Thursday, 30 June 2016

Comms-crabs.


In the late 20th century special reconnaissance missions would normally be performed by small parties of highly trained men. In the TS-era the same mission is more commonly performed by a collection of diverse robotic systems.

A reconnaissance/ surveillance force will usually contain a variety of systems. Some of these systems such as surveillance dust, surveillance fluff, bumblebots, robo-roaches, snakebots and birdbots have been described on other pages.

One of the drawbacks of using small robotic systems is that they are limited to broadcasting in the microwave range. The systems are physically too small to use antenna suitable for longer radio wavelengths. Such microwave transmissions are often limited to line of sight use since microwaves cannot pass around hills or mountains like longer radiowaves can. These relatively low power transmissions are often limited in range too. In populated fifth-wave urban areas this may not be a problem since there are abundant signal boost and relay systems designed to facilitate the operation of wearable computing systems. In abandoned or rural areas buildings and other terrain features may have a significant effect.

Often it is not practical for a reconnaissance system to transmit a continuous, real-time feed. Transmissions are often highly directional short duration bursts.

Due to these practicalities a reconnaissance force will include at least one relay centre. Such a system collects transmissions from reconnaissance systems and passes them on using its more sophisticated broadcast capabilities. One form of relay system in common use is known as a “comms-crab”.

The comms-crab is a small cybershell about the size of a small dog (SM -4). It has four short, stocky legs. Very little detail of the crab will be visible since it is covered with a tangle of varicloth strips. The crab often looks like a bush or patch of forest floor. The crab includes a number of satellite robot systems. This include a repair cyberswarm, utility robo-roaches, a mecho-gecko and a snakebot. The snakebot is of the variety that has graspers at each end and can be used as a manipulative limb by the comms-crab. It is also used as a periscope and as an auxiliary monopole antenna.

At the top of the comms-crab is a folding parabolic antenna. This is primarily used for satellite communications but can also be directed to communicate with high flying aircraft. It can be repositioned to transmit to lower receiving stations.  

Comms-crabs can climb tree trunks to attain better broadcast positions. They are not so adept at climbing rockfaces or narrow trees. In such a situation the comms-crab will attach its satcom antenna to a snakebot or mecho-gecko and send it to climb as high as possible. A hardwire controls the satellite robot and feeds transmissions to the antenna.

Alternately the comms-crab can use HF/shortwave transmissions. HF transmissions can have a global range since shortwaves reflect from the ionosphere. Unfortunately this requires an antenna that takes several minutes to deploy or recover. A HF antenna is a T-shaped construction of wire that may be tens of metres across. The comms-crab deploys this using three small helibots; one at the centre and one at each end. The helibots are designed so their systems minimize interference with the antenna’s performance. If possible the terminal helibots will anchor themselves to a high point. Robo-roaches are used to adjust the antenna.

The comms-crab has a secondary SIGINT role, monitoring and recording local transmissions.  

The comms-crab's main defence is its ability to hide. The legs can be used for digging but it is more common that existing hollows or animal burrows are used. Comms-crabs are also likely to hide in the high boughs of trees. A comms-crab may have several hiding places some distance from the areas from which it broadcasts.

There are many models of comms-crab in service with various nations and organizations. Variants optimized for operation in various environments exist. The basic design is also highly adaptable. A system deployed in an urban environment may be fitted with legs suited to climbing walls, or a unit uses in a desert may be fitted with solar-powered cooling systems.

If enemy surveillance is suspected security detachments may be sent on “crab-hunts”. Ideally a crab is to be captured before it can broadcast its collected reports. Examination of the memory banks may indicate how much the enemy may know. The crab’s hiding abilities make such operations highly challenging. A crab may incorporate a thermite self-destruct charge which it will activate if it is likely to be captured and is not quickly disabled.

Thursday, 16 June 2016

Acoustic Location.


Before the widespread use of radar a number of other means for detecting enemy aircraft were tried. Direct observation of aircraft was only possible during daylight and if clouds and other conditions permitted. An alternate approach was to use devices that could locate an aircraft by its engine noise.



From the First World War and up until the mid-1940s most militaries fielded some form of acoustic locating device. These ranged from relatively portable devices (below) to building-sized concrete sound mirrors (above). Using such devices it was possible to hear an aircraft in flight and establish a relative bearing. With multiple devices an aircraft’s position could be triangulated. While these devices worked the speed of aircraft meant that engine noise only provided a few minutes of warning.





The availability of radar and the use of supersonic aircraft meant that acoustic locators rapidly became obsolete.
In the TS era radar is not as effective as it has been in earlier decades. Various measures are employed to counter radar detection. Military aircraft and UAVs have radar absorbent coatings and are designed for small radar cross-sections (RCS). Not needing to carry pilots or crew many UAVs are quite small to start with, further decreasing RCS. Radar and lidar are effectively line of sight systems so many aircraft use low level flight so terrain conceals them. Electronic warfare can jam or deceive radars and there are weapon systems that can destroy or disable detected radar emitters.
Many military fliers in the TS era operate at subsonic speeds. Some are too small for sustained supersonic flight. For observation platforms high speed would be counter-productive. Many aircraft or cybershells fly at low altitudes where the denser air makes high-speed flight too turbulent.
Advances in electronics and computing have produced a whole new generation of compact and more capable acoustic locators. Most military vehicles and cybershells that use audio pickups include some form of acoustic location software. These can detect, locate and to some extent identify nearby aircraft even when they are concealed by terrain or atmospheric conditions. Acoustic locators have other uses too. They can be used to locate the source of gunfire or the location of artillery positions. Rescue workers use them to locate distress cries or whistles. Outdoorsmen use them to locate animals.
Acoustic location is a TS-era capability that should not be overlooked. Whilst the devices used for this have improved the system is still subject to the same limits. They will not detect supersonic aircraft until after they have passed. Depending on their speed, subsonic aircraft may only be a few minutes away when detected. Most gunshots will only be located after the bullet has reached its target.
As a rule of thumb, treat the speed of sound as 375 yards/sec. This will vary with temperature and air pressure and whether this variation is significant will depend on the scenario. Dedicated TS-era acoustic locating devices include pressure and temperature sensors and automatically compensate for these parameters. A simpler system such as acoustic locating software in a wearable computer may not automatically allow for the fact that the user is now in the polar region of Mars and give less accurate information.

Tuesday, 14 June 2016

20mm Micromissiles and Rounds.

        The 20mm micromissile owes some of its ancestry to an early 21st century South African weapon. The designers of the PAW-20 Neopup had the inspired idea of mounting 20mm cannon shells in a grenade gun casing. The resulting round had a flatter trajectory and higher velocity than larger calibre grenade guns. This resulted in a higher component of kinetic penetration against a target. A 40x46mm grenade would generally explode against a wall or windscreen. The 20mm would penetrate and explode on the other side. On the downside, recoil from the weapon was rather heavy, slowing down follow-up shots.

        Two technological advances were to destined to transform this weapon system. The first was more compact new explosives that allowed for a lighter warhead without compromising target effect. The second was the economical production of high quality miniature rocket motors. The combination of these two things produced a 20mm projectile with light recoil and an improved performance. The micromissile was mounted in a conventional polymer casing and fired like a conventional shell at a velocity of only a few hundred metres per second. A short distance from the muzzle the rocket motor is ignited, accelerating the missile and imparting spin stabilization. Miniature homing and stabilization systems were to make these projectiles even more potent weapons.
        With battlesuits and cybershells commonly used in late 21
st
century conflicts the 20mm micromissile proves a useful weapon against a large variety of targets.
        The standard launcher for the 20mm micromissile resembles a large-bore box or drum loaded shotgun. Launchers designed to be mounted on SMGs or rifles resembled double-barrelled shotguns. It was not long before shotgun-like rounds for the 20mm micromissile launchers began to make an appearance. This was a logical development given that 20mm is just slightly greater than 10 gauge. Compared to the 12 gauge shotshell the new 20mm rounds offered an increase in capacity. Rounds made for a 20mm could not be fired in a 12 gauge so dedicated military rounds could be made in 20mm with the knowledge that they could not be fired in civilian weapons. On the other hand, it was still possible to fire 12 gauge and 10 gauge rounds from the 20mm by changing the barrel or fitting shells with an adaptor band.


        A typical 20mm assault launcher rather resembles a PPSh-41. It takes a drum or box magazine and has a barrel about a foot long. A double-barrelled launcher designed to be mounted on other weapons is also produced and often a pair of these may be fitted together. Such launchers may be fitted with a grip or stock to produce a weapon that looks like a sawn-off shotgun. A variant of police armgun combines an electolaser with four 20mm barrels. These may be loaded with a variety of LLW loads and a homing anti-personnel micromissile.

Weapon
 Damage
 Acc
 Range
 Weight
 RoF
 Shots
 ST
 Bulk
 Rcl
Assault launcher         10.6
 
  14 (3)  11†
  -5
 
Canister round.   2d-1 pi   3  40/800   -/2.16 x 13      
    1
20mm Micromissile   6d pi++
  1
  1000
  0.2
  3
 
 3
  
 
  2

        The development of both micromissiles and shotshells for the 20mm greatly extended its versatility. The 20mm was capable of providing both lethal and less-lethal firepower.

        Typical rounds for the 20mm are:-

Micromissiles: Guns (Gyroc) (DX-4, or most other Guns at -4)
        Military 20mm micromissiles have a velocity of 400 yards/sec. LLW loadings may be designed for lower flight speeds.

SAPHEI. A number of warhead types are possible in micromissile format. Hollow-charge warheads are regarded as an unnecessary complication in such a small calibre. The warhead most commonly used is classed as a “Semi-Armoured Piercing High-Explosive-Incendiary” which is versatile against a large variety of targets.
6dx2 pi ++ linked 2d+1 [2d] cr ex.


Nanodrug/Biochemical /Chemical. (NBC) A 20mm rocket or shell can hold 1 dose of a nanodrug, biochemical or chemical agent. This will cover 1 hex radius. Lasts 300 seconds divided by windspeed in mph. Being of a low capacity 20mm rounds are seldom used for screening agents such as smoke or prism.


Nanoburn. 20mm rounds are too small to carry a cyberswarm. They may be used to carry one dose of nanoburn. See TS 3e: p.158 for nanoburn effects.


Solids: TP (Training/Practice) microrockets have neither guidance systems nor explosive (some do create a flash as they impact the target). They are blue-coloured so troops call them “blues” or “inerts”. TP rounds may also have reduced fuel rocket motors for firing ranges where distance is limited. Inert rockets can still be used as potent anti-personnel weapons or cause damage to objects they are fired at.
        Police departments use inerts as a high stopping power round to take down dangerous aggressors. Such police rounds may be guided. They may also have fast burn rocket motors to limit their range and increase close range effect.

        TP: 6d pi++ Non-homing. Other stats as standard although maximum range may be reduced.
        Police Solid: 8d(0.5) pi++ Usually guided. Other stats as standard although maximum range may be reduced. May be programmed to plunge into the ground if it overshoots its intended target.

Ferret-20 Chemical Round. The Ferret-20 can be fired to penetrate through a window pane, windscreen door or light wall. It will then eject its cargo of chemical inside a room. It is equivalent to the 20
th century “Ferret-12” rounds but has the advantage of larger capacity, better penetration and a smart guidance and fusing system that can allow for the barrier offering greater or lesser resistance than was expected. It can also be used against targets in the open by being set to airburst. Construction is mainly polymer to minimize fragmentation risks. Ferret-20 is usually used to deliver Riot gas. Riot gas has a 4-yard radius cloud lasting 20 seconds.
Riot Gas:
Any living being within the cloud who breathes the gas must make a HT-4 roll to resist every second. If the roll fails, they are nauseated [p. B428] for as long as they remain in the cloud. If it fails by 5 or more, they will become violently ill, retching [p. B429] for as long as they remain in the cloud. After leaving it, they will be nauseated for minutes equal to their margin of failure.

        For other fillings treat as an MBC round.
Ferret-20 4d pi++ May be programmed to self-destruct if it overshoots intended target. LC3


Shockroc. Shockroc is a less-lethal round fired at a relatively modest velocity. Speed 170 yards/sec. Range is 150 yards. As it approaches its target it opens out into a cross shape, slowing the round down (hence the alternate name of “Shockstar”). On impact the shockroc releases an electrical charge through its arms, producing effects similar to an electrical stun-gun or taser. Shockrocs are homing and can be programmed to plunge into the ground without discharging if they overshoot their intended target. The projectile sensor records and transmits time-stamped images of the target for evidence.
        A hit from a Shocroc inflicts minimal Damage (1d-3 pi-). The target must make a HT-5 roll or be knocked down and paralyzed. See Nonlethal Electrical Damage [p. B432]. An afflicted victim remains incapacitated for 5 seconds and cannot intentionally remove the projectile during this time. They continue to suffer the weapon's effects for (20 - HT) seconds after the current switches off (minimum one second). After that, they may roll against HT each second to recover, at a penalty equal of -5. Note that a stunner's electric current may start a fire if the victim is covered in flammable liquid.
Shocroc MagPlus is intended for large animals or similarly tenacious targets. As for Shocroc but delivers an 8 second discharge and requires a HT-10 roll.


Tangler Micromissile. Affects a single target at ST12. Can be made guided, homing etc. May be programmed to plunge into the ground if it overshoots its intended target. Rules as TS 3e: p.159

Non-rocket Ammunition:
Guns (Shotgun) (DX-4 or most other Guns at -2)

        Non-rocket rounds for 20mm micromissile launchers are generally called “shells” or “slugs”, depending on type.

Canister: The 20mm equivalent of a shotshell, the canister is a close range lethal round containing two sizes of buckshot mixed with birdshot. This load is effective against unarmoured targets and useful against small, fast-moving targets such as reconnaissance minbots. Against better armoured targets it is still effective against vulnerable parts and the distraction can buy enough time to allow a unit to bring heavier weapons into action.

   Damage   Acc   Range   RoF   Rcl
20mm Canister   2d-1 pi
  3
 40/800
  n x 13
  1
 

Breeching Round. This is a cylinder of soft but dense polymer. It is used to destroy door locks and hinges with minimal risk to the firer or occupants of the room. Fired against living targets it counts as a large-calibre frangible round.

 Damage   Acc   Range   RoF   Rcl
Breeching Round 5d(0.5) pi++
  3
 50/600
 n
  3

Gelshot. A composite projectile formed from polymer and a sponge-like synthetic. The gelshot is a less lethal kinetic energy impact round. It should not be fired at the head. Weapon AI may be programmed to prevent the user aiming at the head when gelshots are loaded. The round may contain a small capsule of marker dye and/or malodourant.

 Damage   Acc   Range   RoF   Rcl
Gelshot 1d(0.2) cr dkb
  3
  20/150
  n
 2

Tangler Shell. An unguided, non-rocket 20mm tangler round. Affects a single target at ST12. Rules as TS 3e: p.159.
    Acc   Range   RoF   Rcl
Tangler
  3
 50/600
  n
  3

Rubber Shot. A less lethal round, this is effectively a canister round containing 8mm polymer balls. The round is fired at the legs of mobs or at the ground before them to deter them or channel their movements. When “skip fired” (shot at the ground) modify the roll to find hit location by +2.
 
    Damage   Acc   Range   RoF   Rcl
Rubber Shot   1d-3(0.2) cr  
  3
  20/120
  n x 22
  1
 

Muzzle Duster. A less lethal chemical round for very close range, the muzzle duster shell contains a finely-powdered irritant and a small propellant charge. The muzzle duster projects a cone of irritant chemicals, 10 yards long and 4 yards wide at maximum range.
        Anyone within the muzzle duster's discharge cone at a range of 4 yards or less makes two HT-4 rolls: one to resist coughing [see Afflictions, p. B428] and another to resist blindness [p. B124]. At ranges greater than 4 yards these rolls are made at +1 for each extra yard of range, so at 8 yards roll is against HT, 10 yards roll against HT-2.
        Breathing apparatus and sealed eyewear will provide protection from the irritant. Looking away from the blast will not- the powder is very fine and gets everywhere!


    Damage   Acc   Range   RoF   Rcl
Muzzle Duster   Special, Cone
10 x 4 yards
  3
  5/10
  n
  -1


HESH.
        The 20mm HESH slug is simply malleable explosive and a base-mounted fuse. It is a cheap and effective round for close range engagements against armoured targets. Many scouts and pointmen load their assault launcher with a mix of canister and HESH when operating in close terrain.
       If both kinetic and explosive damage fail to penetrate DR the blast may produce spall on the opposite side of the surface struck. This works just like a flat charge [HT (4e):p. 183]: it inflicts cutting damage equal to 1/10 the maximum explosive Damage (as for any contact explosion; see p. B415) resisted by 1/100 the target's DR, rounding up in both cases. These special rules don't apply against laminated armour [p.HT (4e): 229].

       Speed 400 yards/sec.


    Damage   Acc   Range   RoF   Rcl
HESH7d-1 (0.5) cr + linked 7d-1 cr ex
  3
 50/600
  n
  3


Flare.
        
Flare rounds used in 20mm launchers are invariably 12 gauge flares fitted with an adaptor. These are simple signal flare rounds without a parachute. Illumination radius is 185 yards and burn duration is about 10 seconds. They will do 1d burn damage a second for up to 10 seconds if in contact with something. Vision penalty due to darkness is -5 or the actual penalty, whichever is better. Flares are often loaded into the launchers of small patrol cybershells, allowing support units to be rapidly summoned and directed towards an intruder.