Once the 7.5cm PaK 42 L/70 anti-tank gun became available, the German Army sought new ways to implement this weapon into existing tank hulls for service as tank destroyers. The execution finally materialized in early-1944 when a Panzer IV Medium Tank was fitted with the gun and trials followed which proved the mating sound. Once demonstrated to the German high command, the vehicle was ordered into serial production through the concern of Vomag as the Panzer IV/70(V). It carried the Army identifier of SdKfz 162/1 (the "V" in the designation signifying the manufacturer).
By this time, the Jagdpanzer IV, another tank-killer built atop the chassis of the Panzer IV tank, was already in mass production with Vomag. As such, the company took to producing the two forms side-by-side with the existing line equipment. From August of 1944 until April of 1945 some 930 to 940 Panzer IV/70 vehicles emerged from the Vomag factory. The Allied bombing campaign did, however, disrupt Panzer IV/70 production to the point that numbers never recovered heading into April 1945 (the war in Europe ended in May 1945).
As finalized, the Panzer IV/70 was given a low profile thanks to its fixed superstructure housing the gun component and crew workspaces. The superstructure was fully enclosed to protect the crew from the elements as well as battlefield dangers (small arms fire, artillery spray). The operating crew numbered four and included the driver, commander and two gun operators. The radio fit was the Fu 5 system.
Power to the vehicle was provided for by a Maybach HL120 TRM V-12 liquid-cooled, gasoline-fueled engine developing 265 horsepower at 2,600 rpm. This gave the vehicle a road speed of 25 mph and a range out to 130 miles (80.5 miles cross-country). The engine was fitted to a rear compartment aft of the crew cabin.
Primary armament was the 7.5cm (75mm) PaK 42 L/70 gun and 79 projectiles were carried for it. Secondary armament became a single 7.92mm MG42 machine gun and 1,200 rounds of ammunition were available. Also available were any small arms carried by the crew as a last line of defense.
In the field, the Panzer IV/70 proved one of the best late-war tank-killers as its gun proved powerful, effective and could outrange any tank gun fielded by the Allies - a decided advantage in tank warfare. The value of the Panzer IV/70 series was such that, by November 1944, the series had superseded the Jagdpanzer IV along Vomag production lines. Some vehicles were given "Schuerzen", or side-skirt armor, to help protect the upper track reaches from damage. The sloped nature of the hull superstructure, coupled with its low profile, added an inherent survivability to the tank otherwise.
Later-production Panzer IV/70 vehicles reduced the track return rollers to three (down from four of the original). Because of the front-heavy load of the tank destroyer, these models were also given rubber-tired road wheels at the two front-most wheel installations. Additional roadwheels were carried along the rear hull facing should they be needed.
The Panzer IV/70 saw service into the final days of World War 2. Captured post-war stocks by the Soviets were passed on to ally Romania and these soldiered on into the 1950s.
Another offshoot of the Panzer IV/70 line was the Panzer IV/70(A). Like the Vomag vehicles, these carried the PaK 42 L/70 gun but production was managed by Alkett (which also manufactured the StuG III assault gun series). The Alkett model was intended as an interim solution and differed in subtle ways such as a taller profile. About 278 of the vehicles were produced by Alkett from August of 1944 into March of 1945.