Every major land army in the world employs some form of 150mm (or greater) caliber long-ranged howitzer - either towed or self-propelled. The 155mm caliber remains popular in the West while the East has sided with 152mm forms. For the modern Chinese Army, its 152mm battlefield requirement is fulfilled by the "Type 66" - a lethal long-ranged system capable of firing various projectile types over 10 miles away. The Type 66 has roots in the original Cold War-era D-20 devised by Soviet engineers.
The D-20 was first brought online with the Soviet Army in 1955 to provide a far-reaching battlefield weapon system capable of lobbing nuclear-tipped projectiles at a burst rate of six rounds-per-minute. It was the first Soviet-designed and developed artillery piece to feature a semi-automatic vertical sliding wedge breech block. Thankfully, the Cold War never went "hot" and the nuclear side of this artillery system was never tested in battlefields across war-weary Europe. Despite this, the D-20 went on to have a long, successful, and storied service life with the Soviets and its allies - an operational history that has run well into the current decade. Like other weapon systems, the D-20 was eventually adopted - and locally-produced - by China where it remains in service as the aforementioned Type 66.
The gun showcases a conventional arrangement and is faithful to the original Soviet design in many ways. The gun tube sits over a trainable mounting featuring built-in elevation and traverse controls for some tactical flexibility. The tube is capped by a large, multi-slotted muzzle brake and has a heavy-duty recoil mechanism to content with the violent recoil forces inherent in firing such a large-caliber round. The tube is access by the breech situated at the rear, giving complete access to the firing chamber. Elevation and traverse controls are offset to the right side of the gun tube as is the optics set. Both sides of the gun tube are straddled by sections of shielding to provide basic cover for the gunnery crew which numbers eight personnel - each trained in a certain aspect of the gun's function as well as having training overlap to take over a fallen comrades role. The carriage is a single-axle, twin-wheeled assembly with split trail arms allowed the weapon to be towed behind a mover vehicle. The entire system can also be air-lifted by helicopter or transported in the belly of a medium- or oversized- transport aircraft. Prior to firing, a baseplate is lowered under the center mass of the gun while the legs are dug into surrounding earth.
In practice, these weapon systems can be used for in-direct line-of-sight fire against enemy positions many miles away. The shells have an area saturation effect as well as a psychological one and can be used in conjunction with rocket artillery strikes as well as close-support aircraft attacks. Such volleys typically proceed an offensive movement where the attacker hopes to claim enemy-held territory by dislodging the defenders. Available ammunition stocks allow the Type 66 crew to fire High-Explosive (HE), smoke, illumination, anti-infantry flechette, chemical, biological, and nuclear rounds as needed - all meant to dislodge or outright neutralize enemy forces at range.
The Type 66-1 is a recognized, modernized / updated form of the original (and base) Type 66 howitzer. Sri Lanka is a known foreign customer of the Type 66 howitzer system.
At present, the Chinese Army has, on-call, some 6,245 individual towed artillery weapons as well as 1,710 self-propelled forms and 1,770 rocket-projecting pieces - all available in various calibers and designed to fill specific battlefield roles (area saturation, chemical, nuclear, biological attacks, etc...).