YDH-26

YDH-26
Major variants of the YDH-26
Type	Anti-ship missile
Place of origin	Menghe
Service history
In service	2002-present
Production history
Manufacturer	Buksŏng Industries Group
Specifications
Weight	540 kg (YDH-26GJS) 450 kg (YDH-26G)
Length	401 cm (YDH-26GJS) 332 cm (YDH-26G)
Diameter	35 cm
Warhead	130 kg warhead
Detonation mechanism	Contact fuse
Propellant	kerosene
Operational range	110 km
Flight altitude	sea skimming (3 m)
Speed	Mach 0.8
Guidance system	inertial guidance, terminal active radar homing

The YDH-26 (Formal designation: 26식 대함 유도탄 / 二六式對艦誘導彈, i-ryuk-sik daeham yudotan, "Type 26 anti-ship missile;" Short designation 유대함-26 Yudaeham-iryuk "YDH-26") is a type of subsonic anti-ship missile developed in Menghe during the late 1990s and early 2000s. With a mass of 450 kilograms and a 130-kilogram warhead, it is relatively lightweight and compact. It serves as a smaller, cheaper complement to heavier Menghean anti-ship missiles like the YDH-23 and YDH-28.

Development

The YDH-26 was developed by the Buksŏng Industries Group, formerly Institute 92, Menghe's main manufacturer of medium-range subsonic missiles. It was conceived as a lighter replacement for the YDH-24, able to be carried by helicopters and carrier-borne fighters. In this role, it would complement the larger YDH-28, which offered a longer range and heavier warhead at the cost of greater size and weight. Designers also emphasized minimizing production costs, to aid in mass-production and make the missile more attractive on the export market.

At-sea test firings of the YDH-26 took place in 2000, using a modified Plan 261 missile boat as the launch platform. The missile was found to perform well, and in 2002 it was introduced to service on the Sŏwicho-class corvette Hwŏncho, the second in her class.

Design

The subsonic YDH-26 follows a conventional cruciform wing design, with fixed stabilizers mounted halfway down the missile's length and similarly shaped steering fins mounted at the rear. An intake for the turbofan is slung underneath the missile's body. Prior to launch, these fins are folded against the missile's body, allowing it to be stored in more compact launch containers; these fins automatically spring open shortly after launch.

The YDH-28 is relatively compact, even when compared with other subsonic anti-ship missiles. Its smallest air-launched variant has a mass of only 450 kilograms, while its heaviest variant has a mass of 540 kilograms. Tradeoffs of this small size include a short range of 110 kilometers and a small 130-kilogram warhead. Buksŏng's sales manual states that the missile is recommended for use against warships displacing between 4,000 and 400 tons, i.e. frigates and corvettes, though it can also be used to damage larger ships and impair their effectiveness against a follow-up strike.

On -GH, -NH, and -DH variants, a solid-fuel rocket booster on the rear of the missile accelerates it to cruise velocity before dropping away in flight. This boosted variant is necessary for launching from land vehicles, surface ships, submarines, and helicopters. The baseline G, N, and D variants have no booster, but can only be launched from fixed-wing aircraft. In flight, the missile is driven by a kerosene-fueled turbofan engine.

By default, the YDH-26 uses inertial navigation to travel to an attack point designated upon launch. It makes its initial approach at an altitude of 15 meters to avoid striking friendly warships and rogue waves. Once it is 25 kilometers from the target position, the missile climbs in altitude, activates its radar seeker, and begins searching for targets. When a target in the designated area is detected, the missile updates its course and drops to a sea skimming altitude of 3 meters, where it makes its final approach. G variants only carry an active radar guidance system, while N and D variants also incorporate an infrared seeker slung under the missile body to increase resistance to jamming and countermeasures. G and N variants make their final approach on a straight-flying course, while D variants make pseudo-random maneuvers to reduce the probability of interception by gun-based close-in weapon systems.

Due to its small size and relative simplicity, the YDH-26 is considered one of the most cost-efficient missiles in service in Septentrion. This is especially true of the basic "G" variants, which lack imaging-infrared secondaries. The missile is also designed for easy storage and maintenance, and can be stored fully-fueled for a period of up to 15 years.

A submarine-launched variant was unveiled in 2006, though it was rumored to have been in development several years earlier. Submarine-launched missiles are derived from the booster-equipped GH, NH, and DH variants, but with a watertight cover over the turbine air intake and improved watertight sealing on all other joints. In storage, the missile is kept inside a 533mm watertight cylinder, which is ejected from a torpedo tube like a standard torpedo. Shortly after launch, the weighted tube tilts nose-up in the water, its cap ejects, and the missile launches out of it under solid-fuel power, with the intake cover breaking off once airborne. It can only be fired from periscope depth, and it is not compatible with vertical-launch tubes for the YDH-28J and YDH-29J families.

Coastal defense system

In 2005, as part of the country's pivot to defensive warfare, the Coastal Defense Forces of the Menghean Army placed a request for a self-propelled, land-based launcher for the YDH-26 missile. The resulting system, which was publicly displayed in 2008 and bears the designation JYDH-26 (Jaju-Yudotan Dae-Ham, Self-Propelled Missile, Anti-Ship), consists of eight vehicles:

• 1x JYDH-26JS (Jungdae Salyŏngcha), Company/battery command vehicle with radio and wire connections. Crew of five.
• 1x JYDH-26SR (Susaek Reida), search radar vehicle with an elevating mast to detect ships within horizon range. Crew of three.
• 3x JYDH-26BG (Balsagi), launcher vehicle with eight missiles. Crew of four.
• 3x JYDH-26JCh (Jaejangjŏn-Cha), reload vehicle with eight missile boxes and a crane. Crew of two.

The original JYDH-26 system was designed around the Taekchŏn T512 heavy utility truck. It was later supplemented by a lighter system on the Samsan S915, which carries fewer missiles per truck (4 instead of 8) and has a shorter-range acquisition radar, but is cheaper to produce and maintain.

Byŏk container battery

The "Byŏk" ("wall") system is a version of the YDH-26 launch battery in which all components are installed in 20-foot ISO containers. A full-size battery is made up of fifteen 20' containers: three for the command post, two each for the radar and drone posts, and two for each of the four launch platoons. Other combinations are also possible, including a minimum battery with three command modules and one launch platoon. The modules can be linked with VHF radio, SHF radio (a modified MChGJ-0800), or cables running over the ground. The manned modules contain not only control equipment, but also basic living amenities: bunks, lockers, food and water storage, and an electric stovetop. Thus, once the unit is emplaced, the crew does not require separate accommodations.

The Byŏk battery can be arranged as a tightly packed installation, but it is also possible to disperse the individual platoons over an area as much as 20 kilometers in diameter. The modules within each platoon must be closer together - one brochure provides a figure of 50 meters - but otherwise there are no restrictions on their arrangement. They can also be painted in the liveries of private shipping companies, and shuttled between positions on civilian trucks. This allows a commander to disperse the modules across parking lots, construction sites, and shipping centers, making it virtually impossible for an adversary to distinguish battery elements from civilian containers using satellite and aerial imagery.

• Byŏkdul B1: Launch unit with four YDH-26 boxes and a rolling steel door on the roof. This module is uncrewed, and controlled by a B2 module.
• Byŏkdul B2: Launch control unit with control stations, radio antennas, and a generator, as well as bunks and basic amenities for two crew members.
• Byŏkdul S1: First half of the battery command post.
• Byŏkdul S2: Second half of the battery command post.
• Byŏkdul S3: Living spaces for the battery command crew.
• Byŏkdul J1: Long-range surface ducting radar and generator.
• Byŏkdul J2: Control and communications unit for the surface search radar, with four crew, bunks, and basic amenities.
• Byŏkdul M1: Contains two helicopter-type unmanned aerial vehicles with visual and IR cameras, which can visually identify radar contacts and assess post-strike damage.
• Byŏkdul M2: Control and communications unit for the unmanned aerial vehicle, with three crew, bunks, and basic amenities.

Variants

Variants without boosters

• YDH-26G: baseline model with radar guidance only
• YDH-26N: model with backup infrared seeker
• YDH-26D: model with backup infrared seeker and pseudorandom evasive maneuver profile

Variants with boosters

• YDH-26GH: baseline model with radar guidance only
• YDH-26NH: model with backup infrared seeker
• YDH-26DH: model with backup infrared seeker and pseudorandom evasive maneuver profile

Submarine launch variants

• YDH-26GJ: baseline model with radar guidance only
• YDH-26NJ: model with backup infrared seeker
• YDH-26DJ: model with backup infrared seeker and pseudorandom evasive maneuver profile

See also

• YDH-24
• YDH-28