In the 80’s — early 90’s in the leading tankoproizvodyaschih countries — the USSR, the USA, Germany, France, was being developed intensively promising tank. If all this were engaged in active search for solutions for assembly, manning and rassredotachivaniyu its tasks. Improved features of the tank can be achieved by reducing the crew through the installation of the automatic loader, the decision was made in all the promising developments of the western states. This allowed us to reduce the internal volume of the tank, to strengthen the reservation without significant mass growth.

The development of electronics and automation has allowed to go in the development of the assembly even further reduce the crew to 2 persons. Reducing the crew to 2 persons can solve a number of problems: increased protection, duplication of the crew, a full implementation of ergonomic requirements, reducing the weight and dimensions of the tank. Coupled with the fact there is a number of outstanding issues related to the congestion of the crew and management division. [1]
Selecting the assembly of the tank and the composition of the crew was very burning issue, both in the USSR and in Western countries, and the end point in this matter has not yet been delivered.
The article discussed a number of promising concepts build the tank in the United States studied in the late 80’s and early 90’s tactical and technological management of the agency for the development of promising projects DARPA [2] and their comparison with some well-known development is carried out in the former. USSR.
Version of the tank with a crew of two people and uninhabited tower
Tank with a crew two people has the highest performance on mobility, a small silhouette. The ratio of the length and width of the body by the caterpillars in this version is close to flawless 1.5:1, which ensures good maneuverability.
The tank is made by shestiopornoy scheme chassis. The tower height is the height of the turret «Abrams», but its size is reduced by 50% in the front projection and 40% in the side. Reservations frontal part of the desert tower offers the highest protection of the crew compartment of ammunition, attacking from above (if the tower is rotated forward), in addition, there are further splinter-proof screens over the places of the crew.
The center of gravity of the tank is moved forward (between 2 and 3 rink) because the bulk of the reservations (about 9 tons) located in the front of the chassis. The total weight of the tank is predictable 50.3 tons, when installing the motor power of 1500 hp provide the highest specific power (27 hp / ton).
The design is implemented in such a manhole Makar, so the crew could leave the tank even lowered the gun. Hatches have electronic and manual actuators and glass blocks are equipped for driving on marching. At the bottom under one of the seats have an emergency exit hatch, which applies in the event of damage to the covers and unavoidable situations. Close enough to the crew compartment, highlighted by 70 cm for each crew member in width.



The air intake filter system is left for the crew hatches, HLF unit is located in the nose of the tank in a recess in the lower front body parts. The purified air conditioned area juts out into the legs of the crew and then goes to a niche electrical units.
The total fuel capacity of the tank 1250 l., Fuel is partly located inside the front of the engine housing, the rest in the fuel tanks on the fender in the rear of the chassis.


Comparison of the on-board projection M1A1 tank and the tank with the crew of a promising 2 people with desert tower.
A comparison of the frontal projection of the tank with an electric gun, promising a tank with a crew of two people and uninhabited turret and M1A1 «Abrams».
The first time a promising development to create a tank with a crew of two people were taken to KMDB AA Morozova in 70 years, the work was continued by EA Morozov. The layout of the tank with a promising 2 person crew was made KMDB.
Close to the ideology of the project is promising a tank with a crew of two people was developed in Russia of «Spetsmash» in the 90’s. With all of this has been implemented perednemotornaya assembly, in almost all the reasons the introduction of a gas turbine engine. It was running chassis layout.
Version of the tank with a crew of 3 persons and uninhabited tower
Further considering the option of assembling the tank is more than has traditionally version with a crew of 3 persons. In the development of such experts at the South American version offered two possible solutions:
First involves placing three members of the crew in line. Under this option can save the dimensions of the tank circuit with shestiopornoy chassis, the crew is in a fairly comfortable criteria. But in all this there is the ability to implement sufficient protection side of the crew compartment. Even with a decrease in the width of the allocation for each member of the crew seats from 70 to 60 cm ability to provide protection during the shelling in the side portions are small. With all of this railway dimensions do not allow increment width of the body.
In the USSR, that variant was proposed in the development of a promising medium tank AA Morozov in the second half of the 70s.
The second option is to place a 2-crew ahead of them and a third (placing 1st in front of the crew members is not correct for ravnostoykogo booking).
Such option allows you to keep an adequate level of protection for the hull sides and satisfactory conditi ons of comfort for the crew. Although the conditions worse than in the first version because legs third crew member arranged honey with 2 located in front. The released amount at the edges of the third member of the crew can be applied to accommodate the supplies of food, toilets, etc.
With all of this hull length increases by about 80 cm, the weight of the tank is growing at 5 tons. The tank is made by semiopornoy scheme chassis with an estimated weight of 55.3 tons.



The ratio of the length of the body and shireny by caterpillars in this version is 1.7:1. Reservations frontal part of the desert tower provides the least protection from the crew compartment ammunition attacking from above because of the elongated body 80 cm
Close to the ideology of the project of the tank «T-95» was developed in the Russian JSC UKBTM in the 2000s.
Version of the tank with a crew of 3 people with a traditional assembly and automatic loader
In all the proposed options with the placement of the crew in front of the body has a number of shortcomings. One of the more significant of them zabugornye called experts at the lack of ability radial visual observation of the commander. The tanks with the crew accommodation in the body angle at the open hatches of less than 270 degrees.
The assembly with the placement of the commander and gunner in the turret and driver package allows to implement radial visual overview of the commander. In addition, placement in a rotating turret gunner eliminate problems with disorientation, also has the ability to eliminate a number of delays in the shooting.
This assembly is closer to the French tank «Leclerc» in the design of which is also considered a number of options with the placement of the crew in the case, was eventually elected as the more usual low-profile version of the tower.
Drawback of this assembly for a promising tank is a large mass of the frontal armor, restrictions to protect the top, a large area of the frontal projection. Another drawback of the layout is the failure to enforce the autoloader carousel because of the requirement to separate crew accommodation and ammunition.
In the development of such option proposed two possible solutions:
First involves placing the divided ammunition, ready to use shots are located in the autoloader, additional ammunition located in a secluded bay in front of the engine compartment.
Second option involves placing all of ammunition in a single volume autoloader located in an isolated compartment behind the tower. Will claim that variant is quite big and wide tower. This ideology has been implemented in the Russian tank of OKBTM developed in the 90s and has been called «Black Eagle» (object 640).



In this embodiment, the assembly is implemented radial overview of the tank commander, while maintaining lifting masts with complexes follow the commander and gunner.
With all of this to the commander for the radial angle to the tower to climb above the waist. As noted by the introduction of tanks, military theorist R. Simpkin [4], the tank «halfway to heaven» (ie, very vulnerable to enemy fire). Review prevents the central part of the roof of the tower with a lift to provide the required angles lowering the gun.
The possibility of dual access from the driver’s compartment in the fighting compartment (at the position of the gun forward). Both crew members in the turret, the commander and gunner can provide a radial view, raising his head above the roof of the tower.
Because of the larger volume in the body have the ability to apply materials with the lowest overall reservation efficiency, HLF also stronger due to the increased internal volume.
As in other embodiments promising tank assembly, a problematic issue is the realization of desired angles downward guns associated with structural weakening of the tower.
Estimated weight version of the tank with a habitable tower was 67.4 tons.
Version of the tank with a crew of 3 people, with the placement of the commander in the turret
This version of the assembly provides a good overview of the tank commander, for all that implemented the ability to apply the autoloader carousel in the case. As with all of the options presented layouts, it is not without shortcomings. Among them, poor conditions of accommodation commander, the impact on him of the recoil momentum of the main weapons, the need to duplicate system HLF, PPO, etc.



In this embodiment, the assembly ground pressure increased by 34% compared to the embodiment of the tank with a crew of two people and uninhabited tower, with all this tower wider by 74 cm and 20 cm above the calculated weight of such option shall be 67.7 tons.
Firepower
When modeling options DARPA build a promising tank with specified requirements have been growing with the muzzle energy 9MDzh from M256 to 20 MJ and the initial speed of up to 2 km / s.
Mass of the active part of the BTS with the master is 10 kg, the mass of the core of about 5 kg. Length BPS with the ballistic tip and tail surfaces — 750 mm. To achieve the desired traits required powder charge weighing 20 kg with a volume of 17 l. Elected caliber cannon 135 mm sought the introduction of rounds of separate loading.
The caliber of the main weapons used for the analysis of promising developments, was elected on the basis of the available data in the United States on the development of the USSR tank with weapons such caliber.
In the Soviet Union really carried the development of the tank with a 3 man crew with external gun, 130 mm (commander and gunner were placed on the left of the gun), but then (since 1984) for a promising tank was adopted by the caliber of 152 mm [3].

Recharging is an autoloader carousel with placing shots in the container. 850h160h340 mm dimensions of the container. The main charge (BPS) is located in the same cell, a shell with an additional charge — in the other. In the carousel AZ is located 35 cartridges with shots of separate loading.
In the simulation of different options tank assembly was elected autoloader company «Ares inc» consisting of a rotary mechanism in the «basket» of the tower. Lift mechanism raises the container to the line chambering, then shall be sent to the shell, the container is lowered for ramming a charge after that it is chambering.
These promising solutions autoloader tank identical to accepted for autoloader promising tank of UKBTM.

The scheme of the automatic loader with feeder shots. Taking into account the size of the system and the features of its accommodation capacity of the MO of AZ is not provided.
The autoloader is complemented shot separately loaded in the cassettes in automatic mode through a hatch in the turret. This is a step forward in comparison with the manual loading of ammunition, reducing the existing labor-intensive services.
The angles downward cannon -10, +20 deg rise. To ensure the required angle suggested lowering the gun to implement withdrawable roof of the tower.
Controlled hydropneumatic suspension by the configuration of the machine allows you to trim increment angles gun laying in the vertical plane for another -6 / +6 degrees.
Auxiliary armament includes twin gun 7.62 mm machine gun with 10,000 rounds of ammunition. Involves the installation of an additional 7.62 mm machine gun with independent guidance on one of the up-and-masts gun with 3,400 rounds of ammunition
Fire control system
The fire control system was considered with a view to ensuring the highest probability of hitting the target (2 m) at a distance of 4000 m for this error firing should be less than 0.2 mrad. Requirements for the ability to defeat low-flying helicopters require turret drives, providing a turn at 60 deg / s. Modules with sighting and observation complex developer proposes to install up-and-masting the radial rotation. The structure of each of the modules comes to thermal imaging, television daily, laser dalnometrichesky channel. In addition, provides installation of acoustic sensors and radars in the future millimeter range. In addition, the tower can be mounted auxiliary sight. Transfer disk imaging planned to produce on a fiber-optic channels.
Protection
The estimated size of reservations is 1300 mm for the upper body component (700 … 380 for the bottom). 1300 mm for the front of the tower and the protection of the loopholes, barbet supposed to splice the hull and turret, etc. With all of this tower defense frontal attack on top of the covers and the separation of the crew.

Mobility
In promising projects of the tank was supposed to use small-sized logistics turbine engine capacity of 1500 hp MTO has been developed by the company programmke Advanced Integrated Propulsion System (AIPS), GTE version was developed by General Electric version with a diesel engine — Cummins. The main requirement for newcomer MTO reduction of weight from 6400 (M1A1) up to 5000 kg with a volume of 7 to 5.9 m3. The MTO program there AIPS developed for upgrading M1A1 tanks Block III and the heavy infantry fighting vehicles. Name MTO General Electric, made by programmke AIPS — GTE LV-100.

Findings
Based on the analysis of different variants of layouts it became clear that each of them has both advantages and disadvantages. The choice of one or another variant of the ideology of the tank depends on the characteristics of its planned implementation. South American developers (DARPA) provided an overview of possible configurations, showing the advantages and disadvantages of each of them.
With all of this indicates that the tank crew with two people has the best characteristics of mobility, visibility, price.
At the same time, research on the development of the tank with a crew of two people carried out in the 80s in the USSR showed no solutions that provide control of a tank unit with the crew. In the case of performing the functions gunner commander of a tank unit from platoon to battalion of his tank will be unable to carry fire. Load analysis tank crew also testified in favor of the crew of 3 persons.
With all the crew of 3 persons allows simultaneous firing, searching for targets, maintaining communication and control battle tank unit. The advantage in this case is the possibility of simultaneous firing of additional weapons — remote-controlled machine gun or small caliber gun.
Sources
1. The problem of reducing the size of the crew of the main tank. M. Apukhtin, AI Mazurenko, E. Morozov, P. Nazarenko. Bulletin of armored vehicles «. № 6 for 1980
2. An Exploration of Integrated Ground Weapons Concepts for Armor / Anti-Armor Missions. Randall Steeb, Keith Brendley, Dan Norton, John Bondanella, Richard Salter, Teriell G. Covington. RAND, NATIONAL DEFENSE RESEARCH INSTITUTE, 1991.
3. The last spurt Russian tank designers (the daily development of the tank participant «Boxer»). Yuri Apukhtin. Kharkov — 200 9 http://btvt.narod.ru/bokser/bokser_0.htm
4. RE Simpkin, Human Factors in Mechanized Warfare, Brassey’s, New York, 1984.