On the Path to Leopard 2

First-Generation Leopard 2 Prototypes

For the development of Leopard 2 in the early 1970s, German industry and the Bundeswehr could rely on significant experience gained from creating the Leopard 1 and the KPz 70 main battle tank.

Additionally, initial steps were taken within the experimental project (Experimentalentwicklung) known as KPz Keiler. At the project’s early stage, the tank’s direction and layout were not clearly defined. Many advocated maximizing the use of KPz 70 technologies to avoid wasting resources from the joint U.S.-German development effort. However, in most aspects, the development of the Leopard 2K prototype followed new approaches.

Krauss-Maffei in Munich was responsible for the overall management of Leopard 2 development. Porsche handled the chassis, while Wegmann worked on turrets for the prototypes. The path to the production-standard Leopard 2 involved manufacturing 16 first-generation prototypes, as well as two chassis and three turrets of the second generation.
Between 1972 and 1974, 16 hulls were built, designated PT1-17 (number 12 was skipped, PT stands for “prototype”) and 17 first-generation turrets, designated T1-17.

The wedge-shaped gun mantlet design was already known from the KPz Keiler. In principle, all turrets were identical and equipped with the EMES 12 fire control system and the panoramic PERI R12 sight. The most significant change concerned the rear of the turret, where a low-light television night vision system (BM8005A04) and a target illumination spotlight were installed, both of which could be raised and lowered.

The similarity in turret shape between the Leopard 2 prototype and the Leopard 1A3/1A4 was coincidental, featuring a stereoscopic rangefinder linked to the EMES 12 fire control system, instead of the combined stereoscopic and coincidence rangefinder TEM.
One of the development requirements was that the improved fire control system could be installed on the Leopard 1A3/1A4.

Key points about the first-generation Leopard 2 prototypes:

High specific power of 30 hp/t, combined with relatively mediocre spaced armor, made the tank unbalanced in terms of mobility and protection. The 1973 war and ongoing efforts to promote the tank in the U.S. introduced adjustments. The lack of a functional laser rangefinder in West Germany and attempts to unify the Leopard 2 and Leopard 1A3/1A4 turrets led to an initially outdated turret design.

The placement of complex retractable television systems and a spotlight at the turret rear took up space and increased costs, requiring stabilization for the night vision device and spotlight in addition to the daytime and panoramic sights.These shortcomings were addressed through collaboration with the U.S., which provided the EMES 15 fire control system developed by Hughes, featuring a laser rangefinder and, later, a thermal imaging channel.

Prototype T11, generally identical to the others, distinguished by the 20 mm cannon installation inherited from the KPz 70. The BM8005A04 device and spotlight are shown in the raised position.

On the Path to Leopard 2: New Impulses

Even before completing the testing of the first-generation prototypes, further steps were already being considered—the initial 50-ton weight limit had already been exceeded by 1.5 tons. Thus, the goal of developing an MBT in the MLC 50 class was not achieved. Due to insufficient funding, the requirement that developed components could be installed on the Leopard 1 was rejected.

The requirement that the fire control system could be retrofitted to the Leopard 1 as an upgrade was also canceled. This opened new possibilities for turret layout. Wegmann’s wedge-shaped solution, known as “Spitzmaus” (Shrew), saved 1.5 tons of weight and included a correlation rangefinder. However, new armor protection requirements led to the abandonment of this design.

Leopard 2 Spitzmaus Model

Subsequently, Wegmann proposed a new turret shape and the use of a new optoelectronic correlation rangefinder with a 350 mm baseline. This would have reduced weight by 1.5 tons. The result of this invention was the modified turret “T14 Modifiziert.”
This new rangefinder, EMES 13, as mentioned, was developed by Leitz and stabilized by a platform from AEG-Telefunken. The device served as the gunner’s primary stabilized sight.
For testing, a Leopard 2 prototype turret was converted and tested under the designation T14 mod.

Since the EMES 13 fit well into the turret’s front, this allowed for improved armor protection. Simultaneously, within this modification, a fully electric turret and gun drive for aiming and stabilization was developed in collaboration with General Electric and AEG-Telefunken. It became a real alternative to the previously used electro-hydraulic system.
At the same time, the U.S. began a new phase in tank development, also prioritizing protection. Following the first step, T14 mod., the second step soon followed—Leopard 2 AV.

Prototype Leopard 2 with PT16 hull and T14 turret.

The 1973 Yom Kippur War between Israel and its Arab neighbors underscored the importance of armor protection. Israeli tank units, repelling enemy attacks, suffered significant losses from handheld anti-tank grenade launchers and ATGMs. The U.S. rejected the first-series Leopard 2 prototype due to weak armor protection, and by 1974, an alternative to British Chobham armor had already been developed in West Germany, but it became clear that staying within the MLC 50 limit with the new armor was impossible.

In October 1974, a new target was set for the MLC 60 class. Amid attention from the Americas, German authorities saw an opportunity to revive cooperation similar to the MBT/KPz 70 project. In December 1974, Germany signed a Memorandum of Understanding, committing to provide a Leopard 2 prototype for comparative trials with the XM1 by September 1976. However, it did not include provisions that the best tank would be procured by both NATO countries for standardization, as planned in the MBT70 project. Nevertheless, some Germans hoped or even expected such an outcome.

Leopard 2AV, PT19

Under time constraints, the original consortium of German defense companies (Krauss-Maffei, Porsche, Wegmann) delivered machines designated as Leopard 2AV, where AV stands for “Austere Version.” Except for some technical components, the chassis and hulls were entirely new designs. Due to the new armor package, the hull’s external appearance changed: the nose became less pointed, and the sides almost vertical.

Leopard 2AV driver’s hatch.

The original driver’s hatch, similar to that of the Leopard 1, was replaced with a new sliding hatch (into the track space) — a feature that would reappear only on the Leopard 2A5 (the production series adopted an unsuccessful hatch similar to the first series).

The integration of the new turret armor package resulted in straight, vertical turret walls. Relocating the hydraulic system pump and the first-stage ammunition stowage to separate compartments at the turret rear further enhanced crew protection. The loader could access ammunition through an automatically opening door.

The fire control system and sighting equipment also underwent significant changes but were far from their final form—Germany lacked a thermal imaging sight and a reliable laser rangefinder. Initially, the turrets were designed for either a 105 mm or 120 mm smoothbore tank gun. For the comparative trials in the U.S., the T19 turret was equipped with a 105 mm rifled gun. Immediately after the official trials, the tank (still in the U.S.) was re-equipped with a 120 mm smoothbore gun to demonstrate the possibility of such a swap.

The machine above, PT 19/T19, was prepared to U.S. requirements for comparative trials with the XM1—Hughes fire control system, EMES 15 sight, but without a thermal imaging channel, which was not ready, and a remotely operated machine gun in a rotating turret similar to Soviet designs—lacking 360-degree static observation, with three forward-facing observation devices, an unsuccessful idea from Wegmann, 1976. The PT 21/T20 prototype featured a proper turret.

Overhead weapon station designed by Wegmann. The same design was planned to be installed on Leopard 3FT 1979 proposals.

German Army did not adopt this solution. Reason for this was that the commander should concentrate on his command duties rather than engage the enemy with a secondary armament.

The obvious advantage of the Leopard 2AV was the commander’s panoramic sight; the less obvious one was the powerful, economical, and reliable diesel engine. Had the competitor been General Motors’ XM1 concept, I wouldn’t be surprised if the Leopard had been preferred. However, all U.S. attention was on Chrysler’s gas-turbine XM1. The advantage of the 120 mm gun also fell outside the US evaluation criteria.

Leopard 2 History: Armor

Despite West German developments in dynamic armor in the early 1970s (DE2031658A, DE2008156A, DE2460302C1, and others), its use was abandoned. Primarily, Wegmann’s overly complex dynamic armor design would have significantly increased costs. Blohm + Voss AG had sufficiently advanced composite armor designs, and there were also active protection developments from DAIMLER BENZ AEROSPACE AG and other firms (DE2612673C1). Meanwhile, CLOUTH GUMMIWERKE AG worked on a promising armor concept consisting of a steel armor plate with a rubber layer vulcanized to a deformable structural steel backing plate.

Patent DE2439522A1 was issued in 1974 but declassified only in 2006. The concept is well-known: a cumulative jet hitting the outer armor plate creates a shockwave that affects the rubber layer, which deforms the soft steel plate, disrupting the jet. This non-explosive dynamic armor design (30 mm steel + 4 mm rubber + 4 mm steel + 25 mm air, and similar configurations) was called Baulblech, and in the USSR, “reflective sheets” (the USSR connection will be explained later). This achieved an outstanding anti-cumulative protection equivalent of 700 mm for the 1970s.

The diagram shows the protection scheme for the turret sides.

Diagram from Patent DE2439522A1 by CLOUTH GUMMIWERKE AG This protection became the basis for the Leopard 2AV and the future Leopard 2. Note Illustration 1—“reflective plates” are placed in a rubber matrix, ensuring high durability under multiple hits. Soviet and Russian designs still rely on clamping rubber with a metal matrix (on the upper glacis) or bolting (turret package).

General turret armor scheme, with two frontal packages not shown in this section.

Meanwhile, KRAUSS MAFFEI AG patented a filler package (Jalousiepaket) for the hull nose and turret with Baulblech in general. The Leopard 2AV turret transitioned to the production Leopard 2 with minimal changes, and subsequent filler package upgrades occurred only in the early 1990s.

However, the hull nose on the production tank was completely redesigned. Initially, a barrier of two non-explosive dynamic armor packages with a fuel tank placed between them, also serving as a composite armor filler, was planned (see illustration in the next message below).

The production Leopard 2 abandoned this design, retaining only the armor packages, which is one of the main external differences between the Leopard 2AV and the production Leopard 2.

The diagram above shows the Leopard 2AV hull nose protection scheme with two non-explosive dynamic armor packages and a fuel tank placed between them, also serving as a composite armor filler.

While CLOUTH GUMMIWERKE AG developed the principle of non-explosive dynamic armor Baulblech and its implementation in armor packages based on elastic elements, as seen in the turret sides and upper hull nose, KRAUSS MAFFEI AG created a variant of protection for the central hull section based on this development.

Explanation of the Leopard 2AV armor packages.

For mutual fixation of armored elements (71, 72), protrusions (72, 73, 75) and/or recesses (74, 76) are provided in their edge areas (tongue-and-groove principle). On the sections of armored elements in contact with the hull’s armored walls, a material in the form of rubber coatings (77, 78) is applied. On the rear side of each armored element, a 2.6 mm non-explosive dynamic armor layer (rubber + steel) was installed.

Diagram of the Improved Hull Nose Without the Fuel Tank

Further development of the Leopard 2AV design involved abandoning the fuel tank and combining KRAUSS MAFFEI AG’s ideas—two front packages for the central hull section—and CLOUTH GUMMIWERKE AG’s concepts—upper hull nose and rear package.
This further development led to the production hull nose design known from the production Leopard 2.