YMS-1-class minesweeper

	USS YMS-324 in San Francisco Bay, c. 1945–46
Class overview
Name	YMS-1
Builders	35 yacht builders
Operators	United States Navy; Royal Navy; French Navy; Maritime Command; Polish Navy; Japan Maritime Self-Defense Force; Republic of Vietnam Navy;
Succeeded by	Atada class (Japan)
Subclasses	YMS-136, YMS-446
In commission	about March 1942 – 13 December 1957
Completed	481
Cancelled	YMS-482 – YMS-500
Active	0
Lost	32
General characteristics
Type	Minesweeper
Displacement	270 tons
Length	136 ft (41 m)
Beam	24 ft 6 in (7.47 m)
Draft	8 ft (2.4 m)
Propulsion	2 × 440 bhp (330 kW) General Motors 8-268A diesel engines; 2 shafts;
Speed	15 knots (28 km/h)
Complement	32
Armament	1 × 3-inch/50 caliber gun mount; 2 × 20 mm guns; 2 × depth charge projectors;

The YMS-1 class of auxiliary motor minesweepers was established with the laying down of YMS-1 on 4 March 1941. Some were later transferred to the United Kingdom as part of the World War II Lend-Lease pact between the two nations. One ship eventually made its way into the Royal Canadian Navy postwar.

Design

The design for the class had a displacement of 270 tonnes. The ships had a length of 136 feet (41 m), a beam of 24 ft 6 in (7.47 m), and a draft of 8 ft (2.4 m). The vessels were capable of 15 knots (28 km/h; 17 mph), being powered by two 440 shp (330 kW) General Motors (Cleveland) 8-268A, 2-cycle diesel engines which drove two shafts.

The ships had a complement of 32. Their armament comprised one single 3-inch/50 caliber gun mount, two 20 mm anti-aircraft guns and two depth charge projectors.

YMS-1-class ships were relatively small compared to larger contemporary US Navy ships. This led to a view by some sailors that the YMS-designated ships were cramped and particularly unsteady. These conditions were described (and surely exaggerated) by one author in a humorous poem "warning" other sailors to not transfer:

Men don't live on YMS's
they just exist under strains and stresses,
tossed around like a bundle of peas,
inside their ship on the calmest seas.

— Anonymous, "A Plug for a Distinguished Nervuos Cross"^[1]

Subclasses

There were two mostly cosmetic sub-types of the class, sometimes referred to as classes themselves

YMS-135 subclass

This subclass was identical but had only one stack rather than two, and consisted of hull numbers YMS-135 through -445, YMS-480, and YMS-481.

YMS-446 subclass

This subclass was also identical but had no stacks, and comprised YMS 446–YMS 479.

BYMS

Eighty vessels of the class were ordered from US yards for transfer under Lend-Lease to the United Kingdom as the BYMS-class minesweeper. Another 53 built for the US Navy (with hull numbers between YMS-137 and -284) were transferred as further BYMS and another 17 were delivered later.

Other exports

France received 31 YMS-class minesweepers during World War 2, with one (D202, formerly YMS-77) being sunk by a mine in 1944. France kept its YMS-class ships in service after the end of the war,^[4] with seven remaining in service in 1962, used as training ships in the École Navale and as experimental vessels. Three ships of the class were transferred from France to South Vietnam in 1954, while another was transferred to Madagascar in 1961.^[5]

In 1947, Poland acquired former BYMS-2211 (renamed ORP Delfin), BYMS-2257 (renamed ORP Foka), and BYMS-2282 (renamed ORP Mors). ^[6] The vessels were re-armed with Soviet 85 mm air defense gun M1939 (52-K) and four Soviet NSV machine guns. In the mid-1950s, they were removed from service. The ORP Delfin was scuttled in the Bay of Puck, where it remains a diving attraction.

The Japan Maritime Self-Defense Force received 8 vessels of this class in the 1950s. The class was named Ujishima-class minesweeper. The ships were:

Examples

Survivors

USS YMS-328, yacht
RV Calypso, research ship
MV Uchuck III, Merchant vessel, USS YMS-123

References

^ ^a ^b ^c ^d Priolo, Gary P. (2006). "Auxiliary Motor Minesweeper (YMS), British Motor Minesweeper (BYMS) Index". NavSource Online. NavSource Naval History. Retrieved 20 December 2007.
^ Radigan, Joseph M. (2006). "Ruff (MSC[O] 54), ex-AMS-54, ex-YMS-327". NavSource Online. NavSource Naval History. Retrieved 20 December 2007.
^ For both YMS-1 and BYMS classes a total 40 were lost. Of those 40, 32 were YMS-1 class. (See: "YMS class Minesweepers". Uboat.net. Retrieved 20 December 2007.)
^ Masson 1969, pp. 59, 61–53.
^ Blackman 1962, p. 94.
^ Twardowski, Marek (June 2001). "Trałowce typu BYMS w polskiej służbie" [BYMS minesweepers in Polish service]. Morza, Statki i Okręty (in Polish). Vol. VI, no. 31. ISSN 1426-529X.

This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.
Blackman, Raymond V. B. (1962). Jane's Fighting Ships 1962–63. London: Sampson Low, Marston & Co. Ltd.
Le Masson, Henri (1969). Navies of the Second World War: The French Navy Volume Two. London: Macdonald & Co.
Priolo, Gary P. (2006). "Auxiliary Motor Minesweeper (YMS), British Motor Minesweeper (BYMS) Index". NavSource Online. NavSource Naval History. Retrieved 19 December 2007.

External links

[navsrcYMSidx-1] Priolo, Gary P. (2006). "Auxiliary Motor Minesweeper (YMS), British Motor Minesweeper (BYMS) Index". NavSource Online. NavSource Naval History. Retrieved 20 December 2007.

[navsrcYMS327-2] Radigan, Joseph M. (2006). "Ruff (MSC[O] 54), ex-AMS-54, ex-YMS-327". NavSource Online. NavSource Naval History. Retrieved 20 December 2007.

[3] For both YMS-1 and BYMS classes a total 40 were lost. Of those 40, 32 were YMS-1 class. (See: "YMS class Minesweepers". Uboat.net. Retrieved 20 December 2007.)

[massv2_p59,61-3-4] Masson 1969, pp. 59, 61–53.

[jfs62_p94-5] Blackman 1962, p. 94.

[6] Twardowski, Marek (June 2001). "Trałowce typu BYMS w polskiej służbie" [BYMS minesweepers in Polish service]. Morza, Statki i Okręty (in Polish). Vol. VI, no. 31. ISSN 1426-529X.

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