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Rocket HEAT 83mm M8 Blindicide

pzgr40

Well-Known Member
Premium Member
Cutaway model of a “Rocket HEAT 83mm M8” anti-tank rocket.
This rocket was used in the RL-83 “Blindicide” ( Blinde= tank, icide= killer), designed in the 1950’s by the Belgium Mecar company, as a follow up / improvement of the American M20 B1 3,5 Inch (88,9 mm) Bazooka.
The main difference / improvement over the 3,5 inch Bazooka is the rocket motor ignition mechanism. The Bazooka motor had two electric wires which had to be connected to two connection pegs, which took time. The Blindicide uses a firing pin / ignition cartridge mechanism (pict. 04) to ignite the rocket motor, which greatly improves the firing speed of the weapon.
The Swiss army used the weapon under the name “8,3 cm RaketenRohr RR-58”
The RR-80 was an improved version with a night aiming system. The Swiss army had a total of 20.000 RR’s in service.
A derivate of the RL-83 was the RLC-83, a shortened version of the RL-83, which however fired an improved rocket only.
Another derivate was the RL-100, a 100mm version of the RL-83.

Several types of rockets were available; HEAT, HE (anti personel), Illumination, Smoke and Incendiary.

The warhead is made of 1mm thick pressed sheet aluminium, roll crimped together. A red copper cone is placed inside the warhead. On top of the warhead, an inertia activated impact nose fuze is placed. The firing pin (1) of this fuze has a tungsten nose with a grip pattern to ensure detonation even when hitting a target under very low angles.
The base of the warhead is crimped in a machined aluminium receiver, which also acts as a connection piece to the rocket motor.
The explosive charge behind the cone is a two piece PETN/wax charge; a small lower charge around the main detonator, and the large charge around the cone.


The Rocket motor is an aluminium pipe, screwed to the receiver in top, and a venturi bushing screwed into the base of the pipe. The venturi bushing houses six venturi holes, placed around the firing pin served ignition cartridge in the centre of the bushing.
Three of the six venturi holes (every second one) have an angled side machined to the same side of the venturi hole. This is done to induce spin to the rocket.
Note that the top of the Venturi holes have a steel insert piece where the venture hole is at its narrowest. This is done as aluminium would simply melt away, resulting in poor shot accuracy.
Nine sets of fins are riveted to the base of the motor.
Connected to the top of the venturi bushing is a v shaped grid with fine holes, which ensures the venturi holes do not get blocked by broken off pieces of burning powder sticks.
The motor houses 7 powder sticks , 12mm dia. with a 7mm dia hole, 173mm long.

The nose impact fuze (pict. 05):
The firing pin (1) cannot reach the duplex detonator (2) as the balls (3) that fall in the recess in the firing pin and rest on the inner housing (4) are locked inward by the inertia safety ring (5). The ring is kept in upper position by a spring (6). A double zig zag pattern is machined into the outside of the inner housing on which two radial placed pins protruding on the inside of the inertia safety ring fit. In rest, the inertia safety ring rests in forward position. Upon firing, inertia sets the safety ring back, riding down the fine zig zag pattern and the spring; when the velocity is constant the spring pushes the inertia safety ring forward again, it is however stopped by a lock in the forward movement (see pict.06) of the zig zag pattern. The locking balls will fall away, releasing the firing pin. Now the only thing keeping the firing pin away from the firing cap of the duplex detonator is the firing pin spring (7). On impact, the firing pin is hammered into the firing cap of the duplex detonator, exploding the detonator, either the inner housing to which the duplex detonator is screwed moves forward into the detonator (inertia).
The flame of this detonator is led down into the main detonator through the opened hole in top of the detonator, placed below the lower safety cap mechanism.

Lower safety cap mechanism,
This mechanism is placed in the top of the cone. The safety cap exists of an aluminium cap placed over a brass pipe. A double zig zag pattern (pict.03, 06) is machined into the outside of the pipe in which a radial placed pin on the inside of the aluminium cap fits. Below the cap –which closes the flame hole- a spring is placed with a small cap in the base. In rest, the pin rests in the fine zig zag pattern. Upon firing, inertia moves the cap backward, enabling it to ride up the zig zag pattern upward as inertia decreases, pushed upward by the spring; The safety cap, the spring and the small cap at the base of the spring are thrown forward into the cone, opening the flame hole of the main detonator.
In picture 03, the safety cap is placed in a position of just being released, to allow a sight on the parts inside.

Calibre : 83 mm.
Length grenade : 598 mm.
Weight complete rocket : 1,6 kg.
Weight warhead : 500 grams.
Type of explosive : PETN/wax 90/10

Effective range : 400 mtrs.
Max range : 900 mtrs.
Vo : 100 mtrs/sec.
Penetration : 300 mm rolled homogenous armour or 1000 mm concrete @ 90 degrees impact angle.
Rate of fire : 6 rounds per minute.

The RL-83 Blindicide was used by the following countries:

Bangladesh (ret.)
Belgium (ret.)
Burundi (in use)
Israel (ret.)
Mexico (in use 2011)
Rwanda (via France)
Switzerland (ret.)
Netherlands (ret.)

It must be noted that the rocket warhead bears a great resemblance in build-up and design to the Energa Rifle grenade.


Regards, DJH
 

Attachments

  • 01 - Rock HEAT 83 mm M8 cutaway side.JPG
    01 - Rock HEAT 83 mm M8 cutaway side.JPG
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  • 02 - Rock HEAT 83mm M8 backside.JPG
    02 - Rock HEAT 83mm M8 backside.JPG
    72.8 KB · Views: 48
  • 03 - Rock HEAT 83mm M8 warhead.JPG
    03 - Rock HEAT 83mm M8 warhead.JPG
    101.8 KB · Views: 44
  • 04 - Rock HEAT 83mm M8 venturis.JPG
    04 - Rock HEAT 83mm M8 venturis.JPG
    155.5 KB · Views: 40
  • 05 - Rock HEAT 83mm M8 nose fuze.JPG
    05 - Rock HEAT 83mm M8 nose fuze.JPG
    64.8 KB · Views: 36
  • 06 - Zig-zag pattern safety mechanism.JPG
    06 - Zig-zag pattern safety mechanism.JPG
    205 KB · Views: 31
  • Blindicide.jpg
    Blindicide.jpg
    121.6 KB · Views: 31
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