3.7 cm Pak 36

3.7 cm Pak 36
3.7 cm Pak 36
Type	Anti-tank gun
Place of origin	Nazi Germany
Service history
Used by	Nazi Germany Republic of China Finland Estonia Hungary Slovakia Romania
Wars	Chinese Civil War Spanish Civil War World War II
Production history
Designer	Rheinmetal
Manufacturer	Rheinmetal
Unit cost	$2,579
Specifications
Weight	Travel: 450 kg (990 lb) Combat: 327 kg (720 lb)
Barrel length	1.66 m (5 ft 5 in) L/45
Width	1.65 m (5 ft 5 in)
Height	1.17 m (3 ft 10 in)
Crew	2
Shell	37 × 249 mm. R
Caliber	37 mm (1.45 in)
Elevation	-5° to +25°
Traverse	30° right and left
Rate of fire	13 rpm
Muzzle velocity	762 m/s (2,500 ft/s)
Effective range	300 m (328 yds)
Maximum range	5,484 m (5,997 yds)

The Pak 36 (Panzerabwehrkanone 36) was a German anti-tank gun that fired a 3.7 cm calibre shell. It was the main anti-tank weapon of Wehrmacht infantry units until 1942. It was followed in this role by 5 cm Pak 38 gun.

History

Design of a horse-drawn, 3.7 cm anti-tank gun (designated 3.7 cm Pak L/45) by Rheinmetall commenced in 1924 and the first guns were issued in 1928. By the early 1930s, it was apparent that horse-drawn artillery was obsolescent, and the gun was modified for motorized transport by substituting magnesium-alloy wheels and pneumatic tyres for the original spoked wooden wheels. Re-designated the 3.7 cm Pak 35/36, it began to replace the 3.7 Pak L/45 in 1934 and first appeared in combat in 1936 during the Spanish Civil War. It formed the basis for many other nations' anti-tank guns during the first years of World War II. The KwK 36 L/45 was the same gun but was used as the main armament on several tanks, most notably the early models of the Panzer III.

The Pak 36, being a small-calibre weapon, was outdated by the May 1940 Western Campaign, and crews found them inadequate against allied tanks like the British Mk.II Matilda, and the French Char B1 and Somua S35. Still, the gun was effective against the most common light tanks, such as the Renault FT-17 during the Battle of France and the T-26 during Operation Barbarossa. The widespread introduction of medium tanks quickly erased the gun's effectiveness; miserable performance against the T-34 on the Eastern Front led to the Pak 36 being derisively dubbed the "Door Knocker" (Heeresanklopfgerät, literally "army door-knocking device") for its inability to do anything other than advertise its presence to a T-34 by futilely bouncing rounds off its armor.

German soldiers with the 3.7 cm Pak 36 anti-tank gun in Belgium, May 1940.

The Pak 36 began to be replaced by the new 5 cm Pak 38 in mid 1940. The addition of tungsten-core shells (Pzgr. 40) added slightly to the armour penetration of the Pak 36. Despite its continued impotence against the T-34, it remained the standard anti-tank weapon for many units until 1942. It was discovered that Pak 36 crews could^{[citation needed]} still achieve kills on T-34s, but the feat required tungsten-cored armour piercing ammunition and a direct shot to the rear or side armor from point-blank range.

As the Pak 36 was gradually replaced, many were removed from their carriages and added to SdKfz 251 halftracks to be used as light anti-armour support. The guns were also passed off to the forces of Germany's allies fighting on the Eastern Front, such as the 3rd and 4th Romanian Army. This proved particularly disastrous^{[citation needed]} during the Soviet encirclement (Operation Uranus) at the Battle of Stalingrad when these Romanian forces were targeted to bear the main Soviet armored thrust. The Pak 36 also served with the armies of Finland (notably during the defense of Suomussalmi), Hungary, and Slovakia.

37mm Pak 36 L/45 ammunition

Pzgr

• Projectile weight: 0,685 kg
• Muzzle velocity: 745 m/s

Pzgr 40

This was tungsten cored ammunition, lighter and with higher muzzle velocity, produced in small quantities.

• Projectile weight: 0,368 kg
• Muzzle velocity: 1,020 m/s

Hit probability versus 2.5 m x 2 m target

Range	Penetration	in training	in combat
100 m	64 mm	100 %	100 %
500 m	31 mm	100 %	100 %
1000 m	22 mm	100 %	85 %
1500 m	20 mm	95 %	61 %
2000 m	- mm	85 %	43 %

Penetration figures given for Pzgr 40 and an armoured plate 30 degrees from the horizontal.

Stielgranate 41

Pak 36 with Stielgranate 41, as used in the late stage of the World War II

In 1943, the introduction of the Stielgranate 41 shaped charge meant that the Pak 36 could now penetrate any armour, although the low velocity of the projectile limited its range. The Pak 36s, together with the new shaped charges, were issued to Fallschirmjäger units and other light troops. The gun's light weight meant that it could be easily moved by hand, and this mobility made it ideal for their purpose.

Variants

• 40mm 40M - This was a Hungarian design. It was effectively a Pak 36 but rebarrelled to fit a Škoda 40mm A17, the standard Hungarian light anti-tank gun. This could fire the same ammunition as the Bofors 40 mm anti-aircraft gun, and also had a version of Stielgranate ammunition made for it.

References

• Gander, Terry and Chamberlain, Peter. Weapons of the Third Reich: An Encyclopedic Survey of All Small Arms, Artillery and Special Weapons of the German Land Forces 1939-1945. New York: Doubleday, 1979 ISBN 0-385-15090-3
• Hogg, Ian V. German Artillery of World War Two. 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 ISBN 1-85367-480-X