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Cold War North Korean Armor

Chuch’e p’o (M1978 Koksan)

Democratic People’s Republic of Korea (1973-Present)
Self-Propelled Gun – Unknown Number Built

The Chuch’e p’o (Korean: 주체포) was the first heavy Self-Propelled Howitzer (SPH) independently developed in the Democratic People’s Republic of Korea (DPRK) for the Korean People’s Army – Ground Forces (KPA-GF).
This vehicle was developed as an ultra-long-range mobile artillery system meant to strike sensitive targets in the Republic of Korea (ROK) without having to cross the Korean Demilitarized Zone and expose the artillery to opposing counter-battery fire.
The Chuch’e p’o (English: Main Gun) is also named M1978 Koksan by the US Department of Defense, as it was first seen by US and South Korean analysts in 1978. This vehicle has had a fairly notable export success by DPRK standards, being sold to Iran in several tens of units.

The Chch’e’po or M1978 Koksan. Source: pinterest.com

Korean People’s Army SPGs

The first self-propelled guns of the KPA were an estimated 300 SU-76Ms received from the Soviet Union before and during the Korean War. However, most were destroyed during the war and, as of July 1953, there were only 127 left, which were quickly decommissioned.

After the war, the Democratic People’s Republic of Korea also had a very small number of ISU-122s in service, left in the small communist nation by China as soon as the war ended.
Some sources also mention the use of some SU-100s in service after the war. The Stockholm International Peace Research Institute even goes as far as estimating 100 units delivered after the war, and the KPA Journal states that there were still some in service as of 2010, even if no photos of them are available.

An M26 Pershing of the 1st US Marine Corps stopped near an abandoned SU-76M, 3rd December 1950. During the Korean War, the SU-76M was the only KPA Self-Propelled Gun used in action against UN troops. Source: pinterest.com

The first Korean-produced SPGs appeared in the late 1960s when the Korean heavy industry was still underdeveloped. The first vehicles were simply Soviet ATS-59 artillery tractors with the roof and the sides of the cabin removed and a Soviet D-20 152 mm or a M-46 130 mm gun mounted in the rear cargo bay. The guns were modified by the Koreans with an SM-4-1 coastal gun muzzle brake.

In 1972, from this simple vehicle, a family of self-propelled guns known as Tokchon was developed. This comprised different vehicles, such as the M1974 and M1977 armed with a Korean 152 mm cannon derived from the Romanian A411 gun.

The M1991 and M1992 were armed with a version of the 130 mm M-46 cannon mounted on the ATS-59 with a superstructure to protect the crew, while the M1975 and M1981 were armed with the same cannon but without the superstructure.

Chuch’e p’o

The M1978 was developed in the early 1970s by the newly formed Second Economic Committee. Its main purpose was to hit sensitive targets in the Republic of Korea and its capital, Seoul, while taking cover behind the Demilitarized Zone.

Its maximum range was 43 km with conventional projectiles. This meant that a projectile could take more than a minute to hit a target south of the 38th Parallel, allowing the gunners to fire a couple of shots and move to another firing position while avoiding the enemy’s response fire.

Four M1978 Koksans during training. Source: Reuters

The origin of the hull

The origin of the hull is still under discussion. It could be that of the Soviet T-54 or T-55 Main Battle Tanks or of the Chinese version, the Type 59. All three vehicles were supplied to the Korean People’s Army by the Soviet Union and the People’s Republic of China.

The T-54-2 and T-54-3 arrived in the Democratic People’s Republic of Korea between the mid and late 1950s but in very limited numbers. They could not even fully complete the ranks of the 105th “Seoul” Armored Division. In the 1960s, the first T-55s arrived and, according to KPA sources, the first license-built T-55s left the factories in 1968.

However, when the KPA realized that its heavy industry was not advanced enough to provide the Army with the armored vehicles they needed, as production of domestic armored vehicles was slow, several batches of Type 59s (and new batches of T-55s) were purchased from China and the Soviet Union in the mid-to-late 1960s.

T-55 in North Korean service. Source: pinterest.com

The T-54-2 or T-54 Model 1949 was produced in the Soviet Union between 1949 and 1952 and was the first version of the Soviet tank to go into production in large numbers in the USSR. It was armed with a 100 mm D-10T cannon with 34 rounds available and a V-54 water-cooled V12 diesel engine with a maximum power output of 500 hp.

The next version, the T-54-3 or T-54 Model 1951, was produced from 1952 to 1954 and differed from the previous version through its new turret that eliminated the previous shot traps, and new optics for the gun.

The T-55 probably arrived in DPRK in the A version, which was produced after 1958 and had some upgrades. The most important were the new V-55 engine with a maximum power of 580 hp, the ammunition count increased to 43 rounds, a smoke extractor and a new NBC (Nuclear, Biological and Chemical) protection system.

The maximum speed of all three tanks was over 50 km/h, with a maximum range of 450 km (600 with external tanks) and a weight between 35 and 36 tonnes.

The Type 59 was produced from 1959 onwards and was essentially a copy of the T-54A with a Model 12150L water-cooled V12 diesel engine and a maximum power output of 520 hp. The gun was essentially the same, with a smoke extractor and a different name, while range, weight and top speed remained unchanged from the Soviet versions.

Korean People’s Army Type 59s on parade on Kim Il-sung street. Source: jinbaisroomofsandbox.blogspot.com

The hull of the vehicles was heavily modified for the Chch’e’po (which is also why it is difficult to identify which hull it is based upon).

The origin of the main gun

The main armament of the Koksan is a very powerful 170 mm cannon with a barrel length of more than 8 m, meaning it is roughly an L.50. Its caliber is very unusual. In fact, no Soviet, Chinese or even Western artillery pieces have the same caliber.

There is a dispute on the exact origin of this huge weapon given the abnormal caliber. Some sources, like the Korean People’s Army Journal (which is not written by the North Koreans), argue that it may be a derivative of the German 17 cm Kanone 18 in Mörserlafette 170 mm L.47 produced in 1942, which was presumably provided to the Koreans after the Korean War by the Soviets. Some also claim that, along with the guns, the Soviets provided stocks of German ammunition that the Koreans used, but this hypothesis seems more of a conspiracy theory than a real story.

The 170 mm Kanone 18 that was tested at the Aberdeen Proving Ground In March 1944. Source: MMOWG.net

A more sensible hypothesis is that the cannon was derived from the 149 mm Type 96 L.52 Japanese coastal defense cannon. Some examples of this weapon were placed in four Korean fortresses to defend from invasion during World War II, under the command of the 17th Japanese Army.

Two of these fortresses ended up in North Korean territory after the partition of the Korean peninsula in 1945. These were the Rashin Fortress in the eponymous city, on the border with the Soviet Union, and the Wŏnsan Fortress port city on the east coast. The actual origin of the Koksan’s cannon remains unclear and it is also possible that the North Koreans independently developed the cannon.

The 15 cm Type 96 gun. Source: pinterest.com

The cannon has an estimated rate of fire of 2 rounds every 5 minutes. It can fire at least three types of projectiles, including High Explosive – Fragmentation (HE-Frag) with a range of 43 km, enough to hit, for example, Incheon and Seoul from behind the DMZ.

The second type of projectile known for the 170 mm is a High Explosive Rocket-Assisted Projectile (HE-RAP), a type of fragmentation round with independent propulsion that increases the range of the projectiles to 54-60 km, making it one of the longest range projectiles in the world. This range was surpassed only in 2020 by the Extended Range Cannon Artillery (ERCA), which hit a target 70 km away.

However, this ammunition has some disadvantages. It creates very strong friction with the barrel, causing rapid wear of the rifling.

Some sources report that a chemical munition capable of releasing an unknown type of toxic gas on impact has also been developed. If it actually exists, its characteristics are unknown.

The Self-Propelled Gun

The turret and almost all of the top armor plate of the donor tank were removed, although the front part of the upper plate, with the driver’s hatch, remained unchanged. An armored plate was welded to cover the hull and three rails were welded on top, on which the gun could slide.

When the vehicle is in motion or parked in a barracks, the gun mount is centrally located, roughly where the turret was mounted on the tank. This is done in order not to have the center of gravity of the vehicle too far back. The gun is fixed in position by clamps that are fixed to the rails. When the gun has to be fired, the mounting is slid back. At the rear of the vehicle are two spades. These allow the vehicle to transfer most of the recoil directly to the ground, reducing the stress on the suspension.

Front view of a Koksan. The rails for the gun mount are clear. Source: mmowg.net

The spades are attached to the back of the hull and are hydraulically positioned. They can be folded in two, thus taking up less space.

The gun mount has handwheels for elevation and traverse on the left side. Because of the height of the breech from the ground, the Koksan has two walkways with rails on either side of the gun. This allows the gun crew to load the cannon and access the controls.

Before firing, the crew rotates the walkways 90° outward, so that they do not obstruct the recoil of the gun.

A M1978 firing. Notice that the right walkway is moved outwards. Source: sardaraneatash.blog.ir

At the front, the position of the driver remained unchanged, with his hatch on the left and a hatch added on the right, probably for the vehicle commander when on the move. On the frontal armor plate, the headlights on the right and the towing hooks were maintained, but a large travel lock was added to support the gun during marching.

The fenders house both external fuel tanks and spare tracks, like on normal T-54s, T-55s, and Type 59s, and storage boxes for the tools of the gun crew.

Crew

The crew of eight includes the driver, vehicle commander, gunner, and a gun crew of five. Due to the limited space available, only the driver and commander have a seat inside the hull, while the remaining crew members must be transported on a support vehicle that also carries ammunition. No ammunition is carried on the vehicle itself.

It is not known whether there is a special ammunition transport truck of Korean make or some indigenously modified version of Chinese or Soviet trucks. It is possible that regular trucks are used for resupply.

It is assumed that, for each battalion of 12 Koksan self-propelled vehicles, there are at least 30 trucks available. These are most likely Sungri-58 or Sungri-61 models, the backbone of the North Korean logistics services.

The Sungri-58 and Sungri-61 were produced by the Sungri Motor Plant in Tokchon, north of Pyongyang, from 1958 and 1961, respectively, based on the Soviet GAZ-51 and GAZ-63 trucks. The two trucks can carry up to 30 soldiers or a total of about 2 tons of munitions for a maximum ground weight of 3.5-4 tons.

A Sungri 58KA with a late cabin type introduced in the 1970s production run. Source: chinesecars.com
A Sungri 61 with the first production cabin type. Notice that the trucks do not have all four tires of the same type due to the limited quantities of imported rubber. Source: pinterest.com

In the Korean People’s Army service

The M1978 went into production in 1973. However, due to production problems, a sizable production rate was reached only in the following years. The first three dozen examples were spotted by military analysts in the small town of Koksan, halfway between Pyongyang and the DMZ, in 1978, well after production was already underway. This gave the US Department of Defense (DoD) designation for the vehicle, M1978. The vehicle was kept secret for several years, not being shown on parades or exercises until at least 1987.

Supreme Leader Kim Jong-un inspects an artillery unit. June 2018. Source: pinterest.com

The Koksan is supposed to be in service with the independent battalions of the General Staff Department’s Artillery Command. Each battalion has 12 Koksans and 30 trucks, with a total of 150-190 soldiers. It is divided into 3 batteries with four Koksans each and a headquarters unit.

In 1989, a new variant of the North Korean heavy SPG appeared. The M1989 has a longer boat-shaped hull, allowing the transport of 12 170 mm projectiles, four crew members rather than 2, and a man-portable Igla or Strela surface-to-air missile on board.

The total number produced is not known, but some analysts have proposed a total number of 500 between the two variants.

A photo taken before an exercise, showing all the self-propelled guns that took part in a live fire action, March 25th, 2016. Source: pinterest.com

The M1978 Koksans are still serving in the Korean People’s Army. The last major exercise they participated in was on March 25, 2016, near Wonsan Airport. Supreme Leader Kim Jong-un was also present.

During the training exercise, which was held on the sea bank, the island of Hwangt’o-Do was targeted by about one hundred M1978s and M1989s. The craters on the island are still visible on Google Maps in 2021.

M1989s in the foreground and M1978s in the background, opening fire during the exercise. Source: pinterest.com

Propaganda video presented by Ri Chun-hee of the Korean Central TV showing off the training.

Export

The very unusual caliber and the isolation of the nation have limited its potential export success. However, it must be remembered that the Democratic People’s Republic of Korea does export military equipment.

Iranian soldiers near a Koksan with standard T-55 tracks. Source: pinterest.com

On September 22nd, 1980, the Iraqi Army, under the orders of Saddam Hussein, attacked by surprise the newly formed Islamic Republic of Iran (IRI). They hoped to catch the Iranians unprepared due to the chaos created by the February 1979 revolution that had brought Ruḥollāh Khomeynī to power.

The goal of the Iraqis was to take control of the oil-rich Khuzistan region and try to stem the expanding influence of Iran and its revolution that were taking root in Iraq.

An Iranian Koksan with Korean tracks. Source: doblest.club

Seeing in this war the possibility of regaining control of Iran, the United States and other Western nations supported Iraq in the war. The inadequacy of the Iraqi armed forces and the unexpectedly strong Iranian resistance meant that, after an initial lightning advance, Iran regained its footing. After less than two months, the war ground to a stalemate that lasted eight months, during which Iran reorganized and pushed back the invaders.

In June 1982, a peace treaty attempted by Saddam Hussein failed and the war continued for another six years, ending only on August 20th, 1988 without territorial changes.

An M1978 opening fire from a well-prepared position. Source: globalsecurity.org

The Democratic People’s Republic of Korea had a decisive role in equipping Iran. In fact, due to the embargoes placed on the Persian nation, North Korea acted as an intermediary between the People’s Republic of China and the Soviet Union on one side, and Iran on the other, selling billions of dollars worth of tanks, missiles, airplanes, artillery, multiple rocket launchers, ammunition and small arms to the Iranians.

China and the Soviet Union would send the weapons to North Korea, where they would be loaded onto merchant ships bound for Iran, often still in the original crates. In other cases, North Korea sold the Islamic Republic of Iran Army (IRIA) domestically produced versions of Chinese or Soviet weapons or even weapons developed in Korea.

The same Koksan with North Korean tracks with its crew. Source: sardaraneatash.blog.ir

An unknown number of M1978 Koksans was supplied to the IRIA in 1987, along with some ammunition stocks. These self-propelled artillery vehicles were used to bombard Iraqi positions, although it is not known exactly in which engagements they were used and with what results.

It seems that some were used in an artillery unit under the command of future General Qasem Soleimani to hit the city of Basra in Operation Karbala-5. One fact that is reported is that the Iranians were provided with HE-RAP ammunition that allowed them to hit targets at a distance of 60 km, arousing the interest of international observers.

There is no certain data available, but some photos show the self-propelled guns in standard North Korean military green camouflage. Other photos show a two-tone camouflage, military green, and khaki. It can be assumed that the vehicles arrived in Iran in military green and the Iranians camouflaged them later with their own colors.

Iranian M1978 Koksan captured by Iraqi troops exposed in an Iraqi city. Although the photo quality is very low, the two-tone camouflage is visible. Source: pinterest.com

About thirty Koksans were captured during the final stages of the war by the Iraqis, while others are still in service with the Islamic Republic of Iran Army and shown in some parades in Tehran.

An M1978 still serving in the Iranian Army. Source: pinterest.com

Iraqi Koksan

The famous photo of the Iraqi version of the Koksan being towed by an M88A2. Anbar 2008. Source: wikipedia.org

At least one of the captured vehicles was displayed by the Iraqis, together with a Chonma Main Battle Tank.

The Iraqis appreciated the firepower and the incredible range and decided to produce their own version, often mistakenly confused with the original Koksan or considered a variant of it.
Given the almost non-existence of the Iraqi heavy industry, the armament of the new self-propelled artillery was the powerful 180 mm S-23 L.49 gun mounted on a German-made BLG-60 bridge crane vehicle.

The BLG-60 Bridgelayer. Source: militarytechnics.com

This new vehicle, of which almost nothing is known except the various photos of the only example produced, had, if the characteristics of the cannon remained unchanged, a firing rate of about one round every two minutes and a maximum range of 30 km with HE-Frag standard rounds and 44 km with HE-RAP rounds.

The Iraqi Koksan was captured in 2003 by U.S. troops near the al-Anbar University, in the eponymous region of al-Anbar. The specimen was left to rust until 2008, when the Americans removed it from the grounds where it was located.

Because of the poor conditions in which it was after at least 5 years with no maintenance, as soon as the U.S. soldiers began to tow it with an M88A2 HERCULES (Heavy Equipment Recovery Combat Utility Lifting Extraction System) Armored Recovery Vehicle, the tracks broke. Since then, its fate remains unknown.

The Iraqi vehicle towed away from the field. Due to their poor condition, the tracks have broken. Source: tcatmon.com
The Iraqi Koksan being lifted on a US trailer. Source: military-today.com

Conclusion

As with many North Korean vehicles, not much is known about the Koksan’s technical specifications or its deployment, but despite the usual stereotypes levied at military equipment produced in the Democratic People’s Republic of Korea, the M1978 proved its worth and firepower in the Iran-Iraq war, proving to be a good weapon even in the hands of the poorly trained Iranian Pasdaran.

With such a vehicle, in the unlikely event of a new war against the Republic of Korea, the Korean People’s Army could provide excellent support or barrage fire, hitting targets up to 60 km from its position. However, this is also a tool of geopolitical blackmail, as, in case of war with South Korea, the Koksan can fire at heavy population centers, such as Seoul, before they can be evacuated and thus cause significant civilian casualties.

Chch’e’po or M1978 Koksan of the Korean People’s Army. Illustrations by the Glorious Pavel Carpaticus funded by our Patreon Campaign.

Chch’e’po specifications

Dimensions (L-W-H) 6.3 m (~15 m gun forward) x 7.6 m x 3.27 m
Total Weight, Battle Ready around 40 tons
Crew 8 (commander, gunner, driver, 5 loaders)
Speed 30-40 km/h
Range 250-350 km
Armament 170 mm L.50 gun

Sources

The Armed Forces of North Korea, On The Path of Songun – Stijin Mitzer, Joot Oliemans

Korean People’s Army Journal Volume 2 Number 6 – Joseph S. Bermudez Jr.

3 replies on “Chuch’e p’o (M1978 Koksan)”

“Chuch’e Po” (or “Juch’e Po” via alternate transliteration) does not mean “main gun” (“although Juch’e can be translated literally as “main body.”. It is in reference to the ideology of “Self-reliance” (with implications of independence, autarchy, and isolation, all rolled into one) that is the state dogma of DPRK (what Juch’e” means in practice), ie the name of the gun means “the gun of NK state ideology “

M1989 Koksan is not only a mere longer boat-shaped hull. It’s based on Chonma / T-62 hull but reversed (the rear is now front and vice versa), and driver / commander compartment is added in the (new) front of the vehicle.
The clear photo is in the Archive version of this article, but the illustration is wrong and need for correction. The old illustration is still using T-55 hull and not reversed (sprocket is on the rear compared to the photo that shows sprocket is on the front behind driver / commander compartment).

The concept of long-range bombardment was also used by the US Army, which deployed M107 (SP 175mm) along the DMZ in Vietnam, and fired over it into North Vietnam. I believe the DMZ was about 20 miles deep, and the range of the M107 about 25 miles, although nothing of significance was actually within range.

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