 Item Number – SCP-516 Object Class – Safe Special Containment Procedures SCP-516 may be kept in an anomalous vehicle containment bay. Routine vehicle maintenance should be carried out on a bi-weekly basis. SCP-516 is not to be provided with fuel or ammunition, except under controlled testing circumstances. Following incident 516-1A, no personnel with a history of military service should be assigned to SCP-516. Description – SCP-516 is a standard model T-55 main battle tank. Records indicate it was manufactured in 19- At plant, Kharkiv, Ukrainian SSR, and that it had a normal period of service in the armed forces of It exhibits wear and tear consistent with its age. The only part of SCP-516 which is known to exhibit anomalous properties is its main armament. Presently, a 100mm D-10 tank gun and turret assembly from here designated as SCP-516-1. However, as SCP-516-1 has been replaced several times throughout SCP-516 service life without any apparent effects, its anomalous properties seem to be inherent to SCP-516. When loaded with compatible 100mm ammunition, SCP-516-1 exhibits a limited degree of autonomy. When an entity attempts to damage SCP-516, SCP-516-1 will track and fire on it. If it is physically possible to neutralize the threat, regardless of whether SCP-516 is crude, it will not respond to threats outside its range or traverse, such as aircraft. This phenomenon only occurs if the entity possesses reasonable means to damage SCP-516. For example, SCP-516-1 will not fire on a person attempting to attack SCP-516 with their fists. SCP-516-1 may be operated manually, but is selective about its targets. In general, it will only permit its operator to fire on non-living targets, non-sapient biological targets, or armed humans. Under these circumstances, it will fire as a normal armament piece. If a target does not satisfy these conditions, essentially being an unarmed sapient being, SCP-516-1 will jam. Attempts to prevent jamming through maintenance or parts replacement have failed. SCP-516 appears to go to extra lengths to prevent injury to unarmed humans, deliberately placing shots from SCP-516-1 to avoid collateral damage. When operated manually, SCP-516-1 places a higher priority on preserving unarmed life than eliminating armed targets. It will jam if directed to fire upon a group of persons, of which only some members are armed. It should be noted that none of SCP-516's other armaments exhibit these properties, and appear to be perfectly normal. SCP-516 was brought to the attention of the Foundation in 2001, when it was slated to be broken up for scrap. Due to a bureaucratic oversight, ammunition had not been removed from SCP-516-1, causing it to open fire with several casualties. The ensuing government investigation was noted by Foundation operatives, and it was thought worthwhile to take SCP-516 into custody. Addendum 516-1. An upgrade to Euclid status is being considered in light of Incident 516-1A, as this lends credence to Dr. Wendell's theory that the SCP may be sentient in some form. Additional security measures have been approved for SCP-516's containment. Incident 516-1A Synopsis. During routine testing of SCP-516, SCP-516-1 immediately fired upon a group of unarmed personnel in range, as soon as it was loaded with ammunition, leading to the death of two D-Class personnel, D-505, D-596, and one Foundation officer, Agent Wendell. Subsequent investigation showed that D-596, one of the casualties, had attained his D-Class status following a criminal conviction for treason against his native country. D-596 previously held the English equivalent rank of Sergeant in the armed forces, from which SCP-516 was acquired. No other possible links to SCP-516 with D-596, or the other casualties have been found at this stage. This marks the first time SCP-516 has attacked unarmed personnel. Further investigation and safety precautions are warranted. Addendum 516-2 SCP-516 Testing Log This is the testing log for SCP-516. All tests were carried out on the site in firing range. Unless otherwise specified, standard testing conditions were as follows. One F-412-100mm high explosive round loaded. Crew of four Foundation personnel trained in operation of SCP-516. SCP-516 placed in hardened bunker with firing slit, to reduce severity of potential damage to SCP. Target placed at a distance of 1,000 meters from SCP-516, with a clear line of sight. Ammunition loaded once target was placed at 1,000 meters distance. Testing log 516-1A Target Cardboard cut out of human. Result. No activity from SCP-516. SCP-516-1 fired manually. Target destroyed. Testing log 516-1B Target One D-Class personnel. D-1151. Unarmed. No instructions. Result. No activity from SCP-516. SCP-516-1 fired manually. SCP-516-1 jammed. Testing log 516-1C Target One D-Class personnel. D-1470. Given steak knife. No instructions. Result. No activity from SCP-516. SCP-516-1 fired manually. SCP-516-1 jammed. Testing log 516-1D Target One D-Class personnel. D-951. Given 9-millimeter pistol. No instructions. Result. No activity from SCP-516. SCP-516-1 fired manually. Target destroyed. Testing log 516-1E Target One D-Class personnel. D-800. Given 9-millimeter pistol. Instructed to approach SCP-516 in open fire. Result. No activity from SCP-516. SCP-516-1 fired manually. Target destroyed. Testing log 516-1F Target One D-Class personnel. D-820. Given shoulder fired anti-tank weapon. No instructions. Result. No activity from SCP-516. SCP-516-1 fired manually. Target destroyed. Testing log 516-1G Target One D-Class personnel. D-185. Given shoulder fired anti-tank weapon. Instructed to approach SCP-516 in open fire. Result. SCP-516-1 autonomously fired on target. Target destroyed. Testing log 516-1H Target One D-Class personnel. D-202. Given shoulder fired anti-tank weapon. Placed in lead lined box on trolley. D-202 instructed to approach SCP-516. Open box and fire. Result. SCP-516-1 autonomously fired on target. Target bent to open box. Target destroyed. Note. It appears SCP-516 can detect both hostile intent and concealed weapons. Could be valuable as a security device. Testing log 516-1I Target Two D-Class personnel. D-455. D-501. Hand cuffed together. D-455. Given shoulder fired anti-tank weapon. Instructed to approach SCP-516. And fire. Result. SCP-516-1 autonomously fired approximately 50 meters to the right of D-455. D-455 killed by an 8 centimeter shrapnel wound to the head. D-501 sustained minor injuries. Testing log 516-1J Target Two D-Class personnel. D-101. D-521. Hand cuffed together. Two kilograms of C4 plastic explosive strapped to D-101. Instructed to approach SCP-516. And detonate explosives. D-101 fitted with dead man switch to induce explosion if D-101 is killed. Result. As doctor detailed instructions to D-101, SCP-516 data expunged. Testing log 516-1K Test circumstances. Standard shell replaced by SCP-157-ARC Target One D-Class personnel. D-185. Given shoulder fired anti-tank weapon. Instructed to approach SCP-516. And fire. Result. SCP-157-ARC changed into data expunged. Upon being loaded into SCP-516-1, data expunged. Leading to the death of D-185. As well as several further casualties. Doctor who proposed test 516-1K was reprimanded and transferred. Lesson complete. If you missed the previous orientation, go watch SCP-515. Sleeper. Right now. Or for the complete course, watch this playlist.