as you probably already know if you read this blog, Yuri Pasholok recently visited the armor museum in Thun (Switzerland). Another remarkable vehicle that he saw there was the Panzer 58 Swiss medium tank. Here's some info about it.
For numerous reasons (especially economical ones), Switzerland didn't have its own armored vehicles for a very long time, opting to purchase foreign vehicles instead. Switzerland is however now only known for its mountains and banks but also for its quality arms manufacturing industry (that includes not only guns and rifles), previously however there were no real indigenous Swiss tanks. There were attempts during and after the war to build indigenous armored vehicles (such as the Nahkampfkanone project) but it never really went anywhere, since it was much cheaper to buy the Centurions or the G-13 TD's than to develop a vehicle on their own.
This attitude changed in the 50's. It's no secret that Swiss arms companies (Oerlikon, Solothurn) actively cooperated with the Germans in WW2. This cooperation continued after the war and it started to include tanks as well. In 1953, an alliance of German companies (Porsche, Daimler-Benz, Zahnradfabrik and Ruhrstahl) participated in a project of a new tank for India. This was the 30 ton class Indien-Panzer that was to be produced in India by the Tata company. Swiss companies participated in the development of the Indien-Panzer as well. The project was ready in 1954 but the client refused it in the end. There was nothing wrong with the tank actually, but Tata was not able to actually produce it. After some deliberations, the Indians chose to simply buy the British Centurions instead.
But the project did not end there. In 1956, the Germans started the Europanzer project, which was based on the Indien-Panzer 30 ton tank and so it was that the Indien-Panzer evolution resulted with the AMX-30 and the Leopard 1.
The Swiss did not stay idle either. The Indien-Panzer project, not possible to be built in India, was not a problem for the advanced Swiss industry. By the time the Indien-Panzer was developed, the Swiss worked on their own medium tank, receiving the index KW.30 (Kampfwagen 30, 30 ton battle tank). It was developed by Eidgenoessische Konstruktionswerkstaette (EKW) in Thun - it was the principal Swiss military design bureau, dealing not only with armor but designing aircraft as well. The vehicle was supposed to be armed with an indigenous 90mm cannon (9cm Kanone 48) and the engine was to be German - Mercedes Benz Typ 837 (the same one as proposed for the Indien-Panzer).
The prototype development was delayed and it was only ready in 1957, two years after the intended start of mass production. The early mock-up was created with 5 roadwheels, the same as Indien-Panzer.
The second prototype, after which the mass-produced vehicle was named, was armed with the British 20pdr gun (which was by the way license-manufactured in Switzerland as 8,4cm Panzerkanone 58). Instead of the coaxial MG, the vehicle received new 20mm Oerlikon gun (20 mm Panzerkanone 61) and the amount of roadwheels was increased to six. This is the prototype that was saved and remains in the Thun museum. After the trials, 10 pre-series vehicles were ordered, upgunned with the 105mm guns "10,5 cm Panzer Kanone 60" (a license-produced version of the British L7). These 10 pre-series vehicles were later modified to become the first Swiss mass-produced tank, the Panzer 61. 160 of those were made (this number includes the modified Panzer 58's), a rather large number for the neutral Switzerland.
Design-wise Panzer 58 (and early post-war German tank projects) was heavily inspired by the American design school (roadwheels, support rollers, suspension configuration, cast hull and turret and other elements). The "traditional" German elements (interwoven suspension, welded hulls) seemed to have disappeared.
The license-produced 20pdr