Tortoise (shell)

Tortoise
	A39 Tortoise on an 80 t trailer with two Diamond T tractors in Germany (1948)
General properties
crew	7 men (1 commander, 1 gunner, 2 loaders, 1 machine gunner, 1 radio operator / machine gunner, 1 driver)
length	10.06 m
width	3.91 m
height	3.05 m
Dimensions	79 t max
	Armor and armament
Armor	33-228 mm
Main armament	1 × 95mm L / 65 32pdr QF cannon
Secondary armament	1 × 7.92 mm machine gun mounted to the left of the cannon 2 × 7.92 mm machine guns in a turret behind the right hatch
agility
drive	12-cylinder four-stroke, Rolls-Royce Meteor V ; 600 PS (441 kW)
suspension	Torsion bar suspension
Top speed	20 km / h
Power / weight	7.5 hp / t
Range	140 km

Heavy assault tank / tank destroyer A39 Tortoise (company photo 1945)

Preserved A39 Tortoise in the Bovington Tank Museum

The A39 Tortoise ( German : Landschildkröte) was a heavy British assault tank / tank destroyer and, along with the huge TOG, was by far the largest and heaviest armored vehicle ever built in Great Britain .

The gigantic vehicle was specially developed during the Second World War to be able to defeat the previously superior heavy German tanks and tank destroyers with an even stronger cannon and massive armor , and to effectively combat strongly fortified positions. In fact, at the time of its construction, its armor was virtually invulnerable to any known German cannon. Despite all efforts, the first copy was only delivered after the fighting in Europe and therefore this monstrous tank was no longer used. The first Tortoise was already transported to Germany in the summer of 1945 and immediately extensively tested, whereby the super-heavy tank was quite convincing. The British Army did not receive the other five vehicles until 1947. The planned series production no longer took place; it stayed with the six Tortoise built.

history

Two considerations led Britain to embark on the construction of a heavy tank in 1943. On the one hand, because of the planned landing of the Allied forces in Normandy , the new tank should be able to effectively attack the expected strong German defensive positions and, on the other hand, be able to defeat the previously far superior heavy German tanks. Of course, this required a heavy, large-caliber cannon that could fire high-explosive shells such as tank shells of the appropriate size and weight. Another indispensable requirement was very strong armor in order to be able to overcome stubborn resistance from infantry with anti-tank guns and heavy tanks.

Initially, a new, much more heavily armored version of the Valentine with the name Valiant was considered and then built in two prototypes. Technically speaking, the Valiant was the first “real” British main battle tank. However, it soon became apparent that this vehicle could not quite meet expectations. Armament and armor appeared insufficient; the planned series production did not come about.

At the same time work was being carried out on a version of the Churchill that was also reinforced in terms of armament and armor , but this project was quickly discarded due to the unsuitability of the base vehicle for the intended purpose.

It was now clear to the last doubters that a completely new vehicle had to be constructed. A total of 18 drafts from the Nuffield company were examined, and it became increasingly clear that the two completely contradicting objectives could only be achieved with a suitably large and heavy armored vehicle. In addition, the new tank should, if possible, also offer security against the explosion of mines . After further minor changes and adjustments, draft number 16 was adopted on February 9, 1944 and officially named Heavy Assault Tank A39 Tortoise (German: Schwerer Sturmpanzer A39 Schildkröte ). What is striking is that the Tortoise was the first British tank without a rotating turret. This turretless design was chosen in order to combine the largest possible cannon with the strongest possible armor, without ultimately making the vehicle too heavy and too complicated. The height of the vehicle should also be kept within limits, which obviously suggests that the Tortoise was not designed without a sidelong glance at the German assault guns .

After the Allies' successful landing in Normandy in the summer of 1944, the new tank was ultimately intended primarily to defeat heavy German tanks ( Tiger , Panther and King Tiger ) and tank destroyers ( Jagdpanther, etc.) in battle. The Tortoise thus represented more of a heavy tank destroyer, although it retained the ability to fire effective HE shells if the corresponding use or the situation in the battle required it. The Tortoise should make it possible to break through strong enemy front lines and fortified areas. It is therefore to be regarded as a special combination of tank destroyer and assault tank, with armor and firepower clearly given preference over mobility .

The main armament was a new heavy British 32-pounder cannon, which could attack both heavy tanks and fortifications (a similarly ambivalent design of the cannon was, for example, the Soviet IS-2 main battle tank ). The strong side armament consisted of three Besa machine guns . One was in the superstructure to the left of the cannon, the other two in a small rotating tower behind the right hatch, which was an unusual design feature. This side armament made it possible to fight off attacking infantry effectively, which made the Tortoise even harder to fight.

The armor was so thick that the Tortoise was practically invulnerable to all known German cannons (both KwK and PaK ); even the side armor was almost twice as strong as that of comparable German armored vehicles. Given these facts, the term “turtle” was certainly by no means wrong. The lack of maneuverability of the vehicle was accepted, as impact power and armor were given absolute priority. There were three attachment points at the bow where additional armor or mine clearance equipment could be attached.

The appearance of the heavy German Jagdtiger tank destroyer between late 1944 and early 1945 accelerated work on the Tortoise, as it was now to become the British counterpart to the Jagdtiger. Despite all efforts, however, the enormous vehicle was no longer finished in Europe before the end of the war; the Jagdtiger remained the only vehicle of this size on the battlefield.

After its testing phase, the Tortoise was not a long-term success. The heavy tanks became so huge in their dimensions and weights in general that they posed more logistical problems than real tactical benefits. The limit of what was feasible seemed to have been reached and the heavy and overly heavy German tanks (Jagdtiger, Maus , E-100 ) as well as the British TOG and the Tortoise seemed slowly but surely to be overtaken, just as the knight's castles of the Middle Ages did many centuries before. All orders for additional vehicles were canceled and the other five test vehicles were not delivered to the British Army until 1947. The planned series production was therefore ultimately abandoned.

A tortoise has been preserved to this day. It is in the Bovington Tank Museum in England .

commitment

Although the Tortoise has never seen a single battle, the first example was shipped to Germany in the summer of 1945, where trials began immediately. In the test drives on the road and in the field, the heavy tank proved to be mechanically reliable despite initial skepticism and in the ballistic tests to be an extraordinarily powerful and very precise weapon platform. Even the driving characteristics were convincing against all expectations; the elaborate running gear with four roller carriages on each side and two individually attached pairs of rollers helped the tank run extremely smoothly. The very wide chains reduced the pressure on the ground and prevented sinking into softer ground. On top of that, the drive indeed survived the explosion of a few mines and the tank, with its pre-installed demining device, appeared ideally suited for clearing minefields.

However, due to its enormous size and weight, the Tortoise also had its downsides. It devoured vast amounts of fuel (gasoline), which extremely limited its range. It was difficult to transport and, in turn, was extremely slow and immobile at a maximum of only 20 km / h. The fact that it proved to be mechanically reliable can be considered a stroke of luck, because in the event of a defect, towing an approximately 80 t vehicle would have been practically impossible, especially under operating conditions. In addition, the complicated chassis had over 200 lubrication points, which may have been a nightmare for maintenance personnel, especially in field conditions.

Technical specifications

Designation : Heavy Assault Tank A39 Tortoise
Classification : heavy assault tank / tank destroyer
Weights
- Combat weight: 79,252 kg
- Ground pressure : 0.94 kg / cm²
Dimensions
- Length over everything with the pipe to the front: 10.10 m
- Length of the tub: 7.24
- Width overall: 3.91 m
- Height: 3.05 m
- Ground clearance: 45.0 cm
- Pipe overhang: 2.86 m
- Fire height:?
drive
- engine
  - Type: Rolls-Royce Meteor V
  - Design: 12-cylinder four-stroke gasoline engine (60 ° V shape), water-cooled
  - Displacement: 26,000 cm³ (26 l)
  - Power: 600 PS (440 kW)
  - Nominal speed: 2250 / min
  - Installation position: in the rear
- transmission
  - Type: Merritt-Brown
  - Type: mechanical six-speed gearbox
  - Number of forward gears: 6
  - Number of reverse gears: 2
  - Drive type: Drive on one front drive wheel on each side
  - Installation position: in the bow
steering
- Two-wheel steering gear, operated by two steering levers
- Installation position: in the bow
- Turning circle:?
landing gear
- Design: caterpillar drive, four roller carriages per side with eight steel rollers each,
- Suspension: torsion bar suspension with longitudinal torsion bars
- Chain width: 36 "(91.4 cm)
- Gauge:?
- Chain type: hinged chain
- Chain division:?
- Chain contact surface: 4.60 m
Performance
- Maximum road speed: approx. 20 km / h
- Top speed terrain: approx. 10 km / h
- Power-to-weight ratio: 7.57 hp / t
- Gradeability: 30%
- Maximum inclination angle: 30 °
- Climbing ability: 90 cm
- Wading ability:?
- Trench crossing ability: 250 cm
- Driving range road: approx. 70–140 km
- Driving range off-road: approx. 40–80 km
- Fuel consumption road:?
- Fuel consumption terrain:?
- Fuel level:?
Armament
- Main gun: 1 × 95mm L / 65 32pdr QF cannon
  - Muzzle velocity: 920 m / s
  - Barrel weight with lock and muzzle brake:?
  - Barrel length with muzzle brake:?
  - Elevation field:?
  - Directional field: 20 ° left / 20 ° right
- Secondary armament
  - 1 × 7.92 mm -Besa-MG in the setup to the left of the cannon
  - 2 × 7.92 mm Besa machine guns in a turret behind the right hatch
  - If necessary, 1 × 7.92 mm Besa Fla-MG on the roof
- Target means
  - ?
- ammunition
  - 60 rounds (40 tank shells + 20 HE shells, other equipment possible)
  - 4800 rounds for 7.92 mm Besa machine guns
Armor
- Bow 228 mm / round
- Driver front 279 mm / 75 °
- Structure in front of 279 mm / 75 °
- Top side 152–178 mm / 85 °
- Bottom side 112 mm / 90 °
- Side skirts 101 mm / 90 °
- Rear 101 mm / 42 °
- Ceiling 33–50 mm / 0 °
- Bottom 35 mm / 0 °
Crew: 7 men (1 commander, 1 gunner, 2 loaders, 1 machine gunner, 1 radio operator / machine gunner, 1 driver)
Manufacturer: Nuffield Mechanizations & Aero Ltd.
Construction period: 1944–1947
Number of pieces: 6

literature

Peter Chamberlain, Chris Ellis: British and American Tanks of World War Two. The Complete Illustrated History of British, American and Commonwealth Tanks, 1939–45. Cassell, London 2000, ISBN 0-304-35529-1 .
Peter Chamberlain, Chris Ellis: Tanks of the World 1915-1945. Cassell & Co., London 2002, ISBN 0-304-36141-0 .
George Forty: The Illustrated Guide to Tanks of the World. Hermes House, London 2006, ISBN 0-681-45905-0 .
Christopher F. Foss : The Encyclopedia of Tanks and Armored Fighting Vehicles. The comprehensive Guide to over 900 Armored Fighting Vehicles from 1915 to the Present Day. Spellmount, Staplehurst 2002, ISBN 1-86227-188-7 .

Web links

Commons : Tortoise Panzer - Collection of images, videos and audio files