CZK - PM-1 (plameňometný tank)

MNO Main Staff of the Tank Command No. 11035 secret material 1949 issued on 14.2.1949 a requirement for the development of a flame-throwing tank based on the tank fighter ST-I (ex. Jagdpanzer 38(t)).
The development was a cooperative effort between ČKD-Sokolovo, Konštrukta n.p. Praha and the Military Technical Institute (III. and V. department).
Even during the development phase of the project, Škoda Plzeň was commissioned on 5 January 1950 to repair 53 war Jagdpanzer 38(t), which were to be stripped of their gun armament and intended for serial production of this flamethrower tank. Later another series of 22 machines was ordered, but later cancelled. Even so, by the mid-1950s, 83 of the gunless tank fighters had accumulated in warehouses, but even then the project was not completed. The last 30 vehicles were delivered from new production.
A source²⁾ mentions the intention to blind the holes of the prepared platforms for this project with armour plates cut from the wrecks of German Panther tanks and Jagdpanther tank fighters. It also states the intention to deliver 24 of these 50 mm thick cut-out plates.
Due to technological problems and an attempt to blind the gun bore with 60 mm armour from decommissioned ST-I tank fighters, it was tentatively decided to blind the bore holes on the first 8 pieces of the machines with only 5 mm sheet metal. Seven of these vehicles were sent to Milovice to the military unit 5211 on 24.3.1950. Their engine and chassis numbers are known. Whether the eighth vehicle was used to build a prototype is unknown to me, but it is quite possible. In that case it could be a vehicle on which they tried to weld armour of greater thickness, e.g. from the mentioned Panthers or Jagdpanthers. The question is whether the patch was actually 50-60 mm thick and welded on with a fillet weld so that it protruded through the plane of the original hull armour of the ST-I tank fighter, or whether it was a plate about 25-30 mm thick (an estimate after examining the photos). This could have been slightly larger than the hole in the front armour, then laid on the armour and welded. Personally, I am in favour of the latter option. For the flush armour would not only have to be accurately cut, but would have to follow the shape of the hole, including the shape at the widest point of the hole, where there was not a continuous arc, but cut-outs for mounting the gun.
The other vehicles that had been prepared in the interim (up to a total of 83 pieces) were only to be stripped and stored in warehouses for future rebuilding. These did not have the cannon holes plugged. Further modifications to the vehicles in preparation consisted of the removal of the ceiling armour and modifications to the interior.


The prototype was delivered in 2/1951. The tank had the cannon bore blinded with a steel plate, which I estimate to be about 25 mm thick. Initially, the development of the flamethrower to be fitted to the tank was carried out by the national enterprise Sigma Pumps, a prototype of which had been tested as early as 1949. Probably due to the unsuccessful attempt, a German-made Flammenwerfer 41 flamethrower was chosen as the armament for the first form of the prototype. The flamethrower was a small, fully rotatable turret shaped like a truncated cone. The armament was to be supplemented by a machine gun ZB vz. 37, which was to be mounted to the left of the flamethrower. However, the use of the vz. 26 light machine gun is actually photographically documented. The German "Np" type 1,000 litre capacity ammunition tanks were located behind the driver and on the starboard side of the vehicle body interior. On the right side of the vehicle's interior were also mounted cylinders (4 pieces) with compressed gas for "firing" the incendiary liquid. Another pair of cylinders were in an external armoured box on the right side of the superstructure.
After the first tests at VVP Jince on 26.2.1951 and 27.2.1951, an evaluation report was drawn up, in which it is stated on page 3 that the specifications were more or less fulfilled, including the range (130-150 m), which, however, was sporadic and, moreover, had a large dispersion. However, on page 4 of this evaluation report it is stated that the practical range was around 60 metres and with a large dispersion. Dissatisfaction was expressed with the pressure reducing valve, which operated unreliably and allowed more than the optimum 28 atmospheres of pressure into the propellant tanks. When this value was exceeded, the jet of ejected propellant was distorted and the range fluctuated. The quality of the Sh and Np fuels, which were not suitable for use in cold weather, was criticised. These cooled rapidly during the flight to the target and burned poorly (range was reduced by up to a quarter). Therefore, there was a call for the development of a new synthetic ASN propellant (scheduled for completion in 1954) and modification of the pressure reducing valve.


According to the MNO-NM-04284 decree of 27.4.1952, it was ordered to continue the development using a gelatinous incendiary liquid of domestic origin "Sh". VTÚ and Konštrukta n.p. Praha, which went into the development with insufficient experience, learned from the previous experiment and set up a regular test facility. After the research, the design of a new flamethrower design was handed over to ČKD-Sokolovo, which completed the new form of the prototype by 31.3.1953. Instead of the original turret, a modified turret from a light tank LT vz. 38 (the command turret was absent). The flamethrower tube was placed in place of the gun. The armament was supplemented by a DT tank machine gun from the T-34/85. The ammunition supply consisted of 17 magazines and the armament was supplemented by a supply of 18 hand grenades. The flamethrower had a bearing of +20°/-8°. The gunner controlled the aiming manually, activating the flamethrower by means of a foot-operated graduated control. The machine had three interconnected tanks with incendiary liquid with a total volume of 1000 litres (460 litres + 300 litres + 240 litres). Pressure tanks, 7 in number, with compressed gas were placed in an armoured box (the thickness of armoured plates was 8 mm) on the rear armour of the engine cowling. The gunner had an MK 4 episcope from the T-34/85 tank for sighting. Between 2 June 1953 - 5 June 1953, thorough tests were carried out in which a range of 130 metres and a total firing time of 66 seconds were achieved. The refuelling of the fuze mixture was also tested and the machine also passed driving tests. On the last day the German fuse mixture was tested, but it failed completely.
On the results of the tests, the Deputy Minister of National Defence, Lieutenant General Václav Thoř, prepared a report¹⁾ in which he listed the main shortcomings of the project. He cited design problems with the launcher valves and unsatisfactory characteristics of the ignition mixture. He also pointed to the lengthiness of filling the tanks with combustible fuel. Therefore, the project was returned to resolve these issues.
In late 1953, there was a lively discussion regarding the next course of action in the development of the flamethrower tank. Eventually, it was decided to complete the development to final form and commence mass production scheduled for 1955. However, the development dragged on disproportionately. Hopes of success were not fulfilled by the new fully synthetic ASN fuse, with which a shorter maximum range was achieved than with the expensive Sh. At the same time, there was controversy over the tactical use of this type of warfare agent.
Further trials were conducted in 7/1954, comparing the Sh incendiary mixtures (observed range 180 m) and ASN (observed range 125 m). Further tests took place in 2/19/1955 and final tests took place between 19/3/1956 - 24/3/1956. A new flame-thrower launcher, the VZR-252, was also developed. The project was essentially completed, the tests were satisfactory, but the design work was quietly stopped and the prototype cancelled due to the obsolescence of the concept and the platform on which the project was based. A program of such a specialized type no longer had any prospects in the process of technological development of future combat equipment.




u]Jagdpanzer 38(t) fighters repaired at Skoda Works and prepared for conversion to flame-thrower tanks (53 units)[/u




New vehicles delivered by Skoda Plants ready for conversion to flamethrower tanks (unknown serial and registration numbers) (30 pcs)

Vladimir Frantsev, Charles K. Kliment, Milan Kopecký - Jagdpanzer 38(t) Hetzer, MBI, Publishing House, Prague, year of publication 2001, ISBN 80-902238-9-3
Ivo Pejčoch - Flamethrower tank PM-I, HPM No.5/2006, ISSN 1210-1427
²⁾Mgr.Martin Dubánek - Od bodák po tryskáče - Nedokončené Československé zbrojní projekty 1945-1955, Mladá fronta 2011, ISBN : 978-80-204-2515-7
armada.vojenstvi.cz (Vladimír Francev part 2)
¹⁾Report on inspection tests of the prototype flame-thrower on the ST-1 tank chassis, VTU 7/1953 provided by JOK Difrologie from the Military Historical Archive Prague

1. prototyp plameňometného tanku PM-1.

Bílek, Jiří, a.i. : Československá armáda v prvním poválečném desetiletí – ( květen 1945 – květen 1955), MO ČR Agentura vojenských informací a služeb, 2006.ISBN 80-7278-777-7

Pôvodná the form of the prototype with a circular vežou.


*source:


Ivo Pejčoch - Liquid tank PM-I, HPM no. 5/2006, ISSN 1210-1427
archive VHA/the military history institute.

Zrekonštruovaný prototyp s vežou z LT vz.38 prešiel testami v období od 2.6.1953 až 5.6.1953 vo VVP Mimoň. Hlásenie o prevedení kontrolných skúšok je datované k 3.7.1953 (32 strán).

Hlášení o provedení kontrolních zkoušek prototypu plamenometného zařízení na podvozku tanku ST-1, VTÚ 7/1953 poskytnuté JOK Difrologie z Vojenského historického archívu Praha

Refurbished over the prototype with vežou of LT vz.38.


*source:


Ivo Pejčoch - Liquid tank PM-I, HPM no. 5/2006, ISSN 1210-1427
archive VHA/the military history institute.

Viaceré zdroje uvádzajú postavenie dvojice, či dokonca trojice prototypov. Dlhodobo som predsvedčený o tom, že vznikol len jeden prototyp, ktorý bol priebežne modifikovaný. Hľadal som zhodné prvky jednotlivých podôb prototypu s pôvodnou vežou i s vežou z LT vz. 38.
Štandardné ST-I mali úchyty pre príslušenstvo (zdvihák, krabica atď.) na pravej strane nadstavby. V prípade prvej podoby PM-1 sú úchyty presunuté na ľavú stranu. Ak by využívala druhá podoba PM-1 iné vozidlo nebol by presun úchytov na druhú stranu potrebný. Pritom je u druhej podoby pravá strana dokonale očistená od akéhokoľvek úchytu, či oka alebo akejkoľvek konzoly. S trochou snahy snáď možno vidieť na nekvalitných fotkách pozostatky línie zvarov, ktorými bola upevnená krabica pre tlakové nádoby.
Detail, ktorý je identický na oboch podobách PM-1 je poškodenie pravého predného ťažného oka.
Druhým detailom sú skrátené držiaky schurzenov na oboch podobách PM-1. U prvej podoby to bolo kvôli pancierovej krabici pre tlakové nádoby. Pri druhej podobe PM-1 bez tejto krabice, ktorá by mala využívať iné vozidlo by skrátenie držiakov nemalo zmysel.