Cutaway model of a high explosive shell for the 7,5cm Le.I.G.18, or the ‘Leichtes Infanteriegeschütz 18’.
The Le.I.G 18 was designed by Rheinmetal in 1927, and different versions were made; With wooden spoked wheels, with rubber tyres, with small steel wheels for the airborne troops and with ski’s for the mountain troops. There were also versions that could be taken apart in different parts to be transported seperately. In total 12.000 Le.I.G 18 guns were produced.
An interesting detail of this gun is the breech mechanism; the breech is fixed and the barrel rotates forward to enable a new cartridge to be loaded, much like a bascule hunting rifle.
The idea behind the infantery gun is to add a light and highly mobile gun to infantery units for direct fire support and defeat enemy field fortifications. Therefore, the infantery gun has a short range, the shells have a low speed and the gun is nearly always suitable for direct fire as well as plunging fire. As the gun is designed for short distance usage only, the barrel is thin walled and short, adding to the light weight of the gun.
The crew serving the gun however are -although infantrymen - nearly allways trained as artillery crew.
The concept of the infantry gun is quite old (google for ‘leather gun’ or ‘leather cannon’), but was revived during WW1 when short range direct and indirect artillery fire in trench warfare was required.
However, during WW2 the concept of the infantry gun became obsolete as it was surpassed by weapons like the mortar, recoilles guns, rocket launchers, grenade launchers and medium calibre automatic guns placed in armoured cars.
The projectile (7,5cm SprGr. für Le.I.G 18) is steel made and has a -characteristic for the Le.i.g 18 projectile- thin driving band. In top of the shell body the ‘mundlochbüchse’ or booster housing is screwed, housing the C98 Np booster, filled with Penthrite (pink) which ignites the main charge of cast FP02 (TNT) in the projectile body. Below the booster housing a small smoke box is placed, used to mark the point of impact for artillery fire observation purposes.
In top of the projectile the ‘Leichte Infanteriegranaten zünder 23 neuer art’ (Le.I.Gr.Z 23 n.a) or ‘light infantry shell fuze 23 new type’ is screwed, a sensitive nose impact fuze with a graze function mechanism and a superquick or 0,15 seconds delay function, so the projectile can penetrate a target before detonating.
The fuze body consits of an upper- (1) , middle- (2) and lower (3) part. In the middle part the centrifugal weights (4) are placed in a circular array, kept in inward position by the band spring (5). In rest (safe) the centrifugal safety segments keep the inertia cilinder with the firing cap (8) seperated from the firing pin (6). After firing the shell, the cetrifugal force rotates the centrifucgal safety elements outward, overriding the band spring. The firing cap and the firing pin can now move towards one another , kept apart only by a light pressure spring. Above the firing pin , the wooden hammer pin (7) is placed , pushing the firing pin downward into the firing cap upon nose impact.
In the lower part (3) of the fuze the collar weight (10) is placed, kept in center position by a sheet matal flange with five fingers bent upward (11). The hole in the collar weight has a chamfered edge which fits a chamfered edge (9) at the base of the inertia cilinder housing the firing cap. If the shell does not hit a target nose on, but grazes the ground, inertia throws the collar ring downward , swinging the inertia weight with the firing cap forward when sliding off the chamfered edge, pushing the firing cap into the firing pin, igniting the fuze.
In the lower part of the fuze the “0,15 sec delay – non delay” mechanism is placed, consisting of a screw (13) that has to be rotated 90 degrees to set delay. The screw has a slot in which a slider (12) - placed in the central flame channel- fits, which is thrown outward by the centrifugal force after firing.
If the screw (13) is rotated, the slot is rotated 90 degrees, preventing the slider (12) from moving outward. A weight with a spring (14) keeps the slider forced inward in rest. If the delay is set and the slider blocks the central flame channel, the flame of the firing cap (8) is rerouted through the green channel, into the pyrotechnic short delay fuze (15), delaying the ignition of the black powder magazine (16) with 0,15 seconds.
In picture 05 one can see a soldier setting delay with the fuze.
The shellcase is brass made and uses the primer C12 n.a (n.a. = neuer art / new type). The shellcase is 89mm long and is filled with five small bags of powder that can be removed (exept for the lower one ) to reduce or increase the range.
Max. range : 3.350 mtrs (3.880 yards).
Vo : 210 mtrs/sec (690 ft/sec).
An interesting movie showing the Le.I.G 18 in action can be found here on you tube :
https://www.youtube.com/watch?v=ZIdgsyF8mEY
Regards, DJH
The Le.I.G 18 was designed by Rheinmetal in 1927, and different versions were made; With wooden spoked wheels, with rubber tyres, with small steel wheels for the airborne troops and with ski’s for the mountain troops. There were also versions that could be taken apart in different parts to be transported seperately. In total 12.000 Le.I.G 18 guns were produced.
An interesting detail of this gun is the breech mechanism; the breech is fixed and the barrel rotates forward to enable a new cartridge to be loaded, much like a bascule hunting rifle.
The idea behind the infantery gun is to add a light and highly mobile gun to infantery units for direct fire support and defeat enemy field fortifications. Therefore, the infantery gun has a short range, the shells have a low speed and the gun is nearly always suitable for direct fire as well as plunging fire. As the gun is designed for short distance usage only, the barrel is thin walled and short, adding to the light weight of the gun.
The crew serving the gun however are -although infantrymen - nearly allways trained as artillery crew.
The concept of the infantry gun is quite old (google for ‘leather gun’ or ‘leather cannon’), but was revived during WW1 when short range direct and indirect artillery fire in trench warfare was required.
However, during WW2 the concept of the infantry gun became obsolete as it was surpassed by weapons like the mortar, recoilles guns, rocket launchers, grenade launchers and medium calibre automatic guns placed in armoured cars.
The projectile (7,5cm SprGr. für Le.I.G 18) is steel made and has a -characteristic for the Le.i.g 18 projectile- thin driving band. In top of the shell body the ‘mundlochbüchse’ or booster housing is screwed, housing the C98 Np booster, filled with Penthrite (pink) which ignites the main charge of cast FP02 (TNT) in the projectile body. Below the booster housing a small smoke box is placed, used to mark the point of impact for artillery fire observation purposes.
In top of the projectile the ‘Leichte Infanteriegranaten zünder 23 neuer art’ (Le.I.Gr.Z 23 n.a) or ‘light infantry shell fuze 23 new type’ is screwed, a sensitive nose impact fuze with a graze function mechanism and a superquick or 0,15 seconds delay function, so the projectile can penetrate a target before detonating.
The fuze body consits of an upper- (1) , middle- (2) and lower (3) part. In the middle part the centrifugal weights (4) are placed in a circular array, kept in inward position by the band spring (5). In rest (safe) the centrifugal safety segments keep the inertia cilinder with the firing cap (8) seperated from the firing pin (6). After firing the shell, the cetrifugal force rotates the centrifucgal safety elements outward, overriding the band spring. The firing cap and the firing pin can now move towards one another , kept apart only by a light pressure spring. Above the firing pin , the wooden hammer pin (7) is placed , pushing the firing pin downward into the firing cap upon nose impact.
In the lower part (3) of the fuze the collar weight (10) is placed, kept in center position by a sheet matal flange with five fingers bent upward (11). The hole in the collar weight has a chamfered edge which fits a chamfered edge (9) at the base of the inertia cilinder housing the firing cap. If the shell does not hit a target nose on, but grazes the ground, inertia throws the collar ring downward , swinging the inertia weight with the firing cap forward when sliding off the chamfered edge, pushing the firing cap into the firing pin, igniting the fuze.
In the lower part of the fuze the “0,15 sec delay – non delay” mechanism is placed, consisting of a screw (13) that has to be rotated 90 degrees to set delay. The screw has a slot in which a slider (12) - placed in the central flame channel- fits, which is thrown outward by the centrifugal force after firing.
If the screw (13) is rotated, the slot is rotated 90 degrees, preventing the slider (12) from moving outward. A weight with a spring (14) keeps the slider forced inward in rest. If the delay is set and the slider blocks the central flame channel, the flame of the firing cap (8) is rerouted through the green channel, into the pyrotechnic short delay fuze (15), delaying the ignition of the black powder magazine (16) with 0,15 seconds.
In picture 05 one can see a soldier setting delay with the fuze.
The shellcase is brass made and uses the primer C12 n.a (n.a. = neuer art / new type). The shellcase is 89mm long and is filled with five small bags of powder that can be removed (exept for the lower one ) to reduce or increase the range.
Max. range : 3.350 mtrs (3.880 yards).
Vo : 210 mtrs/sec (690 ft/sec).
An interesting movie showing the Le.I.G 18 in action can be found here on you tube :
https://www.youtube.com/watch?v=ZIdgsyF8mEY
Regards, DJH
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