German PzH2000 self-propelled howitzer

Since the German Army received the first PzH2000 self-propelled howitzer manufactured by Wegmann in July 1998, Germany became the first country in the world to deploy a 52-caliber 155mm self-propelled howitzer (the first country to deploy a 52-caliber 155mm towed howitzer was Singapore).
The German Army ordered a total of 594 PzH2000s at a unit price of $4.5 million. In addition to the German Army, countries such as the Netherlands and Italy also equipped themselves with this type of artillery.

Overall structural characteristics
The PzH2000 consists of three parts: a 155mm gun with a 52-caliber barrel, a rotating turret and a tracked chassis. The gun is installed at the rear of the chassis through the turret. The internal space of the turret and the chassis forms a fighting compartment. The driver's cab is set at the right front of the gun vehicle. There are seats for 4 gunners in the fighting compartment: the aimer is in the front right and the gunner is in the back; the projectile loader is in the front left and the charge loader is in the back. The driver's seat is in the cab. All 5 crew members monitor and operate the self-propelled gun through a control display. In addition to the 4 gunners, the fighting compartment also stores 60 rounds of artillery shells, and is equipped with an automatic loader, an automated fire control system, and three-defense, ventilation devices and other equipment.

▲ The position of the Pzh2000 self-propelled howitzer and its crew.

The turret is rectangular with a slightly raised rear. Due to the long barrel of the gun, the turret seat ring is required to be installed as far as possible to the rear of the vehicle body, so that the forward exposed length of the gun body does not exceed 3.3 meters. There is a large double-opening rear door at the rear of the fighting compartment, through which all five crew members can smoothly enter and exit the fighting compartment and the cab. The driver usually enters and exits the cab through the covered hatch on the top of the cab.
Having learned from the failure of the SP70 self-propelled howitzer jointly developed by Britain, Germany and Italy, that is, the rear-mounted engine design limited the storage space for ammunition and the space for the gunner to move around, the engine being located at the left front of the vehicle became an important feature of the overall layout of the PzH2000.
The combat weight of PzH2000 reaches 55 tons, which is basically equal to the combat weight of Leopard 2 main battle tank, which is 55.15 tons. It is the heaviest self-propelled howitzer in the world. The main reasons for the overweight of the gun are: more ammunition, advanced launch device, and a large number of protective measures to improve the survivability of the gun.

▲ The German Leopard 2 main battle tank, although it looks different from the Pzh2000, but they are probably the same in terms of weight, after all, the combat weight is basically the same.

52-caliber 155mm gun While NATO countries generally use 39-caliber 155mm self-propelled howitzers, the PzH2000 was designed with the 52-caliber 155mm gun developed by Rheinmetall. This gun has an advantage in range and high accuracy, allowing the PzH2000 to have a range of 30 kilometers when firing standard grenades and a maximum range of 40 kilometers when firing extended-range shells.

▲ Many NATO countries have been equipped with the M109 self-propelled howitzer, which originally used a 25-caliber barrel and was later upgraded to 39 times.

The gun barrel is 8.06 meters long, the chamber volume is 23 liters, and the maximum initial velocity is 945 meters per second (the initial velocity can be automatically measured using the initial velocity meter installed at the rear of the cradle). The chrome-plated barrel has a lifespan of 2,000 rounds (when using large-sized charges).

▲ Ammunition used by the Pzh2000 self-propelled howitzer.
In order to be used as a vehicle-mounted weapon, the barrel is equipped with a multi-hole muzzle brake (with an efficiency of 48%) and a cylindrical smoke extractor. The gun's elevation range is -2.5° to +65°, and the directional range is 360°. In order to balance the muzzle weight, a new torsion bar type mechanical balancer is used. Another innovation of this gun is the use of an inserted barrel fixture, which does not require the entire elevation aiming section to be removed when replacing the barrel. Under field conditions, it takes about 30 minutes to replace the barrel.

▲ Schematic diagram of the structure of a 52-caliber 155mm artillery.

The breech block is equipped with a semi-automatic wedge-type breech block and an improved gas-locking ring. The gun currently uses a standard percussion ignition system with an ignition tube primer. It is equipped with 32 primers, which are directly inserted into a groove behind the breech block, and can realize automatic primer loading. In order to improve the ignition performance, a laser ignition system will be used instead.

Ammunition and autoloader ammunition Since the PzH2000 meets the requirements of the "Four-Power (US, UK, Germany, Italy) Ballistics Agreement", it can fire all NATO 155mm standard ammunition and extended-range ammunition. It can use both new modular propellant charge systems and existing bag propellants. The main types of ammunition for this gun are as follows:
The L15A1/A2 grenade is mainly used to attack soft targets. It can only achieve damage to semi-hard targets when it hits directly. The projectile weighs 43.5 kg and the killing radius is twice that of the American M107 grenade. The maximum range is 30 kilometers.

▲ Cross-section of the L15A2 grenade

The DM642/DM652 submunitions are mainly used to attack semi-hard targets. The DM642 submunitions contain 63 shaped charge bullets and have a self-destruct device with a maximum range of 27 kilometers.
The Smart homing submunition is a "fire and forget" shell, mainly used to strike armored targets. The submunition contains two bullets. The maximum range of the shell is 28 kilometers.
The DM72 modular propellant charge system is composed of 6 cylindrical modules (large charge). Each module is equal and interchangeable, weighing 2.5 kg. The total weight of the 6 modules is 15 kg.
The automatic loader automates the ammunition loading of the gun, enabling it to have a burst firing capability of 3 rounds/10 seconds and maintain a very high firing rate for a longer period of time: 10 rounds/minute or 20 rounds/3 minutes.

▲ Schematic diagram of PzH2000 system composition.

The automatic loader consists of a feed rail, magazine and feeder, a transfer arm, a pneumatic feeder, seven electric drives and one pneumatic drive. The star-shaped magazine in the middle of the vehicle body is equipped with 60 rounds of projectiles, 288 modular propellant charge units and an ammunition computer. A fuze setter is installed on the feed rail. The electric drive and electric gun control device (part of the automated fire control system) are powered by a 1.9 kW generator on the gun carriage.
When the automatic loader fails to work, two ammunition loaders will manually load the ammunition from the magazine. They can also use the ammunition stacked behind the gun carriage and load the ammunition directly through the rear door of the gun breech.

Chassis and gun carriage protection measures The tracked chassis is a redesigned and developed system using existing "Leopard" tank chassis components and components of the same structural series. The MT881 V8 engine installed on the left front of the gun carriage, like the MT883 V12 engine of the "Leopard" 3 tank (co-developed by France and Germany, the whole vehicle system has not yet been successfully completed), is a small-sized and light-weight 880 series V-type engine. The MT881 V8 engine has a power of 735 kW (1,000 horsepower) and weighs 960 kg.

▲MT881 V8 engine.

The transmission is an electronically controlled HSWL284 4-speed hydromechanical transmission, which has the same structure as the HSWL354 transmission of the Leopard 2 tank.
The components of the running part are selected from the Leopard 1 tank. There are 7 road wheels, 5 shock absorbers and 4 track rollers on each side. The driving wheel is in the front and the idler wheel is in the back. The double-pin rubber track shoe is 550 mm wide, and the upper part of the track is covered by a skirt.

▲ Although the Leopard 1 tank has been retired from the German army, parts of its running gear are used on the Pzh2000 self-propelled howitzer.

The use of a high-performance crawler chassis gives the gun high mobility and off-road performance, allowing it to keep up with the armored mechanized forces it supports. The gun's outer dimensions are: 11.67 meters long (with the gun barrel), 3.58 meters wide, and 3.43 meters high (to the top of the periscope) in marching mode. The gun vehicle has a unit power of 13.2 kW (18 horsepower)/ton, a maximum speed of 60 kilometers per hour, a maximum climbing gradient of 26°, a maximum sideways driving gradient of 14°, a vertical wall height of 1 meter, a trench width of 3 meters, a vehicle bottom height of 0.44 meters from the ground, a wading depth of 1.5 meters, and a maximum range of 420 kilometers.

▲ Three views of the Pzh2000 self-propelled howitzer.

The body and turret of the gun vehicle are made of steel plate welded structure, and the crew and ammunition are armored, which can effectively resist the fragments produced by the close-range explosion of large-caliber grenades and the direct attack of 14.5mm armor-piercing projectiles.
In order to protect against top attack weapons, reactive armor is installed on the top of the turret. The reactive armor is installed quickly by the crew using the equipment on the gun carriage during wartime, and is removed during training. Without reactive armor, the gun weighs 53 tons.

Other protective measures include: the three-defense and ventilation devices enable the crew to fight continuously for 6 hours without restrictions under nuclear, biological and chemical conditions, and can fire all the ammunition they carry; to implement smoke interference protection, it is equipped with 8 smoke bomb launchers; the turret is equipped with a 7.62mm machine gun for self-defense, which can be used to attack ground and air targets, and is operated by a projectile loader; the inner wall of the fighting chamber is attached with a lining that protects against radiation and secondary fragments; the automatic fire extinguishing device has a certain passive protection effect; in the center of the upper deck in front of the gun vehicle, there is a hydraulic gun marching fixer, which is remotely controlled by the gunner, which can improve the protection of the crew and is also conducive to the rapid completion of marching and combat preparations.