FoW: Mortars and Grenade Launchers Obrona Narodowa (National Defence)

Following up from the post that I did on the heavy machine gun support platoons that Poland's National Defence force was equipped with, its time to take a look at what small provision of mortars and grenade launchers they were given.

Often termed the poor mans artillery Poland could barely even afford to give its National Defence any. However, ongoing financial crisis of the 30's notwithstanding they were able to provide their National Defence with at least a token provision.

Polish Obrona Narodowa Granatnik wz.36 Section

Poland had only one version of the medium mortar, and that was a license built version of the French Brandt-Stokes 8cm  M27/31 in Polish service termed the 8cm wz.31. It was a simple but effective and highly influential design that was licensed by over a dozen countries. 905 of these mortars were produced by the outbreak of the war of which 150 had been produced in France.

The Obrona Narodowa practising with their 8cm wz.31 mortar

It consisted of a smoothbore tube attached to a base plate that served to absorb the recoil of launching the projectiles and a lightweight bipod that carried the aiming mechanism. The mortar could be disassembled into three loads and had a basic crew of three men although an entire mortar team consisted of seven. When a mortar projectile was dropped into the tube it would strike the bottom of the tube. The impact sensitive primer would make contact with the firing pin and detonate firing the projectile back out of the tube. The mortars could fire about 20 rounds per minute and were typically equipped with four types of projectile. Light projectiles wz.30, which would weigh 3.25kg, heavy projectiles wz.31, weighing 6.9kg, multi purpose grenades wz.AR27 and smoke projectiles.

A detailed illustration of the License produced Brandt-Stokes 8cm wz.31

After Poland regained its independence in 1918 the experiences of the First World War highlighted the need for the front line troops to have a supporting weapon that had greater range than a hand thrown grenade but could cover the distance up to the minimum range of the mortars.

In the early days the former German Granatenwerfer 16 and French VB (Vivien-Bessieres) Rifle Grenades found a lot of favour but by the end of the 20's they had become obsolete and a need for a new weapon became pressing. 

a WIP battalion support page with the Granatnik Section details on it.

Work on a new grenade launcher was began at the Central Artillery School in Torun. The primary criteria for a new design was set at being lightweight, compact dimensions, simple construction and with a range up to 400m. Major Roman Jarzabkiewicz developed a prototype with a fixed 45 degree angled barrel with a range between 150-400m. Tests were carried out in Torun in November 1929. Whilst showing a collection of design flaws the prototype still outperformed the other foreign competitors such as the Italian 38mm and 50mm Breda grenade launchers.

Granatnik Section Command Team

The next stage of development was undertaken in the Institute of Armament Material Research in Warsaw where in 1931 three more prototypes were constructed. They were passed over to the Infantry Training Centre for field trials on the back of which 412 copies were manufactured and handed over to the infantry in February 1933 and titled as Granatnik wz.30

A single Granatnik 46mm wz.36 team

The military still highlighted a small number of defects, the most serious being that the range finding would drift after each shot due to a faulty fixing of the sighting spirit level, a jammed gas regulators, impractical folding and unfolding of the weapon and a faulty trigger system. Finally the operators submitted complaints that the baseplate was too small to provide adequate support to the weapon when firing.

A rear view of the other Granatnik 46mm wz.36 team

The Institute of Armament Material Research continued to develop the weapon and provided a number of revised prototypes for testing. Eight models in four different types. After further field trials the final development of the weapon occurred with it subsequently reaching production as the Granatnik wz.36. This model was deemed so successful that all other projects were discontinued.

The Granatnik Section supply and transport wagon

Production of the Granatnik wz.36 took place between 1936-1939 at United Fabryka Maszyn i Wagonow L. Zieleniewski and Fitzner-Gamper SA in Warsaw. By August 1939 just under 3,500 had been produced and turned over to the armed forces.

Another view of the same wagon

The 36 calibre 46mm stromotor weapon threw an 8.6kg projectile between 100 and 800m. Mounted on top of the barrel was a cylindrical gas regulator by means of which it was possible to adjust the range. A part of the powder gas would escape through a triangular hole in the barrel, the size of which could be adjusted by means of an adjustment ring. In this way the total range of the projectile could be controlled by releasing more or less gas, thereby controlling the pressure in the barrel.

 A museum example of the Granatnik 46mm wz.36

The sighting mechanism was a simple bow tie sighting mechanism mounted on the muzzle bead and a frame sight which was mounted on the gas regulator. In addition the weapon had a spirit level. Firing was conducted using a trigger mechanism situated on the foot of the grenade launcher which enabled the granatnik to be operated from an horizontal position.

An illustration of the Granatnik 46mm wz.36 with one of its projectiles

The Granatnik wz.36 had a crew of four people, the operator, the aimer and two loaders. Several types of projectile were provided to the Granatnik operators, mostly they were Fragmentation grenades wz.35, Smoke grenades wz.35 and training grenades wz.35. At a pinch older grenades from the previous Granatnik wz.30 could also be used and these were Fragmentation wz.30, Phosphate wz.30, Smoke wz.33 and Training wz.33 grenades.

An old photograph of the original Granatnik wz.30 prototype

The different types of Obrona Narodowa battalions had different provisions of mortars and grenade launchers supplied.

The Obrona Narodowa Mortar Team with its single 8cm Wz.31 team, command team and transport wagon

On establishment levels the Type I battalions were supposed to be provided with a single mortar although it is unlikely that they ever received any before hostilities commenced.

A rear view of the same mortar and command teams

The Type II, III and IV battalions each had a single 8cm wz.31 team provided. In the Type II and III battalions this was as a constituent element in the battalion support platoon that also held the HMG's whilst in the Type IV battalions this was as a team in its own right.

A closer look at the mortar team

A rear view of the mortar team

The Type S battalions were the exception to all of this and were provided with two mortars held in two sections in a battalion support platoon held at battalion level.

Supplies of the Granatnik wz.36 Grenade Launcher was a little easier to provide though. Each of the Rifle Companies in the Type II and Type III battalions had an attached Grenade Launcher section attached each provided with two grenade launchers. 

The modelling for all of this was relatively simple. The 8cm wz.31 Mortar is a standard Battlefront Mortar whilst the Granatnik 46mm wz.36 is only produced in 15mm by one manufacturer, and that's True North Miniatures now owned and produced by Old Glory. The command team is a couple of Peter Pigs Spanish Civil War Carlist Requetes with head swaps. All of the actual mortar teams are Peter Pig's French Motorised Troops with the obligatory head swaps and finally the wagon was provided by Museum Miniatures.

The paint schemes have been explained to death so I wont bore you with it all again...

...and that is, as they say gentlemen, that!

Thats the main support weapons for the Obrona Narodowa battalions dealt with. Now all that is left is the weird, wild and whacky troop types such as the extremely rare artillery pieces and anti tank guns, the sappers and the reconnaissance troops... but they are other stories for other times.

Fix Bayonets!

Remember: NOBODY loves a bayonet like a Pole!