Neutral Switzerland understood the fragility of its sovereignty perfectly well during WWII. However, in case of an invasion, the Alpine confederacy expected to go down fighting. In reinforcing its country's army, the Swiss arms industry created a number of interesting weapons, which include the Tankbüchse 41.
After the defeat of France by Germany, the Swiss adopted the idea of the "National Redoubt", presented by General Gisen on July 25th, 1940. In the event of an invasion by the only likely enemy, Nazi Germany, the Swiss army would retreat to the south of the country, into the mountain region, and continue resistance there. The use of the main ace in Germany's sleeve, their tank forces, would be difficult. The Swiss army required a light and powerful anti-tank weapon to block the few tank-accessible passes in the mountains.
History of creation
The existing 20 mm Solothurn S18-1000 anti-tank rifle was popular on the global arms market, but was no longer satisfactory for the Swiss. They wanted something more powerful. The first realization of this desire was in the development of weapons for light LTH tanks. These Czechoslovak vehicles entered service under the index Panzerwagen 39. In picking a weapon for their tank, the Swiss required superiority over the tanks of the likely enemy, armed with 20 mm guns. Waffenfabrik Bern received an order for a tank gun with an unusual caliber: 24 mm.
Colonel Adolf Furrer, the chief engineer at the Bern factory, designed a semiautomatic gun in a very short timespan, using the Lmg 25 as a basis. The gun was fed from a detachable six round magazine. This solution allowed rapid firing of several rounds, which left no chance of survival for a light tank. To improve the layout, the magazine was inserted from the top. The coaxial machinegun was placed to the right, and the sight was to the left. A small opening covered with a sprung hatch was added to the roof of the tank turret for reloading.
24 mm Panzerabwehr-Befestigungskanone 38 cannon for fortifications.
The Panzerwagenkanone 38 was produced in very small amounts, since Switzerland only bought two dozen LTH tanks. The version built for fortifications, Panzerabwehr-Befestigungskanone 38, was built in larger batches. Soon, infantry took an interest in the weapon. Its main antitank weapons were the aforementioned S18–1000 (20 mm Tankbüchse 40) and the 47 mm 4,7 Infanteriekanone 1935 cannon, produced under license from the Austrian Bohler company. However, these weapons were unsatisfactory, due to low penetration. The muzzle velocity of the 47 mm gun was only 540 m/s, whereas the muzzle velocity of the French 47 mm gun was 885 m/s. A decision was made to develop a new anti-tank gun. The ballistics were the same a the tank and fortification version, but it was classified as an anti-tank rifle, instead of a cannon, named 24 mm Tankbüchse 41 (or Tb 41 for short).
The biggest difference between the tank and fortification versions of the gun was the position of the magazine. Now, it was inserted from the right, instead of from the top. This allowed the reduction of the gun's height, which made it easier to hide. After the fifth shot was fired and the sixth round was chambered, the magazine ejected automatically. There was no need to rack the bolt after the next magazine was inserted.
24 mm Tankbüchse 41 in combat position.
Like its predecessors, the Tb 41 fired a powerful 24x138 mm round. Thanks to an effective muzzle brake, the recoil was minimized. The muzzle brake was assembled from eight rings of two types: "brake" (Bremsringe) or "blind" (Blindringe). The first type had channels for diverting the gases, the second did not. A combination of rings regulated the force of the recoil. The barrel had 12 right-facing grooves.
The Tankbüchse 41 had an effective muzzle brake.
Breech of the Tankbüchse 41, showing sight and magazine.
The Tb 41 used a short stroke recoil operated automatic mechanism. The gun used a hinged breech block. The charging handle was located on top, above the breech. Two adjustable handles with a trigger were located behind the breech. The mechanisms only allowed semiautomatic fire. The practical rate of fire was as high as 30 RPM.
The rifle was equipped with two sights: an open sight with a protected post and a removable 2.2x optical sight. Both sights were designed for firing at targets up to 1500 meters away.
Tankbüchse 41 on position, using a wheeled mount.
Tankbüchse 41 in transport position on a wheeled mount.
The rifle was fairly heavy. The body weighed 77 kg, and the tripod mount weighed 53 kg. During transport, the body was taken off the mount and disassembled into two pieces: the barrel (39 kg) and case (38 kg). The tripod was converted into a two-wheeled mount, which could be towed by a car, motorcycle, bicycle, or pulled by two soldiers. The anti-tank rifle could fire either from the tripod or the wheeled mount. The tripod allowed to adjust the right of the bore axis from 370 to 650 mm. It was also possible to fire without a mount at all, but laying the gun on a support. Using a special adaptor, the gun could be installed on a mount from the Mg 11 machinegun. Finally, the rifle could be installed in fortifications.
Tankbüchse 41 on a fortification mount from the 47 mm infantry gun.
The Tankbüchse 41 could be towed by a cyclist.
Two new types of ammunition were created for the new anti-tank rifle: the armour piercing 24 mm Pz-G.V. and explosive St-G. Both shells weighed 225 g (the full round weighed 460 g, and were 210 mm long). The first was painted gray, the second yellow. The explosive shell was equipped with an impact fuse. There was also a training 24 mm U-G shell, which weighed 225 g and had a delayed fuse and a smaller load of explosives. The training shell was painted black.
When firing on small shooting ranges, the Lmg 25 machinegun was attached to the rifle using a special holder. The anti-tank rifle was loaded with a special inert "manipulation round" (Manipulierpatrone) and the machinegun was loaded with tracer bullets. When the rifle's trigger was pulled, the machinegun fired off a single shot.
Tankbüchse 41 with the Lmg 25 machinegun attached to the barrel.
The high muzzle velocity (860 m/s in some sources, 900 m/s in others) allowed for effective fire up to 2000 m. The round maintained a velocity of 315 m/s at that range. However, the field manual instructed to fire at tanks from a range of 300 meters. An exception was made for light tanks, which could be fired on from 1000 meters, to destroy the tanks before they could approach the rifle position. As you can see, the document was quite optimistic.
The author has no information on the penetration qualities of the Tb 41.
Deliveries of the Tankbüchse 41 began in May of 1941. Waffenfabrik Bern produced 3581 rifles by 1945. They were mostly sent to anti-tank squads of infantry companies.
The crew of a Tb 41 consisted of seven men. The ammunition carried included 120 armour piercing and 40 explosive shells. A single-axle cart was used to carry it. According to the field manual, it transported two boxes of ammunition (one containing 30 armour piercing rounds, the other 30 explosive rounds). Ammunition was also carried in four backpacks (16 magazines in total, 2 of which contained explosive rounds). Interestingly enough, the explosive round magazine only contained 5 rounds, and was smaller than the armour piercing magazine. This was done so they would not be mixed up in combat. A six round magazine weighed 5.12 kg, and a box with thirty rounds weighed about 22 kg.
The 1943 manual defined the roles of the infantry anti-tank squad as follows:
"The biggest part of the anti-tank defense falls to infantry cannons and anti-tank rifles. They take up the following positions:
- On approach to settlements, with the objective of defeating armoured cars and tanks that try to flank the position.
- On outskirts of settlements and inside of them, in locations resistant to tank attacks, with the objective of destroying armoured cars and tanks that broke through, relying on passive anti-tank defenses.
- In fortified locations in the rear. The objective is to prevent tanks from hitting the rear of the main position. If enough anti-tank rifles are available, they can be used to destroy infantry (put them in heavy weapons and machinegun positions)."
Sufficient amounts of Tankbüchse 41 were available in Swiss units only by 1943. By then, it was clear that the rifle would be useless against modern tanks. On the other hand, the German invasion, which was quite possible in 1940-41, was no longer likely. Removal of the Tb 41 from infantry units began in the end of 1944, although they continued service in fortifications until the 1960s (298 Tb 41s were recorded in Swiss fortresses in 1945). These rifles were not exported. Negotiations about export to Ethiopia in 1951 did not succeed.
Tankbüchse 41 in a P-41 motorboat.
The most interesting chapter of the history of the Tankbüchse 41 was their use in the confederation's navy. In 1940-41, the government decided to form patrol boat groups on several of its lakes. Their main objective was resistance to a possible landing of amphibious aircraft, like the kind the Germans used when they invaded the Netherlands. The groups were initially armed with civilian motorboats, 20 mm Tb 40 anti-tank rifles, and 7.5 mm AA machineguns. Later, in December of 1941, the first two P-41 motorboats entered service. Three of these boats were ready in July of 1943, and three more in April of 1944. With a displacement of 7 tons and length of 12 meters, these boats could reach a speed of 40 kph. The main weapon was the Tb 41, installed in the front. In 1962, it was replaced with a 20 mm gun, but the "Uri" (a civilian motorboat pressed into service, and the prototype for the P-41 project) kept its Tb 41 until 1971.
The Tankbüchse 41 appeared at a dangerous time for Switzerland. Even though the gun never served in combat, it played its part in the rearmament of the Swiss army, becoming its first mass anti-tank weapon. From a technical point of view, the Tankbüchse 41 was an intermediate weapon, larger than a regular anti-tank rifle, but not quite a fully fledged anti-tank cannon.
Tactical-technical characteristics of the 24 mm Tankbüchse 41 anti-tank rifle:
Mass with wheeled mount, kg
Mass of a loaded magazine, kg
Mass of one shell, g:
Mass of one round, g
Length of the body, mm
Length of the barrel, mm
Full length in travel position on wheeled mount, mm
Height in travel position on wheeled mount, mm
Maximum height on tripod mount, mm
Muzzle velocity, m/s
Rate of fire, RPM
Maximum effective range