The Object 704 self-propelled gun was a prototype tank
utilising elements both the IS-2 and IS-3 tanks. It was designed to carry the
152.4 mm ML-20SM model 1944 gun-howitzer, with a barrel length of over 4.5
metres (29.6 calibers) and no muzzle brake. It had a maximum range of 13,000
metres. The self-propelled gun carried 20 rounds of two piece (shell and
charge) armour-piercing and high explosive ammunition. The armour-piercing
round, weighing 48.78 kg, had a muzzle velocity of 655 m/s. The rate of fire was
1-2 round/min. The secondary armament of the fighting vehicle consisted of two
12.7 x 108 mm DShK machine guns, one anti-aircraft and one co-axial. The
vehicle was well armoured, up to 320mm in places, which would have made it one
of the most impregnable vehicles of its type, the project was cancelled.
The tests of ISU-152 began in the spring of 1945 and did not
bring the desired results. Because of the large angles of the installation of
armor plates, the combat compartment was cramped. The lack of a muzzle brake
led to the recoil being increased by 900 mm, because of this the driver had to
be moved to the left upper part of the combat compartment. In addition, the
self-propelled gun with the ML-20SM gun could not carry troops on board. All
these shortcomings, as well as a number of other design flaws, led to the Object
704 model of 1945 being not accepted for service.
Only one was completed and this prototype is now preserved
in Kubinka Tank Museum.
Name: Object 704
Type: Self Propelled Artillery [Artillery periscope Goerz
/ Hertz]
Origin: Soviet Union
Year: 1945
Length: 9.05 Meters
Width: 3.07 Meters
Height: 2.24 Meters
Weight: 47300 Kilograms
Engine: 12-cylinder 4-stroke B-2IS engine of 520 hp [electric
starter ST-700] [The self-propelled gun was also equipped with two external
additional fuel tanks (each of 90 liters), not connected with the engine fuel
system.]
Transmission: 5-speed gearbox
Range: 220km road, 120km cross-country
Speed: 37 km/h (12 km/h off road)
Crew: 5
Communication: 10RK-26 radio and TPU-4Bis-F intercom
system
Primary Armament:
-152 mm ML-20SM [telescopic sight TS-17K]
Secondary Armament:
-12.7 mm DSK
Gun Flexibility:
18° Elevation
1° Depression
11° Left
11° Right
Armor:
-Hull
100 mm Front
90 mm Side
60 mm Rear
30 mm Top
20 mm Bottom
-Upper Structure
120 mm Front (160 mm Gun Shield)
90 mm Side
60 mm Rear
30 mm Top
