3.7 cm Pak 36

' 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. {| class="toc" id="toc"

Contents
[hide] *1 History
 * 1.1 Operational History
 * 2 37mm Pak 36 L/45 ammunition
 * 2.1 Stielgranate 41
 * 3 Variants
 * 4 Notes
 * 5 References
 * 6 External links
 * }

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.[2] 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. Even the Soviets used the PaK 36 carriage design for their 45mm M1937 AT gun.

Operational History
During May 1940 Western Campaign, the Pak 36 being a small-calibre weapon, it was found to be inadequate against allied tanks like the British Mk.II Matilda, and the French Char B1 and Somua S35, where German crews derisively dubbed it the "Door Knocker". Still, the gun was effective against the most common light tanks, such as the Renault FT-17 during the Battle of France, where the Char Bs and Matildas represented but a small fraction of the total AFVs. In June 1941, the soviet forces consisted of 10,661 T-26s, 2,987 T-37/38/40/50s, 59 T-35s, 442 T-28s, 7,659 BTs, 957 T-34s, and 530 KVs for acombined total of approximately 23,295 tanks. Thus, during the initial phases of Operation Barbarossa the Pak 36 could still penetrate the majority of soviet AFVs at ranges up to 1000m from the front, with the notable exception of the T-28s and T-35s which it could only penetrate at under 100m. Here the pak36 only had difficulty with the T-34s and KVs which it could not penetrate. Considering a total of 20,500 soviet tanks were lost in 1941 alone, it is clear that many of these must have been destroyed by German anti-tank crews armed with the Pak 36.

By late 1941, however, 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 nicknamed 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.Pak 36 could destroy the Japanese tanks in ChinaThe 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 a direct shot to the rear or side armour from point-blank range. The advantages of the Pak 36 were its ease of handling and mobility where it could be brought into action very rapidly by as little as two men (it weighed only 432 kg),its good quality optical aiming devices, that it was small and easy to conceal, and that it had a very high rate of fire.

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 bore the main Soviet armored thrust, and were unable to stop the Soviet advances due to inadequate anti-tank weaponry. The Pak 36 also served with the armies of Finland (notably during the defense of Suomussalmi), Hungary, and Slovakia.

Although the PaK 36 was generally ineffectual in Europe, it became a real tank-killer in China. A PaK 36 could destroy the Japanese Type 95 Ha-Go and Type 97 Chi-Ha tanks, since their armor protection was quite weak. For example, during the Battle of Taierzhuang, the Chinese PaK 36 destroyed 13 Japanese tanks. This made the Chinese soldiers so excited, and the Japanese soldiers so shocked, that the battle was stopped for several minutes.

37mm Pak 36 L/45 ammunition
This was tungsten cored ammunition, lighter and with higher muzzle velocity, produced in small quantities. Penetration figures given for Pzgr 40 and an armoured plate 30 degrees from the horizontal.
 * Pzgr
 * Projectile weight: 0,685 kg
 * Muzzle velocity: 745 m/s
 * Pzgr 40
 * Projectile weight: 0,368 kg
 * Muzzle velocity: 1,020 m/s

Stielgranate 41
Pak 36 with Stielgranate 41, as used in the late stage of the World War IIIn 1943, the introduction of the Stielgranate 41[4] 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 low 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.
 * 37mm Anti-Tank Gun M1930 (1-K) - This was a Soviet anti-tank gun designed by Rheinmetall, which was very similar to the Pak 35/36, but lacking some improvements.