Panzerkampfwagen XI
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| Panzer XI | |
|---|---|
 A Panzer XI getting serviced during a demonstration | |
| Type | Main Battle Tank |
| Place of origin |  Ostlichtor |
| Service history | |
| Used by | Ostlichtor |
| Production history | |
| Designer | Kessel-Hassen |
| Designed | 1969-1976 |
| Manufacturer | Kessel-Hassen |
| Produced | 1979-Present |
| Specifications | |
| Weight | 55.5 tonnes (61.2 short tons; 54.6 long tons) |
| Length | 9.67 metres (31 ft 9 in) gun forward 7.72 metres (25 ft 4 in) hull length |
| Width | 3.7 metres (12 ft 2 in) |
| Height | 3.0 metres (9 ft 10 in) |
| Crew | 4 (commander, gunner, loader, driver) |
| Armor | Composite |
Main armament | 1x ((Manufacturer)) 128mm L/40 cannon (38 rounds) |
Secondary armament | 2x Biltz & Keckler MG 60 |
| Engine | 27.4L V12 liquid cooled turbo-diesel 1500 PS @ 2600 rpm |
| Power/weight | 27 PS/t |
| Transmission | Automatic (4 forward gears, 2 reverse) |
| Suspension | Torsion bar |
| Ground clearance | 500 millimetres (1 ft 8 in) |
| Fuel capacity | 1,200 L (320 US gal) |
Operational range | 550 km (340 mi) |
| Speed | 72 km/h (45 mph) |
The PanzerKampfwagen XI (PzKpfw XI) is a main battle tank designed and produced by Kessel-Hassen for the Bodentruppen. It succeeded the PanzerKampfwagen IX.
Development
In the mid 1960s, the Bodentruppen expressed interest in acquiring an improved tank after the initial public demonstrations of the Trinovantan TAG-22. The Bodentruppen were concerned that the obviously larger, more well armed Trinovantan tank would significantly outperform the recently developed PzKpfw IX that was currently in production. In response to this, a design requirement was issued to various Ostlander design firms to create a vehicle that would outperform the believed characteristics of this new potential threat. This new vehicle would have to be resistant to the 105mm rifled cannon across the frontal arc, mount a more powerful weapon than the PzKpfw IX that it would replace, and have at least equivalent road and cross country mobility than the PzKpfw IX. In addition to these requirements, the vehicle's combat-ready weight was not to exceed 60 tonnes.
Siegel AG submitted a significantly modified variant of its PzKpfw IX. An entirely new turret, equipped with an autoloader, a new 110mm smoothbore cannon, and an electric powered traverse system, was developed along with an extensive applique armor package to increase the protection of the hull. These modifications increased the weight of the vehicle from 42 tonnes to 50 tonnes. In order to maintain the vehicle's mobility, a new engine producing 1100 PS was developed. Other, minor improvements were also made to the vehicle, including a highly advanced remote anti-aircraft machine gun, an independent commander's periscope, and a new exhaust ventilation system.
The Kessel-Hassen proposal, in contrast, utilized an entirely new hull and turret of their own design. This turret was equipped with a 128mm smoothbore cannon whose design was derived from the [DESIGNATION] towed anti-tank gun previously in use by the Bodentruppen. Unlike the Siegel AG vehicle, this turret used a more conventional manual loader and hydraulic powered traverse. However, it was equipped with an advanced optical rangefinder and a new two-plane stabilization system. The hull was a proprietary design with little commonality to any vehicle currently in service, using an advanced hydropneumatic suspension and a compartmentalized powerpack that contained a new high-output turbodiesel that produced 1500 PS mated to a hydromechanical automatic transmission that had to be designed specifically for the engine. This prototype weighed 55 tonnes in a complete, combat-ready condition. The most notable feature of the Kessel-Hassen prototype was its novel armor design, utilizing a series of steel plates of varying hardness and ductility separated by an elastic rubber filling. This armor system showed promising performance against shaped charge weapons that were popular at the time, and the interaction between the hardened steel plates and elastic rubber filler material induced a higher than normal stress in APDS perpetrators as they passed through each layer of the armor, giving the armor a level of protection against both threats that was greater than its weight would normally allow.
Of the two competitors, the Kessel-Hassen vehicle was the clear favorite. The Siegel proposal's protection level, while a notable improvement over the PzKpfw IX it was based off of, was shown to still be below acceptable levels. Additionally, the new engine over-stressed the older transmission used on the vehicle, and could not produce mobility that was consistently equivalent to the PzKpfw IX. Siegel's new turret was also overly cramped, which resulted in an accident where the vehicle's commander had their arm crushed during trials. The electric turret traverse system, while capable of impressive turning speeds, was also prone to failure. The Kessel-Hassen vehicle, meanwhile, showed acceptable or higher marks in most of the conditions set out by the Bodentruppen's procurement staff. While heavier than the Siegel vehicle, the Kessel-Hassen prototype was not only more mobile than its lighter competitor, it was also more mobile than the 40 tonne PzKpfw IX it was to replace. Its 128mm cannon was superior in most regards to the 110mm cannon used by the Siegel vehicle, and it was demonstrated to be able to resist the 110mm cannon used by its competitor along the frontal arc at combat distances, though it was still vulnerable to the prototype APFSDS rounds used by its own 128mm cannon. The new powerpack design was also a highly praised feature, as it allowed for quick access to the entire powertrain of the vehicle for expedited replacement and maintenance. The hydropneumatic suspension system used by the prototype, while it provided fairly unique capabilities such as adjustable ground clearance and forward/backward tilting, was considered to be prone to failure and difficult to maintain. At the conclusion of the demonstrative trials, the Kessel-Hassen vehicle was selected for further development.
Design
Armament
The primary weapon of the PzKpfw XI is the ((Manufacturer)) 128mm L/40 smoothbore cannon. This cannon is constructed with a chrome-lined barrel to decrease wear from the high-pressure ammunition and is equipped with a fume extractor and a thermal sleeve. The vehicle carries 38 rounds for this cannon, with 14 rounds stored "ready to fire" in the turret bustle and an additional magazine containing 24 rounds located in the front hull. Both magazines are separated from the crew compartment, with the turret magazine being equipped with blow-out panels on the roof of the turret. A variety of ammunition is available for the cannon, including a series of tungsten APFSDS rounds, HEAT, HEAT-MP, and HE rounds. More novel ammunition, such as canister, Enhanced Effect Inert Penetrator, and cannon-launched ATGMs, have also been developed but are not in common use. The most modern variation of its APFSDS ammunition is capable of penetrating over 650mm of steel at a range in excess of 2 kilometers.
For engaging infantry, unarmoured vehicles, and light aircraft the PzKpfw XI is equipped with two Biltz & Keckler MG60 GPMGs. One of these machine guns is mounted co-axially, while the other is mounted on a anti-aircraft pintle mount. Up to 4500 rounds of ammunition can be carried for these weapons.