CZK - OA Š-971 "Jarmila"

When building the new armoured units of the post-war Czechoslovak army, no attention was paid to armoured cars. However, they proved to be a suitable means of reconnaissance during World War II. The change came only after the arrival of the new Chief of the General Staff, General Vaclav Kratochvil, who on 31 March 1952 approved the request of the Tank Mechanised Troops Command for the development of a new light armoured car.

According to the terms of reference for the development, the platform of the new light truck Tatra 805 was to be used for the OA. The platform was to be used without any major changes. The armament was to consist of one machine gun lafeted in the top of the open turret, another machine gun was to be lafeted in the front part of the hull. The maximum height was not to exceed 2,000 mm and the weight 3.5 to 4 tons.

At a meeting of representatives of the VTU and VTMV on 21 May 1952, it was announced by VTU staff that the original platform Tatra 805 was not suitable for an armoured vehicle. They proposed a modification of the platform with the engine located in the rear of the vehicle. In 10/1952 the VTU developed new technical requirements, which however were not implemented by the VTMV commander, Brig. Gen. Vladimir Janko did not approve. He insisted on using the unchanged platform, which was to be armoured like the Soviet BA-64. The vehicle was to be self-built in field workshops. However, a wooden model should be made first.

However, the commissioned company AZNP Mladá Boleslav continued to work on a preliminary project with the engine at the rear. The project was designated Š-971 or also "Jarmila". However, at the research council of the Chief of the III Department of the VTU, which took place on 12.12.1952, the representative of the VTMV insisted on the requirement of Gen. Janek and therefore the VTU was forced to commission the AZNP company to submit a conceptual design for a vehicle that would use the standard Tatra 805 roller platform. The designers promptly drew up the design and submitted it for consideration as early as 5 January 1953. However, the shortcomings of the project, which had been pointed out at the beginning of the project, were immediately apparent. The design of the rear-engined vehicle was approved and accepted probably on 13.6.1953. As was usual with almost every project at that time, there were requests for changes to the specifications. For example, on 7.3.1953, the VTMV requested the deletion of the machine gun mounting in the hull of the vehicle. Originally four prototypes were to be produced, the first of which was to be of unpanned sheet metal. Initially, the MNO requested the delivery of 155 production vehicles.

In 1954 it was decided to build only three prototypes. According to a report dated 5 February 1955, the first prototype in unpanned steel was built in 1954. The second and third prototypes were to be built in the first half of 1955. Some of the prototypes were to have modified engine cooling, which was the biggest weakness of the project.

The year 1955 was marked by active testing of the prototypes. At the beginning of 1956 it was decided to entrust Tatra with the modification of the unsatisfactory engine cooling. This was probably not accomplished until early 8/1956, and military tests were ordered on 8/8/1956. These were to take place from 8/21/1956 to 9/8/1956 at the garrison premises in Tabor. However, this did not happen. On 14.8.1956 the Chief of the General Staff informed the Commander of the VTMV that the Š-971 would not be included in the armament and the project was not envisaged in the prospective production plan. The VTMV commander was ordered to store a pair of prototypes by the end of 1958. In 1958, one Š-971 was kept in the state of the 4th Tank Base in Stráž nad Ralskem, as of 14.8.1961 the army reported two more vehicles. None of the trio of prototypes with registration numbers 59745, 59547 and 59674 survived.

For more details, development background, etc., see this source¹⁾.

¹⁾Mgr. Martin Dubánek - Prototypes of Czechoslovak armored cars on T 805 chassis, HPM No.1/2006, ISSN: 1210-1427
Mgr.Martin Dubánek - Od bodák po tryskáče - Nedokončené Československé zbrojní projekty 1945-1955, Mladá fronta 2011, ISBN : 978-80-204-2515-7
https://www.t805.cz/t805/10-Bojove-prototypy
VHA

The imposition of prototypov Š-971 in storage in 1956, however, wasn't the end of the ich career. After takmer year from zrušenia project sa in 1957 used the one prototype on vytvorenie demonštrátora nosiča novovyvíjaného 82 mm bezzáklzového kanóna vz.59. Motívom bolo dať prieskumným units, which doposiaľ used iba motocykle M-72 with prívesným vozíkom, modern vehicle.

Požiadavka sounded on dokončenie ľahkej version of this kanóna, ktorý by sa gave namontovať on vyvíjaný obrnený transporter OT-64, sovietske airborne vehicle AT-P and Š-971. W-971 malo poslúžiť on overenie this myšlienky.

There were two proposals. Jednoduchším návrhom bolo umiestniť the whole cannon with podvozkom into the hull of the vehicle with možnosťou circular odmeru. The second proposal rátal with montážou kanóna on the pivot firmly connected with vozidlom. Conceptual design developed Výskumné delostrelecké workplace, that a proposal odoslali Veliteľstvu tank troops 6.7.1957.

Umiestnenie guns on W-971 you vyžiadalo veľké interventions in konštrukcie of the vehicle. Odstránená had to even veža, adjustments would zasiahli flanking and vrchné panciere. Pre dosiahnutie vyššej elevácie kanóna had to even flanking panciere sklápateľné. Problémom bolo and umiestnenie munície. The stock 17 nábojov would not allow otváranie genuine bočných dvierok (after vystrelení niekoľkých nábojov), ľavé dvierka would wasn't possible otvárať vôbec. Riešením would be obmedzenie stocks munície on 10 nábojov. The number of členov crew would sa increased by one. In the year 1957 was one funkčná vzorka.

Cons of the design, however, prevažovali and fell rozhodnutie repealing this modifikácie. This effort, however, has revived myšlienku vývoja obrneného car and formed požiadavka to another development of the new pancierovej body on the platform Tatra 805 with motorom in the front. About two years neskôr vznikol a new project OA-82 Jarmila II.

Mrg. Martin Dubánek - Prototypes czechoslovak armored car on the chassis of the T-805, HPM no. 1/2006, ISSN: 1210-1427
Mgr. Martin Dubánek - From bodáku after the jets - Unfinished Czechoslovak armaments projects 1945 to 1955, Mladá fronta 2011, ISBN : 978-80-204-2515-7

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Origo video : https://youtu.be/YA7vKQxDbmc?t=696.