China first received a single unit of Soviet Osa-I class missile boat

Osa class missile boat

The Project 205 Tsunami, more commonly known by their NATO reporting name Osa, are a class of missile boats developed for the Soviet Navy in the early 1960s. The Osas are probably the most numerous class of missile boats ever built, with over 400 vessels constructed for both the Soviet Navy and for...

 in January 1965, and 4 more in 1966 through 1967 and the last 2 in 1968. Eventually the Jiangnan Building Factory built the Chinese version as Type 021 class missile boat at a rate of 10 boats per year with several different versions. Although majority of this class is being transferred to reserve, several dozens remain active and these active units are being rearmed with C-101

C-101

The C-101 is a supersonic anti-ship missile that can be launched from air, ship, and shore. Alternatively, the air launched version is also called YJ-1 by Chinese, with YJ short for Ying Ji , meaning Eagle Strike...

 supersonic anti-ship missile

Anti-ship missile

Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...

s. These boats are effectively used in swarm missile attacks.

Huangfeng class

Huangfeng class missile boat is the direct Chinese translation of Soviet Osa class missile boat, and around 130 were built, including exported units. This class consists of several versions with different armament. Most are armed with twin 25 mm guns, while some are armed with a single AK-230

AK-230

AK-230 is a Soviet fully automatic naval twin 30 mm gun. Its primary function is anti-aircraft. It is mounted in an enclosed automatic turret and directed by radar. AK-230 is probably the most popular gun of its class in the world, mounted on big warships as well as small crafts. About 1450 guns...

 gun mount. The majority lack the fire control radars but some do have a radar radome aft (between the two missile launchers).

The major improvement of the Huangfeng class over the original Soviet Osa-I class is that the Chinese engine, which is the improvement of the original Soviet M503A diesel engine has been so efficient that the range of the boat is more than doubled without significant proportional increase of fuel consumption. However, due to the limited size of the boat, the actual endurance is not drastically increased because there is not enough extra space to store additional provisions needed for the longer endurance. Other improvements over the original Soviet Osa-I class included a much improved fire extinguishing system and life support system.

Hola class

A single unit of Type 021 without the gun is called Hola class missile boat. The Hola class missile boat is slightly larger than the Huangfeng class, with length increased to more than 42 meters. The boat has an additional radar radome that is also onboard many Huangfeng class boats and there is an additional pair of missile launchers added, but this pair can be readily removed when needed. The mast is also redesigned so that it can be folded down when entered the protective cave in the mountains. The design is obviously more successful than the Homa class and despite its age, the Hola class boat remains in active service like a few of its Huangfeng class cousins. This class is also known as Hela class.

Houdong class

Houdong class missile boat is the newest upgrade of the Type 021 class missile boat. The new boat is modified to carry C-801/802/803

C-802

The Yingji-82 or YJ-82 is a Chinese anti-ship missile first unveiled in 1989 by the China Haiying Electro-Mechanical Technology Academy , also known as the Third Academy...

 while retained the hull of the original Type 021. Although the design was successful, more capable missile boats such as the Houxing class missile boat were already becoming available, so the Houdong class was geared for export, with Iran being the first customer and the one in Chinese inventory is used for training foreign crews, and as a demonstrator to other potential customers, as well as other test and trial purposes.

Specifications

For Huangfeng class of the Type 021 class missile boat:

• Displacement: 205 t
  Tonne
  The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
  
  
• Length: 38.6 m
• Beam: 6.8 m
• Draft: 2.7 m
• Speed: 35 kn
• Range: 350 or 800 nmi
  Nautical mile
  The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
  
   @ 30 kn
• Propulsion: 3 Soviet M503A or Chinese diesel engines @ 8,025 or 12,000 hp
  Horsepower
  Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...
  
   with 3 shafts
• Complement: 28 (including 3 officers)
• Armament:
  • Anti-ship missile
    Anti-ship missile
    Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...
    
    s: 4 Silkworm missile
    Silkworm missile
    The Shang Yo or SY-series , and the Hai Ying or HY-series were early Chinese anti-ship missiles. They were derived from the Soviet P-15 Termit missile.The HY-1 and HY-2 received the NATO reporting name Silkworm...
    
    s or 4 C-101
    C-101
    The C-101 is a supersonic anti-ship missile that can be launched from air, ship, and shore. Alternatively, the air launched version is also called YJ-1 by Chinese, with YJ short for Ying Ji , meaning Eagle Strike...
    
     supersonic anti-ship missile
    Anti-ship missile
    Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...
    
    s
  • Guns: 4 AK-230
    AK-230
    AK-230 is a Soviet fully automatic naval twin 30 mm gun. Its primary function is anti-aircraft. It is mounted in an enclosed automatic turret and directed by radar. AK-230 is probably the most popular gun of its class in the world, mounted on big warships as well as small crafts. About 1450 guns...
    
     and 2 25 mm (II x 2)
• Radars:
  • Surface search radar: 1 Type 352 Square Tie
  • Fire control radar: 1 in the aft radome (some)

For Houdong class of the Type 021 class missile boat:

• Displacement: 205 t
• Length: 38.6 m
• Beam: 6.8 m
• Draft: 2.7 m
• Speed: 35 kn
• Range: 800 nmi @ 30 kn
• Propulsion: 3 diesel engines @ 8,025 hp with 3 shafts
• Complement: 28 (including 3 officers)
• Armament:
  • Anti-ship missile
    Anti-ship missile
    Anti-ship missiles are guided missiles that are designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming type, many use a combination of inertial guidance and radar homing...
    
    s: 4 C-801/802
    C-802
    The Yingji-82 or YJ-82 is a Chinese anti-ship missile first unveiled in 1989 by the China Haiying Electro-Mechanical Technology Academy , also known as the Third Academy...
    
    
  • Guns: 2 AK-230
    AK-230
    AK-230 is a Soviet fully automatic naval twin 30 mm gun. Its primary function is anti-aircraft. It is mounted in an enclosed automatic turret and directed by radar. AK-230 is probably the most popular gun of its class in the world, mounted on big warships as well as small crafts. About 1450 guns...
    
    and 2 23 mm (II x 2)
• Radars:
  • Surface search radar: 1 Type SR-47
  • Navigational radar: 1 RM 1070A
  • Fire control radar: 1 Type 341