Mortar (weapon)

60 mm M224 mortar.

Semiautomatic mortar Ruag Cobra.

The mortar is a weapon that generally shoots explosive or incendiary projectiles with great destructive power —larger than grenades— at an angle greater than 45° and at relatively low speeds. These qualities are the opposite of those of artillery pieces, which fire at high velocity and generally at low firing angles.

History

Origins

Although it is difficult to know who first came up with the idea of raising a cannon to drop a projectile vertically, there is reason to attribute it to Mehmed II, during the Great Siege of Constantinople in 1453. Greek manuscripts from 1551 refer to that Mehmed, besieged by an enemy flotilla in the Golden Horn, proposed to create a weapon of these characteristics, succeeding in using it against one of the ships after a few shots. By the 16th century the mortar had become a fairly common weapon, getting its name from the squat, pot-like shape of the early models. The tubes were quite short – no more than two or three times the caliber and this generally greater than 150 mm. They were weapons for the defense of the square or as pieces of siege to fortresses. In the mid-19th century attempts were made to use them as coastal defense weapons, but they almost fell out of use as an artillery piece for infantry.

The first transportable mortar was invented by Baron Menno van Coehoorn in 1701. The Coehorn mortar quickly gained popularity, creating a new type of ship, the bomb ship. Mortars played an important role in the Venetian conquest of the Morea, and in the course of this campaign an ammunition depot located in the Parthenon was blown up. The first use of these more mobile mortars as field artillery rather than siege artillery was by British forces in suppressing the Jacobite rising of 1719 at the Battle of Glen Shiel. High angle trajectory mortars had a great advantage over standard field guns in the rugged terrain of the Western Highlands of Scotland.

The mortar had already fallen out of general use in Europe during the Napoleonic era, although Manby mortars were used on the coast to throw ropes at ships in distress. Interest in its use as a weapon did not revive until the heavy use of mortars by both sides during the American Civil War.

At the siege of Vicksburg, General Ulysses S. Grant reported making mortars on the ground to attack enemy trenches. Three main types of mortars were used during the war: siege and garrison (light), littoral (heavy), and Coehorn. Mortars were useful as siege artillery as they could fire explosive shells over the walls of fortifications, killing defenders and forcing others to stay in dug-outs or preventing artillerymen from working. Mortars could also destroy structures within the fortification and heavier mortar shells could penetrate many dugouts.

During the Russo-Japanese War, the Imperial Russian Army applied the principles of indirect fire from prepared positions in the field and designed the Navy's first shell-firing mortar. Port Arthur was defended with heavy guns, but their direct fire was of limited effectiveness against nearby or sheltered Japanese positions. The situation was solved by taking obsolete bronze cannons that became small portable mortars when they were mounted on wooden platforms. These mortars delivered naval mines, in abundance at the naval base, instead of projectiles. Mine throwers taken from warships were also used. A group of Army and Navy officers, led by Captain Leonid Gobiato, built a prototype mortar.

World War I

Heavy Mortar

The German army studied the siege of Port Arthur, where heavy artillery had failed to destroy defensive structures such as barbed wire and bunkers. As a result, they developed a short-barreled, rifled muzzle-loading mortar called the Minenwerfer. These would be used during the First World War. They were manufactured in three calibres; 7.58 cm, 17 cm and 25 cm. The German idea was thus to have a light siege artillery piece that could be used by the infantry to beat small enemy strong points without having to call in the heavier artillery. In November 1914 the British sent a captured mine-thrower from the Germans to Woolwich where a hundred copies were made and sent to France for Christmas 1914 to keep the soldiers happy until something better could be produced. The armaments industries were informed of this need and the British Army awaited the proposals. For its part, France had searched everywhere and some old iron and bronze mortars from the mid-XIX century returned to service.. They were sent to the front lines to form the initial armament of the new Trench Mortar Service, ironically known as the suicide club", officially created on November 26, 1914.

Infantry Mortar

Despite the obsolescence of the mortar, the exhausting trench warfare that took place on the Western Front during World War I determined the urgent need to use a weapon that could be used to fire from inside trenches and parapets, without exposing themselves to fire, in order to support the infantry and besiege the enemy lines. That is why the idea of the mortar was revived. Faced with the large mortars, a smaller one was needed that could be easily handled by the soldiers. Initially, the English and French used 19th-century mortars that were veterans of the Crimean War, and improvised heavy-duty ones. The Germans also followed these ideas, highlighting the Minenwerfer (mine-thrower).

Small calibers were great but when the enemy was digging trenches small calibers were useless. By 1915 the British achieved a compact smoothbore tube and bipod design, which is considered the first modern mortar. They nicknamed it the Stokes mortar after its creator, Wilfred Stokes. It was developed in various calibres, from 60 to 120 mm.

Modern mortars are generally direct derivatives of Stokes. They consist of a tube into which the projectile is dropped. The butt of the projectile impacts an existing firing pin in the bottom of the tube, which results in the deflagration of a propellant and the consequent firing of the projectile.

Their "grenades" are simpler and cheaper to manufacture than those of conventional artillery, and carry a greater explosive charge per unit weight of projectile, providing greater destructive power by employing lower fall velocities. This also allows a better distribution of the fragmentation splinters and an optimal distribution of the kinetic energy of the explosion.

France

The French army had to resort to putting old Crimean veteran 6" mortars into service. At the same time, since the destruction of the barbed wire was absolutely necessary before launching the attack, it occurred to some unknown French soldier that better than placing explosive charges was to throw them. An empty 75 mm cannon pod was used as the launcher. By having leftover pods to create a primitive spike mortar. This was the birth of the French trench artillery and its evolution was practically the same as the British. The homemade models were replaced by improved and regulatory models. The most common model was a 240mm. that fired a bomb that could produce a funnel 9 meters in diameter by 3.50 meters deep. Its enormous firepower was coupled with a weight of 1.5 tons, which is why a smaller mortar was sought. In 1917 the 150 mm Mortar Mod.1917 was adopted.

After the war, the French company Brandt spread the mortar on a large scale, selling mortars to practically all European armies. The Germans had a hard time appreciating the mortar. They tried to create their own alternative by means of the baptized weapons minenwerfer (mine throwers), in reality they conceived them as a small-scale howitzer. German designs were complex, expensive, unwieldy. The Krupp mortar was made in 1912, but was not accepted by the army then. It was a smooth bore with an approximate caliber of 50 mm. and it was mounted on a platform that could be moved on two wheels. Due to the needs of the war it was finally accepted.

Allied mortar designs were kept as simple as possible, while German models began to become more and more complicated. While the war was static it did not create many problems, but in 1918 things began to change and the deficiencies of such heavy weapons became noticeable.

Austria-Hungary

The Austro-Hungarian Army adopted five models of compressed air, with calibers of 80, 105, 120, 170 and 200 mm. It seems that the main reason for adopting them was the scarcity of smokeless powder. This meant that ordinary types of mortar used entirely black powder, with the consequent problem of smoke.

US USA

The US Army adopted the 4" as regulatory due to its ease of firing both gas and breaker projectiles. It was mainly delivered to the Chemical Warfare Service. The infantry and coastal artillery units were also equipped with different mortars, depending on what was available in each era.

Interwar

After the war, theorists disagreed about the validity of the mortar. The French had used the 37mm trench gun during the war, which provided front-line fighters with a kind of personal artillery. The Germans also used a number of 75mm light guns and howitzers, many of which were mountain artillery pieces. These, along with the mortars, had allowed the infantry to have immediate firepower on any enemy.

All the armies thought about it and it seemed to them that the mortar was the best solution to the problem of fire support to the infantry. A 3 " caliber fired a 10-pound grenade at a distance of about 2,000 meters. There were only two rival models: the Stokes type and a similar French model by Edgar Brandt. The British opted for their experienced Stokes, improving it but retaining its general configuration of base-plate, bipod and tube. The Brandt company produced an almost identical weapon that was purchased by the US Army in 60 and 81 mm calibres.

At the same time the British Army had the Stokes 3" and was looking for something lighter to supplement the rifle grenades for the infantry platoon. In 1934 a Spanish model was experimented with, the 50 mm Ecia mortar. Another competitor was Lieutenant Colonel Blacker's grenade launcher. A 2.5" of the Birmingham Small Arms Company. A comparative test was carried out in 1937 and the Ecia proved to be superior and in February 1938 it was decided to place an order for 500 mortars.

The US Army Chemical Warfare Service had their 4" and decided to increase its range and accuracy in the years that followed. In the late 1920s the Army settled on a French 60mm mortar design. for his infantry and bought a license to build the gun.

In 1935 the French army adopted the 120mm heavy mortar. Mle1935 manufactured by Brandt. This mortar could already be transported by a truck or a tracked tractor. The presence of the jog wheels allowed the calculation to move the mortar over short distances on its own. The Soviet army did not take long to copy the mortar. The Germans would discover their firepower in their own flesh and they will also copy it in 1942.

Spanish Civil War

During the Spanish Civil War, mortars of different calibers were used: heavy mortar (120 mm.), medium mortar (81 mm.) and light mortar (60, 50 and 45 mm.). Heavy mortars also received the name of mine throwers. The most widely used were the Ecia Valero mortars, regulation before the war, specifically the 60mm Model 1926, 50mm Model 1932 and the 81mm Model 1933 i>.

The mortar was one of the most feared and persecuted weapons in the positions of the Madrid front during the civil war. Locating enemy mortars and trying to destroy them became a priority. In the trenches to the northwest of Madrid, the two armies made an effort to do so.

Result of the war the Spanish detected the need to change imitating the Russians and use 120 mm models. The result was the Franco mortar, which, although it was not the best of all mortars, was the only Spanish weapon that participated in the Russian Campaign with the Blue Division. This was the first time that the Spanish used a 120mm mortar in combat.

World War II

During World War II, all countries improved their designs, standing out the Soviet 120 mm models and the American 81 mm caliber, which would continue to operate for decades.

The Red Army appreciated mortars for various reasons and used them extensively. The echelons of the Infantry Company were equipped with 50 mm mortars, each Infantry Battalion with 82 mm mortars and each Rifle Regiment with 120 mm mortars. As the war progressed, the importance attached to mortars did not stop growing. and those of 50 mm. disappeared in favor of the higher calibres. In addition to the 82 and 120 mm mortars. the Soviets manufactured several models of other larger calibers with more or less success.

On the German side, an Infantry Division had 93 40 mm mortars. and 54 of 80 mm., respectively assigned to the Company and Battalion echelon. The Regiment was manned with an Infantry Cannon Company, but no mortars. The experience in Russia with the mortar 50mm. it was a failure. It was too complex and heavy. In contrast to the 80mm mortar, it was a simple design and proved highly effective, both by its own characteristics and by the stupendous instruction of its servants and forward observers. The standard German mortar model was the 80 mm. Granatwerfer 34 which weighed 19 kg. The Germans used many Russian 82mm mortars, designating them Granatwerfer 274(r). The Germans soon realized that their infantry guns were less effective than the 120mm mortars. russians. From 1942 the Germans began to replace the infantry guns with 120 mm mortars. captured and by 1943 they had already copied it and started supplying the units with the 12 cm mortar Granatwerfer 42.

The British Army adopted the standard pre-war Mk.II mortar of World War II. It was reliable and robust but did not have the range of the German Granatwerfer 34 mortar. By 1942 a series of improvements succeeded in increasing the range. The most popular was the 3-inch Ordinance ML mortar, which remained in service until replaced in 1965.

As the war progressed, most of the combatants discovered flaws in their mortars and began to consider the question of improving them. The main need was for them to have more range. In Great Britain it was achieved by the simple procedure of increasing the charges, with an increase in the range from 1,500 meters to 2,500, but the base plate had to be reinforced.

Tactical use

Light mortars are normally included in the armament of infantry units, with the heavier models assigned to supporting artillery battalions, with the added advantage over the latter of not being limited to the logistical infrastructure needs of transport and means of communication required by the artillery.

Mortar sections are also usually assigned as the first echelon of fire support in modern infantry battalions, equipped with liaison means —radio— to coordinate and correct their indirect fire. In the cases of defense, each battery is assigned a sector, which is responsible for beating at the request of the infantry. It depends on the range of the mortar, currently being approximately 6,000 meters.

Different types of ammunition can be used: explosive, perforating, fragmentation, smoke, nerve gas (currently prohibited by the Chemical Weapons Convention of January 1993), or tear gas, lighting with flares, etc.

It is also a weapon that can be used by irregular forces in their siege function, standing out for its mobility.