CZK - VOŽ (VOŽ-1)

In a decree issued by the Ministry of National Defence on 4 September 1950, the Headquarters of the Engineer Army commissioned the development of a heavy amphibious vehicle. The program was referred to as VOŽ (Large Amphibious Vehicle). In the early stages of this program, the sponsors had the idea that it would be a three-axle amphibious vehicle using the Tatra 111 chassis. The vehicle was to be of similar design to the American DUKW. It was to be a vehicle capable of carrying a load of 3-4 tons, or a 75 mm gun with ammunition and crew. The VOŽ program was transformed into a pair of design proposals in 1951, namely a four-axle wheeled vehicle (VOŽ-1) and a tracked vehicle (VOŽ-2). This was because the three-axle design based on the V3S truck chassis could not meet the required specifications. According to the decision of August 10, 1951, the VOS-1 project was to be worked on in 1952, the development of VOS-2 was to be postponed to 1953. However, it was already clear at this time that the required specifications would not be met. The VOŽ-1 would not achieve the required cruising speed of 12 km/h and would not have favourable off-road handling characteristics. In the meantime, there were disagreements between the commissioned firm and representatives of the Army. The firm refused to take over the task of the VOŽ for 1952 (probably due to lack of capacity). Eventually, however, it agreed with the Army to complete the VOŽ-1 project for 1952. The design of the VOV-1 was submitted for approval by Tatra Kopřivnice n.p. on 30 January 1952, but due to deficiencies in the design, the design was not approved.

Due to the controversy about which type of chassis would be more advantageous, the Chief of the VTU ordered Tatra Kopřivnice n.p. to carry out comparative tests in order to find out which design (wheeled or tracked) was more advantageous. The tests involved a German half-tracked artillery tractor Sd.Kfz. 9, an American half-track M 14, a German Büssing four-axle all-terrain vehicle (Sd.Kfz.234 ?) and a ST-I tank destroyer. The tracked version proved more advantageous, and after approval by the VTU and Soviet advisors, work on the tracked VOŽ-2 probably began from 24 March 1952.
There were even two designs of the tracked amphibian. A design based on the artillery tractor DTH 1 by ČKD ended in failure. This would have been a lightly armoured tractor weighing 6,500 kg that could tow 5,260 kg in tow. The tractor would tow a pontoon on a two-axle chassis. The pontoon would have its own auxiliary engine with a propeller and steerable wheels. Its weight would be 3,500 kg and the cargo would weigh the same 3,500 kg. Steering of the pontoon would be provided by a crew using a rudder. The joining of individual pontoons was considered. This proposal was rejected due to the low sailing speed and the poor off-road handling characteristics of the pontoon tow.
Development concentrated on a second version, the design of which, however, exceeded the parameters specified by the Army. Therefore, both the design of the VOŽ-1, and the two VOŽ-2 designs were not approved at the meeting of 28 May 1952. Again, development on a standard truck chassis was called for. However, it had to meet the Army's requirements, which were somewhat reduced. Only the V3S chassis was considered, but the Praga company could not accept this project for capacity reasons. At the same time, however, the long-term development of a tracked version VOŽ-2 was allowed and the Tatra Kopřivnice n.p. company submitted a design on 2.7.1952. It succeeded in reducing the dimensions for which the project had been criticized.
On 21.7.1952 a meeting was held on the VOŽ, where the proposal for a wheeled version from V3S was rejected after several objections. Although the wheeled version of the VOŽ was criticised, a consensus was reached, the demands on the design were reduced and the proposal was accepted in principle with comments.

Mgr. Martin Dubánek - Od bodáku po tryskáče - Nedokončené Československé zbrojní projekty 1945-1955, Mladá fronta 2011, ISBN : 978-80-204-2515-7
Mgr. Martin Dubánek - VOŽ, HaPM No.3/2008, ISSN: 1210-1427
Digital archive of the Provincial Archive in Opava
VOŽ-2