Length : 100mm
Diameter : 58mm
Weight : 375g
Filling : 110 grams, YJ-05, ethylene oxide, energetic nanoparticularised-and-floridated aluminium
Fuze delay : Variable. Default 5secs
Shell : Semi-perforated Kraton polyamide-coated aluminium, tungsten pellet inserts.
Casualty radius:
Kill: 6m
Casualty: 12m
Danger: 30m
Abstract
The LY1002 'Hellsbreath' is an in-service, purpose-built thermobaric hand grenade, designed and built by the Lyran Protectorate. It is known in Lyran service as the 'Hellsbreath' or the 'ten-oh-two'.
Background
While there exist a number of more or less similar hand grenades, the world over, the Lyran Protectorate was not satisfied was the same generic weaponry as the rest of the world. In keeping with the ever-present desire to realise full-spectrum overmatch, Executive Command directed the Protectorate Research and Development Commission to design, develop and manufacture a hand grenade that would optimise combat effectiveness for combat infantrymen.
As part of the development process, several seperate and relevant characteristics of grenades in general were identified and isolated:
1.)Short employment range
2.)Small effective/casualty radius
3.)Delay element/fuze
4.)Shell.
Further to that, hand grenades were determined, by nature, to consist of a body, which contains a filler (normally the explosive charge and/or projectiles) and a fuse, which is the means by which the grenade is made to explode by detonation or ignition.
The aim of the development was to therefore utilize and modify the constituent parts of the grenade to optimize the lethality of each characteristic, to the total combat utility of the package.
Explosive Filler
Perhaps the most important choice for grenade design is the selection of the filler composition. It is, in many respects, the defining feature of a grenade. The selection of the filler for the LY1002 was, as could then be expected, the longest component of the weapon's design process. Conventional (condensed explosive), Fuel-Air and Thermobaric were the three general forms of filler-charge available, and across that spectrum were a whole host of individual explosive mixtures, making the process of explosive selection therefore a very involved one.
A fact well known since ancient times is that generally shrapnel is the major source of lethality for most warheads, as it has an effective radius far greater than blast. Shrapnel is the staple engine of casualty for most modern hand grenades, for that reason. However shrapnel does have its limitations, chief amongst them the limitations of shrapnel penetration of armoured targets. In this regard, blast becomes more useful.
However, if maximum blast is sought, then fuel-air explosives are usually the most effective, and fuel-air explosives generally do not create shrapnel. A fuel-air explosion has two phases: first the gas or aerosol is released to form a cloud which mixes with the air. In the second phase the cloud is detonated, producing an explosion which is much more powerful than the equivalent condensed explosive. However, unlike a condensed explosive, it is unable to split open a casing and convert it into fast-moving anti-personnel shrapnel. So, as a consequence of that, although fuel-air explosives are extremely effective at destroying buildings, they are considerably less useful against other targets.
Thermobaric explosives lie somewhere between pure fuel-air and condensed explosives. A thermobaric explosive can be solid but 'fuel rich', for example such a mix of regular explosive with powdered aluminum or similar material. When it is set off, the thermobaric explosive produces an expanding fireball, with the leading edge containing white-hot aluminum particles which add to the explosive effect as they come into contact with the air and burn.
The following performance-based criteria for fill selection were established:
1. Good fragment driving properties,
2. Enhanced blast properties
3. Good IM characteristics,
4. Evidence of survivability under penetration loading/setback.
Also relevant were ease of training and qualification, and, lastly, but still a factor, was cost of fill in production and installation terms
.
A number of conclusions relevant to selection of an explosive were considered. Most important was with reference to how a grenade is used. Using a grenade is a conscious act for a soldier. Personnel do not snap-fire a grenade. Grenades are employed deliberately, normally against targets in some form of cover. If they were NOT in cover, generally a rifle or direct fireweapon is employed. Blast and overpressure were thus determined to be higher priorities for neutralising hostile forces in cover than had previously been appreciated, especially when used in hand grenade form, rather than, say, tube artillery.
Designers were, from the outset, not married to any given explosive formula, and experimentation and development continued to determine optimum composition, with categories of interest being listed as:
1)Peak pressure
2)Pressure impulse
3)Temperature
4)Fragment velocity
5)Fragment perforations and
6)Heat flux
One explosive fill came out a clear leader, scoring best not only on the blast pressure and blast impulse but also best on fragment velocity and the number of fragment perforations it produced, way outperforming the existing filler in both categories. The explosive composition that generated (at testing on the 4th July, 2004) the highest peak pressure and pressure impulse (23.33psi and 2.23psi/ms respectively) also generated the highest fragment velocity and highest number of fragment perforations (1580m/s and 564). This was up against a peak pressure, pressure impulse, fragment velocity and fragment perforation of 9.91psi, 1.617psi/ms, 1449m/s and 396 respectively for conventional Composition B. While this particular mixture did not feature the highest temperature or highest heat flux, it still performed well in those categories, very comparable to PBXN-109, another baseline composition.
This mixture, YJ-05, designed by Ensign-Bickford Aerospace & Defense, was selected by the Lyran Protectorate for its LY1002 program, on the basis of these results, and also for the US Military's XM1060 40mm rounds.
In usage, the YJ-05 filler drives both the ethylene oxide, and the energetic nanoparticularised-and-floridated aluminium, which is dispersed and rapidly ignites/combusts/detonates. The resultant sustained high pressure wave is phenomenally effective against enemy personnel and structures. The lethality effect results from a thermobaric overpressure blast rather than fragmentation. As a result of the thermobaric reaction, all enemy personnel within the effective radius will suffer lethal effects as opposed to the conventional fragmentation round, which can be halted by such things as heavy clothing or body armour. Body armour will NOT stop the effects of a thermobaric detonation, and the LY1002 consciously seeks to take advantage of this fact. When taken in toto, the thermobaric explosives provide soldiers with a significantly greater probability of killing or incapacitating hostiles within the weapon's effective radius.
Fuse and pin assembly
An aluminium-framed indium-gallium arsenide electronic fuse is fitted to the LY1002, not only so as to ensure the absolute optimum in reliability and consistency, as well as not adding the fuse assembly to the projectiles, also provides several tactically appropriate fusing options. These include variability from 1 second to 10 seconds in delay fuse, and an impact detonation toggle.
For ease of use these options can be selected using just two tumbler-type controls, one to toggle the impact mode, the other to set the time delay option. The Impact dial has the options Impact, Impact + time, and Off. When pulled straight out of the box, the fuses are set to five second delay, and will remain that way unless adjusted. More than one unit has chosen not to adjust at all, but SF units in particular find the function exceedingly useful.
Shell
The LY1002's shell is not dissimilar to a number of other grenade shells. The exterior coating is ribbed for easy grip, and made of non-slip kraton polyamide. The aluminium of the shell is also designed to fracture and add aluminium particulate debris and mass to the ensuing blast wave.
The LY1003 is a reusable/refillable training model of the -1002, made with a reinforced steel shell and a modified fuze, containing a compound intended to simulate the detonation of the grenade.
Carriage
For carriage of the grenades, the Protectorate Research and Development Commission redesigned grenade pouches. Made of a fairly standard xyalane-treated polyester and cotton weave, the pouches are designed to prevent the lever being released (and thus the grenade fuse activated), even if the pin comes loose, while still allowing easy carriage and rapid access. A variety of differing camouflage patterns for the material are available, and the system features easy and modular adaptation to all sorts of load-bearing systems.
Export
An LY1002 is available for NS$25, and DPRs to the LY1002 (and LY1003 with it) are on sale (to approved parties) at NS$10bn. Upon purchase of DPRs, or more than 1,000,000 individual items, approval is granted to the purchasing state to produce the Lyran Arms-patented grenade pouches, without restriction. Purchase requests and enquiries can be lodged through Lyran Arms.
