The whole ensemble was painted the same color as the Pulse Rifle props. The weapons were finished with prop battery control boxes, dressed in the same style as the main gun to look like military hardware and attached with a cable. Thorn EMI Imager Thermal Hand Helds provided by Thorn EMI were placed on top of the guns to represent their sensor suites. The sentries are sometimes incorrectly said to be based on the earlier WWI-era Maxim LMG 08/15 machine gun due to the use of Maxim's drum magazines in the design however, the magazine is the only part of the Maxim that was used. The guns were fitted with the same custom muzzle brakes as the Smartguns and were housed in bulky fiberglass shells. Like the M56 Smartgun props, the core of the sentry guns in Aliens was a German World War II MG 42 machine gun, mounted on a custom-made tripod and standing 45 inches from the ground. The weapon's barrel shroud and sensors have been removed in this image. The F version employs a 40 mm automatic grenade launcher. While broadly similar in operation, the D variant mounts a 20 mW HF laser instead of the M30 Autocannon machine gun of the regular sentry.
The number and grouping of rounds fired in a burst is automatically selected dependent on the target profile, so that the most economical use of ammunition is made. īefore the weapon opens fire, automated servos in the tripod orient it to point at the target. If the system is set to Manual Override or Semi-Automatic, this information is flashed back to the command console, where the system operator can decide whether or not to fire. Enemy IFF transponders can also be detected by the UA 571-C and used to direct fire even if the target is otherwise avoiding the sentry's detection mechanisms. If the IFF return is positive, the weapon will let the soldier or vehicle pass otherwise it will open fire. All Colonial Marine personnel and vehicles carry an IFF transponder in their communications gear which sends back a coded radio signal when interrogated. When set to Auto-Remote, the sentry will interrogate all targets in its sensor cone using an Identification Friend Foe (IFF) transponder. The UA 571-C has three operating modes - Auto-Remote, Manual Override and Semi-Automatic. The information collected by the UA 571-C's sensor is automatically relayed to the visual support systems of nearby soldiers, enabling them to see cloaked Yautja as if they were uncloaked. The sensors used by the UA 571-C are able to detect Yautja even when cloaked. However, the system is usually set to multi-spectral mode, where the sentry's software cross-correlates received data from the different sensors to obtain a full target profile. If a target's visual or thermal profile is known, the system may be pre-set to scan for only these specific targets using infrared or optical. This sensing suite consists of a cooled infrared detector in the 3-5 µm and 8-13 µm band, ambient light optics, an ultrasonic motion tracker and a lidar. The sentry unit's sensor array is mounted above the barrel, aligned to cover a 60° cone in front of the weapon. The weapon has a cyclic rate of 1,100 rpm and is air cooled, with an automatic cutout preventing the loading of any more rounds into the breech should overheating cause a chance of ammunition "cook-off".
The UA 571-C mounts the pulse action M30 Autocannon firing the 10×28mm High Explosive Armor Piercing round used by the Corps' M56 Smartguns. Once emplaced, the system may be set to sweep wide arcs up to 360° (subject to terrain and emplacement restrictions), though doctrine is to set several sentries to cover smaller, interlocking fields of fire on a narrow frontage. A microwave datalink connects the sentry to a remote command console. The major components consist of a snap-open tripod mounting, battery pack, breech and barrel assembly, sensor unit and 500-round ammunition drum. Each remote sentry unit weighs in at 19.6 kg and can be assembled in under 150 seconds.
0 kommentar(er)
