M-1978 Koksan - North Korea's 170 mm SPG - Tank Historia

M-1978 Koksan – North Korea’s 170 mm SPG

In 1978 the United States uncovered the existence of an enormous, mysterious self propelled gun in Koksan, North Korea. Lacking further data, they imaginatively named it the M-1978 Koksan.

40 years later and the Koksan is still a rather mysterious machine, with much of its performance remaining elusive.

The system is comprised of an enormous 170 mm gun, balanced precariously on the hull of what is likely a Chinese Type 59.

With enough range to strike important targets in South Korea, this Frankenstein-vehicle is still a concern to North Korea’s southern neighbour today.

Lets take a look at the the mysterious M-1978 Koksan.

Contents

Background

Very little is known about the Koksan, so the information within this article may become outdated in the future should more data about this vehicle come to light.

The Koksan is a North Korean self propelled gun that possesses extremely long range and was, for a time, the longest range mobile artillery piece in service. The need for such great range was likely to give North Korea the capability of hitting Seoul, South Korea’s capital, from behind the Demilitarized Zone (DMZ).

The threat of North Korean artillery hitting Seoul is very real, with South Korea building an expansive network of shelters underneath the city of 10 million people in preparation for such an eventuality.

DMZ Map.
Unlike North Korea’s capital of Pyongyang, Seoul is situated close to the DMZ.

For a long time North Korea has placed a large emphasis on artillery. This is mostly to make up for their distinct lack of air power, especially against an oponent like the US who has overwhelming air forces.

Furthermore, artillery is particularly suited to mountainous terrain of the Korean peninsular.

Their experience with self propelled guns dates back to the Korean War, when they received respectable quantities of vehicles from China and Russia around this time.

They would naturally need more, but as a young nation unable to design and build such vehicles from the ground up themselves, they had to get creative.

In many cases, North Korea modified the hulls of existing vehicles to receive an artillery piece (usually towed).

Tŏkch'ŏn SPG.
This particular Tŏkch’ŏn is armed with a 152 mm gun. Image by Stefan Krasowski CC BY 2.0.

One of these creations was the Tŏkch’ŏn, which is essentially an artillery gun fitted to a North Korean-made ATS-59 artillery tractor.

If North and South Korea come to blows again, it is almost guaranteed North Korea will quickly start shelling Seoul and other high value targets in the South. They have dispersed artillery units throughout the mountains behind the DMZ that are waiting for orders to fire.

To close the gap between this location and Seoul, North Korea needed an extremely long range artillery system. This brings us to the focus of this article, the M-1978 Koksan.

The Koksan

If range was the goal, range was what they got.

The Koksan was developed in the 1970s to deliver large shells over the DMZ into South Korea, while remaining out of range of South Korea’s own guns.

Thanks to images and some basic data, a general overview of the Koksan exists, however the specifics are still murky.

It followed North Korea’s past tendencies to mount large artillery guns on the hulls of existing vehicles in their service. This simplifies and reduces the cost of construction, training and maintenance.

Iraq's attempt at the Koksan.
A Koksan captured by the US in Iraq. While this vehicle is not identical to the North Korean type, it is very similar in appearance.

Surprisingly though, the exact vehicle used for the Koksan’s chassis is not known. It is of T-54/55 nature, so it could be either of these, but many agree it is likely a Type-59 hull: a Chinese copy of the T-54.

The hull’s armor remains unchanged, but the gun is placed on top without any enclosed structure to protect either itself of its crew.

It is an enormous 170 mm weapon.

The gun sits on a set of three rails, which allow it to slide forwards and backwards depending on the situation. During operation the gun is slid to the back, while during transport it is slid towards the center of the hull to help maintain a “normal” center of gravity.

To transfer some of the immense recoil forces to the ground, the Koksan is fitted with spades at its rear like many SPGs.

The gun mount is also fitted with folding catwalks on each side for the crew.

Due to the exposed nature of the gun, the Koksan can only carry two of its crew. This is the driver and commander.

The rest must be transported separately. There is also no room for ammunition, so this is transported by separate support vehicles.

Upgraded version of the Koksan, the M-1989.
This is the improved version of the Koksan, discovered in 1989. It is known as the M-1989 and can carry 12 rounds of ammunition on board. Image by Stefan Krasowski CC BY 2.0.

The 170 mm gun is tremendously powerful. Its HE rounds have a range of 43 km (27 miles), while its High Explosive Rocket-Assisted Projectile (HE-RAP) rounds have an incredible range of 60 km (37 miles).

For comparison, the 800 mm Schwerer Gustav had a range of 47 km (29 miles).

Intelligence experts suspect that North Korea has developed chemical rounds for the Koksan too, but this is not confirmed.

The Koksan is said to have a fire rate of about one round every two and a half minutes.

It entered production in the early 1970s, with the US discovering its existence in 1978. It wouldn’t be publicly unveiled until 1985, by which time the system was a decade old.

Unsolved Mysteries

Obviously, the Koksan’s distinguishing feature is its enormous 170 mm L/50 gun, however the nature of this weapon is a mystery.

As already seen just from the story of the Koksan, North Korea is no stranger to adopting Soviet and Chinese equipment and standards.

It would make sense then that the Koksan’s gun is a Soviet or Chinese piece, either purchased or manufactured domestically. But neither China or the Soviet Union used weapons of this caliber, creating many questions about the source of this gun.

One of the most popular – and interesting – theories is that it is based on the WWII era German 17 cm Kanone 18.

17 cm Kanone 18.
The German Kanone 18 is a similarly proportioned gun. However it is improbable that this is the basis of the Koksan’s armament, Image by Skaarup.HA CC BU-SA 4.0.

This 170 mm gun is also 50 calibers long. The story goes that this gun and stocks of its ammunition were provided to North Korea by the Soviets.

On the other hand, some dismiss this theory for being too far fetched. Another idea is that the gun was derived from a Japanese, Chinese or Soviet naval gun.

Of course, there is always the possibility that North Korea did, in fact, create this gun on their own, explaining the unique caliber.

Service

The Koksan has been in service with North Korea since the 1970s, and still is today. Like so many aspects of this vehicle, the amount that have been produced is not known, however intelligence experts believe around 500 were made.

Despite being a North Korean vehicle, it is perhaps most famous for its use in the Iran-Iraq War.

North Korea sold the Koksan to Iran, giving it a sizeable fleet of these vehicles which it seemingly used to great effect after Iraq invaded.

Iraq ended up capturing a number of these vehicles and was inspired to create their own. This resulted in an almost identical copy, also on a T-54-type hull. The Iraqis used a 180 mm gun instead, though.

The Iraqi Koksan being pulled by an M88.
The Iraqi “Koksan” captured by the US in 2003. This image shows its removal via an M88. The process caused the tracks to break.

Despite being a different vehicle, it is still often referred to as a Koksan.

In 2003 an Iraqi Koksan was discovered by US troops on a university campus in Iraq. The unit planned to transport the gun back to the US as a trophy, but this never materialised.

Five years later the US decided to remove the gun, which was now in a very rough state. It was photographed as it was being pulled out of its resting place by an M88, breaking the tracks in the process.

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What happened to it after this is not clear.