Type 110 35mm autocannon
| Type 110 35mm autocannon | |
|---|---|
 | |
| Type | Autocannon |
| Place of origin | Menghe |
| Service history | |
| In service | 2012 |
| Used by | Menghe |
| Production history | |
| Designer | Jinjŏng First Artillery Arsenal Samsan Defense |
| Designed | 2000s |
| Manufacturer | Jinjŏng First Artillery Arsenal |
| Produced | 2012-present |
| Specifications | |
| Weight | 115 kilograms (254 lb) |
| Length | 4.246 m (13 ft 11.2 in) |
| Barrel length | 3,227 millimetres (127.0 in) |
| Cartridge | 35×228mm |
| Caliber | 35mm |
| Barrels | 1 |
| Action | Chain gun |
| Rate of fire | 100 rounds/minute (governed) |
| Muzzle velocity | 1,200 metres per second (3,900 ft/s) |
| Effective firing range | 2,000 metres (2,200 yd) |
| Maximum firing range | 4,000 metres (4,400 yd) |
| Feed system | see "Operation mechanism" |
The Type 110 35mm autocannon (Menghean: 110식 35밀리 기관포 / 一一〇式 三五밀리 機關砲, ilillyŏng-sik samo-milli gigwanpo) is a type of autocannon developed in Menghe. In its base variant, it is chambered in the Menghean 35×228mm cartridge, but it can be converted to 50×330mm by changing the barrel and several other parts. Currently, it serves as the main armament of the "N" variant of the BSCh-8, the "M" variant of the BSCh-5, and the "G" variant of the BSCh-12.
Development
Menghean military designers began experimenting with larger-caliber IFV autocannons around 2000, tracking similar development projects in major Western militaries. Following the concept behind the Fragarach 30/40 project in Tír Glas, the Jinjŏng First Artillery Arsenal developed a chain-driven autocannon in 35mm caliber which could be upgraded to a 50mm caliber in the event that stronger enemy armor threats appeared. This weapon was designated Type 103 for the year it entered service, 2003.
Initially, the Menghean Army expressed little interest in the project, citing concerns over ammunition capacity and deeming the 30mm 2A42 adequate for its needs. The Type 103 autocannon remained on the backburner for several years, undergoing minor improvements at Jinjŏng's own expense, but there were no plans to integrate it into operational Menghean IFVs.
This situation changed in 2005, when Menghean relations with Maverica rapidly deteriorated in the wake of the Ummayan Civil War. While it lacked precise figures on protection and armor composition, the External Intelligence Agency estimated from its weight that the 27-tonne PYK-10 IFV under development was potentially protected against 30mm APDS over the frontal arc. Declassified GA armor tests also revealed that BMP-3 IFVs, which served the Maverican Army in large numbers, could withstand 30mm ammunition if fitted with applique ERA. Menghean Army doctrinal planners saw this as a grave problem: if a Menghean mechanized unit equipped with BSCh-5 IFVs encountered a Maverican mechanized unit of equal size, the former would be unable to penetrate the latter's armor, but the latter could defeat the former. This would give the Maverican unit a decisive edge in combat.
In response, the Menghean Army increased the armor requirements for the BSCh-8 IFV, still in late development, and issued a service requirement for a medium-caliber autocannon capable of defeating estimated Maverican IFV armor thickness while retaining an adequate number of ready rounds. The Jinjŏng Arsenal responded by proffering its own 35/50mm Type 103 cannon, but it still had to design a turret capable of accommodating the weapon. Hoping to expedite the development process, the Army invited other designers to propose their own turrets and loading systems for the new weapon.
Jinjŏng's own turret design incorporated a linkless feed assembly in the right side of the turret, linking this to the feed slot via a flexible 90-degree tray. It was limited in elevation to 30 degrees, above which the bend in the feed tray was too great, and required a large amount of empty space in the turret cheek. Taekchŏn Heavy Industries developed a simple but reliable manually reloaded feed tray, and the Chikai Heavy Machine Building Plant began work on a system with a 24-round ready magazine that was automatically reloaded from the sides of the turret basket. Samsan Heavy Industries, still a newcomer to military vehicle design, also entered the design contest, initially looking for a way to improve the Jinjŏng feed system. They made little progress until, according to subsequent accounts, a visiting armaments researcher suggested a P90 style cylinder to turn the rounds 90 degrees. Samsan's design team quickly seized on the design and developed it further, drawing up the Type 112 turret design described below. In the process, they heavily altered the Type 103 autocannon's feed system to incorporate the distinct revolving apparatus, resulting in today's Type 110.
As soon as the Menghean Army's evaluation team saw the new autocannon in action, they immediately tightened its classification level, believing that its highly compact layout conferred a decisive advantage and fearing that this advantage would be lost if Maverica developed a similar weapon. The original Samsan design team was retained, but under direct oversight from the IIA, and workers involved in the project were strictly forbidden from sharing information with other Samsan colleagues, including the company's own CEO.
Type 110G (2010)
Classification
As a result of this newly imposed secrecy, when the Type 110 entered service its operating system remained a mystery to the outside world. No photos were ever published of the turret interior, and the only publicly available about the loading system was its ability to handle 128 ready rounds.
Judging from several features of the turret exterior, including the offset commander's cupola and the large rectangular panel to its right, Maverican intelligence agencies and defense groups were able to speculate that the BSCh-8N had a feed system in the right side of the turret, but the exact feed mechanism remained a mystery. Some independent sources speculated that the turret included a curved belt section which angled sharply to bring the rounds parallel to the breech when viewed from above, but the turret's compact design left very little room for such a feature.
Clues about the Type 110's operation first began to surface during the Innominadan Crisis, when embedded reporters working with the Menghean Army gained access to the turret of a BSCh-8N. Their footage confirmed the existence of a large bulkhead to the right of the commander's position, but offered few other clues about the weapon's operation; Menghean censors took down the images two days after they were first posted, but by that time users had already copied them abroad.
The first definitive evidence came in May 2016, when a local Innominadan journalist photographed a BSCh-8N crew performing maintenance on their vehicle with the cannon removed. This clearly showed a large cylindrical apparatus to the right of the removed autocannon's breech. This time, Menghean censors failed to remove the image in time, and it quickly spread in online discussion and military intelligence circles. By the end of the month, the Menghean Army changed their strategy on the weapon, selectively releasing official information on its operating mechanism to showcase its capabilities. Certain aspects of the Type 110, including the exact dimensions of its component parts, remain classified to hinder efforts at replication, but its general functions have been public knowledge since 2016.
Description
The Type 110G autocannon uses a unique operating mechanism to select and chamber rounds, likely the only one of its kind in Septentrion. Individual rounds are stored standing on their ends in a linkless feed that runs from the turret side to the side of the gun breech, with side-by-side feeds for armor-piercing and high-explosive rounds. There, a hydraulic arm shunts the flexible feed trays forward and backward, aligning either the AP or HE end with the vertical feed slot on the side of the gun.
At this point, the system diverges from common practice. A large wheel-like assembly about 50 centimeters in diameter is positioned between the breech and the ammunition feed, with its axis of rotation parallel to the gun's axis of elevation. In the center of this wheel are two slots, each with the same dimensions as a 35mm cartridge. When the slot is in its vertical position, the linkless feed mechanism can push a single round into it, at which point the wheel rotates 90 degrees (plus or minus the gun's elevation) until the round is parallel with the barrel. There, a second mechanism pushes the round sideways into the feedway, and the bolt rams it forward into the breech. After firing, the empty cartridge is ejected out the left side of the receiver and into a sealed tray, then ejected forward through a hole in the mantlet. The wheel continues rotating clockwise, when viewed from the left, until its loading slot is once again vertical, and the process repeats again.
The entire system is chain-powered from a single energy source, usually the vehicle's battery or an auxiliary power unit if the engine is not running. A moving interruptor system, the details of which are still unknown, ensures that the wheel is at the proper alignment positions when rounds are loaded and transferred to the breech. Some early sources speculated that the rate of fire would vary with the cannon's elevation as the number of degrees between the vertical ammunition and elevation angle changes, but because the wheel must complete a full 360-degree rotation until the next round is transferred in, the rate of fire is essentially constant and the only difference is a fraction-of-a-second delay in chambering the first round of a burst.
Evaluation
Like any innovative loading mechanism hastily pressed into service, the Type 110G suffered a number of teething problems in its early years. While the chain-drive mechanism gave it a very low failure rate during the firing process, as misfired rounds were simply ejected from the breech like spent cartridges, the wheel-based loading system was reportedly prone to jamming if a round was not perfectly aligned when pushed in or out. Under pressure to press the weapon into service before 2012, the Samsan design team lacked the time to address fundamental issues with the loading system, and responded by governing the rate of fire to 90 rounds per minute in service mounts.
The lower rate of fire reportedly reduced the failure rate by giving the wheel more time to ease into position; by default, it also halved the number of failures in a given period of continuous fire. It also hampered the weapon's effectiveness somewhat; in initial tests, it had been run at 200 and 300 rounds per minute. The Menghean Army leadership accepted this tradeoff, as it would force crews to conserve ammunition, and the new APFSDS and smart-fused HE rounds were more expensive to produce than existing 30mm ammunition.
The greatest advantage of the Type 110's new operating mechanism, however, is that it allows a larger number of ready rounds in a more compact space. The Type 112 turret, described below, carries a total of 128 rounds in the right side of the turret, totaling 36 APFSDS and 92 HE/smart-fused rounds. This represented nearly twice as many as the CV9035, which carried only 70 ready rounds of 35 millimeter ammunition. The system is also relatively easy to reload: because the feed is beltless, it is easier to store additional rounds around the vehicle and transfer them to the ready storage space.
Type 110N (2015)
Even as the Type 110G with its loading turntable was being pressed into mass production, many engineers in the Menghean Army foresaw problems with its mechanical complexity and low rate of fire. Under MoND direction, Samsan and Jinjŏng continued work on the weapon, eventually developing an entirely new linkless feed system which relies on two boxes flanking the receiver. These boxes are fixed to the receiver and elevate and depress with it as one piece, keeping the feed ports aligned. This eliminates the need for a separate mechanism to align cartridges with the moving breech, increasing the rate of fire to 200 rounds per minute while also improving reliability. It also adds considerably to the mount's width and height, though the removal of the chain drive to the turntable reduces its length.
A persistent challenge with the Type 110N was how to design a turret around it, given the bulk of the moving ammunition boxes. The first turret designed for the Type 110N was a remote design which placed the ammunition boxes in armored drums. It was tested on a BSCh-7 APC hull in 2015.
A manned turret for the Type 110N was produced in 2018. This design puts the ammunition boxes behind the crew's heads, with a steadily sloping turret roof overhead. To reduce the system's overall width, the capacity of the ammunition boxes was reduced to 38 rounds. A large linkless feed box behind the turret crew contains 176 more rounds, bringing the total to 252. To transfer ammunition from the reserve box to the ready boxes, the gun depresses to an elevation of 0 degrees and a mechanism automatically transfers individual rounds from the reserve boxes to the ready boxes at a rate of 100 rounds per minute per box. The main advantage of this turret design is its small turret ring and relatively small footprint in a 360-degree traverse, both of which which allow it to be dropped into the BSCh-5 hull without any structural modifications.
The latest unmanned turret for the Type 110N autocannon was introduced in 2020 and unveiled in 2021. It is only used on the BSCh-12 amphibious IFV, though it may appear on later IFVs as well. As on the 2018 manned turret, the autocannon has two feed boxes with 38 rounds each, but this time the reserve ammunition box is located inside the turret itself and contains 120 rounds for a total of 196.
Ammunition
The Type 110 autocannon is chambered in the 35×228mm autocannon cartridge, also used by the DGP-35-2 anti-air gun. While this only represents a 5mm increase in diameter compared to the 30×165mm round used on previous Menghean IFVs, it develops 390 kJ of energy, compared to 150-180 kJ on the 30×165. This increase, along with a larger area sabot for pressure forces to work on and a narrower projectile, allows the Type 110's APFSDS-T round to penetrate more armor at its theoretical maximum range of 3,000 meters than the 3UBR8 APDS at point-blank range.
| Distance | 35mm APFSDS-T (NBG-35-1) | 30mm APDS (3UBR8) |
|---|---|---|
| 100 m | 77 mm | 45 mm |
| 200 m | 75 mm | 40 mm |
| 500 m | 70 mm | 33 mm |
| 1000 m | 65 mm | 28 mm |
| 1500 m | 62 mm | 25 mm |
| 2000 m | 58 mm | 22 mm |
State and Army press releases on the Type 110 have consistently emphasized its use of smart-fused, prefragmented airbursting ammunition. These rounds can be programmed to detonate in three modes: contact detonation for standard-purpose use, delayed detonation for engaging bunkers and light vehicles, and timed detonation for an airbursting effect against enemy personnel in cover. A leaked 2013 procurement form, however, suggested that the Army's procurement plan for 35mm ammunition consisted primarily of contact-detonation high-explosive rounds, which are less expensive to manufacture. The 35×228mm still contains a larger bursting charge than its 30×165mm predecessor, and has a larger explosive radius, but it lacks the flexibility of a programmable airbursting round.
Mounting systems
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Type 112 turret
The Type 112 turret is used to mount the Type 110 autocannon in the "N" variant of the BSCh-8 IFV. It was developed in tandem with the Type 110, but was only approved for service in 2012 when the BSCh-9N entered production. The Type 110 autocannon is centered in the turret glacis, with 128 rounds of ready ammunition stored in a protected, sealed-off compartment on the right side. To make room for this compartment, the commander is moved to the rear of the turret and slightly offset to the left, and the gunner sits on the left side but slightly forward.
One drawback of the Type 112 turret's layout is that all ready 35mm rounds is stored above the turret ring, increasing the risk that a penetrating round will ignite the ammunition. To better protect the crew, the turret features an armored box separating the ammunition from the crew space, with blowoff panels in the turret roof to divert the blast upward. After preliminary tests found that the heat from a full ammunition burnout could melt through the base of the armored box, the designers added ceramic tiles to its floor and crew side to contain the heat. Subsequent upgrades to the BSCh-9 have also added applique armor to the turret sides, offering protection against 30mm APDS and certain man-portable anti-tank rockets.
Because the system uses a linkless feed, there is no need to move bulky ammunition belts within the confines of the vehicle; instead, the gunner or crew pass individual 35mm rounds to the commander, who inserts them into the appropriate feed tray through a bulkhead hatch beside his seat. The crew can also perform individual-round reloading while the ready ammunition store is only partially depleted, topping off the ready ammunition load during a break in combat.
Type 115 turret
First displayed to the public during the National Day Parade in 2015, the Type 115 turret is a modified version of the Type 112 turret for the "B" variant of the BSCh-5 IFV. As the BSCh-9 and BSCh-5 both have 1720-millimeter turret rings, the internals of the new turret are effectively identical, but the Type 115 design has thinner armor and a slightly lower crew-side profile to reduce its weight. These weight-saving changes allow the BSCh-5B to retain amphibious capability, but they also increase the risk of penetration into the ammunition storage compartment.
In 2017, the Menghean Navy evaluated a stabilized, manual/automatic Type 110 mount on the helicopter carrier Haejungdo. Prior to that time, the Menghean Navy had mainly relied on close-in weapon systems for defense against light craft. State media reported that the Type 110 naval mount performed favorably, but the Navy leadership currently appears to favor a lighter 30mm system, which would offer identical performance against unarmored light craft.
50mm variant
In order to improve its lethality against future threats, the Type 110 autocannon is capable of being converted to a 50mm caliber system by changing only a small number of components, including the barrel and rotating assembly. Conversion could be performed at Army depots or in the field using a pre-packed upgrade kit.
The 50mm variant fires a specialized 50×285mm round, which uses the same base cartridge as the 35×245mm but is necked out to the 50mm caliber. Both cartridges have a 55mm base diameter and a slight taper before the neck, and share the same overall length. The 50mm APFSDS round is reportedly capable of penetrating 180mm of rolled homogeneous armor from an angle of 60 degrees, and this could be increased further with more advanced propellant and a depleted uranium penetrator. Work is also underway on multiple prototype high-explosive and multi-purpose rounds, including both full-bore and sub-caliber options.