The Korean War (1950-1953) tied up major Western powers both logistically and politically leaving nations such as Switzerland to seek alternative avenues for modernizing their armored corps. Thus began an oft-overlooked Cold War-era indigenous tank initiative which produced the short-lived 38-ton Panzer 58 (Pz 58) appearing in 10 pre-production forms as well as two earlier prototypes. The series entered service in 1958 and was out in 1964 as thought gave way to a more refined form in the Panzer 61 of 1965. The Pz 61 was produced through 150 examples and these saw service into 1994. The 43-ton Pz 61 improved both the range and speed of the original Pz 58 and fielded the excellent British 105mm Royal Ordnance L7 rifled main gun to content with the latest in Soviet armor. All tanks were produced locally by Eidgenossische Konstruktionswerkstatte of Thun and powered by Mercedes-Benz diesel engines.
It was only natural for the series to be refined and improved yet again and this begat the Panzer 68 which saw design in the 1960s and produced the first pilot vehicle in 1968. Production then began in 1971 and spanned into 1983 to which 390 total units were delivered. These served the Swiss Army into 2003 before the line was formally replaced by German Leopard 2 Main Battle Tanks. The 45-ton Pz 68 retained the 105mm L7 rifled main gun and was now powered by an MTU 8-cylinder diesel engine. Performance included a top road speed of 34 miles per hour and an operational road range out to 120 miles. Armor protection remained Rolled Homogenous Armor (RHA) measuring some 120mm thick at critical facings. Pz 68 models directly succeeded the Pz 61 line.
Between the Pz 61 and Pz 68 offerings, the latter brought about use of an all-new main gun stabilization system which sought to improve both first-shot/first kill probability and firing on-the-move. The track arrangement was redesigned to allow for more ground contact through extending track length and wider track plates. Changes to the running gear included an all-new, more powerful engine installation as well as a revised transmission system. Some facets of the design remained in place such as the 2 x 7.5mm machine guns (one coaxial) for self-defense, the torsion bar suspension for off-road travel and the crew of four (driver, commander, gunner and loader).
The Pz 68 measured a running length of 9.5 meters, a width of 3.1 meters and a height of 2.7 meters. Overall, it utilized a most conventional arrangement and form with the crew compartment at front and center and the engine in the rear. The turret was centralized along the hull roof. The glacis plate was well-sloped and the turret cast in a conical shape to promote good ballistics protection at all ranges. The main gun was fitted to the 360-degree traversing turret emplacement and overhung the hull by a considerable degree. The track system incorporated six double-tired road wheels to a hull side with the drive sprocket at rear, the track idler at front and three track return rollers used to manage the upper track span in their channel.
The Swiss government committed to an initial batch order of 170 units and these were delivered from 1971 into 1974. In 1977, a second batch order of 50 vehicles followed and these featured thermal sleeves on their main guns. To differentiate the two, the initial block models were designated Mk I and the follow-up forms as Mk II. Both of these versions were then followed by the Mk III which installed a dimensionally larger turret assembly while including all of the standardization of Mk II production models. The final production variant, the Mk IV, was delivered between 1983 and 1984.
In practice, the Panzer 68 was not a completely successful design for it was eventually considered "unfit" for modern combat - particularly against the expected Soviet foe. No fewer than 50 detailed faults were noted of the type including a limited transmission system requiring the vehicle to come to a complete stop before shifting to reverse was possible. The main gun was prone to involuntary firing when the cabin heating element was activated and fuel stores were found susceptible to fracturing over time. The NBC (Nuclear, Biological, Chemical) suite did not offer the listed protection levels for the crew and radio kit also interfered with the signals used in turret traversal, leading to involuntary movement of the turrets when the radios were in use. Track life proved a concern for many wore out ahead of their scheduled maintenance. It is said that the defects inherent in the Panzer 68 design ultimately led to the resignation of the then-acting Minister of Defence (Rudolf Gnagi).
The many faults concerning the original Pz 68 models were supposedly rectified in a later 1988 initiative which sought to provide a more completed tank product. This endeavor then produced the "Pz 68/88" designation of which 195 vehicles were upgraded of the 390 eventually produced.
Despite the noted deficiencies in the Pz 68, the chassis was put to use in other battlefield forms. The Entpannungspanzer 65 was an Armored Recovery Vehicle (ARV) variant lacking the turret with main gun while the Bruckenpaner 68 was a bridge-layer mounting a 60-foot single-piece span atop the Pz 68 hull. The Fliegerabwehrpanzer 68 was a proposed self-propelled, anti-aircraft platform mounting the German Flakpanzer Gepard gun system (2 x 35mm Oerlikon autocannons) though never accepted into serial production. The Zielpanzer 68 were ten Pz 68 hulls stripped of their usefulness and held to become mobile missile targets in testing. The Panzerkanone 68 - a proposed self-propelled artillery gun carrier - was produced across four prototype examples atop the Pz 68 chassis. These, like the AA designed, were not accepted for serial production (the American M109 was adopted instead).