A Round Too Long

Attempts to create fixed ammunition for the 122 mm D-25 gun in 1944-45

It is no secret that the firepower of tanks in WW2 increased dramatically. Armies of the world began the war wither with 37-47 mm long barrelled guns or 75-94 mm short ones. Some tanks even had armament composed only of heavy machine guns or small autocannons. Firepower of heavy tanks increased the most noticeably, particularly in 1943. German heavy tanks settled on the 88 mm caliber, the Americans focused on 90 mm guns with ballistics of the M3 AA gun. The USSR also initially chose an AA gun, an 85 mm one. However, there was a huge leap forward in the summer of 1943. The design bureau of factory #9 under the direction of F.F. Petrov developed the 122 mm D-25 gun by combining the D-2 122 mm gun (its ballistics were very close to those of the A-19) and the cradle of the 85 mm D-5T-85 gun. After trials in the Object 240 experimental tank, it was accepted into service as the IS-2 (IS-122) on October 31st 1943.

Start of the T-54

 "May 7th, 1945

I report that in mid-February of this year I ordered NKTP factory #75 to develop a mount for the 100 mm gun in the T-44 tank with a new 1700 mm wide turret ring. The design and working blueprints are complete.

On May 5th of this year I gave orders to produce experimental prototypes of the T-44 tank with a 100 mm gun. Trials of these tanks are scheduled for June 10th.

As for stowing 50 rounds of ammunition as requested in your letter, it is very difficult to achieve. 34-35 rounds is much more realistic. Additional orders were given to factory #75 to investigate the possibility of stowing 50 rounds.

I will inform you of the results of this work.

People's Commissar of Tank Production of the USSR, V. Malyshev"

CAMD RF F.38 Op.11355 D.3048 L.9
Printed in Glavnoye Bronetankovoye Upravleniye Lyudi, Sobytiya, Fakty v dokumentakh, 1944-1945 p.487

100 mm Guns

 "May 17th, 1945

I report to you on the work performed by the People's Commissariat and factories #92 and #9 on improving the firepower of T-34, T-44, and T-54 medium tanks.

Two types of 100 mm guns were produced for these tanks with turret rings widened to 1700 mm.

• 100 mm LB-1 gun produced at factory #92 (Gorkiy).
• 100 mm D-10T gun incorporating design elements of the D-10S SPG gun produced at factory #9 (Sverdlovsk)

Both guns were installed in turn into a T-34 tank with an expanded turret ring and tested at the Gorohovets proving grounds from April 6th to April 27th. Trials included firing 100 shots and 500 km of driving.

Armoured Confusion: Victorious '45

There are many misconceptions about the use of tanks in 1945, same as any other period of the Great Patriotic War. These myths muddle the characteristics of tanks, their application, and sometimes even introduce tanks that were not there at all. The final chapter in the series dedicated to myths on Soviet armour in the Great Patriotic War is dedicated to this period.

Intermediate Tank

GKO decree #6209s "On organizing T-44 tank production at factories #75 and #264" was signed on July 18th, 1944. With this order, Stalin gave permission to produce a replacement for the T-34. However, the T-44 never truly replaced the T-34-85. It was only produced at a backup factory and production volumes were small compared to the T-34-85. 1823 tanks is a very small number, and even in 1946 2701 T-34-85 tanks were built. The T-44 shouldered the problems of a revolutionary tank, although its service was long and it even saw battle.

Still With a Cabin

Usually one or two prototypes are built before a tank goes into production with only a few changes. However, there are exceptions. With IS series of tanks there were three of them, two of which were radically different from the final model. The similarly revolutionary T-44 evolved in a similar way. Even without significant changes in requirements,, this tank went through a series of evolutionary steps. The second variant of this vehicle was created as a result of trials held in February-March 1944. One of the main differences of the intermediate prototype was the armour. Trials showed that it was not enough to protect from the 88 mm Pak 43 L/71.

A Step in the Right Direction

Work on a radically new tank often results in the creation of intermediate vehicles. This exact thing happened with Soviet medium tanks in WW2. Several attempts were made to replace the T-34 with modernized vehicles. The first attempt was called T-34M, later the T-43 took a shot at the reigning champion. The results were similar: neither tank replaced the T-34. The first Soviet new generation medium tank, the T-44, travelled a long way and changed a lot before it entered production.

What's In A Name?

When the T-44 was created, the 85 mm gun was already insufficiently powerful. One solution was to install a 100 mm gun, but a widened turret ring was required. The result was the T-44B tank, which eventually evolved into the T-54.

"To the People's Commissar of Tank Production of the USSR, comrade Malyshev

Factory #183 developed a modernization of the T-44 tank with reinforced armour and a 100 mm gun installed on a 1800 mm wide turret ring.

According to my information the lead designer of factory #183 comrade Morozov has already arrived in Moscow with the project materials.

I ask you to instruct comrade Morozov to deliver the materials to the Tank Directorate for review and evaluation of the T-44B project.

Deputy Commander of the Motorized and Armoured Forces of the Red Army, Colonel-General of the Tank Forces, Korobkov.

November 2nd 1944"

CAMD RF 38-11355-2210 p.151

T-44 Under Fire

The T-44 proved a tough nut to crack. Neither the Soviet 85 mm gun nor the German 8.8 cm Pak 43 could penetrate the upper front plate even from 100 meters. The lower front plate could not be penetrated by the 85 mm gun either, but the 88 mm gun managed to break it off after several hits. Despite the welding giving out, the protection was much better than that of the T-34-85, comparable to the Panther.

"Firing trials against the armoured hull resulted the complete destruction of the following welding seams: 

• Upper front plate and left side
• Lower front plate and left side
• Idler carrier and sides
• Hull roof and left side

The welding seam between the hull roof and right side was destroyed by 80%.

The overall view of the hull from the front after trials is show in figure 21.

Photo 21. Overall view of the hull from the front after trials.

CAMD RF 38-11355-2909 p.31

Cabin on the Tanks

"Mechanic-driver's station

The mechanic-driver is located to the left of the ammunition rack in the front of the tank. The driver's seat is immobile. The seat can flip back and its angle can be adjusted.

The tank is driven by looking through the open hatch in front of the driver, through the slit in the hatch protected by a vision block, or through the rotating MK-IV periscope in the top hatch.

Self-Centered

Typically, armoured vehicles have a tendency to sag forward, especially as they are modernized throughout their service life. Heavier cannons and frontal armour often strain the front suspension elements more than the rear. The T-34 was no exception, with the T-34-85's front springs having to be reinforced when the larger and heavier turret entered service.

The T-44 was a revolutionary shift for Soviet medium tanks. In order to rid the front of the hull of the vulnerable driver's hatch, the hatch had to be placed on the roof, which meant shifting the turret backwards. In order to keep the fighting compartment the same size, the engine had to be placed perpendicularly to the hull. This resulted in a lot of weight moving backwards, and the center of mass followed. Calculations may show some detailed insight, but one can even see with the naked eye that the tank is tilting backwards.

CAMD RF 38-11355-2360 p.75

T-44 Prototype #2 Rate of Fire Trials

"Results of firing

Firing from standstill at an angle of 0 degrees. 

Target	Range	# shots	# direct hits	# of hits within 30 meters	Time spent	Rate of fire	Notes
Panther. Aiming was done using manual traverse.	900	10	8	2	1 min 5 sec	9.2 RPM	All rounds in turret rack
Panther and PzIII in a 30 deg arc. Aiming was done using manual traverse.	800	5	5	-	1 min 25 sec	7 RPM	5 rounds in the turret rack, 5 rounds to the right of the driver
	1000	5	5	-
Panther tank, PzIII tank, 3x3 meter target in a 40 deg arc. Aiming was done using manual traverse.	800	3	3	-	1 min 40 sec	5.4 RPM	All rounds stored to the right of the driver
	1000	3	3	-
	1500	4	4	1
Panther tank, PzIII tank, 3x3 meter target in a 40 deg arc. Aiming was done with electric traverse.	800	5	5	-	2 min 40 sec	3.7 RPM
	1500	5	1	2

ZIS-S-53 Gunnery Trials

"VII. Trials of armament

Firing the 85 mm mod. 1944 ZIS-S-53 gun

1. Determining accuracy and precision of fire

Accuracy and precision trials were performed using steel HE grenades. Aiming was done with the stock TSh-15 sight.

Ambient temperature: +32 degrees C.

Visibility: good

Range: 1000 meters

Angle of the tank: 0 degrees

Time for firing: unlimited

Fire correction was performed after every shot

Results:

Conditions	Distance to target	Shots fired	Shots hit	Dispersion radius, cm
				100	50
Firing from standstill at a vertical target initially.	1000 m	10	10	95	45
After mobility trials and 230 shots	1000 m	10	10	54	36

T-44 Tractor

Since the T-34 was clearly not going to stick around on the assembly line for long, the future of the AT-45 tractor on its chassis was bleak. With the T-44 cemented as its successor, it only made sense to design a tractor on that chassis.

T-43 Criticism

"Factory #183 designed and is currently producing an experimental prototype of the T-43 tank. The T-43 tank is designed based on the T-34 tank with the goal of obtaining a better armoured vehicle while keeping as many parts in common as possible.

The main drawbacks of the T-43 include:

Post-War Production

"State Committee of Defense Decree #9488ss
July 9th, 1945
Moscow, Kremlin

1. In order to increase the number of tanks in the Red Army to its authorized strength and create a 3000 tank Stavka reserve, it is necessary to preserve the production levels from June of this year for a term to be determined in the future.
2. Production of heavy ISU-152 SPGs for armament of heavy tank regiments of combined arms armies will be preserved, as their HE performance is much higher than of 122 mm guns.
3. Refill Red Army units to their authorized strength in the following order:
1. Occupational forces (comrades Zhukov, Konev, Rokossovskiy, and Tolbukhin).
2. Border military districts.
3. Internal military districts.

T-44 Upgun

"To the Deputy Chair of the State Committee of Defense, comrade Beriya

[cut off] January 1945

The tank park of the German army consists 50% of heavy Tiger and Panther tanks. Our heavy IS tanks, ISU SPGs and SU-100 SPGs make up about 28% of our total amount of produced tanks and SPGs. The main tank of the Red Army is the T-34-85, which has difficulty fighting heavy tanks. The new T-44 medium tank produced at factory #75 in Kharkov has the same armament as the T-34-85 tank.

To improve the armament and achieve superiority in firepower for our tanks, I consider it necessary to install the 100 mm D-10T gun into this tank. It is very possible to install this gun.

Based on the above, I ask you to order the People's Commissar of Tank Production to produce an experimental prototype of a T-44 tank with a 100 mm D-10T gun to urgently begin mass production of the T-44 with this gun.

Marshal of the Armoured Forces, Fedorenko
Colonel-General of the Tank Forces, N. Biryukov

Soviet Medium Tank Family

Towards the end of WWII, Soviet medium tanks were due for a firepower upgrade. The new T-44, despite having a superior layout and armour to the T-34-85, still carried the same 85 mm gun. While it was possible (with some difficulty) to fit a 100 mm gun in a T-44 or even a T-34-85, the Red Army opted for a brand new tank to carry the gun. Enter the T-54, in its first iteration.

"Comparative tactical-technical characteristics of the T-54, T-44, and T-34-85"

Characteristic	T-54		T-44		T-34-85
Type	Tracked		Tracked		Tracked
Engine	V2-44		V2-44		V2-34
Combat Mass	35500		31800		33200
Hp/ton	14.6		16.8		15.52
Ground pressure without submerging	0.9		0.8		0.84
Dimensions
Length with gun forward	8970		7650		8100
Length with gun backward	8490		7440		7050
Hull length with MDSh	6555		-		-
Width	3185		3150		3000
Height	2275		2400		2700
Height of the hull (from road surface)	1375		1400		1560-1680
Clearance	400		425		400
Width between middle of tracks	2610		2610		2460
Length of the contact surface	3940		3885		3850
Turret ring diameter	1800		1600		1600
Fighting compartment width	1850		1850		1420
Fighting compatment length (from ammuniton rack to engine compartment)	1570		1550 (from driver's seat)		1450
Height of the fighting compartment, from the floor to turret roof	1570		1590		1585
Armour
	Thickness	Angle	Thickness	Angle	Thickness	Angle
UFP	120	60	90	60	45	60
LFP	120	45	90	45	45	60
Side	90	0	75	0	45	40
Upper rear	30	60	30	60	45	40
Middle rear	45	17	45	17	45	47
Lower rear	30	70	30	70	45	45
Engine compartment roof and floor	15	90	15	90	20	90
Fighting compartment roof	30	90	20	90	20	90
Turret front	180	-	120	-	90	-
Turret side	150 to 90 at rear	20	90	20	75	20
Turret rear	75	12	75	12	52	12
Turret roof	15	90	15	90	20	90
Armament
Gun	D-10T-K (experimental)		ZiS-S-53		ZiS-S-53
Caliber	100 mm		85 mm		85 mm
Horizontal traverse	360 degrees		360 degrees		360 degrees
Maximum elevation	17 degrees		20 degrees		22 degrees
Maximum depression	3 degrees		5 degrees		5 degrees
Ammunition capacity	34		58		56
Aimed ROF	5-6 RPM		7-8 RPM		7-8 RPM
Machinegun type	GVG		DT		DT
Amount	2		2		2
Caliber	7.62 mm		7.62 mm		7.62 mm
Hull machineguns	1 (fixed)		1 (fixed)		1 (ball mount)
Coaxial machineguns	1		1		1
Machinegun ammunition	3000 rounds		1890 rounds		1953 rounds
Hand grenades	12		20		20
Commander turret control	Electric motor points turret at target selected by commander		-		-
Smokescreen	MDSh		-		MDSh
Number of smoke charges	2		-		2
Location of charges	Middle rear		-		Upper rear
Speed
Maximum speed	43.5 kph		51.1 kph		56 kph
Average speed:
Highway	30-35 kph		30-35 kph		30-35 kph
Off-road	15-18 kph		15-20 kph		15-20 kph

CAMD RF 38-11355-2867