W-13-class minesweeper

No.13 in 1933
Class overview
Name	No.13 class minesweeper
Builders	Fujinagata Shipyards Mitsui Bussan Ōsaka Iron Works
Operators	Imperial Japanese Navy
Preceded by	No.1 class
Succeeded by	No.7 class
Subclasses	No.13 class (Project Number I3A) No.17 class (Project Number I3B)
Cost	1,330,000 JPY (in 1931)
Built	1931 – 1936
In commission	1933 – 1945
Planned	6
Completed	6
Lost	5
Retired	1
General characteristics No.13-class
Displacement	525 long tons (533 t) standard
Length	74.00 m (242 ft 9 in) overall
Beam	8.20 m (26 ft 11 in)
Draught	2.07 m (6 ft 9 in)
Propulsion	2 × triple expansion stages reciprocating engines 2 × Kampon mix-fired boilers 2 shafts, 3,200 shp
Speed	20.0 knots (23.0 mph; 37.0 km/h)
Range	2,600 nmi (4,800 km) at 12 kn (14 mph; 22 km/h)
Complement	98
Armament	2 × 120 mm (4.7 in) L/45 naval guns 2 × 13.2 mm (0.52 in) AA guns 18 × depth charges 2 × Type 81 depth charge projectors 2 × paravanes or 40 × Mk.5 naval mines
General characteristics No.17-class
Displacement	578 long tons (587 t) standard
Length	72.50 m (237 ft 10 in) overall
Beam	7.85 m (25 ft 9 in)
Draught	2.50 m (8 ft 2 in)
Propulsion	2 × Kampon geared turbines 2 × Kampon mix-fired boilers 2 shafts, 3,200 shp
Speed	19.0 knots (21.9 mph; 35.2 km/h)
Range	2,600 nmi (4,800 km) at 12 kn (14 mph; 22 km/h)
Complement	94
Armament	2 × 120 mm (4.7 in) L/45 naval guns 2 × 13 mm AA guns 36 × depth charges 1 × Type 94 depth charge projector 2 × paravanes or 40 × Mk.5 naval mines

The No.13 class minesweeper (第十三号型掃海艇,, Dai Jūsan Gō-gata Sōkaitei) was a class of minesweepers of the Imperial Japanese Navy (IJN), serving during the 1930s and World War II. 6 vessels were built in 1931-36 under the Maru 1 Keikaku. They have two sub classes, this article handles them collectively.

• • Improved model of the No.1-class. The IJN tried to a small hull than No.1-class to give a performance the same as No.1-class. And this attempt failed when the vessels were discovered to be top heavy by an investigation of the fleet in the aftermath of the Tomozuru Incident.

• • Project number I3A. 4 vessels were built in 1931-1934. No.15 and No.16 were behind with the completed by the Tomozuru Incident. They had clipper-bow.

• • Project number I3B. 2 vessels were built in 1935-1936. Improved model of the No.13-class. About their appearance, bow was changed to double-curvature bow and fitted Kampon geared turbine.

• 
  No.16
• 
  No.18

• Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, "Kaijinsha"., (Japan), February 1996
• The Maru Special, Japanese Naval Vessels No.50, Japanese minesweepers and landing ships, "Ushio Shobō". (Japan), April 1981