Canon of 75 Model 1897

The gun 75 mm models 1897 is a part of Field artillery of the French Army , which is one of the most famous gun S of all times. Of a revolutionary design for its time, it gathers, indeed, all the last improvements occurred in artillery at the end of the 19th century, namely: the use of the powder without smoke, the encartouchée ammunition, the shell fusing, a loading by the cylinder head according to the Nordenfelt process, and of a hydropneumatic brake of retreat. This synthesis, while eliminating the effects of the retreat, made finally possible an old dream of the artillerists, the fast shooting. It is because of its characteristics that it was called the gun king.

Become an emblem of the French military power, known soon like the sixty fifteen , even our glorious sixty fifteen , it is the subject of a worship on behalf of the soldiers and patriotic French, who see in him a miracle solution with any problem. This enthusiasm will result in neglecting inter alia the modernization of heavy artillery, error which will be hard paid at the time of the First World War. Indeed if the 75 is the best field gun of the time, it is much less at ease and useful in a war of position, where one needs heavy artillery, to reach the cut off troops. It will be distinguished nevertheless in a glorious way, but mainly thanks to its being useful which will pay a heavy tribute. Still in service in great number in the French Army of 1940, it was shown this time exceeded in the mobile warfare, because one had been long in making it suited to automobile traction, from now on necessary. He will know however, the one second youth like part anti-tank device, with the hands of the Wehrmacht and the free French Forces.

Birth

In September 1892, an experimental gun with fast shooting of 52 millimetres of gauge, designed by the Captain Holy-Claire Deville, is tested with the Arsenal Bourges. The general Mathieu, director of artillery, asks the commander Deport, polytechnician and officer of artillery, which directs the workshops of Puteaux, to undertake the realization of a version increased with a gauge of 75 millimetres. The project takes the designation of 75C . In parallel two other projects, especially intended are launched to induce the German information in error, the 75A and 75B . A first shooting of tests of the 75C is carried out beginning 1893, but of the problems of sealing and reliability of the brake of retreat still arise. It will be the same during the shootings of November 25th 1893 and of May 19th 1894, nevertheless after the second, the Minister for the war, the Mercier general, decides to order 340 parts. In November 1894, discouraged Offset, decides to leave to the retirement, and is replaced by Holy-Claire Deville, who is assisted by the captain Rimailho. It decides to entirely re-examine the brake, but by using the blocks of steels ordered for the manufacture of those of the first model; three years of studies will be necessary to arrive at a satisfactory result, the brake II . It increases also the field of the study, by including all there that is necessary to the service of the part, i.e. in particular the problem of an effective supply in ammunition, made essential by the great rate of shooting. The general Hippolyte Langlois also orders to him to envisage the use of the Tir fusing, by modifying the apparatus of clearing of the vents, which it had carried out for his part of 52.

To solve the problem of the supply, Holy-Claire Deville breaks with the use of the artillery which hitherto placed its boxes at ammunition well behind of the guns. He designs a box of before train, which overturns just beside the part, thus reducing the tiredness of the providers, who do not have to transport the shells any more on several meters to feed the parts. The swing of the box solves elegantly, at the same time the problem of the transport of the cartridges, which transported horizontally, would be likely to undergo unacceptable deformations, but also gets to the providers a shelter, because during the shooting they is covered by the bottom of the box and its doors, and can relatively protected, to extract and prepare the shells for the remainder of the team of shooting. At the level, several innovations, in addition to the brake of retreat, are implemented, to allow the fast shooting, to immobilize the part, the two wheels are equipped with brake for abatement, from which the shoes come to interpose between the ground and the tread, moreover one spade to the back of the arrow, is inserted in the ground, during the first shooting.

In December 1896, the tests of the new part appear extremely conclusive: ten thousand blows are drawn at a rate from twenty blows per minute, without incident. An order of six hundred specimens is thus launched for 1897. The production of each element of the 75, is carried out in two associated manufactures, measurement preached by Deville, to support a better interchangeability of the spare parts. The guns are manufactured with Bourges and Tarbes, the mountings with Tarbes and Tulle, the boxes with Saint-Etienne and Châtellerault, and the slides and brakes, with Puteaux and Saint-Etienne. A commission of the armaments, creates in December 1897 and directed by the Gras general, is charged to coordinate and control manufacture of it. The gun returns officially in service in the French Army, on March 28th 1898, and is presented to the public, for the first time that on July 14th 1899, at the time of the procession on the Champs Elysées. Meanwhile, to continue to mislead Germany, the Delloye general, successor of Mathieu, makes continue the tests of the 75A and 75B, going until suggesting that the 75B risk to be adopted. This company of misinformation, in the context of the Business Dreyfus, bears its fruits: the army of Kaiser adopts indeed precipitately, in 1896, a model of gun of 77 mm, with rigid mounting, completely exceeded compared to the model 1897, and does not continue the studies on a similar part, presented by Conrad Haussner, in 1891, which suffers from the same problems as the first French brakes.

Description

The system of weapon composing the Material of 75 mm model 1897 , is composed of three travelling elements, the gun, the front-axle unit and the back train-box, which combine to give two types of attachment: the car-gun and the car-box. As it is traditional in French artillery since the system of Vallière, the elements as the wheels are interchangeable. Three types of wheels will in addition be produced: the wheel n°7, the wheel n°7 reinforced and coil it n°7C reinforced, the two first are composed of seven wood rims connected to the Moyeux, by fourteen Rai S of wood too. The hub engages on the Stub axle, via a casing in Bronze. The reinforced wheel is equipped with metal shoes which reinforce the connection between the lines and the rims, and with a metal circle which reinforces the circumference of the rims, as for the wheel 7C, it does not have by measurement of simplification, more than two curved rims out of wooden.

The gun

The gun in him even consists of a single steel tube, reinforced with the back by a sleeve breech ring, it long 2,72 meters and is equipped with twenty-four stripes for constant step towards the line and deep of 0,5 millimetres, over a 2,23 meters length. It rests on a bronze jacket which is used as carriage at the time of the retreat. It is closed with the back by a block cylinder head with offset screw of Nordenfeld type. This element allows a shooting very fast and made safe, the opening and the closing of the cylinder head, are done by a simple movement of approximately 120° of the handle of crank, which sealed the room, by a rotation of the screw-cylinder head, of which the sealing moreover was ensured by the brass casing of the shell. The striker being opposite the starter of casing only when the cylinder head was very locked, any premature action on the cord of the Tire-feu could not start the shooting, making the operation very sure. After the shooting, the opening of the cylinder head actuated a mechanism of extraction of the casing, which is drawn by its posterior pad.

The gun is connected to the mounting only by the device of brake of shooting, the pivots of this one rest on the flasks, and with the gun by a stem. The principle of the long retreat is rather simple in its principle, but it was difficult to develop and to make reliable, with technologies of the time. The brake of the type I of Offset and type II, of Holy-Claire Deville, although they do not differ little in their principle, are definitely different in their manufacture. Rather than a Spring, one uses the compression of a volume of air locked up to obtain the recuperation of the energy of the retreat and the handing-over out of battery thanks to this one. The liner stem is equipped with a piston for its back which pushes on the oil contained in the higher tube, and forces that to pass by a vent in the lower tube, where it makes move back the free piston which separates it from the compressed air. The kinetic energy of the retreat and the force exerted by the compressed air, balance thus gradually, deadening carefully the movement of the gun. This one once stopped, the air slackens again then pushing back oil and thus the gun. On the whole the mobile unit weighing 461 kilograms, moves back a length located between 1,14 and 1,22 meter.

The mounting of the gun is composed of a Flèche made up of two Flasque S, made interdependent by Entretoise S, all into strong Tôle S of steel, the unit is ducted on the top by a finer sheet, which comprises a cushion, on which puts back the brake of the gun, in position of road. On the flasks, are fixed, the two axle-trees, the spade of stick and two handles of stick. On the two axle-trees, come to set the tubular axle whose two conical ends begin in the hubs of wheels, but also the two steel shields independent, which protect serving them on the battle field, that of left is reinforced by a paring arc which fixes it at the flask. In 1909, the shields being revealed too fragile in shift, one will modify their arrangement, the paring arc is moved on the shield of right-hand side, and a removable cross-piece, connects them to the top of the gun, as well as angles with the lower part.

In lower part of the arrow, one finds the mechanism which is used to install the brake of wheel, during the shooting, the rigid whole of the two shoes, when it is unbolted, goes down towards the ground, behind the wheels, while swivelling around the axle. A slide comes to block the rod with the back of the unit, at the time of the setting out of battery by being useful which raises the stick of the gun. The two wheels are then forced to go up on the shoes and the part rests then on three fixed points, the two shoes and the spade of stick. The latter is inserted in the ground during the first shooting, the moving back gun of approximately ten centimetres, thereafter it becomes almost completely motionless, during the following shootings, which makes it possible being useful to remain with its immediate proximity.

The front-axle unit

It consists of an axle, of a way of 1,51 meter, carrying a trunk where are placed vertically in four cells groups, 72 shells. it weighs 774 kilograms supplied out of high-explosive shells, and 830 when it is charged with shells with balls. It is surmounted by a bench for two being useful and is prolonged by a Timon of 2,7 meters on which six are harnessed, or sometimes four horses of feature. At the time of the setting out of battery of a part, before train of a gun, part is placed on the left and is reversed, to give easy access to the ammunition which are found with the horizontal one. The apparatus plunger of rocket, is fixed at the center of the trunk with ammunition. This mechanical whole of utmost precision, makes it possible to regulate precisely and quickly, the duration of combustion of the rockets of delay 22/31 of the shells with balls. The adjustment of the schedule is carried out by a cut built in the snail powder wick of the rocket, the device thus includes/understands a blade holder actuated by a lever, and a whole of gears which converts the distance desired into position of the blade on the rocket, the whole in double to accelerate the operation. Thereafter a modified model, with two graduations, will be introduced making it possible to also regulate the rockets 22/31A which have they a maximum delay of 31 seconds instead of 24.

The rear-axle unit box

This trailer which sticks to the same front-axle unit that the gun, carries it 48 additional shells, that is to say a total of 72 shells for each car box. Each part is accompanied by its box, which gives him a total of 120 blows available. in addition, each battery of four parts, has eight cars additional boxes, which are distributed between 5th, 6th and 7th parts of the battery, that is to say a total of 1248 shells for the battery or 312 for each part. With the combat, the first four parts known as of shooting, is a car gun and a car box, as well as the fifth, with two cars boxes, is spread on the position of shooting. The two other parts of each one three cars box, are placed they at four or five hundred meters behind, in a sheltered position, to constitute the level of combat. It are accompanied by an eighth part, which gathers a car of forging mill and the van of battery. The ninth part of battery, which gathers three vans of vivres and a fodder car, is generally assigned to the regimental train, to release the chiefs of battery of the tasks of intendance.

Bodies of aiming and accessories

Ammunition

The ammunition employed by the 75 model 1897, are of encartouché type, i.e. Shell is crimped on casing in Brass, which contains the propelling load, which allows the fast loading of the blow, but which ensures, by its base, also the perfect sealing of the gun during the shooting. The propelling mixture used is the Poudre B (according to the name of the Boulanger general), developped at the point in 1884, by the chemist Paul Vieille. It is without smoke, which allows the fast shooting, the blasting powder would make the shooting fast impossible because of the released vapors and of the clogging of the tube, but its lack of stability under the hot climates will oblige the engineers to paint the material in a clear color, the blue gray will be adopted in the place of the usual green olive. Thereafter, the service of the powders will improve the mixture by associating an minor amount there of Diphénylamine. Three types of loads are available, the normal load, that reduced which allow shooting more plunging and fatigue less, and the special loads of stripping of copper, which contain small quantities of Plomb and tin, to clean the stripes of the tube, copper remainders left by the shells. The three types of loads are distinguished by marking, initial speed obtained, on the cartridge.

Two great types of shell are assembled on the cartridges, the high-explosive shells and those with balls, commonly called Shrapnel. The first high-explosive shell, the explosive model model 1897, is equipped with a strong steel wall and an minor amount of explosive load (170 grams of blasting powder). It is equipped with a rocket for double purpose OF 22/31, which explodes with the contact or with a maximum delay of 24 seconds. Its evolution, will give the model 1900, with finer wall, weighing only 5,4 kilograms, but in charge of 695 grams of mélinite, whose employment requires the use of a detonator relay to mélinite pulverulent. It uses also new types of rockets exploding with the impact or after this one, the series from percussion the 24/31 (model 1899, model 1899/1915, model 1914 and model 1916), to give him effectiveness against the fortifications. Some of the shells of the type 1900, moreover are equipped with mixture Fumigène, to facilitate the adjustment of the shooting. An aerodynamic screw-locking device, simple plate being fixed on the point of the warhead, will be also used, to give more curve to the trajectory and to achieve masked goals, but its use harmed the precision of the shooting. At the end of war will appear the types 1917 and 1918, of the Dessaleux general, who better shaped will reach ranges of about eleven kilometers.

The shells with balls, them also are two types M and A. the M, of 1897, known as with mixed load, contains 440 grams of blasting powder and 290 spherical balls of twelve grams, out of lead hardened with the Antimoine, the whole surrounded by fine steel walls. It will be practically supplanted by the type has, or with back load, where the load powders lighter (110 grams), instead of being mixed with the steel balls is gathered with the back of the shell. The 261 balls was then projected towards the ground, in a way more effective than with the model Mr. These two shells were modified thereafter for the anti-aircraft use, the shell M giving the M modified 1911, has becoming modified 1917, which used a rocket delay of maximum a forty seconds. Of another shell will be conceived in the course of war, the smoke shell of 1915, which contains in the body of the high-explosive shell, a composition containing Phosphore producing a thick cloud of smoke, during a few minutes, after its detonation, the lighting shell of 1916, based on the shell with ball, whose rocket OF 22/31, caused the ejection of a lighting cartridge and its parachute, which lit then the battle field during approximately forty seconds. The same year appeared the standard incendiary bomb G, which contained in the body of the shell with ball M, six bags filled with a mixture of tarred oakum and phosphorus, the whole fired by an minor amount of blasting powder and a high-sensitive fuse model 1914. More sadly still celebrates, the toxic shells, based on the high-explosive shell, but equipped with an only sufficient load to break the wall and to let gas escape. Always in 1916, engineer André Lefèvre, developed a perforating shell, known as Al, which was made out of very thick cast iron aciérée and was responsible for 285 grams of TNT, fired by a rocket 24/31 Schneider 1916, weighing 7,2 kilograms, it could reach the range of 9500 meters.

Service of the part

In addition to the chief of part which directs the operations, a team of six being useful is necessary to use the gun to the maximum of her possibilities. During the shooting, the team is thus divided:

the gunner takes seat on a seat on the right, vis-a-vis the part, it is responsible for the opening and the closing of the cylinder head and the shooting, but also of the changes of Hausse.
the sitted pointer him on the left, deals with the pointing in site and drift.
the charger behind the pointer, engages the cartridge in the room.
behind the box, three other men work, two providers who supply the apparatus plunger out of shell, the debouchor, bores the vents of the rockets then to him then transmits the shell prepared to the charger.

A team of being useful well trained manages to draw up to 28 blows in one minute, but of such rate cannot be held very a long time, because of need for restocking with shell, but also of generated tiredness and the heating of the tube, in practice constant rate is rather of six blows per minute. If the shooting must continue, one uses initially the ammunition of the trunk of before train, then those contained in the box associated at piece-rates, then the cars box turn over to the level of combat, which directs them towards the deposit of army corps, to be reloaded there, and sends one of the cars box, it has, to supply the part. At the time of a long phase of shooting, it is then established a noria, which supplies the battery of shooting starting from the deposit of army corps, which him is located at a few kilometers behind.

To charge the gun, it was enough to open the rotary cylinder head and to insert the cartridge there, then to close again the cylinder head of a fast movement of the wrist. After having drawn, the recoil of the gun did not involve the mounting behind as in the old models. The mounting of the 75 remained on the spot, but the tube of the gun itself left behind in its housing at a distance 1,20 m, then slipped again into its initial position thanks to a system of hydraulic relaxation. When the tube returned in place, it was enough to open the cylinder head, which ejected to it empty cartouche automatically, then to place some another inside.

The military advantages of this new gun were obvious. The artillerists did not need to jump behind when one drew with the gun, as they were to make it when the mounting moved. By consequence they could more quickly charge the gun which in addition, remained in position, which avoided having to readjust the target with each shooting. The gun of 75 had a rate of approximately 6 blows per minute with a range of 11 km. In critical situation, it could draw up to 20 blows per minute.

Alternatives

One of first derived from the model 1897, the car gun of 75 De Dion Button model 1913 , intended for the anti-aircraft defense with the armies, is an extremely innovative model, with its gun on the platform of a truck, being able to swivel on all the azimuth. It appears however badly adapted, because of a low speed of pointing, absence of an adapted ammunition, and its cost. Only one specimen exists at the entry in war, but groups of let us autocanons are formed dice 1916. In 1918, four hundreds of them, ensures the defense of the French lines against German aviation, it are organized within five anti-aircraft artillery regiments, the 63e, 64e, 65e, 66e and 166e, which has each one four batteries of four autocanons, two companies of projectors and one of balloons of protection. It will be modified in 1934, by the assembly of a central station of direct shooting, and will remain in service, for want of anything better, during the Second world war, 236 of them still serving in March 1940. For the protection of the zones, within the air defense of the territory, one postpones brings into service another type of material, the 75 mm model 1897 on platform model 1915 , this part fixed can be deployed in twenty four hours, the platform makes it possible the tube to be pointed 0 with 75° in site and on an azimuth of 360°. During Years 1930, the speed of the aircraft having become too important, one replaced these mountings, by platforms models 1939, lighter. In April 1940, it remains only one score of them on platform model 1915, and fifteen on platform model 1939.

To renovate, the 75 in its role of field gun, between the two wars, the French Army will try to adapt it to the automobile traction, which starts to supplant, that horse-drawn, during the Années 1930. The absence of suspension and the wheels out of wooden, indeed limit its rate of travel to approximately eight kilometers per hour, beyond that, the vibrations are likely to damage the part. After proposal of Andre Citroen, which proposes a train carrying which places under the gun, during transport, one decides to modify the part it even by modifying the train of bearing, two new versions the 75 appear:

Material of 75 model 1897 modified 1938 , modification to adapt the model 1897, at automobile traction, by the replacement of the original wheels by moulded wheels with pneumatic S full, the brake of demolition is preserved and the increase in the mass to 1,5 tons, returns the operation of the more painful part, there be approximately seven hundred modified specimens in this way, some will be equipped with pressed rims and tires with tire tube.
Material of 75 model 1897 modified 1938-1940 , improvement of the precedent, with tires with tire, and brake tube of demolition replaced by brakes drum in the wheels.

In service

Units equipped with 75 model 1897

In 1897, when the part enters in service, the French Army aligns, forty field artillery regiments, from which most recent were created in 1894. Thereafter, the adoption of the National service three years, their number passes to sixty two. They are divided into three types, the regiments assigned to the Army corps with four groups of batteries, twenty, and those assigned to the Division S which are with three groups, except ten which have in more one fourth group called to horse, which must be detached of the division of cavalry. Each group includes/understands three batteries is a total of 648 batteries of four parts.

The regimental staff includes/understands seventeen men, including three officers and three officers of reserve, with thirteen horses, including eleven of saddle, a van and two Bicyclette S. the state major of group, is even more important to him with twenty and one men, including six officers, it gathers specialists as various as the officer veterinary doctor and that, but also the butcher. He is equipped with an ambulance, of with meat, two vans of luggage and fifteen horses, including eight of saddle. In normal weather, its personnel is affected with the ninth part of the first battery of the group, but in time of war, the unit is gathered in the regimental train.

The battery is the basic unit of French artillery, the adoption of the model 1897, causes its reduction, because of rate of shooting, six to four parts of shooting. This organization becomes official by a ministerial ordinance in 1899, then is fixed by the law of July 24th 1909. Its total staff complement is of three officers and one hundred sixty eight men. The material includes/understands sixteen cars, including four guns, twelve boxes, to which a forging mill and four vans are added. Hundred sixty-eight horses, of which thirty-six of saddle, ensure its mobility. It is subdivided into new group S of parts, ordered each one by a Sergeant, assisted from one or two Brigadier S. With the combat, the five first form the battery of shooting, ordered by the lieutenant of active, the last four form the level of combat directed by the second lieutenant of reserve, however the ninth is gathered most of the time with that of the other batteries, within the regimental train. The thirty horse batteries, differ from it few with a manpower of four officers and one hundred seventy-five men, however to increase the mobility the majority of being useful are assembled on saddle horses, one thus finds two cent-quinze horses, including four twenty-two, in this type of battery.

First actions

The material of 75 model 1897, for the first time is used in operations, in June 1900, during international forwarding against the Boxers. Three batteries are used, in particular at the time of the catch of Beijing on August 13rd, where them effectiveness impresses the feld marchall Von Waldersee, ordering the force expeditionary, which hastens to bring back to its government the superiority of the new French piece of artillery.

Later, in 1912, the Serbia, the Greece and the Bulgaria, which bought the French gun, are opposed first of all to the Turks, at the time of the First war Balkan. The Turkish army, it, is equipped with guns of 77 mm German, which appear very definitely lower. The Second war Balkan, it, sees to be opposed of the 75 mm between them, Bulgaria being turned over against its old allies.

In action during the First World War

In 1914, the France enters in war with four thousand guns of 75 at its disposal. In spite of their lower effectiveness in the context of the trench warfare, they nevertheless will take a determining role during the war, contributing in particular to the stop of German at the time of the Bataille of the Marne in 1914, and to Verdun in 1916. They are been useful by crews of very high competence, a good part of the artillery officers having left universities like Polytechnique. They are one of the main weapons of the French Army and not less than 17.500 guns are built during the war, the ammunition they being produced with more than two hundred million units. The consumption of shell of 75 becomes disproportionate: for example, not less 3,75 million of them is drawn at the time of only March 1916 with Verdun.

France passes through a serious crisis to the end of the year 1914 when the production and stocks of shells, however important, appeared insufficient. One then decides to resort to private industry, in order to increase the day laborer production from twenty to a hundred and thousand shells. Many civil industries are reconverted, and, thanks to female work and with the use of new manufactoring processes, like the realization of shell by machining and not per forging mill, the production increases quickly. In September 1914, eleven thousand shells are produced, one passes to forty six thousand at the beginning of 1915, then to sixty fifteen thousand in June of the same year. But, consequently, the quality of the ammunition declines, more often causing of the burstings and swellings of the tube of the weapon (1 bursting all 3.000 shootings on average, against 1 whole 500.000 in 1914). The situation is such as the command ends up ordering to use the 75 mm only as a last resort. Become colonel, Holy-Claire Deville is in charge of the problem and succeeds in as of September 1915 rectifying the standards of production, thanks to more strict controls. However, quality reaches that of pre-war period never again.

In action during the Second world war

Still largely in service at the beginning the Second world war in the French Army in 1940, with 4.500 parts in stock, and in other forces, it is used as part anti-tank device as opportunity at the time of the last phase of the Bataille of France.

It is employed in the rows of the army of armistice at the time of the combat of the Campagne of Syria.

It is illustrated at the time of the Bataille of El Alamein. At the time of the Battle of Bir Hakeim, in June 1942, the guns of 75 of the brigade of Free French, been useful by the 1 {{er}} RAFFL, is an effective tool of the defense of the oasis. The forces of the Axis lose 51 tanks and a hundred vehicles, for a good part because from the 75.

In the French hands, it is useful then at the time of the Campagne of Tunisia before being replaced by more modern Anglo-American material in 1943; one still punctually finds it in the Guerre of Indo-China.

The Germans, recovering all the material available, use it under the name of FK231 (F), but the shell does not have a great value as a weapon anti-tank device, its initial speed being too weak to worry a T-34 of the Red Army ; the Complexe German militaro-industrialist thus substitutes to him a shell with Hollow-charge.

The mounting does not have enough clearance out of battery to be really effective in this role. Also the tube it went up on that of Pak 38 of 5cm under the denomination of 7,5 Pak 97/98. A tubular Brake of mouth, bored many holes, is brought back.

The heart of the French gun is however too heavy and has a too long retreat for the German frame.

This one misses stability so much so that harms the precision of the shooting. The 7,5 Pak 97/98 is definitively withdrawn from the active service in 1944.

Anecdotes

At the time of the ceremony of establishment of a new president of the French Republic, 21 blows are drawn by 2 guns from 75 mm in front of the esplanade from the Invalides.

See too

the Canon Pak of 75 mm German used between 1942 and 1945
m3, an American tank with a gun of 75.
M4, an American tank with a gun of 75.
M24, an American tank with a gun of 75.
the model 1919
the model 1928
m3 GMC, an American caterpillar tractor armor-plated with a gun of 75.

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