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Soviet Union's SU-85 (Samoknya Ustanokova) tank destroyer:

SU-85 tank destroyer: Aberdeen Tank Museum	SU-85 tank destroyer: Aberdeen Tank Museum	SU-85 tank destroyer:	SU-85 tank destroyer: Imperial War Museum
SU-85 tank destroyer: School of Tank Technology	SU-85 tank destroyer: Imperial War Museum	SU-85 tank destroyer: Imperial War Museum	SU-85 tank destroyer: Imperial War Museum
SU-85 tank destroyer captured by the Germans:

Diecast 1/72 Armor
Dragon Armor
60091:	60092:

Design

At the Uralmash works in Chelyabinsk a project was lead by the development bureau of General F. F. Petrov to develop a self-propelled gun on a T-34⁷ chassis with an 85 mm gun.² The designers were S. N. Machinowa, L. I. Gorlickiego, and L. S. Trojanowa.⁷

From the beginning it was designed as a tank destroyer to take on the German Panthers and Tigers.¹

The SU 85 was based on the superstructure that was used in the SU-122.

Crew

The front plate had a driver's hatch to the left of center.⁷ This was mounted in a gimbal mount.⁷

On the right side of the fighting compartment is the commander's station.⁷ There was a fixed periscope in the hatch.⁷

The gunner is on the left side behind the driver.⁷ The loader is in the rear of the compartment and can move around behind the gun.⁷

The driver had three foot controls, from left to right, clutch, footbrake, and accelerator.⁷ The hand controls were a lever for the brakes in the right hand and in the left a change speed lever.⁷ There was a hand operated air pump for priming the fuel system for starting.⁷ In front of him were gauges that showed oil temperature and pressure.⁷ To the left was a revolution counter, speedometer, ammeter, voltmeter, starter and electrical switches, and an air pressure gauge for the air starter.⁷

Engine

The V2 engine was at the rear of its own compartment.⁷ On each side was a radiator and a fuel tank.⁷ There were a total of eight fuel tanks that could hold 135 gallons.⁷ An additional four auxiliary fuel tanks, that could hold 30 gallons each, were located on the outside of the engine compartment.⁷

The block, cylinder head, and crankcase were made of aluminum.⁷

Bosch type injectors were used in the SU-85's engine.⁷ The injectors were between the banks of cylinders.⁷

Wheels

There are 5 rubber tired wheels on each side.⁷ The rear three wheels are evenly spaced while the front have larger gaps with the largest being between the second and third wheel.⁷ This was to distribute the weight evenly to the wheels.⁷

The wheels are independently sprung.⁷

Tracks

The tracks are made from cast manganese steel.⁷ On alternate links are a guide horn.⁷ The plates were drilled and slotted to assist in going through mud and snow.⁷

Links weren't secured.⁷ The pins had a rounded head and when it started to wiggle loose it would strike against a double wedge shaped cam to push it back in.⁷

Main Armament

The 85 mm gun was based on an anti-aircraft gun and was mounted in a ball mantlet. The main armament was mounted to the right of center in the front plate.⁷ The breech block was semi-automatic.⁷ There was a Goertz dial sight that allowed for indirect firing.⁷

Ammunition is stored around the fighting compartment vertically and horizontally.⁷ Two clips hold each round in place.⁷

Ammunition used by the D-5S:6
Type	Name	Overall Weight	Shot Weight	Muzzle Velocity
HE6,7	O-3656	15.95 kg6	9.2 kg6
	O-365K6	16.3 kg6	9.54 kg6
	O-365KV6	14.95 kg6	9.54 kg6
	O-365G6	14.95 kg6	9.54 kg6
AP6	BR-3652,6	16 kg6	9.2 kg6	792 m/sec2,6
APBC7
APC6	BR-365K6	16 kg6	9.2 kg6	792 m/sec6
APCR (subcaliber)6	BR-365P6	11.42 kg6	4.99 kg6	1,050 m/sec6
APHE7		33 lb7	20 lb7
AP-T5				2,575'/sec5
HVAP5				3,650'/sec5

Prototypes

There were three prototypes constructed:⁶

• SU-85-I: An SU-122 with a C-18 gun.⁶
• SU-85-II: An SU-122 with a D-5S gun.⁶ After tests it went into production with the SU-85 name.⁶
• SU-85-IV: An SU-122 with a C-18 gun in a modified superstructure.⁶

Production

Production was cancelled in July 1944 when SU-100 production started.⁶

However, due to a lack of 100 mm APC ammunition, the SU-85M was produced from August to December 1944.⁶ It was the SU-100 with an 85 mm D-5S gun.⁶

• SU-85
  • May - December 1943: 100⁷, 750^1,2, 2,050
    • Manufactured by: Soviet Arsenals⁵
  • 1944: 1,300^1,2
  • ? - September 1944: 2,000³
  • Manufactured by: Uralmashzavod¹, Kirov¹, Uraimasz i Czelabinskie factory⁷
• SU-85M
  • August - December 1944: 315⁶

Usage

First 100 appeared in September 1943 on the Dneiper.^6,7 By early 1945 it had been withdrawn from the front and replaced by the SU-100. Used in all self-propelled gun regiments or brigades.

	SU-85	SU-85 19432 / SU-85M6
Crew	Commander, gunner, loader, radio operator, driver7 41,3,5, 57	42
Physical Characteristics
Weight	65,408 lb 29,200 kg3, 29,600 kg1 28.7 tons3, 29 tons7, 29.13 tons1, 29.2 tons1, 29.6 tons5	29.2 -29.6 tons2
Empty weight	28 ton7
Length w/gun	21' 7"1, 21' 10"5, 26' 8"7, 27' 2" 6.58 m1, 8.15 m1	8.15 m2
Length w/o gun	19' 5"7	5.93 m2
Height	7' 4"3,5, 7' 9"7, 8' 4"1 2.25 m3, 2.45 m1, 2.54 m1	2.4 m2
Width	9' 9"5, 9' 10"1,3,7, 10' 2.99 m1, 3 m1,3	3 m2
Width over tracks
Ground clearance	15"5, 1' 4"7	0.4 m2
Ground contact length	158"5
Ground pressure	10 psi5, 11.2 psi7	0.81 kp/ cm2 2
Turret ring diameter
Armament
Main	85 mm DS-S-857, 52 calibres7 Late models: 85 mm D-5 S-85 A2 85 mm D-5S1,3 85 mm5	85 mm D 5-S-852
Secondary
MG
Side arms
Quantity
Main	45, 481,5,7	482
Secondary
MG
Side arms
Armor Thickness (mm)	2.1"1 20-543, 541
Hull Front, Upper	3"@0°5, 451, 45 @ 50°7	45-752
Hull Front, Lower	45 @ 50°7	452
Hull Sides, Upper	1.75"@0°5, 451, 45 @ 90°7	452
Hull Sides, Lower		452
Hull Rear	1.75"@0°5, 451, 45 @ 50°7	452
Hull Top	201	202
Hull Bottom	201,7	202
Engine (Make / Model)	V27 W-2, V-21,3 Model W-25,7	W-2/342
Bore / stroke		4 stroke2
Cooling	Water5,7
Cylinders	125, V-121,7	V-122
Capacity	38.88 liters7
Net HP	5001,4,5, 500@1,800 rpm7	500@1,800 rpm2
Power to weight ratio	17 bhp/ton7	16.8 hp/ton2
Compression ratio
Transmission (Type)	Constant mesh5, Sliding mesh7 4 forward, 1 reverse5,7
Steering	Clutch brake5
Steering ratio
Starter	Electric and compressed air7
Electrical system	Starter: 24 volt7 Lighting and communication: 12 volts7
Ignition
Fuel (Type)	Diesel5,7
Octane
Quantity	135 gallons7, 100 gallons + 104 gallons in auxiliary tank5, 178 gallons1 810 liters1	865 liters2
Road consumption	2.3 mpg5
Cross consumption
Performance
Traverse	20° each way2,7, Hand7
Speed - Road	29 mph1,3, 30 mph1, 34 mph7, 35 mph5 47 kph1,3, 48 kph1	47-55 kph2
Cross country sped
Range - Road	200 miles1, 210 miles5, 248 miles3, 249 miles1, 250 miles 320 km1, 400 km1,3	350 km2
Range - Cross Country	124 miles1, 186 miles7 200 km1
Turning radius
Elevation limits	-5° to +20°2,7
Fording depth	2' 11"5, 4' 3"7	1.3 m2
Trench crossing	8' 2"5,7	2.5 m2
Vertical obstacle	2' 3.5"7, 2' 6"5	0.73 m2
Climbing ability	35° slope5,7	35°2
Suspension (Type)	Christie7, Christie coil spring torsion bar5
Wheels each side	55,7
Return rollers each side
Tracks (Type)	Steel, dry pin5 Cast manganese steel7
Length
Width	20"5,7
Diameter
Number of links	725,7
Pitch	6.9"7, 7"5
Tires
Track centers/tread	8' 2"7, 97"5

Sources:

1. Russian Tanks of World War II Stalin's Armored Might, by Tim Bean & Will Fowler, 2002
2. Russian Tanks and Armored Vehicles 1917-1945, by Wolfgang Fleischer, 1999
3. The Encyclopedia of Tanks and Armored Fighting Vehicles - The Comprehensive Guide to Over 900 Armored Fighting Vehicles From 1915 to the Present Day, General Editor: Christopher F. Foss, 2002
4. Removed
5. Tank Data 2, Aberdeen Proving Grounds Series, E. J. Hoffschmidt and W. H. Tantum IV, 1969
6. Peter Porai-Koshits, Sudden Strike team member
7. Armour in Profile #21 SU 85 and SU 100 Tank Destroyer, Colonel E. F. Offord, DSO, MBE, ?