PIBWL presents:

Polish experimental tankettes (TKW and TKS-B)
and special equipment for tankettes

Polish tankettes part V

PIBWL Polish Armour page [ Main page ] [ Polish armour / tanks ] [ Polish armoured units ] [ Steel Panthers ] [ Links ]Po polsku
© Michal Derela, 2007 Updated: 7. 8. 2008 - revised text, added photos


Part I: Development history & production models --- Part II: Camouflage, description, specification, modelling
Part III: Service with photo gallery --- Part IV: Tankettes with 20 mm cannons --- Self propelled guns
Part V: Experimental tankettes & special equipment --- Part VI: Foreign service --- TKS gallery

The TKS on the 'autransport' chassis.
The TKS on the 'autotransport' chassis, in an early camouflage, 1934-36.
In a background are Vickers E tanks. A motorcycle is CWS M-111 (Sokół 1000). [7]


This article is a supplement to the Polish tankettes TK-3 (TK) and TK-S (TKS), presenting their experimental variants TKW and TKS-B, and a special equipment for tankettes. Experimental self-propelled guns TKD and TKS-D are described on a separate page.


TKW tankette

From 1931, the Polish Army began to be equipped with tankettes - small turretless reconnaissance tanks TK-3 (TK), designed in Poland, modelled after the British Carden-Loyd Mk.VI. Thanks to mounting an armament - a machine gun in a hull, the tankettes had low silhouette, making them difficult to spot and hit, and were cheaper to produce. On the other hand, a major drawback of such weapon arrangement was a limited angle of fire. The whole vehicle had to turn to fire at side targets, and quick engagement of some targets was difficult or impossible. It was especially notable in tankettes used on rails as armoured draisines. Trying to find a solution, the Armoured Weapons Construction Bureau of the Army Engineer Research Institute (BK Br.Panc. WIBI) in Warsaw designed a tankette with a revolving turret, named TKW ("W" for "wieża" = turret).

The TKW with an early (up) and late turret (below) [AJ]

It realized a similar idea, as other British designs of that time, like Carden-Loyd Patrol Tank (an unsuccesful development of the Carden-Loyd tankette). The TKW construction was based upon the TK-3 chassis. Its combat compartment was lower, and there was a small turret above the commander, armed with a standard 7.92 mm air-cooled wz.25 Hotchkiss machine gun. Turret armour was 8 mm, sides were riveted to a frame, it had a hatch on the roof and in a rear curved plate. A driver's head was protected with a big box hood, fitted with a reversible tank periscope for all-around observation (invented in Poland, by Rudolf Gundlach), a two-part observation hatch in front and an access hatch on the top. The commander had vision slots only in his turret.

At first it was decided to build 6 experimental tanks. The prototype was converted from the TK tankette nr. 1164 (of the first series, made of mild iron plates) in the end of 1932 or early 1933. The machine gun was soon changed to a water-cooled wz.30 of the same caliber, in a new universal ball mounting with a telescopic sight. However, trials in October 1933 revealed turret faults, like: lack of space, bad stability of gun mounting, poor observation, and especially poor ventilation. As a result, the second improved turret was developed in 1934, with a lengthened box-like front part, and ventilation slots under the hatch on the top. The machine gun was mounted in an universal ball mounting (judging from the mounting, the wz.25 machine gun was used again, although there are no photos known of the improved TKW with the machine gun fitted and the mounting could be converted to the wz.30 MG).

Further field trials in summer 1934 showed, that this design was not succesfull at all. Its right side was overloaded and the crew members could not communicate with each other, while turret rotation and crew observation possibilities were limited. The driver's hood limited turret rotation to 306°, while the turret limited driver's field of view. In February 1935 the TKW design was abandoned and a production of further 5 tanks was canceled. It was evident, that a bigger tank was needed to fulfil reconnaissance tasks, that could be fitted with a turret without such problems and carry more adequate armament. In that period, the works upon bigger and more capable reconnaissance tank 4TP started. The TKW prototype was given to the Armoured Weapons Technical Research Bureau (BBT Br.Panc.). In February 1935 it was used for testing new rubber and metal tracks of Stefan Kardaszewicz design, but they appeared a failure (during trials it had the older turret again). Later the prototype was broken to parts. The newer turret was most probably utilized in the PZInż.130 amphibious tank prototype.


The TKW prototype on the 'autotransport' chassis (see below), most likely with an interim turret variant, being a subject of further modifications. [AJ,8].    The TKW prototype with the improved turret. [8]

Contrary to 1/35 RPM plastic kit, the TKW was not meant to be fitted with 20 mm cannon wz. 38 model A (FK-A) (see modelling section). When the FK-A was manufactured, the TKW program had been abandoned for a long time. Besides, it would be difficult to fit this cannon into the existing small turret. There were no designations: "TKW I", "TKW II" as well.


TKS-B tankette

The TKS-B during trials in summer of 1936, with weapon mounting removed. Note older camouflage scheme (the "Japanese-style"), with an interesting pattern of patches. [1,6]

Works upon a light artillery tractor C2P prototype, based on the TKS tankette showed, that the TKS steering system is unsuitable for towing guns. Both TK and TKS tankettes made turns by simply braking one track. In 1936, the Polish designers decided to add side clutches to the transmission of the tractor, and make rear idler wheels bigger, so they became also last roadwheels. At the same time, the chassis of one TKS tankette was converted this way (it was the tankette nr. 1510, of the first series, made of mild iron plates). The conversion was designated TKS-B (or TK-SB, or TK-S-B) - for "sprzęgła boczne" = 'side clutches'.

During trials in summer 1936, an average speed of the TKS-B was higher by 5 km/h over the TKS, both on road and off road. It was also easier to steer and consumed less fuel. Its traction performance improved greatly and trials were succesfull, but the production of the TKS was ending at that time, and they were not considered modern fighting vehicles anymore. It was estimated, that a conversion would cost as much, as 10,000 złoty (compare prices), therefore a conversion of produced TKS tankettes was considered unworthy. The prototype TKS-B was next converted to a tank destroyer TKS-D.

Contrary to the 1/35 Mirage plastic kit, the TKS-B was not fitted with 20 mm cannon FK-A, and in 1939 the TKS-B prototype was not existing.



Polish experimental tankettes (drawing Janusz Magnuski) [9]


Special equipment

Trailers

Basing on the British designs, bought by Poland along with Carden-Loyds, a tracked two-axle universal trailer for tankettes was produced in Poland as well. According to organization charts, there should be one trailer per a tankette platoon (two in a company), used for carrying spare parts by a tankette of a repair patrol. The tankettes could also tow a typical fuel trailer, with three 200l fuel barrels and two 50l oil barrels.

Left: the TK-3 with a tracked transport trailer [1]


Below: the TK-3 with a fuel trailer [1]
   

The TK-3 equipped with the RKB/C radio.

A two-axle, two-part trailer for the RKD long range radio set and its 4-men crew was also developed. It was derived of a horse-drawn radio trailer, differing with pneumatic tyres instead of wooden ones. It was meant to provide armoured units with a radio contact with major units. There are no details in publications about their usage, but most likely they were used until late 1930s only, then replaced with radio cars in armoured units.

Right: The TK-3 with the RKD radio trailer of the 5th Armoured Battalion in Cracov, 1938. [1]


Transport means

A new, unique usage of tankettes, conceived in Poland, was employing them as armoured draisines - reconnaissance rail vehicles, used in armoured trains. For this purpose, they used special rail runners - frame-shaped two-axle carriages. The tankette on a rail runner drove on rails using own tracks. The rail runner had a hydraulic mechanism to lift the tankette, and a ramp to unload it. The tankette could mount and dismount without the crew leaving the vehicle. By 1939 there were about 50 rail runners produced. Part of TK and TKS tankettes (at least 20) used as armoured draisines were equipped with a short-range radio RKB/C. They differed in having two additional boxes with equipment on front or rear fenders, a long pole folding aerial on a right side and some minor changes in external and internal equipment (see more at armoured draisines page).


The TKS on a rail runner as an armoured draisine.


In order to avoid too much wear of tankettes' drive mechanism, another unique device was developed in Poland: a wheeled chassis called "autotransport". It was meant for transporting tankettes over longer distances without using trucks. It was a two-axle engineless chassis, basing upon Ursus A truck parts. The tankette was riding onto this chassis through a rear ramp, then its crew was disconnecting tracks and chaining sprocket wheels with a gear driving rear wheels. Front wheels were steered, connected with a tankette's steering wheel. The empty chassis could be towed by the tankette, and steered by the commander, sitting on it.

Several dozen of "autotransport" chassises were built and used in tankette units before the war. There is no record in publications, if any were still used in 1939. Organization charts of mobilized wartime tankette units do not mention them. Apparently they were impractical, for empty chassises demanded other vehicles to tow, while their use was limited to a safe area, without a danger of contact with the enemy. They were useless for broken down tankettes as well.

The TKS (left) and TK-3 (right) on the 'autotransport' chassis [1 / AJ]

  
 The TK-3 towing an empty 'autotransport' chassis [1]


Broken down tankettes were transported by 4x2 trucks: about dozen of Ursus A30 (1 tankette), several Polski FIAT-621L (1 tankette) and few Saurer (2 tankettes on a platform). These tank transporters were not numerous, and according to organization charts, there was only one transporter in a tankette squadron or company.

The TK-3 being loaded upon the Ursus A, pre-war. [AJ].An abandoned TK-3 on the Ursus A truck, examined by the German soldiers in September 1939


You can read about scale models and camouflage of the tankettes in Part II: Camouflage, Description & Modelling



Other parts:

Part I: Development & production
Part II: Camouflage, Description, Specification, Modelling
Part III: Service with photo gallery (not ready yet)
Part IV: Tankettes with 20 mm cannons
Part VI: Foreign service
Self propelled guns
TKS gallery





Sources:
1. Janusz Magnuski, "Karaluchy przeciw panzerom"; Pelta; Warsaw 1995
6. "Czołg rozpoznawczy TK-S", Militaria i Fakty Nr. 31 (6/2005)
7. "Czołg rozpoznawczy TK-S cz.2" - Militaria i Fakty Nr. 33 (2/2006)
8. Janusz Magnuski, Andrzej Kiński, "Tankietka TKW" in Poligon nr. 3/2006
9. Janusz Magnuski, "Czołg rozpoznawczy TKS (TK)"; TBiU nr. 36; Wydawnictwo MON; Warsaw 1975
AJ - photos from a collection of Adam Jońca


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Corrections and comments are welcome.

All photos and pictures remain the property of their owners, some are public domain. They are published in non-commercial educational and research purpose.
Text copyright to Michal Derela © 2007.