Cutaway model of a French WW1 VB (named after the designers Viven and Bessière) rifle grenade.
The VB rifle grenade was introduced with the French army in 1916 and was fired by means of a launching cup, placed over the barrel of a Lebel rifle (see pict 05).
The clever part of the design is that the rifle grenade was launched by using a ball cartridge instead of a launching cartridge by firing the bullet through a central hole in the VB rifle grenade. This is a big advantage over rifle grenades using a seperate launching cartridge which can easily be forgotten to be chambered in the heat of battle, leading to death or serious injury.
A second hole is situsted on the side of the central hole and houses the brass pyrotechnic delay tube, the detonator and the base screw, all placd in a brass pipe. The sheet metal pressed firing pin is fixated below the top part of the pyrotechnic delay tube. On the opposite side the zinc filler plug is placed. A pressed brass transport cap is placed over the top of the fuze and filler plug, preventing the firing pin from damage -or worse- from premature activation. This cap is normally removed before firing, but as it has a hole in top i.w.o. the central hole I assume it can also be fired with the cap in place. On picture 05 one can see however all caps are removed.
The grenade is placed in the launchig cup, upon firing gas presure throws the rifle grenade out. At the same moment the bullet passes through the central hole (picture 03), pushing the firing pin inwards, activating the pyrotechnic fuze. This fuze burns for 5 seconds , after whichh the detonator is activated, exploding the grenade.
The cast projectile body is made from pig iron (crude iron with between 4 to 5% carbon content) which fragments easily as it is brittle.
The VB grenade was very effective and changed French infantery tactics; each company got 16 specially trained VB grenade gunners. This greatly improved offensive and defensive firepower. Another advantage was that the VB Rifle grenade could be fired much further than a handgrenade could be thrown, an important advantage in trench warfare.
Normally, the grenade was launched with the rifle butt placed on the ground; with the rifle placed in an 80 degree angle the VB grenade had a range of 85 meters, with the rifle placed in a 45 degree angle the grenade had a 190 meters range.
To allow for predictable fire, special racks containing one or more lebel rifles were constructed in which the rifles could be placed in marked angles which refered to a specific range, allowing for predictable fire.
On pict 04 one can see the smoke-practice version of the VB grenade. It is filled with smoke composition and has a quickmatch in the place of the detonator. Holes in the pipe around the quickmatch allow the smoke composition to be ignited and the smoke to escape through the hole of the burned down pyrotechnic time fuze. The projectile body is marked in top with a blue paint ring i.w.o the ogive.
Weight VB grenade : 475 gram
Weight explosive charge : 60 gram Cheddite
Complete length : 84 mm
Length grenade body : 65 mm
Diameter grenade body : 50 mm.
The VB grenade has been used by the French army until 1940 when it was declared obsolete.
Regards, DJH
The VB rifle grenade was introduced with the French army in 1916 and was fired by means of a launching cup, placed over the barrel of a Lebel rifle (see pict 05).
The clever part of the design is that the rifle grenade was launched by using a ball cartridge instead of a launching cartridge by firing the bullet through a central hole in the VB rifle grenade. This is a big advantage over rifle grenades using a seperate launching cartridge which can easily be forgotten to be chambered in the heat of battle, leading to death or serious injury.
A second hole is situsted on the side of the central hole and houses the brass pyrotechnic delay tube, the detonator and the base screw, all placd in a brass pipe. The sheet metal pressed firing pin is fixated below the top part of the pyrotechnic delay tube. On the opposite side the zinc filler plug is placed. A pressed brass transport cap is placed over the top of the fuze and filler plug, preventing the firing pin from damage -or worse- from premature activation. This cap is normally removed before firing, but as it has a hole in top i.w.o. the central hole I assume it can also be fired with the cap in place. On picture 05 one can see however all caps are removed.
The grenade is placed in the launchig cup, upon firing gas presure throws the rifle grenade out. At the same moment the bullet passes through the central hole (picture 03), pushing the firing pin inwards, activating the pyrotechnic fuze. This fuze burns for 5 seconds , after whichh the detonator is activated, exploding the grenade.
The cast projectile body is made from pig iron (crude iron with between 4 to 5% carbon content) which fragments easily as it is brittle.
The VB grenade was very effective and changed French infantery tactics; each company got 16 specially trained VB grenade gunners. This greatly improved offensive and defensive firepower. Another advantage was that the VB Rifle grenade could be fired much further than a handgrenade could be thrown, an important advantage in trench warfare.
Normally, the grenade was launched with the rifle butt placed on the ground; with the rifle placed in an 80 degree angle the VB grenade had a range of 85 meters, with the rifle placed in a 45 degree angle the grenade had a 190 meters range.
To allow for predictable fire, special racks containing one or more lebel rifles were constructed in which the rifles could be placed in marked angles which refered to a specific range, allowing for predictable fire.
On pict 04 one can see the smoke-practice version of the VB grenade. It is filled with smoke composition and has a quickmatch in the place of the detonator. Holes in the pipe around the quickmatch allow the smoke composition to be ignited and the smoke to escape through the hole of the burned down pyrotechnic time fuze. The projectile body is marked in top with a blue paint ring i.w.o the ogive.
Weight VB grenade : 475 gram
Weight explosive charge : 60 gram Cheddite
Complete length : 84 mm
Length grenade body : 65 mm
Diameter grenade body : 50 mm.
The VB grenade has been used by the French army until 1940 when it was declared obsolete.
Regards, DJH
