The newly-founded Czech Army - born by way of independence from the Austro-Hungarian Empire just before the end of World War 1 (1914-1918) - moved quickly to establish its inventory and this allowed local industry to thrive during the Inter-war period. In 1920, initiative for a new armored car produced the largely-forgettable Skoda-FIAT "Torino" based on an Italian truck chassis (detailed elsewhere on this site). This led engineers to develop a purpose-built system which became a pair of prototypes under the "PA-I" designation (notable in featuring a symmetrical "double-drive" system allowing the vehicle to retain its maximum speed and handling even when traveling in reverse). The PA-I served as the foundation for a more refined form that followed, the PA-II "Zelva" ("Turtle"). This iconic car design featured a rounded armor superstructure which accounted for its unofficial name. Officially the vehicle was designated "Obrneny Automobil Model 1923" and shortened to "OA vz.23".
Army authorities approved of the new vehicle plans and ordered the type into production through a twelve-strong commitment and these arrived in late-1924 / early-1925. The PA-II followed the same internal arrangement as the PA-I before it, retaining the key double-drive quality but its most unique feature was its rounded armor scheme. Instead of the sharp lines apparent in the earlier design, Skoda engineers elected for a smoother approach to their second attempt. The entire armored superstructure was shaped by hammer as opposed to being casted and armor protection reached 5.5mm. The shell components were riveted to the framework during final assembly to help create a strong overall bond - serviceable as protection against small arms fire and artillery spray. Vision slits were cut into the superstructure for situational awareness and cooling slots were present at the engine installation. Entry-exit by the crew was by way of hull-mounted hinged side doors.
As in previous iterations of Czech armored cars, armament was solely machine-gun-oriented. However, the PA-II was allowed internal space for 4 x 7.92mm Schwarzlose MG08 ball-mounted water-cooled machine guns and over 6,000 rounds of ammunition were carried for them. These were positioned at the four corners of the hull to provide for maximum flexibility concerning engagement angles. The crew numbered five, same as in the PA-I prototype, and this forced the dedicated gunners (of which there were two) to move from gun-to-gun as needed. There were also two drivers (for front and rear direction driving) and a vehicle commander. Power was served from an in-house Skoda 4-cylinder unit outputting 70 horsepower. Coupled with the armored superstructure, on-road speeds could reach just under 30 miles per hour but the vehicle suffered mightily in off-road performance due to a weak suspension system despite a 4x4 drive quality being built-in.
The series was evaluated by the Czech Army service in 1925 but failed its review - detrimental features included cramped fighting conditions, a low ground clearance, and heavy weight brought on by the armor scheme which led to what was essentially a low-profile cumbersome fighting machine - worthy of the "turtle" name. The design was ultimately rejected by the Army which instead moved on the Skoda PA-III and this vehicle promoted a much more modern appearance with better performance.
Skoda managed to sell its Turtle to Austria for use by capital police (three examples were delivered) and, in the 1930s, Czech police eventually procured the nine unclaimed Army examples. Twelve were manufactured in all - though only ten of the lot were actually armored, the remaining two were stripped for driver training.
Those examples that were still in service by the time of the German annexation of Czechoslovakia in 1939 came under Germany Army ownership and ended their days as such. Their primary role for the duration of the war was as a mobile communications relay platform where they carried German radio kits. By and large, the series was wholly obsolete by the time of the war but found this role nonetheless.
A 1927 offshoot of the Turtle was born as the Skoda PA-II "Delovy" and this design introduced a revised armored superstructure mounting a powerful 75mm Skoda L/28 gun. The gun was fitted offset to portside to account for the driver being seated along starboard in the hull. A commander's cupola was also added to the superstructure roof and a pair of machine guns were installed through ball mountings for local defense. The vehicle was intended as an artillery support platform but appears to have had only a single prototype constructed.