HOME | DD

Description
"The K1 is a South Korean main battle tank designed by Chrysler Defense (later General Dynamics Land Systems ) and Hyundai Precision Industry (later Hyundai Rotem ) for the Republic of Korea Armed Forces . The vehicle's design was based on Chrysler's M1 Abrams together with some proven subsystems from M60A3 .[3] The K1A1 is an upgunned variant with a 120 mm 44 caliber smoothbore gun, and outfitted with more modern electronics, ballistic computers, fire control systems, and armor. Hyundai Rotem produced 1,511 K1 and K1A1 tanks between 1986 and 2010.

In the early 1970s, South Korea received an intelligence report about North Korea locally producing Soviet T-62 tanks. Meanwhile, the U.S. 7th Infantry Division began withdrawing from South Korea from 1969 to 1971 under the Nixon Doctrine . South Korean President Park Chung-hee requested the latest variant of M60 tanks to maintain the balance of power. However, the United States responded by transferring used M48 tanks and providing upgrades instead; South Korea received 25 M48A5s from the United States Forces Korea and numerous M48A3s that were used, but in good condition, during the Vietnam War .[4]
Under the agreement, South Korea received the technical data package (TDP) of M48 Patton and its upgrade kits for 12 major enhancements. Korean engineers were sent to the United States Army Depot in Alabama for training such as armor cast steel wielding and production, precision manufacturing, assembling skills, quality inspection, and test evaluation. Around the same time, Park Chung-hee ordered to develop a domestic tank and personally summoned Chung Ju-yung , the founder of Hyundai Group , to recommend building a tank factory. Chung Ju-yung, thinking that the president asked for a train factory, promised to build one.[note 1] The chairman was shocked after learning about his misunderstanding from the secretary as he was leaving the building.[4] [5]
Not satisfied with M48 Patton upgrade, South Korea began looking for a new tank that could overwhelm every North Korean counterpart as the existence of T-62 and its manufacturing facility were confirmed by satellite images in 1976. South Korea first asked Chrysler Defense for a solution to acquire a better tank, and Chrysler suggested the purchasing M60A3 or producing it in South Korea. Because the American offer was an outdated design, South Korea then contacted KraussMaffei of West Germany to receive technology assistance, which KraussMaffei offered a unique tank design based on Leopard 1 . Both South Korea and West Germany kept the cooperation in secret, because the two nations believed that the United States would intervene once the information leaks. In 1977, as expected, Chrysler Defense showed interest in the Korean tank project after its engineers became available and wanted to generate more profit after the development of M1 Abrams . This time, Chrysler offered a new tank based on the newest M1 Abrams. Eventually, the American design was chosen, and a memorandum of understanding (MOU) was signed on 6 July 1978 to supply two prototypes, and the executive contract was signed on 1 December 1978.[3] [4] [6] [5]
Between 1979 and 1980, several MOUs were signed between the two nations, mostly regarding intellectual rights and royalty payments. According to the MOU, the United States will provide its state-of-art Special Armor Package (SAP), in which the material and protection is identical to M1 Abrams, while limiting Koreans from access until the installation due to national security reasons. Exporting of K1 is strictly controlled and needs authorization from the United States as many sensitive systems are installed, and South Korea requires to pay royalty to Chrysler Defense. Also, 44 designated parts (gradually reduced to 14) cannot be changed without United States approval, and some parts must be purchased periodically. In addition, South Korea will have the rights on, and limited to, the technologies developed uniquely with the money provided by South Korea, while Chrysler also claims the rights to use in the future. On the other hand, South Korea benefitted on the development cost from the cooperation with Chrysler; South Korea paid $60 million for the prototype development, far below than $700 million spent on M1 Abrams. However, Hyundai Precision Industry, which planned to produce the tank at its new factory, was excluded from direct involvement in designing the tank, and it was the biggest problem since Koreans had never produced tanks before. Under these conditions, Koreans will be unable to produce tanks as they do not understand the structure and technology of the tank even with prototypes in hand.[3]
From October 1980 to April 1981, Chrysler had three meetings with Hyundai to confirm the required operational capability (ROC), and presented a small scale mock-up along with reports. During the production of the prototypes, Chrysler Defense was sold to General Dynamics Land Systems (GDLS) in March 1982. A total of 2 prototypes named ROKIT (Republic of Korea Indigenous Tank) were produced with designations PV-1 (MTR - mobility test rig) and PV-2 (FTR - firepower test rig) in 1983 after 3 years of the development, and went trial at Aberdeen Proving Ground based on American military standards. During the trial, PV-1 failed to climb longitudinal slope of 60%, experienced fire on 1,200 hp Teledyne Continental Motors AVCR-1790 engine, and had issues on its transmission. PV-2 also reported issues with its fire control system; LOS (line of sight) was shaking due to frost in winter season, taking too long for warmup, interference from electromagnetic waves, and lockup of the ballistic computer. Protection tests were done on separately built ballistic hull and turret, which showed some flaws during the test. Eventually, the known problems were fixed and improved by the time of delivery of the two prototypes. At the end, GDLS transferred the PV-1 along with 1,370 pages of blueprints and the TDP, but the number of blueprints was insufficient for manufacturing.[6] [5]
During the trial, a team of Korean engineers from Hyundai Precision Industry was dispatched to join Chrysler's developer team to look over the progress. Although the contract limits technological access to Koreans, engineers from both nations freely shared information during friendship interactions including a classified specification of M1 Abrams. When the upper management of Chrysler found out about this, they built a wall in the office to prevent information leakage. However, Koreans managed to obtain significant data during their 3 years of presence at the facility. In addition, the manufacturing team of Hyundai came for a tour to the American tank factory to understand how to build a tank factory. Koreans could only go to the specified path, but they memorized types of machineries and calculated the required sizes of the facility by counting the footsteps, which helped them to build the new factory at Changwon .[6] [5]
In 1983, Hyundai accepted GDLS' new offer, and acquired special welding of armor plates, assembly of major devices, and weapon testing technologies. 30 engineers from GDLS were also sent to Korea, and participated in producing and testing preproduction models. From September 1984 to August 1985, a total of 5 XK1s were completed (2 for the Agency for Defense Development , 2 for the ROK Army, and 1 for the Army logistics), and went for further testing in South Korea. However, Hyundai realized that GDLS had made a crucial mistake by providing outdated blueprints that did not reflect the latest fixes, and XK1s began to experience the same issues they saw from early prototypes. In addition, the lack of detailed blueprints forced Korean engineers to rework the tank and create 5 thousands design changes and 10 thousands pages of blueprints. The biggest change during this process was the switching of the mobility system from American to German, in which the design change was done by GDLS. The air-cooled AVCR-1790 had lower torque thus unable to drive at high incline angles, and also experienced fire several times, which contributed to unexpected fire tests that proved survivability of the tank. For this reason, the MTU Friedrichshafen MB871Ka-501 water-cooled engine and the ZF Friedrichshafen LSG 3000 transmission were chosen for the new power pack.[6] [7] [8] These preproduction variants entered service with South Korean military in February 1986.[9] [5]
On the other hand, Hughes' GPSS (Gunner's Primary Sight System) continuously saw issues with low accuracy and operational uses, while Hughes forced South Koreans to give up localization of the GPSS by doubling up the price when licensing. GDLS, which acquired Hughes in 1985, revealed that the system uses parts from Canada, West Germany, and Switzerland, and thus requires time-consuming multi-national cooperation in order to solve to problem. In 1986, another contract was signed between Hyundai and GDLS for updating the GPSS, increasing the cost of the gunner's sight, and this unsatisfactory lead South Koreans to look for alternative options immediately. In April 1987, the K1 tank test evaluation for conditional mass production was completed, and serial production began in September 1987. On 18 September, the tank was given the nickname 88-Tank by South Korean president Chun Doo-hwan to celebrate upcoming 1988 Summer Olympics .[6] [7] [10] [11] [12] [5]
A total of 1,027 K1s were produced between 1986 and 1997 in 3 batches with design changes on each batch. Since 1995, the K1s received their first depot maintenance at Hyundai Precision Industry in the order of production (10 year cycle). The work includes the application of 3rd batch updates on the earlier produced vehicles.[5] [13]
General characteristics[edit ]
The K1 retains most of the features of the M1 Abrams , but also shows differences. Its main armament is a licensed M68A1 105 mm 52 caliber tank gun under designation KM68A1 by Hyundai Precision Industry, and carries 47 rounds of ammunitions at the hull and turret as it lacks bustle storage in the rear of the turret, which is filled with radio systems. The main gun is assisted by 16-bit fire control system and digital ballistic calculator. The tank has either M2 Browning or SNT Dynamics K6 12.7x99 mm NATO on commander's hatch mount, a M60D 7.62×51mm NATO machine gun on loader's hatch mount, and a M60E2-1 7.62×51mm NATO coaxial machine gun for gunner as secondary armaments.[14] [15]
The K1 has size of 9.67 m (length with gun forward) x 3.60 m (width) x 2.25 m (height), and weighs 51.1 t or 51.5 t.[15] It is powered by German power pack consisting 1,200 hp (23.5 hp/t) from MTU Friedrichshafen MB871Ka-501 8-cylinder water-cooled turbocharged diesel engine licensed by Ssangyong Heavy Industries (now STX Engine) and ZF Friedrichshafen LSG 3000 transmission licensed by Hyundai Precision Industry (now Hyundai Transys). The tank can drive at a maximum speed of 65 km on paved roads and 40 km on cross-country with 500 km cruising range. Its chassis uses hybrid suspension combining hydropneumatic suspension on wheels 1, 2, and 6 and torsion bar on wheels 3, 4, and 5. It allows the tank to use kneeling to supplement the depression of the main gun, which is limited by the small sized turret, to minus 10 degrees, and provides crew comfortability on rough terrains.[7] [8] [14] [15] [16] For comparison, M1 Abrams is 9.77 m x 3.66 m x 2.37 m, and weighs 54 t.
The Gun/Turret Drive and Stabilization System (GTDSS) measures and compensates yawing and pitching, which occur on uneven and curved roads for gun turret to be capable of the precise fire while running. The GTDSS consists elevation servo system, elevation drive system, reference gyro, traverse servo system, traverse drive system, feed-forward gyro, electronic unit for gun and turret drive, and steering handle for artillery man. The system is locally produced in South Korea by Dongmyeong Heavy Industries (now Mottrol) since 1992.[17]
The gunner's sight was initially a problematic Hughes GPSS, which uses a Nd:YAG laser rangefinder , a similar model used for the M1 Abrams. Despite Koreans having decided to upgrade the existing GPSS, Samsung Electronics signed a deal with Texas Instruments to supply and locally produce the GPTTS (Gunner's Primary Tank Thermal Sight) in 1986. Hyundai originally planned to install GPTTS in 1987, but serious problems such as a failure of the laser rangefinder forced Hyundai to postpone the plan. Due to the delays, a total of 445 K1s were manufactured with imported Hughes GPSS until 1991. Meantime, after failing to repair the GPTTS, Texas Instruments gave access to technology to the Agency for Defense Development . Within a year, a combined team managed to fix the sight and further improve it by increasing the sight's distance from 2 km to 3 km. Samsung Electronics began supplying the GPTTS in 1991. Later, during the parliamentary investigation, it was found that there were lobbies involved in selecting the GPTTS, leading to a selection of the product without proper testing, which caused an additional development cost of 16 billion KRW on the sight. Regardless of the involvement of lobbies, upgraded GPTTS showed superior performance when shooting the hidden target behind the smoke screen, which the GPSS failed to do so during the test on 2 September 1993. The GPTTS uses a carbon dioxide laser range finder, which is safer to the human eye upon being hit by the laser, while Nd:YAG can blind the victim. However, the GPTTS was a complex and heavier system. Ironically, access to GPTTS technology enabled Koreans to design their own gunner's sight. The ADD began the research in 1992 for domestic gunner's sight (later known as KGPS: Korean Gunner's Primary Sight) using the Raman laser believing such technology would be used for future weapon systems. In 1995, by the time Koreans were at the end stage of development, Europe announced it would use Raman lasers for tanks followed by the United States.[12] [18] [19] [20] [21]
The commander's sight is from SFIM (now SAGEM ) of France, and it has a hunter killer ability that allows tank crews to engage multiple targets at once by allowing the commander to search 360 degrees and direct the main gun.[7] [12] [14] The hunter killer feature was a major difference compared to the M1 Abrams, which becomes available on later M1A2 upgrades. The commander's sight was not, however, equipped with light amplification or thermal optics, which led to the commander to rely on personal night vision goggles for night operation, while the gunner's sight was equipped with a thermal observation device, which meant that the K1 had superior sensors until the introduction of the M1A2.
The Special Armor Package (SAP) is a classified composite armor used for the K1 tanks crafted by the United States using identical materials and technologies used on the armor of M1 Abrams. Its specifications are strictly restricted for public release, and limits South Koreans from accessing the armor. The SAP is applied on the turret and the front of the hull. Meanwhile, the side of the hull is protected with additional RHA plates , which provide protection to all types of 115 mm ammunition fired from T-62 in the hands of North Korea by the time of the development.[7] According to the media report, frontal armor of the K1 baseline is between 400 and 500 mm against KE projectiles.[22] Smoke grenade launchers are located on each outer side of the turret front. The vehicle is also equipped with a fire-extinguishing system in the engine room, where the system notifies crews to activate automatic extinguishers when a thermometer detects a critical temperature.[14] The extinguishant used is Halon1301, commonly used by western main battle tanks. The vehicle lacks an overpressure system for CBRN defense , thus requires tank crews to wear personal protective gears to operate in chemical , biological , radiological and nuclear warfare environments."

-Wikipedia

Description
"The K1 is a South Korean main battle tank designed by Chrysler Defense (later General Dynamics Land Systems ) and Hyundai Precision Industry (later Hyundai Rotem ) for the Republic of Korea Armed Forces . The vehicle's design was based on Chrysler's M1 Abrams together with some proven subsystems from M60A3 .[3] The K1A1 is an upgunned variant with a 120 mm 44 caliber smoothbore gun, and outfitted with more modern electronics, ballistic computers, fire control systems, and armor. Hyundai Rotem produced 1,511 K1 and K1A1 tanks between 1986 and 2010.

In the early 1970s, South Korea received an intelligence report about North Korea locally producing Soviet T-62 tanks. Meanwhile, the U.S. 7th Infantry Division began withdrawing from South Korea from 1969 to 1971 under the Nixon Doctrine . South Korean President Park Chung-hee requested the latest variant of M60 tanks to maintain the balance of power. However, the United States responded by transferring used M48 tanks and providing upgrades instead; South Korea received 25 M48A5s from the United States Forces Korea and numerous M48A3s that were used, but in good condition, during the Vietnam War .[4]
Under the agreement, South Korea received the technical data package (TDP) of M48 Patton and its upgrade kits for 12 major enhancements. Korean engineers were sent to the United States Army Depot in Alabama for training such as armor cast steel wielding and production, precision manufacturing, assembling skills, quality inspection, and test evaluation. Around the same time, Park Chung-hee ordered to develop a domestic tank and personally summoned Chung Ju-yung , the founder of Hyundai Group , to recommend building a tank factory. Chung Ju-yung, thinking that the president asked for a train factory, promised to build one.[note 1] The chairman was shocked after learning about his misunderstanding from the secretary as he was leaving the building.[4] [5]
Not satisfied with M48 Patton upgrade, South Korea began looking for a new tank that could overwhelm every North Korean counterpart as the existence of T-62 and its manufacturing facility were confirmed by satellite images in 1976. South Korea first asked Chrysler Defense for a solution to acquire a better tank, and Chrysler suggested the purchasing M60A3 or producing it in South Korea. Because the American offer was an outdated design, South Korea then contacted KraussMaffei of West Germany to receive technology assistance, which KraussMaffei offered a unique tank design based on Leopard 1 . Both South Korea and West Germany kept the cooperation in secret, because the two nations believed that the United States would intervene once the information leaks. In 1977, as expected, Chrysler Defense showed interest in the Korean tank project after its engineers became available and wanted to generate more profit after the development of M1 Abrams . This time, Chrysler offered a new tank based on the newest M1 Abrams. Eventually, the American design was chosen, and a memorandum of understanding (MOU) was signed on 6 July 1978 to supply two prototypes, and the executive contract was signed on 1 December 1978.[3] [4] [6] [5]
Between 1979 and 1980, several MOUs were signed between the two nations, mostly regarding intellectual rights and royalty payments. According to the MOU, the United States will provide its state-of-art Special Armor Package (SAP), in which the material and protection is identical to M1 Abrams, while limiting Koreans from access until the installation due to national security reasons. Exporting of K1 is strictly controlled and needs authorization from the United States as many sensitive systems are installed, and South Korea requires to pay royalty to Chrysler Defense. Also, 44 designated parts (gradually reduced to 14) cannot be changed without United States approval, and some parts must be purchased periodically. In addition, South Korea will have the rights on, and limited to, the technologies developed uniquely with the money provided by South Korea, while Chrysler also claims the rights to use in the future. On the other hand, South Korea benefitted on the development cost from the cooperation with Chrysler; South Korea paid $60 million for the prototype development, far below than $700 million spent on M1 Abrams. However, Hyundai Precision Industry, which planned to produce the tank at its new factory, was excluded from direct involvement in designing the tank, and it was the biggest problem since Koreans had never produced tanks before. Under these conditions, Koreans will be unable to produce tanks as they do not understand the structure and technology of the tank even with prototypes in hand.[3]
From October 1980 to April 1981, Chrysler had three meetings with Hyundai to confirm the required operational capability (ROC), and presented a small scale mock-up along with reports. During the production of the prototypes, Chrysler Defense was sold to General Dynamics Land Systems (GDLS) in March 1982. A total of 2 prototypes named ROKIT (Republic of Korea Indigenous Tank) were produced with designations PV-1 (MTR - mobility test rig) and PV-2 (FTR - firepower test rig) in 1983 after 3 years of the development, and went trial at Aberdeen Proving Ground based on American military standards. During the trial, PV-1 failed to climb longitudinal slope of 60%, experienced fire on 1,200 hp Teledyne Continental Motors AVCR-1790 engine, and had issues on its transmission. PV-2 also reported issues with its fire control system; LOS (line of sight) was shaking due to frost in winter season, taking too long for warmup, interference from electromagnetic waves, and lockup of the ballistic computer. Protection tests were done on separately built ballistic hull and turret, which showed some flaws during the test. Eventually, the known problems were fixed and improved by the time of delivery of the two prototypes. At the end, GDLS transferred the PV-1 along with 1,370 pages of blueprints and the TDP, but the number of blueprints was insufficient for manufacturing.[6] [5]
During the trial, a team of Korean engineers from Hyundai Precision Industry was dispatched to join Chrysler's developer team to look over the progress. Although the contract limits technological access to Koreans, engineers from both nations freely shared information during friendship interactions including a classified specification of M1 Abrams. When the upper management of Chrysler found out about this, they built a wall in the office to prevent information leakage. However, Koreans managed to obtain significant data during their 3 years of presence at the facility. In addition, the manufacturing team of Hyundai came for a tour to the American tank factory to understand how to build a tank factory. Koreans could only go to the specified path, but they memorized types of machineries and calculated the required sizes of the facility by counting the footsteps, which helped them to build the new factory at Changwon .[6] [5]
In 1983, Hyundai accepted GDLS' new offer, and acquired special welding of armor plates, assembly of major devices, and weapon testing technologies. 30 engineers from GDLS were also sent to Korea, and participated in producing and testing preproduction models. From September 1984 to August 1985, a total of 5 XK1s were completed (2 for the Agency for Defense Development , 2 for the ROK Army, and 1 for the Army logistics), and went for further testing in South Korea. However, Hyundai realized that GDLS had made a crucial mistake by providing outdated blueprints that did not reflect the latest fixes, and XK1s began to experience the same issues they saw from early prototypes. In addition, the lack of detailed blueprints forced Korean engineers to rework the tank and create 5 thousands design changes and 10 thousands pages of blueprints. The biggest change during this process was the switching of the mobility system from American to German, in which the design change was done by GDLS. The air-cooled AVCR-1790 had lower torque thus unable to drive at high incline angles, and also experienced fire several times, which contributed to unexpected fire tests that proved survivability of the tank. For this reason, the MTU Friedrichshafen MB871Ka-501 water-cooled engine and the ZF Friedrichshafen LSG 3000 transmission were chosen for the new power pack.[6] [7] [8] These preproduction variants entered service with South Korean military in February 1986.[9] [5]
On the other hand, Hughes' GPSS (Gunner's Primary Sight System) continuously saw issues with low accuracy and operational uses, while Hughes forced South Koreans to give up localization of the GPSS by doubling up the price when licensing. GDLS, which acquired Hughes in 1985, revealed that the system uses parts from Canada, West Germany, and Switzerland, and thus requires time-consuming multi-national cooperation in order to solve to problem. In 1986, another contract was signed between Hyundai and GDLS for updating the GPSS, increasing the cost of the gunner's sight, and this unsatisfactory lead South Koreans to look for alternative options immediately. In April 1987, the K1 tank test evaluation for conditional mass production was completed, and serial production began in September 1987. On 18 September, the tank was given the nickname 88-Tank by South Korean president Chun Doo-hwan to celebrate upcoming 1988 Summer Olympics .[6] [7] [10] [11] [12] [5]
A total of 1,027 K1s were produced between 1986 and 1997 in 3 batches with design changes on each batch. Since 1995, the K1s received their first depot maintenance at Hyundai Precision Industry in the order of production (10 year cycle). The work includes the application of 3rd batch updates on the earlier produced vehicles.[5] [13]
General characteristics[edit ]
The K1 retains most of the features of the M1 Abrams , but also shows differences. Its main armament is a licensed M68A1 105 mm 52 caliber tank gun under designation KM68A1 by Hyundai Precision Industry, and carries 47 rounds of ammunitions at the hull and turret as it lacks bustle storage in the rear of the turret, which is filled with radio systems. The main gun is assisted by 16-bit fire control system and digital ballistic calculator. The tank has either M2 Browning or SNT Dynamics K6 12.7x99 mm NATO on commander's hatch mount, a M60D 7.62×51mm NATO machine gun on loader's hatch mount, and a M60E2-1 7.62×51mm NATO coaxial machine gun for gunner as secondary armaments.[14] [15]
The K1 has size of 9.67 m (length with gun forward) x 3.60 m (width) x 2.25 m (height), and weighs 51.1 t or 51.5 t.[15] It is powered by German power pack consisting 1,200 hp (23.5 hp/t) from MTU Friedrichshafen MB871Ka-501 8-cylinder water-cooled turbocharged diesel engine licensed by Ssangyong Heavy Industries (now STX Engine) and ZF Friedrichshafen LSG 3000 transmission licensed by Hyundai Precision Industry (now Hyundai Transys). The tank can drive at a maximum speed of 65 km on paved roads and 40 km on cross-country with 500 km cruising range. Its chassis uses hybrid suspension combining hydropneumatic suspension on wheels 1, 2, and 6 and torsion bar on wheels 3, 4, and 5. It allows the tank to use kneeling to supplement the depression of the main gun, which is limited by the small sized turret, to minus 10 degrees, and provides crew comfortability on rough terrains.[7] [8] [14] [15] [16] For comparison, M1 Abrams is 9.77 m x 3.66 m x 2.37 m, and weighs 54 t.
The Gun/Turret Drive and Stabilization System (GTDSS) measures and compensates yawing and pitching, which occur on uneven and curved roads for gun turret to be capable of the precise fire while running. The GTDSS consists elevation servo system, elevation drive system, reference gyro, traverse servo system, traverse drive system, feed-forward gyro, electronic unit for gun and turret drive, and steering handle for artillery man. The system is locally produced in South Korea by Dongmyeong Heavy Industries (now Mottrol) since 1992.[17]
The gunner's sight was initially a problematic Hughes GPSS, which uses a Nd:YAG laser rangefinder , a similar model used for the M1 Abrams. Despite Koreans having decided to upgrade the existing GPSS, Samsung Electronics signed a deal with Texas Instruments to supply and locally produce the GPTTS (Gunner's Primary Tank Thermal Sight) in 1986. Hyundai originally planned to install GPTTS in 1987, but serious problems such as a failure of the laser rangefinder forced Hyundai to postpone the plan. Due to the delays, a total of 445 K1s were manufactured with imported Hughes GPSS until 1991. Meantime, after failing to repair the GPTTS, Texas Instruments gave access to technology to the Agency for Defense Development . Within a year, a combined team managed to fix the sight and further improve it by increasing the sight's distance from 2 km to 3 km. Samsung Electronics began supplying the GPTTS in 1991. Later, during the parliamentary investigation, it was found that there were lobbies involved in selecting the GPTTS, leading to a selection of the product without proper testing, which caused an additional development cost of 16 billion KRW on the sight. Regardless of the involvement of lobbies, upgraded GPTTS showed superior performance when shooting the hidden target behind the smoke screen, which the GPSS failed to do so during the test on 2 September 1993. The GPTTS uses a carbon dioxide laser range finder, which is safer to the human eye upon being hit by the laser, while Nd:YAG can blind the victim. However, the GPTTS was a complex and heavier system. Ironically, access to GPTTS technology enabled Koreans to design their own gunner's sight. The ADD began the research in 1992 for domestic gunner's sight (later known as KGPS: Korean Gunner's Primary Sight) using the Raman laser believing such technology would be used for future weapon systems. In 1995, by the time Koreans were at the end stage of development, Europe announced it would use Raman lasers for tanks followed by the United States.[12] [18] [19] [20] [21]
The commander's sight is from SFIM (now SAGEM ) of France, and it has a hunter killer ability that allows tank crews to engage multiple targets at once by allowing the commander to search 360 degrees and direct the main gun.[7] [12] [14] The hunter killer feature was a major difference compared to the M1 Abrams, which becomes available on later M1A2 upgrades. The commander's sight was not, however, equipped with light amplification or thermal optics, which led to the commander to rely on personal night vision goggles for night operation, while the gunner's sight was equipped with a thermal observation device, which meant that the K1 had superior sensors until the introduction of the M1A2.
The Special Armor Package (SAP) is a classified composite armor used for the K1 tanks crafted by the United States using identical materials and technologies used on the armor of M1 Abrams. Its specifications are strictly restricted for public release, and limits South Koreans from accessing the armor. The SAP is applied on the turret and the front of the hull. Meanwhile, the side of the hull is protected with additional RHA plates , which provide protection to all types of 115 mm ammunition fired from T-62 in the hands of North Korea by the time of the development.[7] According to the media report, frontal armor of the K1 baseline is between 400 and 500 mm against KE projectiles.[22] Smoke grenade launchers are located on each outer side of the turret front. The vehicle is also equipped with a fire-extinguishing system in the engine room, where the system notifies crews to activate automatic extinguishers when a thermometer detects a critical temperature.[14] The extinguishant used is Halon1301, commonly used by western main battle tanks. The vehicle lacks an overpressure system for CBRN defense , thus requires tank crews to wear personal protective gears to operate in chemical , biological , radiological and nuclear warfare environments."

-Wikipedia