Fall 1942: the best medium tank on field

[Vincenzo]

Armour protection comparation
Pz III L (from onwar.com)
Armor Detail Front Side Rear Top/Bottom
Hull 50mm@69° 30mm@90° 50mm@81° 16mm@0°
Superstructure 50+20mm@81° 30mm@90° 50mm@73° 18mm@011°
Turret 57mm@65° 30mm@65° 30mm@78° 10mm@0-7°
Mantlet 50+20mm@45-90°

Crusader III (from wwiiequipment.com, angle from onwar.com)
Armor Details Front Side Rear Top/Bottom
Hull 14+10+5mm@60° 14+14mm@90° 14+14mm@90° 66+4mm@0°
20mm@30°(upper nose)
20+13mm (lower nose)
Superstructure 18+22mm@60° 14+14mm 14mm@45° 712mm@0°
9mm@8°(glacis)
Turret 32+19mm@90° 14+10mm@40° 17+13mm@60° 12mm@18°,0°,8°

Pz IV F2 (from onwar.com, added glacis)
Armor Detail Front Side Rear Top/Bottom
Hull 50mm@78° 30mm@90° 20mm@81° 10mm@0°
20mm (glacis)
Superstructure 50mm@80° 30mm@90° 20mm@78° 12mm@0-5°
Turret 50mm@79° 30mm@64° 30mm@74° 10mm@0-7°
Mantlet 50mm@60-90°

T-34-76 Model 1942 (from armour scheme&data on russian wikipedia)
Armor Detail Front Side Rear Top/Bottom
Hull 45mm@30° 45mm@90° 40mm@45° 20mm@0°
lower nose 45mm@47°
Superstructure 45mm@30° 40mm@50° 40mm@48° 20mm@0°
Turret 45mm@60°&round 52mm@60° 52mm@60° 20mm@0°
Mantlet 40mm@3090°

M4 Sherman early type (from afvdb.50megs.com)
Armor Detail Front Side Rear Top/Bottom
Hull 51mm@45-90° 38mm@90° 38mm@80°-90° 25mm@0°(front) 13mm@0°(rear)
Superstructure 51mm@35-53° 13-19mm@0-7°
Turret 76mm@60° 51mm@85° 51mm@90° 25mm@0°
Gun Shield 76mm@round Rotor Shield 51mm@round (the rotor shield not cover all the gun shield)

 

[Shortround6]

adding MG info
all tanks except Crusader had two rifle caliber mg, coaxial and in the bow, the Crusader had only the coaxial
the Sherman had also a .50 on the top (usable only unbuttoned)

MG firepower is a lot more confusing. The bow gun was of rather limited use. Many tanks, like the Sherman, used a periscope to "aim" the gun. Aim is rather loose as the "gunner" merely observed the tracers through his normal viewing periscope which was not connected to the gun and had no aiming marks. Effective range was rather limited. Being closer to the ground there were more things that could get in the way, especially if the tank was 'hull down'. As the war went on the bow gun was seen as not worth the space it and more importantly, it's gunner, took up.
The Russian MGs were fed by 60 round drums and had rather light barrels.
The Brownings were feed by 200 round belts and had heavier barrels.
The Besa was probably the best of the bunch, it had the heaviest barrel for sustained fire, it fired as the barrel was going forward for less recoil/vibration, it was feed by 225 round belts, some versions had a selectable rate of fire or were fixed at 800rpm.
And again some tanks carried almost twice as much MG ammo as some other tanks.

While the tanks did not engage so much in sustained fire MG operations like ground mounted medium mgs, the ground guns were generally rated at 200 rpm sustained fore ( not cycle rate) so even 2000 rounds for one gun might not last all that long in combat.

 

[Vincenzo]

the bow mg stay there also in early 50s so i don't think was so useless in a WW2 operation
rifle caliber MG ammo load
Pz III L: 4950
Pz IV F2: 3192
Crusader III: 5000
T-34-76 M1942: 3150 (with radio 2394)
Sherman: 4750

 

[parsifal]

t-34 CHARACTERISTICS

T-34/76 Armour distribution
Hull front 47 mm /60° (upper part)
45 mm (1.8")/60° (lower part),
Hull side 45 mm/41°(upper part),
Hull rear 40 mm,
Hull top 20 mm,
Hull bottom 15 mm;
T-34-85 Turret front 90 mm (3.54"),
T-34-76 Turret front 52-45mm mm (2-1.7"),
T-34-85 Turret side 75 mm/30°,
T-34-76 Turret side 52-45 mm/30°,
T-34-85 Turret rear 60-52 mm,
T-34-76 Turret rear 45 mm,
Turret top 16 mm (all)

Main armament
76.2 mm (3.00 in) F-34 tank gun
(T-34-85: 85 mm ZiS-S-53 gun)

Secondary armament
2 × 7.62 mm (0.308 in) DT machine guns

Engine
Model V-2-34 38.8 L V12 Diesel engine
500 hp (370 kW)
Power/weight
17.5 hp/tonne
12.4 (MkIV by comparison)
Suspension
Christie
Ground clearance
0.4 m (16 in)
Operational range
300 (early)-460 km (T-34-43)
200 (Mk Iv by comparison)


Discussion

Armament

The F-34 76.2 mm (3 in) gun, equipped on the vast majority of T-34s produced through to the beginning of 1944, was able to penetrate any early German tank's armour at normal combat ranges (500m or less). When firing APCR shells, it could pierce 92 mm of armour at 500 m. The best German tanks of 1941, the Panzer III and Panzer IV, had no more than 50 or 60 mm frontal armour, generally poorly sloped and distributed. The F-34 also fired an adequate high explosive round.

The gun sights and range finding for the F-34 main gun (either the TMFD-7 or the PT4-7 were crude, especially compared to those of their German adversaries, affecting accuracy and the ability to engage at long ranges.This was made worse by the generally poor standard of crew training. T-34 performance was in summary adversely affected by the T-34's two-man turret, crew training, somewhat cramped layout, weak optics, and poor vision devices, according to contemporary the Germans reports. Soviet sources dont agree with that assessment. There was a lack of radios in the early versions that affected co-rdination of forces

T-34s operated in a disorganised fashion with little coordination, or else tended to clump together like a hen with its chicks. Individual tank commanders lacked situational awareness due to the poor provision of vision devices and preoccupation with gunnery duties. A tank platoon would seldom be capable of engaging three separate targets, but would tend to focus on a single target selected by the platoon leader. As a result T-34 platoons lost the greater firepower of three independently operating tanks.

The Germans noted that generally the T-34 was very slow to find and engage targets, while their own tanks could typically get off three rounds for every one fired by the T-34.

When new German tanks types with thicker armour began appearing in late 1942, the T-34's 76.2 mm cannon was unable to deal with them effectively . As a result, the T-34 was upgraded to the T-34-85 model. This model, with its 85 mm (3.35 in) ZiS gun, provided greatly increased firepower compared to the previous T-34/76 gun. This tank also had significant improvement to the armouring scheme, indicating the basic soundess of the design and its considerable "stretching ability in the design. The 85 mm gun could penetrate the front of a Tiger I tank between 200 and 500 m (220 and 550 yd), though in reverse the 88mm KWK could defeat the t-34 past 1000m . Against the frontal armour of the Panther, the T-34-85 could only penetrate the non-mantlet of its turret at 500 m (550 yd), meaning that even upgraded models of the T-34 usually had to flank a Panther to destroy it.

The greater length of the 85 mm gun barrel (4.645 meters) made it necessary for crews to be careful not to plough it into the ground on bumpy roads or in combat. A.K. Rodkin commented: "the tank could have dug the ground with it in the smallest ditch. If you fired it after that, the barrel would open up at the end like the petals of a flower." Standard practice when moving the T-34-85 cross-country in non-combat situations was to fully elevate the gun, or reverse the turret

Gunpower then started out as adequate, but was let down badly by other factors. The greatest advantages of the T-34 over its german counterparts and why it is a superior tank design overall, was in its range and overall mobility. The T-34 was powered by a Model V-2-34 38.8 L V12 Diesel engine of 500 hp (370 kW), giving a top speed of 53 km/h (33 mph). It used the coil-spring Christie suspension of the earlier BT-series tanks, using a "slack track" tread system with a rear-mounted drive sprocket and no system of return rollers for the upper run of track, but dispensed with the heavy and ineffective convertible drive.

During the winter of 1941–42, the T-34 had a marked advantage over German tanks through its ability to move over deep mud or snow without bogging down. The Panzer IV, its closest German equivalent at that time, used an inferior leaf-spring suspension and narrow track that tended to sink in such conditions. This was a very significant advantage in conditions of mud or heavy snow, conditions that affected the Russian Front for more than half the yearly cycle.

Edit
There is one, non battleground related area worthy of note. Whilst difficult to quantify, it seems pretty clear that the T-34 was much more cost effective than its opponents. Some sourcews claim that the average man hours per unit was 4000 for a T-34, whereas the Panther was about 55000 man hours. There are a LOT of caveats that need placed on that, bit the fact that the Soviet Union managed to out produce the Germans in just about every category of equipment suggests a serious systemic problem in the German procurement machine.

 

[Vincenzo]

Mobility data all from onwar.com

Pz IV F2
Engine Make Model Maybach HL120TRM Track Links 99/track
Type Displacement V12, 11.7 liters Track Width 40 cm
Horsepower (max.) 300hp@3000rpm Track Ground Contact 352 cm
Power/Weight Ratio 11.3 hp/tonne Ground Pressure 11.8 psi
Gearbox 6 forward, 1 reverse Ground Clearance (m) 0.4
Fuel Gasoline (Petrol) Turning Radius (m) 5.92
Range on/off road (km) 210/130 Gradient (degrees) 30°
Mileage (liters/100km) 250 on/350 off road Vertical Obstacle (m) 0.6
Fuel Capacity (liters) 470 (3 tanks) Fording (m) 1.0
Speed on/off road 40/16 km/h Trench Crossing (m) 2.2

Pz III L
Engine Make Model Maybach HL120TRM Track Links 99/track
Type Displacement V12, 11.9 liters Track Width 40 cm
Horsepower (max.) 300hp@3000rpm Track Ground Contact 286 cm
Power/Weight Ratio 14.0 hp/tonne Ground Pressure 13.6 psi
Gearbox 6 forward, 1 reverse Ground Clearance (m) 0.4
Fuel Gasoline (Petrol) Turning Radius (m) 5.85
Range on/off road (km) 155/95 Gradient (degrees) 30°
Mileage (liters/100km) 182 on road Vertical Obstacle (m) 0.6
Fuel Capacity (liters) 320 Fording (m) 0.8
Speed on/off road 40/19 km/h Trench Crossing (m) 2.0

Crusader III
Engine Make Model Nuffield Liberty Mk. IV Track Links n.a.
Type Displacement V12, 27 liters Track Width n.a.
Horsepower (max.) 340hp@1500rpm Track Ground Contact n.a.
Power/Weight Ratio 16.9 hp/tonne Ground Pressure 14.1 psi
Gearbox 4 forward, 1 reverse Ground Clearance (m) 0.41
Fuel Gasoline (Petrol) Turning Radius (m) n.a.
Range on/off road (km) 204 (with auxiliary tank) Gradient (degrees) 30°
Mileage (liters/100km) 312 on road Vertical Obstacle (m) 0.67
Fuel Capacity (liters) 500+136 (auxiliary) Fording (m) 0.99
Speed on/off road 43/24 km/h Trench Crossing (m) 2.59

T-34-76 M1942
Engine Make Model V-2-34 Track Links 72/track
Type Displacement V12, 38.9 liters Track Width 55.0 cm (22")
Horsepower (max.) 500hp@1800rpm Track Ground Contact 372 cm (146")
Power/Weight Ratio 16.7 hp/tonne Ground Pressure 0.73 kg/cm2 (10.4 psi)
Gearbox 5 forward, 1 reverse Ground Clearance 0.4 m (1' 4")
Fuel Diesel Turning Radius 7.6 m (24' 11")
Range on/off road 280+/180+ km Gradient 35°
Mileage on road 150 l/100km Vertical Obstacle 0.8 m (4' 1")
Fuel Capacity 420 (+ 140 external) l Fording 1.3 m (4' 3")
Speed on/off road 55/40 km/h Trench Crossing 2.5 m (8' 2")

M4&A1 Sherman
ngine Make Model Continental R975 C1 Track Links 79/track
Type Displacement R9, 15.9 liters Track Width 42.1 cm
Horsepower (max.) 400hp@2400rpm Track Ground Contact 373.4 cm
Power/Weight Ratio 13.2 hp/tonne Ground Pressure 13.7 psi
Gearbox 5 forward, 1 reverse Ground Clearance (m) 0.43
Fuel Gasoline (Petrol) Turning Radius (m) 18.9
Range on/off road (km) 193 Gradient (degrees) 31°
Mileage (liters/100km) 412 on road Vertical Obstacle (m) 0.61
Fuel Capacity (liters) 796 Fording (m) 1.0
Speed on/off road 34 km/h Trench Crossing (m) 2.3

 

[RCAFson]

Good article on the RAM:

Canadian Ram Mk.II

 

[parsifal]

A words of caution on comparing power to weight ratios. Its a common failing to use or interchange the units of measuremenet and this can often skew the result one way or another.

The T-34 is 26.5 Long tons, and 29.2 short tons. A long ton is the Imperial unit of measurement and is 2240lbs, the short ton is 2000 lbs. both are 20cwt, but the imperial unit of measurre for a cwt is 112lbs, whereas the US unit of measure is 100lbs.

On that basis the power to weight forthe T-34 can be reported as 17.1, if you want to downplay its advantages, or as high as 18.9, if you want to go the other way. Same deal with the german tanks. A Mark III is powered by a 296HP engine, and weighs 25.4 short tons, or 22.6 Long tons. if you want to ham up its power to weight, you use the Long tons figures and quote the engine as 300 HP. that gives you a figure of 14.7, as reported above. If you want to compare it to the 17.1 quoted for the T-34, you need to use the same units of measurement and use the lesser, more accurate power ratings for the MAN diesels. That gives you a power to weight of 11.6.

So if we are comparing new T-34 to new MkIII, and we want to use Long tons as the unit of weight measurement, the corrected figires are 17.1 to 11.6. If we want to use short tons, the corrected figures are 18.9 to 14.7.

Of course, this is not a particularly useful number either way. Most engines are at some point of wear and tear rather than new. that means they produce less power, and that means the power to weight for a t-34 is going to be 18.9 or less, and the Mk III 14.7 or less. Given the supply system basically broke down for the germans during the winter, that means their tanks in winter are a lot less mobile than even these figures would suggest.

 

[Shortround6]

Power to weight is a nice indicator but for tanks that are somewhat close other things come into play. Like the number of gears in the transmission, the actual gear ratios (nobody was driving cross country in high gear) and the torque of the engine. The Crusader had more torque than a Tiger tank (or darn close).
Ease of shifting comes into too. Tanks that were hard to shift tended to be left in the lower gears or the driver only used a few gears. Some gears might only be for special situations, a super low for hill climbing? or an 'overdrive' for highway cruising.

Some tanks used 'crash boxes', no synchronized gears anywhere, others did use synchronizers, at least on the upper gears and some tanks used "pre-selector" transmissions. Driver moved a control to 'select' the next gear he wanted to use and when he depressed the clutch pedal an air cylinder moved the actuating rods to actual shift the transmission.

Proving ground mobility with good drivers could vary considerably from "field" performance with even mediocre drivers let alone poor ones.

Some British tanks (not Crusaders) with poor power to weight ratios and slow top road speeds actually had decent cross country performance and very good hill climbing due to a good (or lucky) choice of gear ratios. Low gear allowed them to pick their way up hill at a walking pace when other tanks simply stalled or moved too fast for conditions and ran into things.

BTW I used to drive a few fire trucks with 5 speed crash box transmissions. Not tanks but we drove them as 4 speeds, ignoring 1st gear (which was actually marked LL {low low} on the shift pattern) Granted we were not being shot at but procedure if you missed the 2nd to 3rd shift (or any other but that was the most difficult shift) was to bring the vehicle to a halt and start over rather than try to cram the thing into gear while moving. Getting to the fire/medical 20 seconds late was preferable to wrecking the transmission and not getting there at all.

Other crash boxes may have been different.

 

[parsifal]

the question to all that though is the MkIII and MkIV all that close to a t-34? I have my doubts

 

[Vincenzo]

Shortround6 i know power to weight is not all, and actually onwar give us many other informations not all but many

 

[gjs238]

Ease of shifting comes into too. Tanks that were hard to shift tended to be left in the lower gears or the driver only used a few gears. Some gears might only be for special situations, a super low for hill climbing? or an 'overdrive' for highway cruising.

Some tanks used 'crash boxes', no synchronized gears anywhere, others did use synchronizers, at least on the upper gears and some tanks used "pre-selector" transmissions. Driver moved a control to 'select' the next gear he wanted to use and when he depressed the clutch pedal an air cylinder moved the actuating rods to actual shift the transmission.

Proving ground mobility with good drivers could vary considerably from "field" performance with even mediocre drivers let alone poor ones.

Some British tanks (not Crusaders) with poor power to weight ratios and slow top road speeds actually had decent cross country performance and very good hill climbing due to a good (or lucky) choice of gear ratios. Low gear allowed them to pick their way up hill at a walking pace when other tanks simply stalled or moved too fast for conditions and ran into things.

BTW I used to drive a few fire trucks with 5 speed crash box transmissions. Not tanks but we drove them as 4 speeds, ignoring 1st gear (which was actually marked LL {low low} on the shift pattern) Granted we were not being shot at but procedure if you missed the 2nd to 3rd shift (or any other but that was the most difficult shift) was to bring the vehicle to a halt and start over rather than try to cram the thing into gear while moving. Getting to the fire/medical 20 seconds late was preferable to wrecking the transmission and not getting there at all.

Other crash boxes may have been different.

This reminds me of an earlier discussion here about ease of or complexity of operation of the P-38.
Particularly for a less experienced pilot, it was pretty daunting switching from cruising along to combat.
Many P-38's were lost while the pilots were busy working with all the controls.

I imagine the same goes for tanks.
During summers in high school I worked on a farm.
Some of the old tractors were very difficult to shift.
(Driving a modern stick /standard shift car does not qualify anyone to profess an understanding of working an unsynchronized transmission.)
As SR posted, if a shift was missed on some of those tractors, you had to stop and wait for the gears in the box to stop before shifting.

 

[parsifal]

and the T-34 gearboxes in the early examples were diabolical. ive read it was standard issue to give a wooden mallet to the drivers of these early examples. There were times when the tank simply refused to go into gear and sometimes a god solid wallop would do the trick. I used to play a game called Panzerblitz, and as a special rule in the gamne, every time you put a T-34 into reverse, you had to make a breakdown roll....15% chance of the gearbox blowing a gasket...

Later versions of the T-34 had largely eliminated this problem. by later I mean from mid '42 on roughly

 

[Shortround6]

KV drivers got the mallet also, same engine and transmission made worse by heavier tank.

US Army publications give an 80 octane fuel requirement for the Sherman tank with both the radial engine or the V-8.
The cast hull tanks don't hold as much ammo as the welded tanks.

The radial engine came in two power ratings, R-975-C1 350hp/2400rpm and R-975-C4 400hp/2400rpm and the torque was either 840ft/lbs at 1800 rpm or 940ft/lbs at 1700rpm.

I don't know when the 400hp version came into use but it was interchangeable with the 350hp engine.