Jagdpanzer IV

Combat experience gained during the 1942 campaigns indicated to German staff planners that the existing Sturmgeschütz close support artillery vehicles would have to be up-gunned if they were to continue to be used as tank destroyers, and the future standard weapon was selected as the long version of the 7.5-cm (2.95-in) tank gun fitted to the Panther tank. This gun was 70 calibres long (as opposed to the 49-calibre length of the tank and antitank versions of the Pak 40 family) and to house this gun in vehicles such as the Sturmgeschütz III would require considerable modifications. These modifications would take time so it was decided to adapt the larger PzKpfw IV tank chassis to act as a 'fail safe' model. Design work was soon under way on this new model, which emerged in 1943 as the Jagdpanzer IV Ausf F für 7.5-cm Pak 39 or Panzerjäger 39, but by the time the first examples were ready the long 7.5-cm guns were earmarked for the Panther tanks and so the first examples had to be content with 48-calibre guns.

The first of these Jagdpanzer IVs appeared in October 1943. They consisted of the well-tried suspension and engine layout of the PzKpfw IV allied to a new armoured carapace with well sloped sides. This hull was much lower than the hull/turret combination of the tank, and mounted the gun in a well protected mantlet on the front hull. The result was well-liked by the Panzerjäger crews, who appreciated the low silhouette and the well-protected hull, so the Jagdpanzer IV was soon in great demand. The gun was powerful enough to tackle virtually any enemy tank, and in action the Jagdpanzer IV was soon knocking up appreciable 'kill' totals, especially on the Eastern Front where most were sent. The secondary armament of two 7.92-mm (0.312-m) MG34 or MG42 machine guns also proved highly effective.

Jagdpanzer IV muzzle brakes were removed even from the earliest vehicles. This was to reduce dust kicked up by gun firing, which would give away the vehicles position. Muzzle brakes also send sound waves in all directions. This makes for an apparently louder report. Not so good, if you are trying to ambush armor. A gun without a brake will send its sound waves, basically, in the direction of the projectile. Also, the brake will tend to have an effect on the accuracy of the gun.

Many Panzer commanders considered that the Jagdpanzer IV was good enough in its original form to require no up-gunning but Hitler insisted that the change to the long gun had to be made.

Guderian believed the StuG III to be sufficient as a self-propelled gun, and felt production should have been focused on tanks. Because of its nose-heavy characteristics and General Guderian’s view that the Jagdpanzers were unnecessary, the crews christened the Panzer IV lang variants Guderian’s Ente, meaning Guderian’s Duck.

Thus during 1944 some Jagdpanzer IV mit 7.5-cm Stuk 42 equipments with the longer L/70 gun appeared, but the changeover on the production line took time, too much time for Hitler, who insisted that the changeover to the new gun had to be made even if it meant diverting all PzKpfw IV tank production to that end. Thus a third Jagdpanzer IV appeared, this time a hasty conversion of a basic PzKpfw IV hull to take a form of Jagdpanzer IV sloping carapace and mounting the 70-calibre gun.

This conversion was known as the Panzer IV/70 Zwischenlösung (interim) and was in production by late 1944. In service the 70-calibre gun Jagdpanzer IVs proved to be powerful tank killers, but the extra weight of the long gun made the vehicles nose-heavy to the extent that the front road wheels had to be ringed with steel instead of rubber to deal with the extra weight, The gun weight also reduced the overall performance of the vehicle, especially across rough terrain. But by late 1944 and early 1945 such drawbacks simply had to be overlooked, for the Allies were at the gates of the Reich and anything that could be put into the field was used. The Jagdpanzer IV proved to be a sound Panzerjäger that enabled the Germans to utilize existing production capacity and maintain the PzKpfw IV line in being when it would otherwise have been phased out. In service the Jagdpanzer IV was a popular vehicle and a powerful tank-killer.

Specification
Jagdpanzer IV mit 7.5-cm Stuk 42
Crew: 4
Weight: 25800 kg (56,879 lb)
Powerplant: one Maybach HL 120 petrol engine developing 197.6 kW (265 hp)
Dimensions: length overall 8.58m (28 ft 1.8 in); width 2.93 m (9 ft 7.4 in); height overall 1.96 m (6 ft 5.2 in)
Performance: maximum road speed 35 km/h (22 mph); road range 214 km (133 miles); gradient 57 per cent; vertical obstacle 0.6 m (23.6 in); trench 2.3 m (7 ft 6,6 in); fording 1.2 m (3 ft 11 in)

LINK