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  © Michal Derela, 2013 Updated: 23. 11. 2019

120 mm wz. 1878/09/31 and wz. 1878/10/31 field guns

Drawing of 120 mm wz.1878/09/31 gun [Janusz Magnuski] Drawing of 120 mm wz.1878/09/31 gun.
[Janusz Magnuski]

120 mm wz.1878/16 (mle 1878/16) de Bange gun in Polish service in 1920s.
Original 120 mm de Bange wz.1878/16 gun in Polish service in 1920s. Note wedges behind wheels to assist in returing to a position.
120 mm wz.1878 gun in marching order, 3 May 1927, Warsaw. The wedges are carried upon the tail. [NAC 1-P-2865-3]
Armata 120mm wz.1878/09/31
120mm wz.1878/09/31 gun on exercises, evidently in a moment of a shot (a barrel is caught in a partial recoil).
120mm gun wz.1878/09/31
120 mm wz.1878/09/31 gun in a marching order.
A rare photo showing apparently wz.1878/10/31 gun (a shield between wheels), captured by the Germans. A barrel is in a transport position.
120 mm gun, probably wz.1878/10/31, on "roller-skates", with Citroën-Kegresse P14 tractor.
Polish 120mm wz.1878/09/31 gun
120mm gun wz.1878/09/31 with early small solid tires for motorized artillery.
Polish 120mm wz.1878/09/31 gun
Poor quality, but rare view of 120mm gun wz.1878/09/31 in combat position (with early small tires for motorized artillery).
[source 2]
120mm gun wz.1878/09/31 (with Michelin DS tyres) hauled by the C4P tractor, during Zaolzie operation in 1938.

After World War I, Polish Army was equipped with a moderate number of French heavy 120 mm field guns Materiel de 120 Long Mle 1878, known in Poland as armata wz. 1878 (1878 Pattern cannon). It was a successful 19th century design, conceived by Charles de Bange, who was an inventor of a screw breech sealing method, later adopted worldwide. It was still used in France in a big number during World War I, and even in World War II, although it was an antiquated piece already by the time of the Great War due to its rigid gunbed. Reconstructed in Poland in 1930s as wz. 1878/09/31 and wz. 1878/10/31 guns, it changed completely its appearance, and served during World War II in Polish and Finnish armies, remaining in reserve for next twenty years.

Note: letter W indicates external links to relevant Wikipedia articles.


Wz.1878 guns in Poland

The first Polish unit to use wz. 1878 guns was allied General Józef Haller's Blue ArmyW, created in France in 1917. They were used in two Heavy Artillery Regiments - there were 48 of them, in four detachments (two in each regiment; the regiments were also equipped with 105 mm guns and 155 mm howitzers). After World War I, in 1919 the army returned to independent Poland with its equipment.

It seems, that few 120 mm guns were used in line units during the Polish-Soviet warW 1919-1920 – on 1 October 1920 there were 8 guns used in two batteries, and 40 in reserve (one might guess, that they were found not suitable for manoeuvre warfare, typical for that war). After the war, they were used in the 1st Heaviest Artillery Regiment in Warsaw. Apparently some additional guns were acquired from France, because in 1931 there were 54 guns in an inventory. Part of them were a modernized model with a newer barrel - wz.1878/16 (without strengthening rings and with constant rifling instead of progressive one).


Since their barrels were considered as excellent, offered quite good range, had still relatively modern breeches, and Poland had stocks of ammunition for them, it was decided at the outbreak of 1920s and 1930s to modernize the guns. Main problem were antiquated high rigid carriages, with some recoil system, but without recuperators, which had to be pulled back onto a position after each shot. Therefore, it was decided to fit their barrels onto carriages from captured Russian 152 mm howitzers M1909 (obr. 1909 g.) and, in a smaller number, M1910, which were withdrawn from Polish service as non-standard material.

Both howitzers were Schneider designs, manufactured in Russia, and therefore their carriages were similar, single-box-tail, with a hydro-pneumatic recoil brake combined with a recuperator. The M1909 (obr. 1909 g.), originally classified as a fortress howitzer, was very similar to later French 155 mm mle 1917 howitzer, which was Polish standard heavy piece. The heavy field howitzer M1910 (obr. 1910 g.) was a bit lighter and had a shorter barrel. Most notable difference was in a shield: curved to cover wheels in M1909, and straight, narrower, with cut-outs for wheels in M1910. Also a craddle was a bit different, though similar.

The reconstruction was made by the Society of Starachowice Mining Works in Starachowice. Fitting with more modern carriage allowed to increase a maximal rate of fire from 2 to 3 shots per minute, and also increased elevation. The barrel completely changed its appearance and was rotated by 180 degress, so that a breech opened to right side, typical for newer equipment used in Poland. The breech itself was modernized as well and fit to newer primers. Modernized guns were designated wz. 1878/09/31 and wz. 1878/10/31, depending on a carriage type (31 stood for a year of acceptance of modernization).


Usage in Poland in 1930s

The modernized guns started to appear in the 1st Heaviest Artillery Regiment from September 1933, but soon they were removed from this regiment and replaced with 220 mm wz. 32 Škoda mortars[6].

Then, from April 1934, twelve modernized guns were gradually assigned to the 1st Motorized Artillery Regiment (1 Pułk Artylerii Motorowej, 1 pam) in StryjW, which was the only Polish motorized artillery unit. These guns were used in its heavy detachment, replacing 105 mm guns and 155 mm howitzers there. They were towed by Citroën-Kegresse P14 halftrack tractors, then by slightly stronger Polish C4P halftrack tractors. A common problem with such guns was, that wooden unsprung wheels and their bearings were fir for horse traction, and were unsuitable for faster ride. Initially the guns retained original wheels, but were towed on special four-wheeled sprung bogies, so called "roller skates". They had 610 mm diameter wheels, with 70 mm wide rims. A weight of a set was 400 kg. It was little practical, because embarking and disembarking of the gun took several minuts or more, and the roller skates had to be removed in rough terrain. At least 8 guns remained on the roller skates by early 1935. Trying to find best solution, four guns were completed with Polish-developed small steel wheels with full rubber rims, equipped wih significant fenders. Each wheel was sprung independently by twin spiral springs, and the guns equipped with them could have been towed with 28 km/h speed. They were first applied in late 1935 or early 1936. Their drawbacks were: wider track, than the tractors' furrows, and complicated spring mechanism.

Finally, all 12 guns were equipped in 1938 with big steel wheels with Michelin DS pneumatic tires, bought from France. It is not known, if any wz.1878/10/31 guns were used in a motorized artillery on tires as well (there are no photos known so far, except for one photo on "roller skates").

Already in December 1935, equipping the motor artillery with 120 mm cannons was critically assessed by the commander of the 1 pam, Lt. Col. Stanisław Rola-Arciszewski, who was a supporter of the 100 mm howitzers. He raised the issue of not very common ammunition, requiring sending from central depots, which reduced the advantages of their mobility. His opinion, that 120 mm cannons were more suitable for horse-drawn artillery seems accurate - except that the most suitable equipment for motorized heavy artillery from among the available guns should have been 105 mm wz. 29 cannons, offering much longer range (15.5 km), or 155 mm wz.17 howitzers with slightly lower range than 120 mm guns (max. 11.2 km, practical 8 km), but firing much heavier shells. In the case of 120 mm guns, the maximum range of 12.4 km could have been obtained only with selected wz. 1915 grenades, which had even slightly smaller explosive weight than 105 mm shells (heavier 120 mm grenades wz. 1914 could only be used to fire at distances up to 10 km). The advantages of 120 mm motorized cannons were described as greater flexibility of projectile trajectory (thanks to wide elevation range and use of separately loaded ammunition), and already advanced works upon their motorization problem. Therefore, the Head of the Artillery Department postulated in January 1936 to motorize eight batteries, i.e. almost all 120 mm guns. It should be noted however, that 105 mm guns wz. 29 could have been adapted to use Michelin DS wheels as well, as later trials would have demonstrated. As for the 100 mm wz. 14/19P howitzers, their maximum range was smaller, than of 155 mm howitzers, and they fired lighter projectiles, hence they would not be the right gun for the heavy artillery (these howitzers were later also found in the 1.pam, but not as a heavy artillery, but for motor cavalry brigades). It should be noted, that according to General Miller's report, 120 mm cannons were scheduled to be replaced by 155 mm howitzers in the motorized artillery at the turn of January / February 1940.

In 1935, most of remaining horse-drawn guns on wooden wheels were assigned to the 1st Heavy Artillery Regiment (1 Pułk Artylerii Ciężkiej, 1 pac) in ModlinW. Both regiments were peacetime practice units only, and were meant to create smaller mobilized units in case of war.

In September 1938 both detachments of the 1st Motorized Artillery Regiment were included into "Śląsk" Independent Operational Group, formed to seize Czech ZaolzieW province, inhabited by Polish majority and taken by force by the Czechs after World War I. Two batteries of 120 mm guns on DS wheels took part. The province was taken without fighting, and after a parade before Gen. Bortnowski, the Operational Group was disbanded in December 1938.

In 1935 there were 32 complete guns wz.1878/09/31 and 6 guns wz.1878/10/31 in the inventory; in addition there were 4 guns wz.1878/09/31 lacking full equipment – 42 altogether. In 1939, before World War II, there were still 32 and 6 guns in the inventory[1]. According to General Miller's report on artillery from June 1939, there were 43 guns in total, including 36 in line and 7 in reserve. Average condition of barrels was estimated at 79,7% (enough for 4500 shots). There were around 1700 rounds per gun available in total (for 36 guns), i.e. 42 calculated units of fire (40 rounds). As a result, the ammunition stock for these guns was very big, however 120 mm ammunition was little widespread and had to be delivered from central depots.

In 1935 there were also 13 old wz.1878 barrels reported[7], and in 1938, 5 barrels. It might be noted, that sometimes Russian old 152 mm wz.1877 guns are mistaken for 120 mm wz.1878 guns (at least 12 of them were captured in Modlin fortress by the Germans).

Combat use in 1939

The 120 mm cannons were used during the war in three Heavy Artillery Detachments (Polish: dywizjon artylerii ciężkiej, dac), assigned to C-in-C reserve, each with 12 guns in three batteries. There were two horse-drawn detachments, Nos. 46 and 47, and one motorized detachment No. 6. Heavy Artillery Detachments Nos. 46 and 47 were mobilized by the 1st Heavy Artillery Regiment on 6 and 7 September 1939 respectively, and took part in Warsaw defenceW. No.6 detachment was mobilized by the 1st Motorized Artillery Regiment, and fought in eastern Poland.

The 6th Motorized Heavy Artillery Detachment (6. dywizjon artylerii motorowej ciężki, 6. damc) was mobilized by 5 September 1939, its commander was Major Stanisław Łukawiecki. According to plans, it was assigned to Army "Łódź", but due to destroyed track and difficult general situation, it did not reach its destination, but was directed to an area around Lublin, changing its subordination several times. On 12 September the detachment departed for ZamośćW, and on the next day, was assigned to the Southern Front of Gen. SosnkowskiW and directed southwards, towards Lviv. On 13 September, the 1st battery, resting by Zamość – Tomaszów LubelskiW road near KomarówW, was attacked by German tanks of the 2nd Panzer Division, and lost three guns and most cars (the last gun of the battery separated and joined later "Dubno" Operational Group in LutskW). The combat of the 1st battery's soldiers saved remaining batteries, which opened fire and managed to withdraw north, and also a headquarters of "Kraków" Army in BarchaczówW.

An abandoned 120mm gun wz.1878/09/31 of the 1st battery of the 6.damc on Zamość – Tomaszów Lubelski road, with the C4P tractor visible (the barrel is in transport position)
An abandoned 120mm gun wz.1878/09/31, probably the same location, as above (the barrel in transport position)
An abandoned 120mm gun wz.1878/09/31 with the C4P tractor of the 6.dam, September 1939, probably after the last combat (a barrel in a transport position)
Another abandoned wz.1878/09/31 gun with the C4P tractor (the barrel in combat position)
120mm gun wz.1878/09/31 gun with original wooden wheels and, behind it, wz.1878/10/31 gun with Finnish tires, in Hämeenlinna Artillery Museum. See full-size photo at wikimedia.org (author: Balcer, cc-by-sa-3.0 licence).

On 14 September remaining two batteries arrived at ChełmW, and were included into a combined 13th Infantry Brigade of Colonel Szalewicz, which was being organized there from broken up units. The guns were deployed in non-typical way, as anti-tank defence on approaches to the town, in spite of lack of special sights. On 17 September the 3rd Battery indeed repelled several enemy tanks with direct fire, destroying one tank, near Serebryszcze, north-east of Chełm. On 19 September the detachment departed for HrubieszówW with a Polish combined division of Gen. Jerzy Wołkowiecki, and next night to ŁaszczówW village. Last fights of the 6th Detachment took place in area of villages and forests south-east of Zamość. At Łaszczów, on 21 September both batteries helped the Polish infantry of the 45th Infantry Regiment (13th Infantry Brigade) to repel an attack of the German infantry supported with tanks. Two tanks were abandoned, and reportedly used by the motorized artillery troops on the next day against the Germans, causing a confusion among them. On 22 September the detachment was in action in Jarczów – Jurów villages area. It was next assigned to the 86th Infantry Regiment (19th Infantry Brigade) and at night took positions at PodlodówW village.

A whole day 23 September the detachment supported Polish troops of the 86th Regiment in a heavy combat at WierszczycaW. The Germans, supported by the 2nd Panzer Division, destroyed Polish 44th Regiment and Colonel Ocetkiewicz's infantry group, and the combined division was disbanded. German artillery caused losses among the detachment troops; its commander and 3rd Battery commander were injured. The 6th Artillery Detachment tried to withdraw from encirclement with the 13th Infantry Brigade, but it proved impossible with heavy equipment. Therefore, at night 23/24 September the guns and tractors were destroyed by the crews, and remaining artillery troops withdrew on 7 trucks and 4 jeeps. Finally, the rest of the unit was surrounded on 25 September by German and Soviet units, which had invaded Poland over a week earlier, and the detachment was disbanded. Part of troops managed to break home, part were captured by the Soviets.

Combat track of the 6. damc proved a value of modernized guns, and also of motorized artillery, which offered a good mobility. Unfortunately, it was one of few Polish motorized artillery units.

The 46th Heavy Artillery Detachment (46. dac) completed its mobilization at Rybitwy village near Modlin on 6 September 1939. Its commander was Cpt. Stanisław Kozłowski. Soon the detachment was subordinated to Warsaw Defence HQ (DOW), and it moved to Warsaw. On 7 September it took its positions in Praga eastern district. The 1st battery entered action on 8 September, bombarding Skaryszew. On 9 September the remaining two batteries supported defence of Ochota district against German first attempt of Panzer assault. In following days the 46th detachment took active part in Warsaw defence, shooting at different targets and changing positions. It suffered some losses as well, mostly from air attacks. On 18 September all four guns of the 1st battery were lost due to air attacks and counter battery fire. The battery was next recreated, armed with 155 mm wz.17 howitzers.

Due to lacks of 120 mm ammunition in besieged Warsaw, starting from the third week of the campaign the detachment fired less frequently. Probably towards the end of fighting 120 mm guns were changed to more typical pieces, possibly 100 mm wz.14/19 howitzers. Finally, on 27 September Warsaw surrendered and the detachment was ordered to gather its equipment in Warsaw CitadelW. The commander was awarderd with Virtuti Militari 5th class order for the campaign, several soldiers got other decorations. Among the killed was the 2nd battery commander, Lt Józef Plewa-Plewiński.

The 47th Heavy Artillery Detachment (47. dac) completed its mobilization at Nowy Modlin village near Modlin on 7 September 1939. The commander was Maj. Michał Kubicki. Initially the detachment was subordinated to Operational Group of Gen. Juliusz Zulauf, defending Dębe – Zegrze sector, north of Warsaw. On 8 September the detachment took positions in forests near NieporętW. Its 3rd battery entered action that day, and other two batteries on the following day, bombarding the enemy on norther direction, among others on the Narew river crossing near RyniaW (German 217th Infantry Division). On 12 September positions of the 3rd battery near Nieporęt were under direct German attack, firing point-blank, the guns were even abandoned, but were next recaptured. On the next day, the detachment still bombarded the enemy near DębeW and Rynia.

At night 13/14 September the 47th detachment withdrew to Warsaw and came under Warsaw Defence HQ, taking positions in the western sector of defence. During following days it supported Polish defenders there. Facing lacks of ammunition, on 19-20 September the detachment was rearmed with 100 mm wz.14/19 howitzers at Bem's Fort, and the rest of 120 mm ammunition was handed over to the 46th dac. On 27 September Warsaw surrendered and the detachment was ordered to gather its equipment in Warsaw Citadel. The commander was awarderd with Virtuti Militari 5th class order for the campaign, several soldiers received other decorations.

Usage in Finland

24 guns wz.1878/09/31, including some wz.1878/10/31, captured by the Germans, were sold to Finland in October 1940. They were used against the Soviet Union during the Continuation War (1941 - 1944) in four Heavy Artillery Battalions. In Finland both modernized guns were simply known as 120 K/78-31. Finland also used original French Mle 1878 guns, and had a stock of ammunition for them. According to Jaeger Platoon website, among Finnish soldiers these guns gained reputation as durable and good cannons, but the primer chamber proved a weak part of the weapon and recoil system wasn’t always reliable, especially in winter. Two guns were lost in 1944. After WW2 the rest were equipped with sponge rubber tyres and remained in reserve until late 1960s. Later some guns were assigned to museum purposes, and some remained in stores until these days (one was bought to a private collection in Poland in 2007, another for the Ground Forces Museum in Bydgoszcz in 2013).

You can read more of original Mle 1878 guns and Finnish 120 K/78-31 guns on our friend Jaeger Platoon site and see more photos on Wikimedia Commons.


wz.1878/16 wz.1878/09/31
Caliber: 120 mm 120 mm
Maximum range: 12 400 m (?) 12 400 m
Practical range: ? 10 000 m[2]
Elevation:-17 +30°0 +41°30'
Traverse:? 5°20' (95/1000)
Muzzle velocity: 613 m/s 585-613 m/s
Shell weight: 18.2 - 20 kg 18.8 - 20.3 kg
Max. rate of fire: 2 rounds/min 3 rounds/min
Crew: 1+8 1+8
Length (combat position): ? 6970 mm
Length (marching position): ?9850 mm (with a limber)
Barrel length: 3250 mm (L/27) 3250 mm (L/27)
Rifling length: 2442 mm ?2442 mm
Width:? 1910 mm
Track width:? 1535 mm (outer edge)
Wheel diameter: ?1330 mm (wooden wheels)
Wheel rim width: ?150 mm (wooden wheels)
Limber's wheel diameter: ?1330 mm
Limber's wheel rim width: ?70 mm
Height of a line of fire: ?1435 mm (wooden wheels)
/ 1470 mm (Michelin DS tires)
Combat weight: 2784 kg 3143 kg
Transport weight: 3500 kg 3501 kg
Limber weight: ? 358 kg
Barrel weight: 1200 kg1280 kg
Breech weight: ? kg35 kg
120 mm wz.1878/09/31 gun before the war, in combat position.

Specifications of wz.1878/10/31 gun were similar to wz.1878/09/31 gun, only dimensions differed and it was slightly lighter (pre-war manual did not even give specifications of that gun). Both guns had either a barrel wz.1878 with 17 strengthening rings and progressive rifling (7° at a muzzle) or wz.1878/16 without rings and with constant rifling (7°) - both had 36 groves, right-hand twist. A suggested rate of fire was ¾ round per minute; maximum: 3 rpm for 2 minutes or 1.5–2 rpm for 5 minutes or 1 rpm for 15 minutes (these times could be doubled with a reduced charge). A crew were 8 gunners and a commander.

Modernized guns were towed by eight horses, using a limber put under a tail (a lower spade was folding forward in this purpose). In transport position, a barrel was withdrawn. In motorized artillery, it was towed by special variants of halftrack tractors with a hook arranged in a similar way to a fifth-wheel mount.

There were no caissons for heavy artillery adopted in Poland by the war, and their ammunition had to be carried in horse wagons and dumped behind guns. There was given a figure of 28 wagons with 12 rounds each per a battery (7 wagons with 84 rounds in total per gun - possibly it was only 80, i.e. two calculated units of fire), but actual number could be different. In the motorized artillery, the ammunition was initially transported in big one-axle semi-trailers for 80 rounds, towed by same Citroen-Kegresse P14 halftrack tractors (four men rode on the trailer, another four on the tractor, the commander in a driver's cab). They were adaapted French semi-trailer caissons for 155 mm howitzers, bu they were not regarded as successful and were withdrawn in late 1930s. Right before World War II, the ammunition was carried in wz. 34 halftrack trucks.

A point of quick identification of 120 mm cannons among other Polish artillery pieces with Schneider gunbed is the barrel, slimmer at a muzzle and longer, than in 152/155 mm howitzers, without strenghtening collar. In a rear transport position, the barrel was slightly longer, than its craddle. Besides, like in original Model 1909 howitzers, the shield in wz.1878/09/31 guns was more gently curved, than in 155 mm howitzers, and had no hood above the barrel on the inside of the shield. Also, it had gunsights window in the shield opening downwards, while in 155 mm howitzer it was opening to a side.

120 mm wz.1878/09/31 gun ammo
120 mm ammunition: HE grenade wz.1914 (steel) and HE grenade wz.1915 (cast steel).
Head color indicated explosive type: yellow - TNT, green - melinite.[3]

Ammunition used in Poland:
  Round weight without fuzeexplosive weight
HE grenade wz.1914 (steel)19.55 – 21.05 kg (average 20.3 kg)approx. 4.34 kg
HE grenade wz.1915 (cast steel)18.05 – 19.55 kg (average 18.8 kg) approx. 2 kg

The ammunition was of a split type, separately loaded. A propellant was in silk bags. The charge system consisted of packages, that could be removed from the bag to get lower range. There were two kinds of charges: 000 charge, which could be reduced to charges 00 and 0, and 0 charge, which could be reduced to charges 1, 2, 3 (lower numbers were stronger). The grenades had different body colours, depending on marks (yellow for wz.1914 and black for wz.1915 grenades), while head colour depended on an explosive type. Only wz.1915 shells marked with black band on a head could be used with the strongest charge 000 to obtain maximum range.

Drawing of 120 mm wz.1878/09/31 gun from a military manual Drawing of 120 mm wz.1878/09/31 gun from a military manual.


Polish 120 mm wz.1897 cannon, December 1927.
[NAC 1-W-1215-2]
120 mm wz.1897/09/31 cannon with small wheels, in transport position.
Abandoned 120 mm wz.1878/09/31 cannon with C4P tractor and 37 mm wz.36 Bofors AT gun.Abandoned 120 mm wz.1878/09/31 cannon with C4P tractor. Note a motorcycle on the tractor.

1. Andrzej Konstankiewicz: Broń strzelecka i sprzęt artyleryjski formacji polskich i Wojska Polskiego w latach 1914-1939, Lublin, 2003, ISBN 83-227-1944-2
2. Konrad Nowicki: Artyleria polska oczami jej dowódcy, in "Poligon" Nr.2(37)/2013
3. Regulamin artylerii. Opis i utrzymywanie sprzętu i amunicji 120 mm armaty wz. 1878/09/31, Warsaw 1938 (military manual)
4. Piotr Zarzycki: 1 Pułk Artylerii Motorowej, Pruszków: Ajaks, 1992
5. Jędrzej Korbal, Paweł Janicki: Armaty kal. 120 mm wz. 1878/09/31 i 1878/10/31, series: Wielki Leksykon Uzbrojenia Wrzesień 1939, vol.44, Warsaw, 2014
6. Jędrzej Korbal: Motorowa artyleria ciężka Wojska Polskiego. Część I, in: "Technika Wojskowa Historia" Nr. 5/2017
7. Karol Rudy: Nie zdążyli - o modernizacji artylerii polowej Wojska Polskiego w latach 1936-1939, in "Poligon" Nr. 1(42)/2014


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