Tuesday, 8 April 2014

Panther Trials

The Panther tank made its debut in the Battle of Kursk. Naturally, the Soviets captured some and subjected one of them to trials. A comparison with the newest Soviet heavy tank at the time, the IS-2 model 1943, is made, as well as a less detailed comparison with PzIII, PzIV and Tiger tanks.

Overall view of the Panther tank.
Photo #1. View from the right, at an angle.
Photo #2. View from the front.

"Amount and conditions of trials.

The Panther tank #824, captured on July 17th, 1943 by General [illegible, likely Krivoshein]'s forces near the Novoselovka village in the Kursk region, was subjected to trials. Before the start of the trials, the tank travelled 452 km (from its speedometer). The tank travelled 220 km during trials between August 8th and October 5th, 1943, with repaired components, including:
  • asphalt highway: 58 km
  • dirt roads: 162 km
The engine worked for 13.9 hours.

During these trials, the tank broke down three times, and had to be towed back to the proving grounds. In addition to the above distance, the tank travelled 36 km while being towed.

The tank was fueled with aircraft gasoline KB-70. The oil system was filled with MK aircraft oil. The transmission remained lubricated with German grease. The suspension was lubricated with grease. 

The road conditions were as follows:
  • Highway: paved with asphalt, Moscow-Minsk highway. The road is 12 meters wide and has grades up to 5 degrees. Movement along the highway was not fast.
  • Dirt road: forest and field, wide, with a large amount of deep ditches, grades up to 10 degrees. The roads are muddy in places. External temperature was between 8-17 degrees Celsius, no precipitation. 
Mobility trials were conducted with the tank in travel position, without ammunition.

Gunnery trials

The 75 mm gun was tested by shooting from a stationary position at one and two targets at 1000 meters in order to evaluate accuracy, rate of fire, and convenience of working in the fighting compartment while shooting.

Special trials were conducted to determine the penetration and maximum effective range for the AP and subcaliber AP shells of the Panther and Ferdinand.

The evaluation of precision was done by observing the explosions from HE shells and examining damage to armour plates from AP shells.

The rate of fire was recorded by groups of 5 shots, timed from the "fire" command to the last shell.

A lack of 75 mm shells limited the amount of possible armament trials.

Results of mobility trials

Maximum speed

The maximum speed of the tank was determined on a straight stretch of road between the 42nd and 43rd kilometer of the Moscow-Minsk highway by two trials in opposite directions. The maximum speed attained was 50 kph. The tank drove in 7th gear.

Agility

Trials determined that the planetary mechanism lets the tank turn well. Due to a hydraulic servo, the tank is easy to control. 

The Panther's turning mechanism does not have the properties of a differential mechanism, which increases the tank's stability on straightaways and increases its off-road performance. This gives the tank an advantage over the Mk-IV Churchill and PzVI Tiger. In practice, it was impossible to turn the tank in place. Due to the difference of resistance on either side, the tank could only turn by locking one track and letting the track from the opposite side of the turn go forward or backward. Turning in place can only be done with equivalent resistance on both tracks, which in practice can be done very rarely.

Conclusions

1. The Panther tank, widely used by the German army since summer of 1943, is a new type of heavy tank, vastly different from other heavy tanks in tactical purpose. The difference is in the use of Panther tanks as tank destroyers, and not as breakthrough tanks. This is indicated by thick front armour and a powerful gun, but poor side, rear, and turret armour.

The following are tactical characteristics of the Panther tank compared to the IS-122 tank, which has a more powerful gun than the Panther.

Characteristic
Panther tank (Germany)
IS-122 tank (USSR)
Combat mass (tons)
45
Up to 46
Crew
5
4
Dimensions


Length (with gun)
8850
9830
Length (without gun)
6900
6770
Width
3430
3070
Height
2910
2730
Clearance
480
470
Turret ring diameter (mm)
1650
1800
Ground pressure (kg/cm^2)
0.84
0.81
Armour thickness (mm)


Front
85-65
120
Side
40
90
Rear
40
60
Turret
100-45
100 (cast)
Roof and bottom
27
30-20
Amount of guns and caliber
1 75 mm
1 122 mm
Gun length in calibers
67.25
47
Muzzle velocity (m/sec)
1000
790
Machineguns
2 7.92 mm
3 7.62 mm
Ammunition
80 rounds
28 rounds
Observation devices


Periscopic sights
0
1
Telescopic sights
1
0
Periscopes
4
4
Observation slits with armoured glass
7
7
Observation slits with armoured cover
1
0
Engine
Gasoline
Diesel
hp/ton
14.4-15.55
11.3

2. The Panther tank has a powerful 75 mm long barreled gun. Its shells have high penetration, achieved through increasing the propellant, higher muzzle velocity (1000 m/s) and good shell toughness.

The new model 1942 subcaliber shell allows for aimed fire at up to 2000 m, unlike the old subcaliber shell that was only effective at 500-600 meters.

The convenient position of aiming mechanisms, an electric firing mechanism, and a high quality binocular (refracting) sight, high accuracy and rate of fire (6-8 RPM) are achieved. 

The ammunition rack is positioned inconveniently. Only a part of the ammunition is stored in the turret, and the rest requires aid from other crew members to load. 

The IS-122 tank possesses a more powerful D-25 122 mm gun. The two-piece shell and screw breech lower the rate of fire to 1.5-2 RPM. The higher caliber reduces the ammunition capacity to 28 rounds.

3. The armour of the Panther tank is much thicker in the front than on the sides. This is achieved by a high slope of the front plates and a 2:1 ratio of thickness between the front and side plates. The Panther has a new hull shape for heavy tanks, inspired by the domestic T-34 medium tank. The sloped armour allows for the use of thinner armour while increasing the hull's resistance to shells. 60-80 mm is not a lot of armour for a heavy tank, but penetrating it is difficult due to the chance of ricochet.

The IS-122 is significantly superior to the Panther tank in its side, rear, and turret armour. The side armour of the IS-122 tank is only slightly less than its front armour, unlike the Panther, which makes the IS-122 tank more tactically adaptable. The Panther uses advantages of sloped armour more fully in the front than the IS-122.

4. The Panther no longer has a large amount of observation hatches like on the PzIII and PzIV, in order to increase protection. The Panther is equivalent to the IS-122 in observation quality. The commander and driver can see well. The visibility of the radio operator is satisfactory. The lack of observation devices for the gunner and loader reduce the observation quality of the Panther compared to the PzIII and PzIV.

5. The use of a gasoline engine on the Panther tank reduces its usage characteristics compared to the IS-122 tank, which has a diesel engine. Despite the higher hp/ton, the Panther has little advantage over the IS-122 in speed. The fuel economy of the Panther tank is greatly inferior to the IS-122 tank. The Panther has identical operational range as the IS-122 when using internal gas tanks, and 50-60% less if external fuel tanks are used.

The trials established that KB-70 aircraft gasoline works in Panther tanks.

6. The reliability, overall design and technological level of the components and assemblies of the Panther is less than that of the PzIII and PzIV. 

The least reliable component is the HL 230 engine that is not finished in either design or implementation. This was confirmed by constant breakdowns during trials (tearing of the valve pins, etc). The fan drive is another unreliable component, due to rapid wear on the drive's gears. The tank's suspension and transmission worked well during trials and did not break down.

Evaluation of the design

Armour
  1. The Panther tank is armoured with rolled homogeneous chrome-nickel-molybdenum steel, cast chrome-molybdenum steel. The armour screens are made from low carbon (less than 0.1%) pot metal. Compared to Tiger, PzIII and PzIV tanks, the Panther's armour contains more nickel up to 0.6%-1.7%
    The armour is harder on the outside than the inside, which indicates surface hardening or cementing. 
  2. The use of interlocking plates increases the toughness of the welding seams.
  3. The Panther's size is a disadvantage. It is longer than the IS-122 by 130 mm, wider by 360 mm, and higher by 180 mm.
Engine
  1. The use of a gasoline engine can only be explained by the specifics of the German fuel economy, which relies on synthetic gasoline.
  2. The Maybach HL 230 engine is a special tank engine designed with the requirements of a tank in mind.
  3. The engine is compact in design. Its installation gives good access to components that require periodic maintenance or can break down.
  4. The installation or removal of the tank's engine is relatively simple, which is achieved by:
    1. The drive shaft connection with the transmission, which removes the necessity for precise adjustments.
    2. Two rubber pads suspending the engine.
    3. All oil system components (including the tank and radiator) are mounted on the engine.
    4. The accessibility of most pipes and controls is satisfactory.
  5. The high power of the engine is achieved through high filling coefficient, compression, RPM, and compact combustion chamber.
    The high filling coefficient is achieved through a very large exhaust valve,  aerodynamic head, short and gradual exhaust channels, lack of preliminary heating of the fuel mix, and a separate carburettor for each of the 3 cylinders, with a separate power section which is enabled only when maximum power is close to being reached.
  6. The engine has good starting properties due to special starting sections of the carburettors and  magneto acceleration clutches. In low temperatures, the engine is easier to start due to:
    1. Injection of startup fuel into sucking collectors from a separate tank.
    2. Pumping hot water through the coolant system from an external heater or by heating up the coolant system with a blow torch along with the external heater, which simultaneously heats up the oil due to the oil-water radiator.
  7. The engine compartment fire safety is increased by:
    1. Isolation of the engine compartment from coolant system airflow.
    2. Screening of the exhaust pipes, special airflow, and increased tightness of all connections.
    3. Positioning of air filters directly above the carburettors, which reduces the possibility of a back-fire.
    4. Secure insulation of all electrical elements.
    5. Careful design of all oil reservoirs and connectors to prevent oil and fuel from leaking out onto the compartment floor.
    6. Automatic fire extinguishers in the engine compartment.
Transmission
  1. The planetary mechanism is of interest. It is a continuation of the planetary mechanism used on the Tiger tank, which is evidence that the Panther tank was produced after.
  2. The layout and design of the turning mechanism are simpler than that found on the Tiger tank, retaining all the advantages of this design over other mechanisms.
  3. The turning mechanism of the Panther and Tiger tanks provides a stiff connection with the tank's tracks when the tank turns. This allows the use of power from the drive wheel of the lagging track, and passing it on to the leading track (power regeneration effect).
    Combined with the reduced loss of power from the turning mechanism, this significantly reduces the engine power needed to turn and allows the tank to turn well.
  4. Advantages of the Panther's turning mechanism over the Tiger's turning mechanism include the lack of a differential mechanism, which leads to more stable straight line movement and higher off-road performance. 
  5. The turning mechanism of the Panther tank only exhibits differential properties when turning in place, with the gearbox in neutral position. Turning the tank in place can only be done when the resistance on both tracks is identical. Due to the differences in resistance, turning is usually achieved around the track with the higher resistance.
  6. The hydraulic servo makes steering the tank easy. It is necessary to evaluate the servo's performance in the winter.
  7. The main friction clutch, gearbox, and turning mechanism are very compact. The assembly takes up relatively little space in the hull.
  8. The method of lubrication of the gearbox, turning mechanism and final drive gears with a stream of oil aimed at the contact point deserves investigation.
Suspension
  1. The most interesting component of the suspension is the design of the torsion bar suspension, with two parallel torsion bars for each road wheel. This design allowed the Germans to achieve a soft suspension, while retaining robustness of the torsion bars.
  2. All suspension elements are well designed.
  3. The suspension requires little maintenance. The use of a central lubrication through oilers grouped in two places deserves attention.
Electrical equipment
  1. The Panther's electric network contains a simple and reliable automatic fire extinguisher, as well as a simple and reliable electric firing mechanism for the gun.
  2. A disadvantage of the electric network is the large and complicated rotary connection."

1 comment:

  1. I am surprised that the final drive did not cause any problems. It was one of the main weaknesses, and hardly fixable because it had been designed for a 35 ton vehicle.

    ReplyDelete