New Grenade Designs.
New Grenade Designs
The above graphs are taken from Janes Infantry Weapons 1976. This attributes them to an article in International Defence Review, June 1973.
The shape of the first graph is very interesting, notably the plateau at the start. The thrown range of a grenade drops significantly at a mass of more than 250 gm (c. 9 oz). Making the grenade lighter than this does not significantly increase its throwing range. That oval grenades throw slightly better than spherical is not that surprising. I have often mentioned the importance of sectional density to ballistics.
I have no reason to doubt the data above. If you wish, these experiments could easily be duplicated by throwing suitably-shaped lumps of clay of varied masses.
The second graph shows that a certain model of small grenade has only a slightly smaller effect area than another model four times its mass. The smaller variety is identified as a Dutch NWM V-40, which masses only 120 grams, less than half the “optimal” mass the experiments indicate.
Oddly, very few grenades have been made of around 250 gm mass. Most are considerably heavier, usually being between 450-900 grams (1 to 2lbs). Many of these grenades have an effect area that endangers the thrower if they do not have cover. A reduction in effect and danger area would make many grenades more tactically useful.
One model of grenade that did have the correct mass was the Belgium PRB Nr.423 (M72). This massed 230g yet had a 9.6 metre casualty radius, and was safe at 20 metres. The Nr.423 used a combination of pre-notched wire and pellets to produce a more homogeneous effect sphere.
Large quantities of hand grenades are needed for certain military operations. There are obvious advantages in reducing the mass of grenades if it also increases their throwing range and increases their utility.
I propose two new models of hand grenade, both of which will have a mass of 250 g. Both grenades would use the same fuse, which would have the familiar “pin and lever” mechanism used in many existing designs. The fuse body would include a clip to prevent the ring rattling. The lever might remain attached to the fuse body to avoid tell-tale noises when throwing the grenade.
Once the lever is released an all-ways impact-sensitive mechanism would arm after about one second. If an impact does not detonate the grenade, a self-destruct (SD) mechanism explodes it after three to four seconds. The self-destruct would be redundant, using both an electronic and pyrotechnic system. A similar impact/ SD system is used on the Russian RGN/ RGO grenades. Reportedly, if thrown in a high arc the SD feature can be used to make the RGN/ RGO grenades airburst. The exact timings may need to be adjusted to allow for the greater throwing range of the “Quarter-Kilo”-series grenades.
The delay in arming the impact mechanism negates the usual objections to impact-fusing. If the grenade is dropped soldiers have the same time to get clear as they would for a dropped time-fused design.
The Quarter-Kilo-series fuse would have an optional bounce” mode that delays detonation to half (or three quarters) of a second after impact. This allows the grenades to be bounced off walls or other hard surfaces.
The bottom of the grenade body would have a standard fuse-well so grenades can be fired by demolition systems.
An alternative fuse, offering a more traditional “time-only” mode would be available as an option. Markings on the safety lever/spoon distinguish the fuse type.
There would be two models of Quarter-Kilo-series grenade:
The fragmentation grenade might have a pear-shaped body and the surface would be dimpled for identification by touch. The body would be coyote-brown with a sand-yellow stripe. If practical the fragmentation grenade would behave like a “weeble” or “roly-poly” so that it lands fuse upwards and the majority of its fragments are thrown in an annular pattern. The attached lever may add a measure of drag stabilization and ensure the grenade arrives base first. The utility of self-righting features must be balanced against ease of production and simplicity.
The concussion grenade variant would have a smooth, faceted surface. Body would be charcoal-grey. It would have a higher explosive content than the fragmentation variant, the mass of the fragments being replaced by additional explosive. The concussion grenade will be useful for close-range engagements where fragments may be a hazard to the thrower or comrades. Its higher explosive content also makes it more useful for demolitions. The flat surfaces of the facets allow a small adhesive pad to be attached to one side. This facilitates the use of the concussion grenade as a breaching device. For example, the grenade can be placed next to a door lock, the pin pulled and the self-destruct feature used to detonate the grenade after several seconds. A WW2 manual notes of the No.69 concussion grenade: “In town fighting, if thrown during dry or dusty weather it will raise a cloud of dust to cover movement if no smoke generators are available.”
Several concussion grenades spaced along a length of wood could be use as Bangalore charge.
A further innovation occurs to me. The fragmentation-sleeve of the fragmentation grenade could be an easily removed component, as is already done for some larger grenade designs. Should a soldier with only fragmentation grenades find himself in a situation where using a frag’ would be unsafe, he can easily remove the sleeve and use the rest of the grenade as a small concussion grenade. Usually a fragmentation-sleeve is an addition to make a weapon more lethal. In this case the reverse is the intent. Logically, a “blast-sleeve” of additional explosive could replace the fragmentation-sleeve to create a concussion grenade of full quarter-kilo mass. The blast-sleeve may include alternate fuse-wells for when the grenade is used for demolition purposes. Thus concussion and fragmentation grenades use the same fuse and core, which itself serves as a small concussion grenade when required. The low-mass “core grenades” will be useful for units that carry a lot of gear and only use grenades to help break contact. The core grenade will be dimensioned so that it can be inserted into a vehicle fuel tank. Securing the lever with a rubber band or tape creates a delay mechanism and converts the core grenade in to a useful sabotage device against POL stores.
The capability to join grenades together is currently in vogue, although certain Hungarian and Swiss grenades have offered this for decades. Provision to join sleeves or whole grenades together should be included in the design.
Packing containers for the grenades will be dimensioned so that they can be used to construct “tin-can” booby traps.
These two variants would be complemented by rifle-hand grenades and the M84 Stun Grenade (236 g). A stun grenade using the Quarter-Kilo series fuse is a possibility.
Being the same mass, both grenade types can use the same practice grenade. This is a tubular mass into which a standard firing mechanism can be fitted. An inert, dummy grenade would have only the lever and pin as moving components.
The Quarter-Kilo series grenades should be supplemented by a third munition. In other articles I have covered Ralph Zumbros suggestion of a paperback book-sized claymore mine that can easily fit into standard pouches and pockets. The “sticky book” is a device of similar shape and dimensions. Its main purpose is to provide infantry and other non-specialist personnel with a handy, easy to use, demolition munition.
The sticky book is a box of about 11 x 17 cm. It will probably contain around a pound of explosive and weigh less than a kilo overall. On one of the larger faces is a large patch of adhesive, similar to that used on adhesive rat traps. Each corner has a hole so the charge can be tied to an object if the adhesive cannot be used. Magnets can be screwed into these holes to create a limpet charge. These holes can be used to hang the charge from nails, screws or pegs. At one corner of the munition is a lever and pin mechanism connected to a fuse of around five to seven seconds length. How to use this will be obvious to anyone with basic familiarity with grenades. The pin allows the munition to be triggered by a pull-cord or tripwire. The lever can be utilized as a pressure-release trigger. The munition will also have fuse wells for electric and non-electric detonators, one for each plane.
The sticky book will find numerous applications. It can be stuck to the track or tire of a lightly armoured or unarmoured vehicle to disable it. Fuel caps, fuel tanks, radiators and engine louvres may also be targeted.
A “necklace” of sticky books can be pulled out ahead of a vehicle and detonated with instantaneous fuse or by sympathetic detonation. Spaced along a plank, a Bangalore-type charge can be made to breach barbed wire or other obstacles. Such a plank-charge can be pushed under a vehicle.
The sticky book is of a size and shape that easily fits in the web between the head and foot of a railway line.
Two charges can be attached to the upper ends of an “X-shaped” wooden frame to create a mousehole through a wall. For thicker walls, four or five charges can be spaced across the frame. In addition to these pre-made assemblies, a pattern of individual charges can be stuck directly onto a wall.
Two charges can be connected by a short length of cordage. One charge can be swung over the top of a WAPC wheel so that both charges are draped over the axle. Thrown across the barrel of a tank gun the detonation will probably also damage the sighting optics.
Some of the above design features could also be applied to the proposed mini-more. The two ideas might be combined. A mini-more that can be placed with its shrapnel face towards a surface may serve as a breaching or demolition charge. A mini-more detonated inside an aircraft cockpit or vehicle interior will render it out of action for some time.
An alternate configuration for the sticky book-sized charge might resemble that of a square-sectioned bottle. Both bottle and book configuration charges might be issued. Many of the uses proposed for the sticky book can be met by the bottle bomb. Both would have a label on one side detailing suggested number of charges for various thicknesses of certain materials.
The bottle bomb might be more easily hand-thrown, and thus useful for situations where a more potent explosive charge than the concussion grenade is wanted. Possibly a core grenade screwed into the handle would form the primary ignition system. Applications for the bottle bomb overlap with those of the magnum grenades proposed on another page. The grip section of the bottle bomb can be fitted to mortar bomb warheads. Both the bottle bomb and magbomb are clearly “defensive grenades”, where the user must ensure there is cover between them and the intended target.
The cylindrical Chilean Cardoen-Metalnor grenade has a hollow-charge cavity at its base, increasing its potential as a demolition device. This feature may be considered for the bottle bomb.