Rusty
Purveyor of Fine Weaponry
(This is a rough approximation and does not accurately represent the final product)
Image Source
Intent: To create a viable means to intercepting incoming mortar and artillery fire
Development Thread: If Needed
Manufacturer: Rusty's Custom Firearms and Cutlery
Model: AA-3 Tribarrel
Affiliation: Open Market
Modularity: No
Production: Mass
Material: Durasteel, blaster components, minigun components, sensor suite, traverse and elevation equipment, power generator, socketguards
Classification: Blaster
Size: Man portable
Length: 1.7 meters
Weight: 150 kilograms
Ammunition Type: Blaster Gas, Power generator
Ammunition Capacity: Theoretically unlimited, so long as power generator doesn't overload
Effective Range: 300 Meters
Rate of Fire: 5,000 rounds per minute
Special Features: Advanced sensor suite and targetting system allows the weapon to automatically track and engage incoming indirect fire.
Description: The AA-3 Tribarrel was designed as Rusty's answer to the age old problem of how to deal with incoming artillery fire.
Traditionally, incoming artillery fire has been dealt with by putting something in between the soldier and the shell. Whether that be the roof of a bunker or a shield, the answer is almost always to hunker down and wait for the fire to pass. While this solution has the advantage of simplicity, it's far from perfect.
What Rusty had always wondered was why no one tried to shoot the incoming fire down.
In theory, it was easy enough. Incoming shells can't dodge, and they follow predictable trajectories. And while they're small and fast (relatively speaking), they're not exactly stealthy. Furthermore, they're fairly fragile. The casings might be tough, but they're loaded with high explosives and the stuff to set them off. Even a relatively weak blaster bolt can cook a shell off.
An effective anti artillery system would therefore require three things: a weapon system capable of engaging incoming shells, a sensor suite capable of tracking them, and a targeting system capable of using the sensor data to aim the weapon at incoming shells.
The weapon system was the easy part. The rotary cannon was an old design dating back to the Z-6, and there were slugthrower rotary weapons that were positively ancient. The design was complicated and heavy, and it ate through ammo like nobody's business, but rotary cannon were reliable and could sustain rates of fire best described as cataclysmic.
For the AA-3, Rusty went with a three barreled design. Three barrels still gave the weapon the blistering rate of fire it would need, but the design was much lighter than a traditional six barreled weapon. That would put less stress on the motors that would aim the weapon, and would allow for a snappier response to threats. Much like the E-web, the AA-3 can continuously fire so long as the power generator is functioning.
In order to prevent the weapon from overheating, Rusty incorporated a cryogenic cooling jacket around the barrels. He also dialed down the power of the bolts significantly. They didn't have to penetrate heavy armor, after all. They just had to be able to set off an artillery shell. Individually, the bolts were little more powerful than the ones fire from a holdout blaster, though the longer barrels of the tribarrel allow them to remain coherent at much greater range. This limits their utility against troops, as even basic soldier armor would be able to shrug them off with ease, but this weapon system was never designed to function against soldiers.
The integrated sensor suite uses radar, magnetic, and acoustic sensors to track incoming shells. Radar is the primary detection method. It has longer range than the other sensors, and is capable of tracking dozens of incoming shells with pinpoint precision. However, it's not a perfect system. Pack the shells in tightly enough and they'll fail to register as individual targets. Nonmetallic shell casings also won't reflect the radar waves very well, which makes detection difficult. It can also be decoyed by high concentrations of metallic particles in the air. In other words, the radar can be decoyed by chaff. Range masking also has to be taken into account, as things like trees, hills, power lines, etc can interfere with the return. In optimal conditions, the radar can reliably detect shells up to 1 kilometer away.
The magnetic sensor has a much shorter range than the radar, but also has a much higher degree of precision. So long as the sensor has the chance to map existing magnetic fields from nearby metallic objects (weapon emplacements, equipment, so on and so forth), it can be used to supplement the radar. In order to prevent it from overloading and freezing the weapon, the factory default programs it to ignore any fields within 25 meters of the sensor, so anything within that bubble should be fine, but anything beyond that will have to be mapped. Once mapped the fields can be moved, so you don't have to worry about troops with pocketknives throwing it off, but failure to follow proper mapping procedures will greatly reduce effectiveness. Furthermore, EM decoys can spoof the sensor. The magnetic sensor has an effective range of 500 meters.
The acoustic sensor is the third and final line of defense. It's a series of extremely precise microphones that uses the distinctive sound of incoming shells to track them. Though capable of extreme precision at short range, the acoustic sensors are a last ditch defensive measure if all else fails. Unlike the radar and magnetic sensors, which effectively work at lightspeed, the acoustic sensor can only detect soundwaves, which do not. Thus, it's only really effective at ranges less than 75 meters. By the time the acoustic sensor comes into play, the weapon is considered to be in last ditch defense mode, and is spraying fire at anything that might be a threat. If it comes down to that, no distinction is made between incoming and outgoing fire.
The data from the sensors is fed to a targeting computer that turns the sensor data into spatial coordinates. The tribarrel is affixed to a rapid-aiming turret system that allows it to traverse in a 360 degree arc in 1.3 seconds, and to elevate or depress 90 degrees in .6 seconds. When a shell enters sensor range, it's assigned a priority rating. The closer it gets to the effective range, the higher the rating. As soon as it crosses the 300 meter mark, it is targeted and engaged by a 5 round burst. If that fails to destroy the target, it will be engaged again.
The AA-3 is not designed to work as a standalone platform. A single AA-3 can protect provide complete protection for an encampment up to 150 meters in diameter, provided the rate of incoming fire is no more than 20 rounds per minute. At that point, can effectively track shells coming in from any direction. Anything more than that and it can no longer guarantee complete protection.
Ideally, you want one AA-3 for every 50 meters of perimeter. The targeting computers are designed to be networked. Data can be shared between individual platforms to form a coordinated defensive net. If one AA-3 goes down, its neighbors know to pick up the slack, and the entire network will adjust accordingly. To prevent outside interference, the AA-3 is equipped with socketguard technology, which makes slicing difficult, though not impossible.
Each AA-3 has an integrated power generator at its base. The generator is extremely heavy, enough so that the weapon will require four humanoids to lift safely. It is recommended that the generator be protected at all costs, as a direct hit from a sufficiently powerful weapon will cause it to explode with the force of a 500 pound bomb. It is recommended that the base of the AA-3 be buried, with at least 15 centimeters of space left around the sides in order to allow the heat exchangers to function properly. Though the generator is stable for extended use, daily, weekly, and monthly maintenance schedules will be included in the instruction manual. Failure to follow the maintenance schedules can result in catastrophic failure, and will void the warranty. If the onboard diagnostic detects a potentially catastrophic fault, it will shut down, on the grounds that incoming artillery fire is safer than a large explosion accompanied by radioactive fallout.
The AA-3 is available in matte black, olive drab, snow camouflage, and desert tan.
Primary Source: Z-6 Rotary Blaster Cannon
