KAAV II - Design
The Korean Amphibious Assault Vehicle II (KAAV II) is the next amphbious landing vehicle that looks like a clone of the US Marine Corps Expeditionary Fighting Vehicle [EFV] design, a project that was abandoned in 2011. The speed is much slower than the EFV could muster. The Japanese have something basically the same in the works. This new platform features improved mobility, firepower, and survivability, and the development trend of three-dimensional high-speed amphibious operations.
Republic of Korea Navy and Marine Corps were closely studying the change in the United States Marine Corps' amphibious doctrine. In early 2010s, the USMC abandoned the doctrine of over-the-horizon amphibious operations. This was due to the fact that increased range and lethality of shore-based weapon systems nullified the merit of over-the-horizon operations. USMC concluded that in order to safely conduct over-the-horizon operations in modern battlefield, they'd need to operate at least 100 miles (185 km) from the shore. This was far beyond the range of most amphibious assets in US arsenal. As such, they opted to conduct littoral amphibious operations at approximately 12 miles (22 km) from the shoreline. This was considered an adequate distance to identify and intercept hostile missiles and to be out of range of coastal mines and artillery batteries.
The change in USMC's doctrine was reflected in ROKMC's KAAV-II program. While the EFV focused primarily on high speed, the newly set criteria meant that future AAVs didn't need to be extraordinarly fast nor did they have to be lightly-armored.
The KAAV-II has several notable technical characteristics. It is approximately 7.6 meters long, 3.2 meters wide and 2.4 meters high. The vehicle weighs about 24 tons and by one account can carry up to crew 21 fully equipped Marines or 4536 kg of cargo. It is equipped with a diesel engine, which allows it to reach a maximum speed of 70 kilometers per hour on land. Its water speed is intended to be more than twice the previous KAAV-I's 13.2 km/h, reaching 25-30 km/h.
In terms of weapons, the KAAV-II is armed with a 40mm CTA automatic grenade launcher and a 12.7mm machine gun. KAAV-II would be armed with an uninhabited turret with a 40mm autocannon, for which telescopic ammunition is being created, which can reliably defeat opposing armored vehicles, and will have sufficient protection against various ground threats. The grenade launcher provides the vehicle with a high rate of fire and the ability to destroy both infantry and lightly armored targets. The machine gun is effective against personnel and light equipment. Additionally, the KAAV-II can be equipped with an anti-aircraft missile system for air defense purposes.
Case Telescoped Ammunition. CTA ammunition is a type of cartridge where the propellant charge partially or completely surrounds the bullet. This design is also used in hand weapons and artillery. The “telescoped” aspect means the bullet is partially/completely enveloped by the propellant charge. CTA International is a company that makes a 40mm cannon for light armored vehicles. The 40CTAS has a rate of fire of up to 200 rounds per minute. It also has a high accuracy mode that is compatible with a coincidence firing system.
Most traditional firearm ammunition cartridges are constructed using a metal shell casing (e.g. a brass casing). The metal casing of a traditional cartridge typically contains some amount of propellant (e.g. gunpowder, smokeless powder, etc.) in a rearward portion of the cartridge that is sometimes referred to as the cartridge “body”. The metal casing of a traditional casing also holds a projectile in a frontward portion of the cartridge that is sometimes referred to as the cartridge “neck”.
In contrast to traditional metal case cartridges, cased telescoped (CT) ammunition cartridges completely encase the propellant and the projectile within a cylindrical shell that is made of polymer. By eliminating the relatively heavy metal casing used in traditional metal case ammunition, CT ammunition provides a significant reduction in ammunition weight, enabling relatively larger numbers of rounds to be carried per unit weight.
CTA weapons are overall bad in recoil terms because they tend to be wasteful of powder particularly with high velocity sabot rounds, that was one of the technical hurdles to overcome to making them work at all. But that trade off is acceptable when it allows much better ammo storage and turret bulk is seen as a bigger limitation then gun weight.
The KAAV-II's combat role is primarily focused on amphibious operations. It serves as a vital asset during the initial stages of a beach landing, allowing Marines to move quickly. The vehicle's amphibious capabilities allow it to overcome water obstacles and operate in the coastal zone. In addition, KAAV-II can provide fire support to infantry with its weapons, increasing the combat effectiveness of the Marine units it supports.
Each new armored vehicle will be able to transport up to 21 marines, with a crew of 3 military personnel. By one report, KAAV-II's waterborne speed is expected to be at around 20 km/h. This is faster than the existing AAVs, but not as fast as EFV's 46 km/h speed. By another report, the maximum speed on land will reach 70 km/h, on water - 25 km/h (13.5 knots). The fuel range will be 480 km or 2 hours when driving on the sea surface. To reduce weight and increase speed, the KAAV-II will be equipped with rubber tracks.
Good water performance will be ensured by powerful water-jet thrusters and special equipment deployed in the front part of the hull and under the tracks. To achieve good performance on the water, the underside of the hull features a system which can deploy some side flaps under the tracks in order to reduce water resistance. When on the water, the KAAV-II is propelled by two large (600mm diameter) water-jets designed by a local supplier.
On the American EFV the engine could only produce 2,700 horsepower in the water by flooding the entire engine bay for more cooling, achieving the rating on land was impossible and the system was designed to lock out that power rating as soon as operators dropped the tracks to pass through the breakers and start getting out of the wate. The climb out of the water - land power rating was IIRC 1,200hp. EFV had major in water range issues, but it also had a number of unarmored fuel tanks that were only intended to be used for the ship to shore movement phase. The Koreans may end up doing the same thing if they want to have any hope of this working.
KAAV-II uses a hydraulic suspension system that can adjust the height of the vehicle to adapt to different terrains. According to a development official of the South Korean Marine Corps, the KAAV-II can operate regardless of the high or low tide of the landing beach. The KAAV-II's armor material is a composite material that can withstand attacks from small-caliber weapons and grenade fragments. KAAV-II is also equipped with auxiliary equipment such as an automatic fire extinguishing system, a nuclear, biological and chemical protection system, and night vision equipment, which improves the vehicle's battlefield adaptability and supportability.
