BSCh-4

BSCh-4
File:BSCh 4.png Troop transport variants of the BSCh-4, with the year they entered service
Type	Armored personnel carrier
Place of origin	Menghe
Service history
In service	1973-present
Used by	Menghe
Production history
Designer	Inmin-Chŏlgang-Nodongja design bureau
Designed	1966-1972
Manufacturer	Songrimsŏng Automotive Plant
Produced	1972-1998
No. built	~30,000
Specifications (BSCh-4N)
Weight	8.76 tonnes
Length	7.54 m
Width	2.64 m
Height	2.36 m to roof
Crew	2 (driver, gunner)
Passengers	11 (10+1)
Armor	welded steel plate
Main armament	12.7mm GCh-75Ch heavy machine gun
Secondary armament	none
Engine	SRS-150 petrol 201 hp (150 kW)
Power/weight	17.1 hp/tonne
Suspension	wheeled 4x4
Ground clearance	59 cm
Operational range	900 km (internal fuel)
Speed	95 km/h (road)

The BSCh-4 is a 4x4 wheeled armored personnel carrier designed in the Democratic People's Republic of Menghe, now the Socialist Republic of Menghe. It was developed in the late 1960s and early 1970s to provide a fast wheeled transport for the Menghean People’s Army. From the 1970s through the 1990s it was the main APC in Menghean service, though it has since been replaced by the BSCh-7 in all active units and about half of all Mobilization Reserves.

Development

In the late 1960s, after the Menghean War of Liberation, the Menghean People's Army consolidated its forces around three main squad transports: the BSCh-1 light wheeled APC, the BSCh-2 tracked APC, and the BSCh-3 tracked IFV. The BSCh-1 was initially slated to be the most numerous of the three, but it had a number of serious drawbacks. First, it offered poor protection to the crew, due to its open roof and 5mm side armor. Second, it had poor mobility, with a low road speed and poor offroad mobility. Third, it lacked amphibious capability and could only ford shallow water obstacles.

The Menghean People's Army responded by ordering the development of an entirely new APC which would correct these problems. The Army's requirements included all-around protection from 7.62mm or 7.5mm small-arms fire, a road speed of at least 70 km/h, a swimming speed of at least 5 km/h, and a 12.7mm heavy machine gun as defensive armament. Following revisions to squad structure, the required capacity was set at ten squad members plus one member of the platoon headquarters, in addition to the driver and gunner.

The Teakchŏn Heavy Vehicle Factory drew up a prototype in 1970-1971, with evaluation taking place in 1972. The procurement team from the Ministry of National Defense was impressed by the prototype's characteristics, and accepted it for service the following year.

Description

Layout

The BSCh-4 was the first Menghean APC to be designed around an existing squad structure; all previous Menghean APCs and IFVs had either adapted foreign designs or been built for flexible squad composition. It was also the first to be designed from the drawing board up as an APC; the BSCh-1 essentially consisted of an armored body on the chassis of a MAZ 502 utility truck.

The driver sits in the front right corner of the crew compartment, with one passenger seat beside him. This seat is typically occupied by the squad sergeant, though in the first vehicle in each platoon, the platoon lieutenant occupies it instead. Two rear-facing passenger seats are located just behind the driver and front passenger positions and just inboard of the wheel wells. These spring-loaded seats fold upward when not in use. The gunner, who is part of the vehicle crew rather than a squad member, sits on a platform under the turret, and stands on that platform when operating the machine gun. The gunner's platform is spring-loaded and folds up when not occupied. The remaining eight passengers sit facing outward on a double-sided bench in the center of the hull. The engine is located in the rear of the vehicle, over and slightly behind the rear axle. It is separated from the crew by a protective firewall which can also shield the engine from shrapnel and incoming fire.

Passengers and crew normally enter and exit through a pair of large clamshell doors on each side of the vehicle. These open into the space around the turret, forward of the crew bench and just to the rear of the rear-facing seats, allowing easy access for all crew members. It is possible to open only the top half of this door, creating a larger firing port, or only the bottom half, to compromise protection less. There are also two large hatches over the rear part of the crew compartment, for emergency escape or rapid dismounting over the sides, and two smaller hatches over the driver and front passenger positions, for emergency escape or better visibility. A downside of the engine-rear arrangement is that there is no way for passengers to exit through the rear of the vehicle, a problem addressed by the BSCh-7.

Protection

The hull of the BSCh-4 is made from welded steel plates. Unlike the BSCh-1, which is open-topped, the BSCh-4 has an armored roof, which provides protection against grenades, airbursting shells, and small-arms fire from high angles. The armor is able to protect against small-arms fire and shrapnel, and offers good protection against 7.62mm and 7.5mm rounds over the frontal arc, but it is easily defeated by 12.7mm ammunition.

• Upper front: 10mm at 45 degrees
• Lower front: 7mm at 35 degrees
• Upper sides: 7mm at 25 degrees
• Lower sides: 7mm at 25 degrees
• Rear: 5mm at 18 degrees
• Roof: 5mm
• Floor: 5mm

While it did feature a roof, the BSCh-4G did not feature protection against nuclear, biological, chemical, and radiological weapons. The machine gun turret had no hatch, the forward windows had no glass panes, and the viewing ports around the front of the vehicle were simple slits cut through the armor. The doors and firing ports were also manufactured with wide tolerance levels, and did not always create a firm seal when closed, which also hampered amphibious operations.

The BSCh-4N, introduced in 1978, corrected both of these problems. It added permanent glass panes behind the metal port covers forward, replaced the vision slits with glass slots or periscopes, and added rubber edges around the doors and firing ports to seal the vehicle against both water and toxic gases. The closed turret and redesigned firing ports also eliminated potential sources of leakage. This variant also added a new air circulation system which filters air entering the crew compartment and generates internal overpressure to prevent air ingress through small gaps around the vehicle.

Armament

Both the BSCh-4G and the BSCh-4N are armed with a single 12.7mm machine gun. On the BSCh-4G, this is a DShK machine gun on an open ring that rotates through 360 degrees. The BSCh-G1 modification adds armor plates around the gunner's position, offering a degree of protection against shrapnel and small-arms fire.

The BSCh-4N replaces this open ring position with an enclosed turret armed with a GCh-75Ch machine gun. The gunner does not actually sit inside the turret, as the GCh-75's receiver is close to the rear of the turret; instead, he sits underneath the turret and slightly to the side, with only the top of his head extending into the left side of the turret ring. The BSCh-4N turret is driven entirely by hand cranks worked by the gunner.

All variants of the BSCh-4 have ten firing ports scattered around the vehicle, with five on each side. On the G variant, the firing ports are 15-centimeter diameter rings which allow the gunner to look down his weapon's iron sights and can accommodate a variety of weapons. On the N variant onward, the firing ports use ball mounts with small keyhole gaps sized for JS-67 assault rifles, and the gunners aim by looking through glass viewing slits and correcting their aim by tracer fire and dust kicked up by impacts. Though less accurate, the latter method offers better protection against small-arms fire and CBRN contaminants.

It is also possible to open the top hatches and upper side hatches to fire grenades and rocket launchers from within the vehicle, provided that the rear end of any rocket launcher is also outside the vehicle. Training manuals discuss this strategy for both the BSCh-4 and the BSCh-7, but discourage it, as the squad should enter battle fighting dismounted.

Mobility

All variants of the BSCh-4 are powered by a single 170-horsepower V-8 diesel engine in the rear of the hull. All four wheels are powered, though only the front pair can steer. On level roads, the BSCh-4 can reach speeds of 80 kilometers per hour, though its speed suffers on rough or muddy terrain.

Underneath the engine are two waterjets, one on each side of the hull. These draw water from around the rear wheel wells and propel it backward, driving the vehicle forward at speeds of up to 10 km/h in the water. Because its doors, firing ports, and vision ports are poorly sealed, the G variant often leaks water during amphibious operations. The Menghean People's Army restricted BSCh-4Gs to short-distance river crossings over calm water, and since 1993 the Menghean Army has forbidden the use of G variants in amphibious exercises. Variants N onward have much better seaworthiness, though the BSCh-6 remains the backbone of Menghean Marine Infantry units.

Role

Compared with the BSCh-1, the BSCh-4 is better protected, better armed, and more mobile, and the Ministry of National Defense quickly ordered it into mass production with the goal of fully replacing the BSCh-1 in active motorized units. Yet compared to a proper IFV like the BSCh-3 or BSCh-5, the BSCh-4 had thinner armor, a lighter armament, and worse offroad mobility. As such, Menghean Army doctrine treated it as a "battle taxi" APC rather than a front-line combat vehicle, recommending that passengers dismount before entering combat and that crews keep the vehicle further back rather than supporting the troops directly, especially if there were armored vehicles in the area.

As a cost-saving measure, the Menghean People's Army procured BSCh-4s and BSCh-5s in a 3-to-1 ratio in mechanized infantry divisions, either by having two motorized (APC) battalions per regiment or by having two motorized (APC) regiments per division. Where possible, APC-mounted infantry units would be used for urban combat and defensive combat, with IFV-mounted infantry units forming the spearhead of offensive operations in the field.

Variants

Troop Transports

• BSCh-4G: the original design which entered service in 1973, with a 12.7mm PM43 heavy machine-gun in an open cupola mount. Slightly over 15,000 were produced in total.
• BSCh-4N: an upgraded variant from 1982. The most visible change was the replacement of the open cupola with an enclosed turret, which mounted a 12.7mm GCh-75Ch heavy machine-gun. Combined with the installation of improved seals on the doors and firing ports and the addition of an overpressure pump and air filter, this change allowed the vehicle to operate more effectively in a CRBN-contaminated environment. Roughly 18,000 were built, making this the more common variant, though the BSCh-4G is still widely seen in low-readiness reservist units.
• BSCh-4D: The most thorough upgrade, this variant changed the main armament to a new turret which paired a 7.62-millimeter GPMG with a JYB-38 automatic grenade launcher. The armor was also greatly improved, with thicker plates on the front and sides and an additional spall liner on the inside to catch penetrating fragments. Finally, the old petrol engine was replaced with a 300-horsepower diesel unit, allowing a higher top speed of 110 kilometers per hour despite the increased weight. Nevertheless, due to High Command’s endorsement of the BSCh-7 as a replacement, the BSCh-4D only saw limited production, with about 350 hulls produced following its introduction in 1993. Today it mainly equips Gunchal rear-area patrol units.

Combat Vehicles

• DChP-415 BSCh-4: A self-propelled anti-aircraft gun, this variant had four JGG-65 15mm heavy machine-guns in an open-topped mount on the roof. Because the guns were manually traversed and aimed, it had very poor accuracy against fixed-wing aircraft, but was found to be very effective at suppressing infantry.

Specialist Vehicles

• BSCh-4 Naean: A specialized variant for service with the Internal Security Forces. Its cupola gun is replaced by a water cannon, with a tear gas grenade launcher on a pintle mount on top of the turret. Screens over the side windows provide protection from stones, bricks, and other thrown objects. The internal compartment can be used to carry ten armed personnel, usually riot police of the Rapid Response Brigades. Several dozen of these were produced for Menghean service, most of them converted from decommissioned BSCh-4Gs.
• BSCh-4DS: Battalion command vehicle (Daedae Salyŏngcha). The machine gun cupola or turret is removed, and additional radios including a telescoping mast are added.
• BSCh-4DMG: Battalion radio vehicle (Daedae Mujŏn'gi-cha). Similar to the BSCh-4DS, except that some radio sets are different, a wirelaying kit is added to the back, and there is a large wraparound radio antenna instead of a telescoping mast.
• BSCh-4JG: Armored ambulance (Janggab Gugŭbcha) typically used at the Battalion level to evacuate wounded soldiers to a battalion medical point or higher. It can carry four stretchers in addition to the driver and three assistants, but crew reports suggest it is difficult to move loaded stretchers through the narrow side doors. As on the BSCh-4DS, the turret is removed.
• BSCh-4JG1: Improved armored ambulance. The conventional side doors are replaced by larger sliding doors, making it easier to onload and offload stretchers. The BSCh-4JG1 also contains additional medical equipment to stabilize patients.
• BSCh-4JGCh: Armored recovery vehicle (Janggab Gunan Chalyang) with an A-frame crane and a powered winch.