TK-3 Tankette

Introduction

The TK-3 was a Polish tankette made during the 1930’s, based on the British Carden-Loyd tankette. The TKS was an improved model with a redesigned hull and better engine.

TKS Tankette

Design

In 1928, Vickers-Armstrong produced the two-man Carden-Loyd Mark VI, and the design attracted much attention. Poland purchased one in mid-1929, and it was tested on June 20 of the same year in Rembertow. On June 29, ten more tankettes were ordered, along with five trailers and several spare parts. This arrived in September, and large scale tests were carried out. The Poles decided that the design had much potential as motorized cavalry and reconnaissance vehicles. A license was purchased, and Polish designers began to modify the design. The main problem was the suspension. This was strengthened, but even after the modifications, it was decided to instead develop a completely new design based on the Carden-Loyd.

In late 1929, a prototype TK-1 was made, which was followed by the second prototype, TK-2. These were opened at the top, and armed with a single 7.92mm wz.25 or wz.30. Their armor was 3-7mm thick. The only differences were the mechanical layout and the engines – the TK-1 being powered by a Ford Type A, and the TK-2 by a Ford Type T. Both were tested in the summer of 1930 in Modlin, and more development followed.

TK-3 Tankette

In 1930, a heavier and improved model, the TK-3, was produced at Ursus, and was ready for testing by March of 1931. It was accepted into the army on July 14, 1931. Production began in late 1931, and from 1931-34, about 300 were produced by the Panstwowe Zaklady Inzynierii (National Engineering Works) at Ursus. They were the first all-Polish armored vehicles. They were powered by a Ford Type A, hosted a crew of two, had 3-8mm of armor, and were armed with a single 7.92mm wz.25. In 1931, a special trailer was produced to be towed by the TK-3. Other trailers were also made to carry ammunition, supplies, fuel, radio equipment, and soldiers.

TKS Tankette

In June of 1933, the prototype of a more heavily armored version of the TK-3 was made, with the designation of STK. Eventually the designation was changed to TKS. Production began in February of 1934, and 390 were produced by the Panstwowe Zaklady Inzynierii until September of 1939. They were powered by a license-produced Polski Fiat 122B engine, and had many modifications including a strengthened suspension, and more armor which was 3-10mm. They too were armed with a single 7.92mm wz.25 or wz.30.

Estonian TKS in a Parade, February 1937

Estonian TKS in military testing

On November 6, 1934, Estonia bought six tankettes from Poland with a contract deal worth over 180,000 crones. The contract also included one tracked lorry, and a free motorcycle.

Attempts to replace the 7.92mm gun with a 13.2mm Hotchkiss heavy machine-gun never left the drawing boards. But at the same time, a single TK-3 was rearmed with a 20mm Solothurn automatic cannon, and subsequently with a Polish 20mm wz.38. However, it was decided to rearm only the TKS tankettes. During tests, tests with the Danish Madsen automatic cannon, and the Swiss Solothurn 20mm automatic cannon showed these weapons to be inadequate, and it was decided to use the Polish 20mm FK-A wz.38 L/73.5 (which was capable of penetrating 40mm of armor from 656 feet). In January of 1939, the prototype TKS armed with a 20mm gun was ready. Its front superstructure was redesigned to hold the gun in a large ball-mount. It was planned to rearm 100-150 TKS tankettes until January 30, 1940. Only a small number were rearmed before September of 1939, and given to the 10^th Mechanized Brigade, and they were used as commanders’ vehicles.

Another Estonian TKS Tankette

A lineup of Estonian TKS Tankettes

Combat History

In September of 1939, the Polish TK-3 armada was in bad shape, and in need of repairs, but all of them were put into combat. They formed the bulk of Polish armor at the wars start, and they suffered heavy losses. Usually they were the only available armored vehicle. But since the armament was only a single light machine-gun, they stood no chance against the bigger, heavier German tanks, with the exception of the Panzer I. But their small size made them suitable for reconnaissance missions, and infantry support.

The handful that had 20mm guns did have a better chance against German tanks. On September 18, during the Bzura Offensive, the 20mm armed TKS commanded by Officer Cadet Roman Orlik destroyed three German PzKpfw (Panzerkampfwagen) 35(t) tanks from the 11^th Panzer Regiment, 6^th Panzer Division, near Pociecha, Central Poland.

Specifications

TK-3

Weight: 2.43-2.6 tons

Length: 8ft 5.5in

Width: 5ft 10in

Height: 4ft 4in

Crew: 2

Armor: 4-10 mm

Armament: 1x 7.92mm km wz25 machine gun, 1800rnds

Engine: Ford A/Polski FIAT-122 petrol engine, 40-46hp

Power to Weight: 17-18hp per ton

Suspension: Bogie

Fuel Capacity: 18.5 gallons

Operational Range: 124 miles roads, 62 miles country

Speed: 28.5mph

TKS

Weight: 2570kg (early), 2650kg (late) 2800kg (20mm)

Length: 8ft 5in-8ft 5.5in; 9ft 9in (20mm)

Width: 1.76m-1.78m

Height: 9ft 9in-9ft 10in

Crew: 2

Armor: 3-10mm

Armament: 1x 7.92mm Hotchkiss wz.25 (2000rnds) or wz.30 (2400rnds); 20mm FK-A wz.38 L/73.5 (250rnds)

Engine: Polski Fiat 122AC 6-cylinder 42hp (early); Polski Fiat 122B 6-cylinder 46hp (late)

Power to Weight:

Suspension: Bogie

Fuel Capacity: 70 liters

Operational Range: 112 miles road, 68 miles country

Speed: 25mph

Sources:

www.achtungpanzer.com

www.wikipedia.org

www.wwiivehicles.com

Type II Unterseeboot

Introduction

The Type II Unterseeboot (under sea boat, or U-Boat) was a German U-Boat modeled after the CV-707 Submarine. Too small for sustained operations far from home support, it primarily was used for the training of new German U-Boat commanders.

Background

After World War I, Germany was stripped of her U-Boat fleet by the Treaty of Versailles. In the late 1920’s and 1930’s, the Germans started to rebuild their armed forces. The first Type II U-Boat was laid down on February 11, 1935. Since the world would see this as a step towards major rearmament, Hitler reached an agreement with Britain to build his navy up to 35% of the size of the Royal Navy in surface ships, and equal in submarines. This was agreement was signed on June 18, 1935, and U-1 was commissioned on June 29.

Characteristics

Type II U-Boats were small in size, and earned the nickname of Einbaum (dugout canoe). They could work in shallow water, dive more quickly than contemporary sized ships, and were more difficult to spot due to its low conning tower. However, it had a shallower maximum depth, a short range, cramped conditions, and only five torpedoes.

Type II’s had a single hull, and no watertight compartments. There were three torpedo tubes forward and two torpedoes just aft of the torpedo tubes. There was one 20mm twin-gun mount for anti-aircraft, and no deck gun.

The Type II U-Boat had diesel-electric propulsion. The two diesel engines gave it 700hp for a maximum surface speed of 13 knots. Twelve tons of diesel fuel was carried, which gave it a maximum range of 1600 miles at 8 knots. While submerged, the two electric motors gave 360hp, for a maximum submerged speed of 6.9 knots. The batteries gave 35 miles while submerged, at 4 knots. Later variants had larger electric engines, larger batteries, and/or more diesel fuel.

While maximum depth for submarines varies by each ship (the major factors contributing being quality of construction and degree of damage to the hull), there are design depths. The Type II’s design depth was 490ft. However, on a pre-war dive, U-12’s hull cracked at 340ft – this led to urgent modification to all Type II U-Boats at the time.

Most of the 24-man crew lived around the torpedoes, sharing twelve bunks. Four more bunks were aft of the engine room for the engine room crew.

U-1 - the first Type II U-Boat, and the first U-Boat of Hitlers WWII Navy

Operational History

Most Type II U-Boats only saw combat in the early years of the war. Most of them were then used in training schools. Six Type II’s were stripped down to just the hull, then transported by river and truck to Linz, and finally reassembled for use in the Black Sea against the Soviet Union.

Few Type II U-Boats were lost, mainly because they were training ships, though several were lost to actions. The Type II U-Boat was Germany’s first major step towards re-armament, and gave them experience in construction and operation, laying the foundation for larger U-Boats.

Type IIA

The IIA, the first type of all Type II U-Boats, was a single-hulled, all-welded boat with internal ballast tanks. Its bridge was smaller than other Type II sub-types. It could carry G7a or G7e torpedoes, or TM-type mines.

IIA Specs

Displacement: 254 long tons surfaced; 303 lt submerged; 381 lt total

Length: 134ft 2in overall; 91ft 2in pressure hull

Beam: 13ft 5in o/a; 13ft 1in pressure hull

Height: 28ft 3in

Draught: 12ft 6in

Diesel Engines: 2x MWM RS127S 6-cylinder diesel engines, 700hp

Electric Motors: 2x SSW PGVV322/26 double-acting electric motors, 402hp

Speed: 13 knots surfaced; 6.9 knots submerged

Range: 1300 nautical miles @ 8 knots surfaced; 30 nautical miles @ 4 knots submerged

Test Depth: 490ft

Crew: 22-24

Torpedo Armament: 3x forward torpedo tubes, 5x torpedoes

Guns: 20mm Twin Flak, 850rnds

Type IIB

The Type IIB was a lengthened version of the IIA. Three more compartments were inserted amidships, and more diesel tanks were fitted beneath the control room which increased the range. Diving time also improved to 30 seconds.

IIB Specs

Displacement: 279 lt surfaced; 328 lt submerged; 414 lt total

Length: 140ft 1in o/a; 92ft 6in pressure hull

Beam: 13ft 5in o/a; 13ft 1in pressure hull

Height: 28ft 3in

Draught: 12ft 6in

Diesel Engines: 2x MWM RS127S 6-cylinder diesel engines, 700hp

Electric Motors: 2x SSW PGVV322/26 double-acting electric motors, 402hp

Speed: 13 knots surfaced; 7 knots submerged

Range: 2700 nautical miles @ 8 knots surfaced; 38 nautical miles @ 4 knots submerged

Test Depth: 490ft

Crew: 22-24

Torpedo Armament: 3x forward torpedo tubes, 5x torpedoes

Guns: 20mm Twin Flak, 1000rnds

Type IIC

The Type IIC was lengthened again; another two compartments were inserted amidships for an improved radio room and a second periscope. The diesel tanks beneath the control room were enlarged, increasing the range again.

IIC Specs

Displacement: 291 lt surfaced; 341 lt submerged; 435 lt total

Length: 144ft o/a; 97ft 1in pressure hull

Beam: 13ft 5in o/a; 13ft 1in pressure hull

Height: 27ft 7in

Draught: 12ft 10in

Diesel Engines: 2x MWM RS127S 6-cylinder diesel engines, 700hp

Electric Motors: 2x SSW PGVV322/26 double-acting electric motors, 402hp

Speed: 12 knots surfaced; 7 knots submerged

Range: 3300 nautical miles @ 8 knots surfaced; 36 nautical miles @ 4 knots submerged

Test Depth: 490ft

Crew: 22-24

Torpedo Armament: 3x forward torpedo tubes, 5x torpedoes

Guns: 20mm Twin Flak, 1000rnds

Type IID

The last sub-type was the Type IID. These ships had external saddle tanks for more diesel fuel. As the oil was consumed, sea water would gradually fill the tanks to give compensation for the positive buoyancy. Its range nearly doubled, which enabled it to operate around the British Isles. It also was fitted with Kurt nozzles, which was intended to improve propulsion efficiency.

IID Specs

Displacement: 314 lt surfaced; 364 lt submerged; 460 lt total

Length: 144ft 4in o/a; 97ft 9in pressure hull

Beam: 16ft 1in o/a; 13ft 1in pressure hull

Height: 27ft 7in

Draught: 12ft 10in

Diesel Engines: 2x MWM RS127S 6-cylinder diesel engines, 700hp

Electric Motors: 2x SSW PGVV322/26 double-acting electric motors, 402hp

Speed: 12.7 knots surfaced; 7.4 knots submerged

Range: 4900 nautical miles @ 8 knots surfaced; 49 nautical miles @ 4 knots submerged

Test Depth: 490ft

Crew: 22-24

Torpedo Armament: 3x forward torpedo tubes, 5x torpedoes

Guns: 20mm Twin Flak, 1000rnds

Sources:

www.wikipedia.org

www.ww2ships.com

www.uboataces.com

Maschinengewehr 34

Introduction

The Maschinengewehr 34, or MG 34, was a German machine gun produced and accepted into service in 1934. It utilized the 7.92mm x 57mm Mauser cartridge, and was air-cooled which was an improvement over earlier water-cooled types. It was used extensively in the German Army, Luftwaffe (as the MG 81), and Kreigsmarine.

It was designed as a general purpose machine gun. As a light machine gun, it had a bipod and a fifty round ammo belt in a drum magazine. For heavier roles it was mounted on a tripod, and fed with fifty round belts. German infantry usually used it as a medium infantry support weapon, with a bipod and belts.

Operational History

The MG 34 was designed mostly by Heinrich Vollmer, and was based on the Rheinmetall-designed Solothurn 1930 (MG 30), which was entering service in Switzerland. Vollmer edited this design by switching the feed-mechanism to the left of the breech, and adding a shroud around the barrel. Changes to the operating mechanism improved the rate of fire to 800-900rpm.

The gun was accepted almost immediately, and usually liked by the German troops, who used it effectively in the Spanish Civil War. It was the primary machine gun during the late 1930’s, and was the primary tank and aircraft defense weapon throughout World War II. Its main glitches were the time and material cost (108lb of steel) of production, and also that it was very temperamental, easily jamming when it was dirty.

The MG 34 was supposed to replace the older MG 13 and other machine guns, but there was so much of a demand for machine guns, that the older guns remained in use for much of the war. The MG 34 was to be replaced in the infantry by the MG 42, but since there were never enough MG 42’s to go around; the MG 34 remained in service for all of the war. Some MG 34’s captured by the Soviets or French were supplied to the Peoples Liberation Army/Peoples Volunteer Army, Korean Peoples Army, PAVN, and the Viet Cong during the Cold War.

Bi-pod Mounted MG 34 in France, 1944

  

Characteristics

The MG 34 was equipped to receive both magazines and belts. The belts were fifty rounds long, but could be linked together for longer belts. Fixed emplacements (machine-gun nests and bunkers) used boxes of five belts, linked to make a 100 round and 150 round belt.

Assault drums would hold a fifty round belt, or the gun could be configured for a 75 round ‘double drum’ magazine. The top cover needed to be replaced with one specifically made for a 75 round drum before one could be used, and the cover needed to be switched back to the standard one before other configurations could be used. But by 1941, magazine-fed MG 34’s weren’t used in the infantry except on some armored personnel carriers.

The barrel was designed to be replaced easily during operation. The operator would disengage the latch that held the receiver to the barrel sleeve. Then the entire receiver pivoted off to the right, which let the operator pull the barrel out of the sleeve and put the new barrel in. Then the receiver rotated back in, and latched. With a well-trained operator, this process only took a few seconds.

Another unique feature was its double-crescent trigger. The upper segment fired semi-automatically, while the lower section fired full-automatic. This removed the need for a selector switch. While this was considered to be innovative, it was not used on the MG 42 because of the complexity.

In the light machine-gun role, the MG 34 used a bipod. In the medium machine-gun role, it could use either a smaller or larger tripod. The larger one had a number of features such as a telescopic sight, or other special sighting equipment for indirect fire. The legs could be placed to let the gun fire in a sweeping arc while aimed through a periscope attached to the tripod. Also, the legs could be extended to be used in the anti-aircraft role.

Tripod Mounted MG 34

Twin MG 34 Anti-Aircraft mount

Variants

MG 34/41

The MG 34/41 was requested after war experience showed that a higher rate of fire caused more bullet dispersion. The MG 34/41 was designed to fire at 1200 rounds per minute (20 rounds a second). It was slightly heavier than the standard MG 34, and a limited number was made. Later it was beaten in trials by the MG 39/41, which became the MG 42.

MG 34 Panzerlauf

The MG 42 was found to be ill-suited for internal mounting because of how the barrel was changed, and the MG 34 Panzerlauf was used as the secondary armament on most German tanks. The main difference between this and the standard MG 34 was that the shroud lost almost all of its ventilation holes, and the gun also lost the butt-stock. Conversion kits carried inside tanks had a butt-stock, bi-pod, and front sight assembly.

MG 81

The MG 34 was adapted for use by the Luftwaffe, and received the new designation of MG 81, which will be explored in a later article.

Specifications

Weight: 26.7lb (42.3lb with tripod)

Length: 48in

Barrel Length: 24.7in

Cartridge: 7.92mm x 57mm Mauser

Action: Recoil Operated

RPM: 800-900

Muzzle Velocity: 2,477 fps

Feed System: 50/250 round Belts, 50 round Drums, or 75 round drum with modification

Sights: Iron Sights

Sources:

www.wikipedia.org

www.militaryfactory.com

www.philaord.com