AP-104 howitzer (Pacifica)

AP-104 howitzer
Type	Towed gun-howitzer
Place of origin	Pelinai
Service history
In service	2002—present
Used by	Pelinai
Production history
Designer	Botanhata Military-Technical Institute
Manufacturer	Yarimaka Artillery Foundry
Unit cost	~$1.57 million (2018)
Produced	2000—present
No. built	~5,500+ (as of 2022)
Variants	AP-104, AP-104M, AP-104M2
Specifications
Mass	5,600 kg (AP-104M2)
Length	Combat: 12.1 m Travel: 10.7 m
Barrel length	8.2 m
Crew	8
Shell	Type A3082, Type A3182, Type A3382, Type PT2411R3, 2G4, 2S17, Type AN4
Caliber	155 mm
Breech	Vertical semi-automatic sliding wedge
Recoil	Hydropneumatic recoil absorber
Carriage	Split trail carriage
Elevation	-5° to +68.3°
Traverse	-25° to +25°
Rate of fire	Burst: 6-8 rounds per minute Sustained: ~330 rounds per hour
Muzzle velocity	Up to 906 m/s
Effective firing range	30.7 km (Type A3382) 36.2 km (Type A3382D)
Maximum firing range	~44.3 km (2G4)
Sights	x6 direct fire sight; digital fire control system

The AP-104 howitzer (Pelinese: АП-104) is a towed 155mm gun-howitzer manufactured by Yarimaka Artillery Foundry since 2000. It is currently the primary towed 155mm artillery piece of the Pelinese White Army, which adopted it in 2002 as a replacement for the AP-55. Two revisions (AP-104M and AP-104M2) have since been introduced to increase performance, reduce mass, and simplify construction.

The manufacturing of howitzer barrels, breech assemblies, and most carriage components for the AP-104 takes place in Yarimaka, Yukisora, along with final assembly and testing; digital components such as the fire control system are sourced from Samororiya in northern Stelossia. Spare gun barrels are sourced from the primary factory in Yarimaka as well as a smaller artillery production facility in Korolyeviya. Production of the AP-104 has expanded since 2002 and is estimated to have a maximum yearly manufacturing capacity of at least 1,000 barrels, with possible capacity for further expansion.

Development

Initial definition work for the AP-104 began in 1986 after recent combat experience in the Pelinese Civil War demonstrated multiple outstanding deficiencies with the AP-55 model that was currently in use as the standard Pelinese 155mm towed artillery: these included its high mass (7840kg) and relatively short effective range with contemporary ammunition (17.3km), as well as numerous components that were found to possess substantially shorter service lifetimes than expected. The project was assigned by the reestablished Ministry of Defense to the Botanhata Military-Technical Institute in Botanhata, Sevaria due to the generally intact condition of its facilities and personnel roster relative to other design bureaus, with the following list of major project requirements:

• An effective firing range of 22 kilometers using A3182 projectiles.
• A calculated component mean time to failure of at least 1.3x that of the equivalent part on the AP-55 and at least 2x for identified problem components, particularly several parts of the hydropneumatic recoil absorber.
• Increased field repairability, including the ability for personnel to perform all standard maintenance operations using a standard wrench set and hammer; this requirement was later expanded to also include the ability to quickly replace non-repairable components such as the electronics of the fire control system.
• Capability for towing by a KMZ-145 6x6 military truck using standard towing linkages.
• An elevation range of at least 65° and a traversal range of at least ±22°.
• A minimum sustained rate of fire of 320 rounds per hour.
• The ability to use all previous 155mm in Pelinese inventories, particularly the A3082 & A3182, the Type PT2411 series, the 2S17, and the 2S17Kh shell types.

Detailed design work proceeded slowly after the conclusion of the product definition and initial development stages due to widespread damage to Pelinese industrial facilities and the preference for a design that could be manufactured domestically, with the first complete prototype being delivered for testing in 2000. An early digital fire control system was added to the design in 1996 and was found to greatly increase the accuracy and reaction speed of the howitzer, leading to its inclusion in the production version. The gun was eventually adopted into service by the Pelinese White Army in 2002 after field testing, with responsibility for mass production of the design being given to Yarimaka Artillery Foundry.

Design

The AP-104 is a towed gun-howitzer design intended primarily for usage in the indirect fire role, with a limited direct fire capability using optical sights. It uses a much higher percentage of titanium and other low-density components in its structure than the preceding AP-55 howitzer design in order to reduce mass by 25% while also increasing the size of the gun barrel.

The cannon itself has a rifled barrel of 8.2 meters in length, a semi-automatic, vertically sliding breech for loading, and a conventional hydropneumatic recoil absorption system. The heavier barrel is 1.8 meters longer than the preceding AP-55 gun-howitzer, allowing for increased range and rate of fire in the AP-104, and ends in a muzzle brake that also possesses a forged-in tow connection ring.

The AP-104 is relatively mobile for a 155mm howitzer, and is light enough to be air transportable: inter-theater airlift mobility is accomplished through military transport aircraft such as the KaR-11M2 Lebed, which can carry it in pairs, while battlefield air deployment is done by suspending the howitzer under a heavy lift helicopter like the Ha-5. Terrestrial movement over up to moderately difficult terrain can be provided by a standard 6x6 military truck.

Ammunition

The AP-104 howitzer has the capability to fire a variety of contemporary and legacy 155mm separate loading cased charge shells, including high explosive shells, cluster shells, guided shells, and nuclear artillery shells. The most common types to be issued to Pelinese artillery batteries operating the AP-104 in the past or present are listed below.

Name	Shell type	Mass as fired	Description
A3082	High-explosive/fragmentation	44 kilograms	Pelinese 155mm HE-F shell adopted in 1954; carries 7.1 kilograms of RDX/TNT explosive filling. Removed from frontline service; existing stocks not consumed during the Pelinese Civil War are used for artillery crew training purposes.
A3182	High-explosive/fragmentation	45 kilograms	1968 revision of the A3082 to replace RDX/TNT filling with 7.5 kilograms of plasticized explosive in order to improve long-term compound stability and reduce cook-off risk. No longer in production after the adoption of the A3382 shell, though significant legacy stockpiles are still in active usage.
A3382	High-explosive/fragmentation	48.3 kilograms	New artillery shell introduced in 1989; allows greater propellant usage. Possesses 11.4 kilograms of plasticized explosive filling. Currently in active production at an approximated rate of 400,000 shells per year, with maximum manufacturing capacity estimated at 2.4 million shells per year. A3382D variant adds a base bleed module to increase range and accuracy of fire.
Type PT2411R3	High-explosive anti-tank	35 kilograms	Anti-tank shell introduced in 1961 and repeatedly updated up to the latest revision in 2002. Rarely used.
2G4/2G4M	Cannon-launched guided projectile	50 kilograms	155mm cannon-launched precision guided munition capable of using satellite- and laser-based targeting. The 2G4 was adopted into service in 2015, while the modernized 2G4M is currently entering service.
2S17	Cluster munition	47 kilograms	Cluster munition carrying dual-purpose anti-personnel/armor shaped charge bomblets. Currently in production and service.
Type AN4	Tactical nuclear artillery shell	44 kilograms	155mm nuclear artillery shell with a maximum yield of approximately 2.4 kilotonnes of TNT equivalent. The Pelinese White Army is estimated to possess several thousand AN4 shells at minimum, with current production of more being likely.

Variants

• AP-104 (AKA AP-104IP): Initial production version, using many steel components and an early digital fire control system. The AP-104IP offered substantially increased range, accuracy, and mobility over the preceding AP-55 due to its improved construction and its new, integrated digital fire control system. Frequent reliability issues affecting the digital components, common to Pelinese electronics of the early 2000s, led to the necessity of a sooner-than-expected retrofit/replacement process that introduced the AP-104M.
• AP-104M: Updated design of the AP-104 that entered service in 2009; major changes from the IP version include a full redesign of the electronic components, as well as the substitution of multiple steel structural components and linkages with titanium replacements in order to reduce total mass and corrosion-related maintenance requirements.
• AP-104M2: 2015 retrofit to the AP-104M developed concurrently with the 2G4 guided artillery shell in order to allow for its usage and effective targeting. Other minor software updates and changes to the manufacturing process were also made at this time in order to correct miscellaneous problems and reduce production cost.

Operators

Current operators

• Pelinai — circa 5,500

See also

• List of equipment of the Pelinese White Army