On January 11, 1934, the Army Weapons Department drew up specifications for a mitteren Traktor (medium tractor).5,6,10,11,12 It was to be a maximum of 24,000 kg8 / 24 tons6 as it had to be able to cross most of the bridges in Europe.11 These were to equip the fourth company of each battalion.11 Its roll was originally intended to be artillery support and was designed with a low velocity, large caliber gun for HE.8
To disguise their development they were given the code name Batailonsführerwagen (BW) (battalion commander's vehicles).6,8,9,10,11 It's original designation was Begleitwagen (BW) (escort tank).2
On May 26, 1941, in a conference with Hitler at the Berghof, it was decided to investigate the possibility of up gunning the PzKpfw IVs with 50 mm PaK 38s.11 They were wanting about 20 tanks per armored division to act as a spearhead with better guns to penetrate enemy tanks, have heavier armor, and have speeds no less than 40 kph. Krupp received a contract to introduce a prototype by November 15, 1941. The 50 mm L/42 gun was to go into proof testing on August 1, 1941.11 However, after the invasion of Russia, the plan was dropped as being unworkable as the 50 mm L/42 was useless against the heavier Russian tanks.11
The electricity to traverse the turret was provided by a shunt motor. This was a type P/6 DKW 2 cylinder, 2 stroke engine which produced 15 hp at 2,800 rpm, and had a capacity of 585 cc.
The engine exhausts were fitted on the right side of the engine compartment which sucked in the air and this was expelled out the left side after passing through the radiator. The fans were driven by belts and double V-belts from the crankshaft.
There were eight road wheels on each side suspended in pairs from leaf springs.1 The suspension was 4 pairs of bogies on each side8 that were size 470x75-660 and mounted on longitudinal twin quarter elliptic springs, with 4 return rollers8,9. The sprocket wheel was in the front with the idler in the rear.1
The welded turret had seats for the commander, gunner, and loader.6,10 The loader was on the left, and gunner on the right.2,5
The cupola was towards the rear of the turret and had 5 ports. The commander's cupola was centered in the rear of the turret.2,5
There was a hatch in the turret sides.10
The joints were austenitic steel welds and the plates were made of chromium-molybdenum steel.6 The hull was separated by 2 bulkheads into the driving, fighting, and engine compartment.6
The transmission and the final drive assemblies were housed in the driving compartment.6 The driver and hull gunner / radio operator had their seats located in the front.6 The driver was on the left and the radio operator/machine gunner was on the right.5,10
The welded superstructure was bolted to the top of the hull.6 The superstructure extended out over the sides of the hull to make room for a large turret.8
Hatches for the driver and hull gunner were in the roof.6
Comparison of Main Tank Armament Performance