BMM-4C (BSEM-4K)

Ukrainian Medivac APC, 2009-2016, c16 built

The BMM-4 is a derivative of the BTR-4 "Bucephalus" amphibious 8x8 wheeled infantry fighting vehicle designed in Ukraine by the Kharkiv Morozov Machine Building Design Bureau. After the development of the BMM-4A, B, the BMM-C (or BSEM-K) is the only one active today, with 12 vehicles produced so far, active notably in the recent Russo-Ukrainian War from 2022, but also four with Iraqi Forces, taking part in the capture of Jurf al-Nasr from ISIL.

Development

The BMM 4 started as a simple conversion of the BTR-80 based BMM-1 medical evacuation vehicle, with the same suite asd the model A. The model B was developed as a Batallion level evacuation vehicle with the same raised roof aft, tall enough for standing personal and up to four stretchers. But the true best seller was the BMM-4C, derived from the BTR-3C as a more advanced battlefield medical treatment, and not just evacuation vehicle.

The BMM-4 Recalls characteristic shortcomings of the BTR-3С ambutank, associated with the layout of the rear cabin, inherited from the soviet legacy previous armored vehicles. It was just too cramped. Due to the aft engine compartment, medical personal was constrained to stay at the center of the hull and entry or exit with stretchers through the narrow side hatches, dangerous in the best of times. The location of these hatches combination to a small sized compartment seriously complicated loading of wounded men on stretchers, worsened by poor internal ergonomics. There was just not simple solution while keeping the BTR-3 as a base.

However at the same time the BMM-3C was adopted by default in small numbers, there was one vehicle in development in Ukraine at the time with greatly improved conditions for the wounded, a chassis with a rear ramp that was the start of a promising medical vehicle with an omptimized, much larger rear compartment with much improved ergonomic and better access. New requirements were setup to match the Kharkov engineering design bureau's A.A. Morozov new armored personnel carrier BTR-4 "Bucephalus". Its characteristic feature was its rear troop compartment layout with a central engine compartment, aft troop access and exit. It was a no-brainer to turn it into an armored medical vehicle.

Development of what became the BMM-4 based on existing terminology was carried out simultaneously with the creation of other specialized variants of the BTR-4. The organization behind was hoping to receive orders from its own and foreign armed forces to decrease the R&D cost. In the early stages, the BMM-4A was designated as sanitary-evacuation vehicle, called BSEM-4K. Equipment was produced and tailored in the interests of the customer. In the future it was believed a late version will be built on updated Ukrainian requirements, after which the final version was called the BMM-4С. This is still its current designation. Ab "export first" approach which helpe to sustain the whole development.

Prototypes were built and tested at the end of the last decade. According to reports, it was recommended for production on the international market. In September 2009, Ukraine and Iraq signed a contract for the supply of 420 armored vehicles of the BTR-4 family, a immensely important contract, including three dozen medical BSEM-4Ks. It is known that part of the ordered vehicles (four allegedly) were eventually transferred to the Iraqi armed forces. However Uraine's economics at the time and an unacceptably high reject rate of the order led to halt deliveries altogether. Eventually only a quarter of the required BTR-4s of all variants were deliovered to iraq, and saw action.

In parallel with this production, further development was carried out and the final vehicle changed in appearance, receiving the designation BMM-4С. Produced after approval from 2014, they were offered to the armed forces of Ukraine. Given the context from that time in the Donbass, Ukrainian troops needed a large number of sanitary-evacuation and medical machines to complement their growing fleet of BTR-4s. However, the army and security forces lacked the budget to purchase a significant quantities of these, and from 10 to 12 were eventually delivered. Production is assumed to have been terminated in 2016.

Design of the BMM-4C

Being a specialized modification of the BTR-4, both the BSEM-4K and BMM-4С medical vehicles retains its main features and layouts. To evacuate wounded personal, the BTR-4 rear troop compartment was considerably increased in size, raised for a meter, allowing personal to stand inside and enabling far more room for medical operations on board. To cut the budget down it was decided to minimally rework the original design, taking the existing BTR-4Rkh command vehicle as a base, which already had this raised compartment. Thus, a sufficiently high degree of unification was obtained which lowered costs, simplified production and maintenance.

Precise Design specifics

Hull

The body shape of the armored personnel carrier was partially preserved, but was supplemented and revised. Its base shared the same rear enlarged compartment with the command vehicles BTR-4KSh which also saw a limited production. The KSh was designed as an upper echelon unit Staff and command vehicle (18t, 7-man crew) with operators which sat in the raised rear compartment in order to accomodate them in better conditions, in addition of extra communication sets. The BMM-4 retains thje same recognizable forward part as the BTR-4 with a forward cabin for two seats, protected by armored windows. The BMM-4C measures 7,7 m long, for 2,90 m wide and an height of slightly less than three meters and battle order weight of 20 tonnes.

The rear cab is basically designed to house 10 men in two row of side folding seats. There were extensions welded into the hull that could received extra frames, and when the seats were folded up, was large enough to accomodate a stretcher, on each side. Added to this, the tall side walls had enough space for strapping two more stretchers above, for six wounded patients laying, and potentially one or two more on the floor. If not, the vehicle could evacuated up to 10 men seated plus up to four laying. The rear compartment's roof had four hatches, two side windows, and a large eletrically raised or lowered ramp, enough to bring stretchers in and out without much effort.

Protection

The medical cabin retains a significant portion of the existing armor, using rolled steel plating, providing protection against small arms, weapons and splinters. As per NATO standard oit was declared to match the Type 2 mine protection level standard, STANAG 4569. The belly of the vehicle was V-shaped in order to resist to 6 kg TNT under a wheel or bottom. There was however no active protection provided, no warning sensors, NBC, or smoke projectors.

Powerplant

The BMM-4 is powered by a 3TD diesel engine as like for the BTR-4E, of the adapted Deutz EBPO III type, rated for 500-600 hp coupled to a 5 forward, 1 reverse gearbox. It is decribed built by Zavod im. Malysheva. This 3-cylinder liquid cooling engine initially develops up to 500 hp. The 8x8 chassis is a bit larger and work with individual torsion bar suspension and hydraulic shock absorbers. The diesel is also coupled with an hydro-mechanical transmission with pass-through axles, also powering after switching transmission, the rear propeller for swimming. Like the BTR-4, the BMM-4 can receive other engines.

Performances

The BMM-4 likely keeps the performances of the BTR-4, a top speed of 110 km/h. It could cross water obstacles at 10 km/h. Ppower-to-weight ratio is at least 28.6hp/ton. Cruising range is beyond 690 km. The BMM-4 is likely capable of the same feat as the BTR-4 as tested, climbing a 60° gradient, stay stable on a 40° side slope, climb a 0.6 m vertical obstacle, gap a 2m trench. There is doubt of the BMM-4 coul be airlifted due to iyts height (at least by existing transports), but it's certainly light enough. Like the BTR-4 it is fully amphibious, albeit the rera door sealong is not designed for it and perhaps not perfectly sealed. But buoyancy is better. Having the same shaped nose and trim vane, it is probably capable of sustaining a Sea State 3 in 1.25m waves. When swimming is ises the same rear propellers, added to the bilge pumps. The fenestron type propellers can be angled to modify the vehicle's direction when simming.

Equipments

The regular crew of the BMM-4С comprises a core of three, driver, medical officer and nurse. On the march, the latter are seated in forward cabin, entering through side doors with armoured glass. In combat these windows could received protective mesh framing. With the shutters down forward, the crew can use periscopes for observation. Whine underway with wounded aboard, the medical personal is at the rear to provide primary treatment. The new electric aft ramp provided with mechanical drives is common to the BMM-4 and BTR-4KSh, greatly facilitating access, but coupled with a regular door ccut inside in case of power failure.

Armament

There is none as planned. The crew however still can use personal weapons. Operationally, the vehicle had been depployed with the Ukainian national Guard and patroopers. So far Oryx website states 4 BMM-4C lost since 2022, 2 destroyed, 2 captured. The mosy common Ukrainian ambutank remained the MT-LB-S by far, tracked and with a much lower profile.

Variants

BSEM-4K

Recovery and medical vehicle (initial export production, up to 8 made), modular utility vehicle.

BMM-4A

Similar in role to the BMM-1 of the BTR-80 family, first-aid and battlefield evacuation vehicle, experimental, forward wall rear cab sloped.

BMM-4B

Same as the BMM-2, but battalion level initial medical treatment vehicle, experimental.

BMM-4C

Main production armoured Medevac. Slightly different from the BSEM-4K, 10-12 produced so far, flat forward rear cab wall.

Exports

So far the BMM-4C has been sold to the following:

Iraq: First customer, 4(8) total.
Ukraine: 10-12. +2 prototypes

BMM-4C specs
Dimensions	7.76 x 2.93 x 3m (25.5 x 9.6 x 10 ft)
Total weight, battle ready	17.5+3 t or 25+3 t with addon armour
Crew	3+10, see notes
Propulsion	3TD diesel engine 500 hp
Suspension	wheeled 8×8, torsion bars, hydraulic dampeners
Speed	110 km/h (68 mph) or 10 km/h (6.2 mph) swimming
Range	690 km (430 mi)
Armament	None.
Armor	Welded steel, small arms fire STANAG level 2.
Production	Circa 12(+4).