UNITED STATES NAVY (UNITED STATES OF AMERICA)

COASTAL FORCES

"PC" (173-ft) submarine chasers (1940-1945)

"PGM" (173-ft) gunboats (1944-1945)

PC597 1943

PC466 1945

Project history: In 1938 requirements have been prepared for the small patrol ship (PC, patrol craft) which should come instead of morally and physically out-of-date ships of Eagle class. Basic purpose of this ship would be escort of coastal convoys and anti-submarine service in base area. The task provided speed not less than 22kts and an endurance of 3000(12)nm. Under the FY1938 program two "prototypes" were built: 173-ft flush-decked turbine-engined РС452 and 165-ft diesel-engined РС451 with forecastle. During trials in 1940 РС452 has shown the better seaworthiness and higher speed, however low reliability of her experimental machinery have not allowed to mass-building this in remaining the successful ship. At the same time the diesel-powered variant, РС451, also did not suit a series: unsatisfactory seagoing capacities make use of armament very difficult. It was not represented possible to correct this lack by increasing of dimensions because of imminent decreasing of speed. The matter is that in the USA then was not available diesels appropriate for installation on small ships with more than 1500hp power. In addition to complexities with machinery choice the mite in the list of problems with designing was brought by President Roosevelt, demanded to establish the second 76mm gun.

The way out has been found after study of variant of installation of diesels into the hull of 173-ft "prototype". Thus, the truth, was necessary to refuse from 22kts. Contract speed was lowered on 2kts, and on trials lead РС461 reached 21.16kts, the truth, at the displacement close to standard. Increasing, in comparison with "prototype", on 0.2m of a hull breadth has allowed to place heavier armament. The project was ready in the early 1941, and in March, 1942 Navy received first serial ships.

Ships of early series were commissioned with design armament, later aft 76mm gun was changed by 40mm Bofors, and 12.7mm MGs by 20mm Oerlikons. From plans to fit Hedgehog it was necessary to refuse, as it was possible only at dismantle of fwd gun. As temporary alternative a variant with two Mousetraps was accepted: it was possible to do without removing of 76mm gun. Subsequently this scheme has been approved as ultimate.

In November, 1940, even before the termination of works under the project of PC, the decision on building of minesweepers in 173-ft hulls was accepted. In total 18 minesweepers of Adroit class were completed. At the expense of installation of less powerful diesels and decrease of speed to 16kts it was possible to get a place for diesel-generator for magnetic sweep. As minesweepers these ships have appeared unsuccessful and in June, 1944 they were re-classified as patrols.

In 1944 24 incomplete ships at expense of dismantle of ASW equipment received strengthened gun armament, having reoriented from ASW role on fight against Japanese small craft. Though armament structure became unique difference of these ships from standard PC, they were outlined into separate subclass of motor gunboats with assignment of new indexes (PGM9-32).

Modernizations: 1943 - 1944, almost all survived early PC: - 1 x 1 - 76/50, 3 x 1 - 12.7/90; + 1 x 1 - 40/56 Mk 1.2, (3 - 4) x 1 - 20/70 Mk 4, 2 x 4 - 178 Mousetrap Mk 20 ASWRL

mid-1944 - mid-1945, 35 PC were converted to PC(C): - 1 x 1 - 40/56, (3 - 4) x 1 - 20/70; additional communication and HQ accommodations were mounted.

7 - 9.1944, PC1255, PC1548: were converted to PGM: - 1 x 1 - 40/56, 2 x 4 - 178 Mousetrap ASWRL, 2 DCT, 2 DCR; + 1 x 2 - 40/56 Mk 1.2, 2 x 1 - 20/70 Mk 4, 1 x 2 - 60/12 M19 mortar, 2 x 1 - 12.7/90

1.1946, PC: 1 x 1 - 76/50 Mk 22, 1 x 1 - 40/60 Mk 3, (3 - 4) x 1 - 20/70 Mk 10, 2 x 4 - 178 Mousetrap Mk 20 ASWRL, 2 DCT, 2 DCR, SF or SO or SU radar, QHA sonar

1.1946, PC(C): 1 x 1 - 76/50 Mk 22, 2 x 4 - 178 Mousetrap Mk 20 ASWRL, 2 DCT, 2 DCR, SF or SO or SU radar, QHA sonar

1.1946, PGM: (1 x 1 - 76/50 Mk 22, 1 x 2 - 40/60 Mk 1) or 2 x 2 - 40/60 Mk 1, 6 x 1 - 20/70 Mk 10, 1 x 2 - 60/12 M19 mortar, 2 х 1 - 12.7/90, SF or SO or SU radar

Naval service: In days of war 7 ships were lost. PC496 and PGM18 were mined, PC558 was sunk by German submarine U230, PC1129 by Japanese ships and PC1603 by kamikaze.

PC472 1942

PGM11 1945

© Ivan Gogin, 2014-15