What's the safest way to carry and throw marble sized high-explosive grenades?

Question

Pull the context and count to three sentences

Let's imagine an army has created a kind of explosive similar to grenades, but much smaller in size while maintaining a good chunk of offensive output.

Known simply as "flakes", you can hold a good 8-12 in one hand, and due to their higher numbers, you can target a much wider area, such as big, open-field battles.

They work like a mix of incendiary, suppressing¹ and concussion grenades, doing the most physical damage by the sheer explosive force, then ejecting a hot, incendiary liquid in its vicinity, potentially igniting covers and frightening even more anyone who heard and saw the explosions².

My question is : How can I make these explosives safe for the grenadier?

So first, let's talk about harm capacity : Flakes are known to be really dangerous to anyone under a 1 meter (~3.3ft) in radius, combusting with a powerful invented chemical (either powder or liquid). But also remember there is a small incendiary left-over, which is prone to expand and force a tactical retreat to anyone standing near in the minute after the throw. We don't really want them exploding near us too much so, more at a good distance to have some time to adapt to the battlefield.

The technology to make it safer can go as high as today's technology. As far as I am aware, modern civil explosive devices use a remote detonator, like for instance professional firework shows and building destruction companies, but in the case of grenades it's more often controlled by chemical fuses triggered by a lever you pull³ : after you pull the lever, a small hammer is thrown full force towards a spark-inducing plate, igniting the fuse.

Disregarding the fuse reduced length due to the tiny size, the problem with modern timed grenade system is that, wellie... You'd need to pull the pins of every flake, which could be quite an hassle given you have 8 times more. Moreover, I want them to be thrown in groups, kind of like a shotgun shoot many pellets at once, and the above point prevent this. Therefore, and as you probably guessed it : how can I control when the grenade becomes dangerous is the main issue to me and the reason I ask here.

Since I've thought a little through the matter, I know you might also be interested in something which could be easily forgotten : How to ensure you don't lose a flake while throwing them. Indeed, when you have a big handful of tiny grenades in your bare hand, it's easy to slip one of them. I decided at the time of writing to put them inside a big shepherd sling, then spin it vertically in formation and horizontally when alone, and finally reload by just grabbing a bunch of flakes from a pouch. It's a little bit "rustic", yes, but I don't wish to use firearms for that matter, including grenade launchers. However, if there's a more appropriate way of sending the flakes with your ignition technic (excluding grenade launchers), you can consider it as an annex, bonus question. Still, remember this is only secondary and not the main topic here, and if you do decide to extend on this, that flakes must be delivered to the enemy in groups.

Final tusk of interest : these grenades are carried by explosive specialists, so expect them to carry quite a few of them in their backpacks. Also note that they work with other soldier units, so the solution of having them being heavily armoured and fireproof is nice, but not a solution for their friend next to them.

So how can you increase the average number of days since last accident from 0 to a lot higher and comforting level for the flake grenadiers?

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^{1 : By "suppressing", I mean the noise, multiple impacts and such are capable to deter the opposing side's morale and frighten out anyone out of cover.}

^{2 : They aren't fragmentation grenades, because, well the shrapnels are too light to have enough kinetic energy to make meaningful damage ^^.}

^{3 : There are also impact type grenades, which explode... On impact, but I don't know exactly how they work (I guess there's a "spark machine" in them, but it's just a guess), so I'm a little bit left out on it.}

Answer 1

If the flakes were time delayed and individually activated by a pull string, they could come bundled in groups with each group of pull strings braided together and forming a loop. The slings would have hooks or clips at the ends of the sling pouch. The grenadier would reach in his satchel to grab a pre-made group of flakes, load the group of flakes in the pouch, attach the string loop to the pouch hook and use the sling as one normally would.

Assuming the resistance of the strings pulling was low then this might not have any effect on accuracy that's not able to be overcome with training.

To increase safety the flake bundles could have the string loop securely taped to the body of the group. The grenadier breaks this tape to disengage that safety then hooks the string and throws it with the sling, similar to a modern day solider pulling the pin before he releases the spoon to activate it.

Answer 2

The only sensible way I can think of to deploy such things would be a cluster munition patterned after a stick grenade (See https://en.wikipedia.org/wiki/Stielhandgranate). The central "stick" would contain a standard fuse and a pyrotechnic charge that both disperses the "flakes" surrounding the stick and triggers their fuses so that they detonate a moment later.

Controlling when the cluster grenade detonates can either be done by an adjustable fuse or by the old fashioned "cooking off" technique of pulling the pin but not throwing the grenade immediately (which is highly dangerous, of course).

Answer 3

Never carry them loose

As much as possible, grenadiers would avoid working directly with a naked flake, unless performing a task that calls for directly manipulating them one at a time (e.g. setting a booby-trap that calls for a naked flake, filling a container, etc).

They would not be transported as if they were marbles, loose in a bag. That's asking for trouble. They would be snugly fitted in custom carrying cases for transport. Most ways to use them would involve custom deployment equipment designed to keep the flakes secure as part of their function.

Shoot them from a grenade launcher

Look at the size of a 50 caliber bullet. Specifically at the diameter of the base. That's about marble-sized. In other words, 50-cal gun barrels are about the right size to take custom engineered ammunition delivering a flake in a sabot. This turns any fifty-caliber firearm into a grenade launcher.

This, of course, requires careful engineering of the sabot to keep the flake isolated enough that firing the round won't blow up the flake in the barrel. In fact the flakes may be designed so the round firing is what arms them (say by jostling the internals just right to bring the arming mechanism into place). This would also make them harder to accidentally set off.

Such ammunition would be bulky enough to mitigate many of the problems you're asking about.

This may be difficult to engineer, but existing grenade launchers can already fire high explosives without blowing up the wielder, so it doesn't seem that far-fetched.

Answer 4

It really sounds to me as if you are throwing White Phosphorous marbles around!

This can work very well as offensive weapons, mainly in an incendiary and anti-personnel role.

Take a blob of White, cover it in a liquid that is even more pyrophoric. Something like a bit of NaK.
Put this devil-drop in a frangible glass sphere.
For storage and transport, the capsules are carried in an airtight, soft rubber sheath that both physically shields it as protects it from air in the event of accidental breakage.

To use in combat, just eject the capsule from it carrier, and gently throw at the enemy. It will break on contact with a hard surface, exposing the pyrophoric contents to air, which promptly causes it to splatter and ignite with immense heat and toxic fumes.

If your capsules are manufactured to sufficient precision, you can even use a device like a paintball gun to shoot them. Just >>>don't<<< have a firing malfunction that breaks the capsule in the barrel!

Oh, your actual question is "My question is : How can I make these explosives safe for the grenadier?"...
Ummmm... next question please?

Answer 5

You want an explosive that's low sensitivity- either a secondary or tertiary explosive. Essentially you want an explosive you could hit with a hammer, burn or otherwise abuse and not do anything, but when properly set off, go boom.

If you had a mechanically or magnetically initiated detonator, kept from going off by switchable magnets - switching the magnet off would disconnect it from whatever is holding it in place, and start the count-down.

Combine that with something like a revolver's speedloader - you twist the top of the 'carrier' which turns off the magnets holding the flakes in place. Demagnatisation lets reed switches in the flakes close, which arms the detonation mechanism. You can then either have a timer, some secondary mechanism for starting detonation on launch from the carrier (say little pins that come out when the flakes are launched), or some microelectronic system.

Answer 6

I think you were getting close with the idea of a shepherds sling. Instead, perhaps a Staff Sling.

Lets start with your Flake carrying system. Lets make each grenadelette a marble sized ball of nastiness containing a very small radio receiver and detonator on the side of a wad of the explosive/incendiary goop. It will not detonate without the appropriate signal. Pack a fist sized lump of these into a net bag that has a radio signal separation seam (or seams) so that the grenadelettes can separate after leaving the sling but before hitting the target area. The launcher can control this timing for a greater or lesser spread depending on desired outcome.

Now for the sling. It's a staff sling. they were used for many things, up to and including throwing old crockery type grenades Yours, however, is not just a stick and some string. You staff will have the following features: It is the arming device and the radio transmitter for net bag separation and detonation. When you load the bag of grenadelettes, it keys the detonation frequency to that staff alone. When you swing the staff and launch the net will separate in 3 seconds unless you trigger it sooner and the marbles go five seconds later unless you trigger it sooner or later. The handle of the staff will have 2 buttons that have to be held while performing the launch motion. Lift a finger off the first and the bag separates, lift off the second and the grenadelettes go boom. If you hold the detonation button you delay the boom as long as you like, allowing you to seed an area and wait for the enemy to get into a good place to die.

A staff sling is easy to use, and with practice you can get pretty precise with one. As a bonus, your grande guy has a staff for close quarters, and he can also throw things from regular grenades, to rocks, to water balloons at the enemy

Answer 7

Have each flake contain a radio frequency (RF) device. Each grenadier also has a RF device. Whenever the flakes are near the grenadier's RF device they will not detonate, but once they are at least a specified distance from the grenadier's RF device the flakes explode.

A similar type of system has been proposed to prevent unauthorized people from taking fire arms from law enforcement officers and using them against the officers.

Answer 8

Magic Magnets - Crazy enough to work...?

Since you don't want these things SHOT, and you want to be able to trigger them safely, potentially many at a time, with a reasonable range (yet close), how about a magnetic trigger in a throwing stick? This is close to your sling idea, but with a dedicated but relatively low-tech lightweight tool for activating the grenades and simultaneously giving leverage.

The idea would be that the grenades are attracted to magnets (metal casings, fuses, whatever). But three magnets in a very specific arrangement will prime the fuse, then REMOVING the magnet will activate it. This allows your grenades to be activated ONLY when placed in the perfect proximity to the right arrangement of magnets.

Now you carry a throwing device like a lacrosse stick/atlatl/jai alai cesta with seven (or however many you want) magnetic pockets on it. The grenades drop into these pockets, are held firmly into place, and the triggers are primed by the correct configuration of magnets. In/on the stick is a trigger that is slightly tricky to push/squeeze, and this pulls the internal magnets away from the grenades as you sling them at the enemy. Obviously, this would require some training to do safely, but it beats having a handful of live grenades in your hand, and will be silent, while getting you better range than trying to toss a handful of marbles.

You can still have the ability to throw individual grenades, either by plucking them off the stick individually, or having a plate with a magnetic spot (capped) on their uniform or have a ring that can be touched to the grenade to activate it. In those scenarios, the grenade is held in place until you're ready to throw it (hopefully not that long).

A suicide vest version of this would include an electromagnet that activated all the munitions, then released dozens (hundreds?) of these at once with a repulsive electromagnetic field scattering munitions in all directions akin to the typhoon ball-bearing shooter from Deus Ex. It MIGHT not be suicidal, but this would be really dangerous to use if you wanted to live, so limit this to kamikaze tactics. A vest like this could be an adaptation of the storage vest for your regular grenadier, making capturing your grenadier a really risky proposition.

The same priming mechanism could be used to arm grenades inside any kind of grenade launcher you might want, either by permanent magnets or electromagnets, so your throwable munition would be equally standardized to a wide range of potential grenade launchers, including an electrically triggered caseless grenade launcher where the launching charge detonation and the priming charge are simultaneous. Such a system with low-velocity grenades could be made cheaply, so a multi-barrel launcher working much like a cheap firework (paper barrels, etc.) could be deployed as an offensive or defensive (booby trap) weapon. If a cheap remotely triggered launcher fails, so what?

You may want a second device with four magnets that disarms the grenades, so the grenade you decide NOT to throw still has a way to be disarmed. Perhaps a color change for each state the grenade is in would be helpful as well (green= not armed/yellow= primed/red= armed/black= disarmed).

But grenadiers were considered elite troops because you had to have a certain reckless courage to voluntarily use hand-delivered explosives as a weapon.

Answer 9

Lets make a two stage fusing system:

Stage 1 is the transport container they come in. So long as they are in the container they will not detonate. Your choice whether they are again safe if put back into the container.

Stage 2 is they contain a small multi-axis accelerometer. When the accelerometer senses a two second period where the acceleration remains below 1 m/s it arms (Edit: Remember, gravity. The accelerometer will be sensing the local gravity--they are arming from being in free fall), it then detonates once acceleration returns to at least 5 m/s for a period of 1/2 second. (Note that these values might need to be revised for different worlds.)

If you drop a flake it does not experience the 2 seconds of low gravity, it does not arm and thus does not explode when it lands. A collision with a minor object in the air does not set it off, the acceleration must be sustained--it only goes off when it comes to rest, but it goes off soon enough after that to make it hard to get away.

Answer 10

The only way that I can see of making flake grenades safe is to have a proximity safety system. Flakes are stored with a small, low-powered transmitter. When removed from the vicinity of the transmitter - say five metres - they are armed on a time delay, and then detonate a couple of seconds later.

All members of a team would have identical transmitters.

That way, a dropped flake won't accidentally blow up team members... but leaving a bunch in a trench as you leave and enemies arrive will give them a nasty surprise.

Answer 11

Rely on C4 explosives

I'm honestly surprised nobody mentioned C4 earlier, since it's the most stable explosive ever invented and it can only be practically triggered by a detonator. The hardest challenge with designing a powerful grenade relying on C4 is to develop a reliable trigger to delay the explosion until the grenadier launches the grenade where it needs to go.

Provide the grenadier with a grenade launcher, develop a grenade detonator so the grenade arms itself after being launched from the grenade launcher and detonates after a pre-determined amount of time has passed (several seconds). This way the grenade is inert and safe until it's properly applied by the grenadier.

https://en.wikipedia.org/wiki/C-4_(explosive)

Answer 12

Solid state

I propose mini solid state circuits as triggers.

One solution would be to put Hall effect sensors in the circuitry, and store the flakes in magnetic containers. As long as the marbles are in the container, they are inactivated. However, remove them from the magnetic field, they activate. The process of removal from the magnetic field could also charge internal battery/capacitors to power the circuitry and provide for a spark detonation. Maybe shake them in the magnetic field before removal? In storage, they could be kept very low powered, not enough for detonation.

If used as a thermobaric device (see below) the removal from the magnetic field could also cause local heating in the flakes (eddy currents) sufficient to pre-heat the gases.

This weakness may be eliminated by designs where the fuel is preheated well above its ignition temperature, so that its cooling during its dispersion still results in a minimal ignition delay on mixing. The continual combustion of the outer layer of fuel molecules as they come into contact with the air, generates additional heat which maintains the temperature of the interior of the fireball, and thus sustains the detonation.[10]

GPS as detonators

GPS circuitry has been reduced to the microchip level in such devices as smart phones and cameras. Once activated by removing then from the magnetic field, they could be field programmed to explode only when they reached certain GPS co-ordinates. Outside of these co-ordinates, they would be harmless.

Hive mind

There is no reason that every single flake should be identical. These flakes are used in congregate scenarios. Only a few need to be trigger units. They could send out an RF signal that detonates the 'slave' units. All of the flakes work in co-ordination with each other, but each one could have a specialized function. They share one intelligence.

Air fuel explosion

if they contain pressurized gas, then the trigger mechanism could just chemically burst the exterior shell, releasing the very explosive gas into the atmosphere. Given that the flakes are dispersed over a wide area, the air fuel thermobaric mixture would also cover a wide area.

They are, however, considerably more destructive when used against field fortifications such as foxholes, tunnels, bunkers, and caves—partly due to the sustained blast wave and partly by consuming the oxygen inside.

Also

According to a U.S. Central Intelligence Agency study,[15] "the effect of an FAE explosion within confined spaces is immense. Those near the ignition point are obliterated. Those at the fringe are likely to suffer many internal, and thus invisible injuries, including burst eardrums and crushed inner ear organs, severe concussions, ruptured lungs and internal organs, and possibly blindness." Another Defense Intelligence Agency document speculates that, because the "shock and pressure waves cause minimal damage to brain tissue ... it is possible that victims of FAEs are not rendered unconscious by the blast, but instead suffer for several seconds or minutes while they suffocate".[16]

Detonated all at once by 'trigger' flakes, the explosion shock wave would be greater than that of just a single flake. The air fuel explosion would raise temperatures to incendiary levels, igniting everything in the vicinity, and as a secondary effect, consuming all of the oxygen. It would not be a kinetic impact weapon, but a blast wave weapon followed by an incendiary weapon followed by an asphyxiation weapon.

By using them not as a point weapon but as a dispersed weapon, it enhances their functionality as multiple small units rather than one large unit. It would be destruction by a thousand cuts, instead of one big knife.

Launch method

If these flakes were kept in the magnetic canister, the entire canister could be attached to a lanyard, swung around to gain momentum, and then a trigger mechanism would open the can, dispersing them in mid-arc of the swing. Aiming would be a problem, but they are wide-area weapons anyway. Close counts.

Answer 13

Put them in shotgun cartridges and fire them from a shotgun.

This idea is basically a very convenient version of a grenade launcher. With numerous variants of the shotgun you have lots of ready made options of how to carry and fire them, including fully automatic shotguns and/or with high capacity drum magazines for sustained firing.

You can also build the cartridge to protect the tiny grenade from accidental detonation. Considerations could include protection against accidental detonation:

• from mishandling - perhaps a hard casing to protect against crushing forces (eg stood upon and driven over)
• while being fired/launched by using less powder to soften the jolt of being accelerated, albeit at the expense of range
• by using longer barrels to compensate for using less powder
• by encasing the grenade in lead to increase its weight, giving longer range for a given muzzle velocity, and/or providing higher inertial mass to slow acceleration to protect again launch jolt

Answer 14

So, you are looking for a binary  explosive. Something perfectly safe to carry around in two separate pouches.  I would use some combo of long pole with a semi-curved cup on the end. Sort of cross between a Atl-Atl and a Jailai...Hi-Li, IDK how to spell it.  

The cup contains your 2nd activation ingredient. Pour the marble like part 1's in the cup, contact between the them plus a few seconds and they are active, Throw them with a long pole gives you the ability to throw them a hundred yard or more without much skill or effort. The grenadier has always had extra inherent risk, so he is away from the main party by whatever margin a cup full of these bad boys needs in case he is taken out mid throw.

All the ones unmixed are fine even if he get blown to bits cause only a few worst case will land in a small curved cup on a long pole.