When you look at the huge ‘monster’ that is A39 Tortoise it is very tempting to draw immediate comparisons with the German tank destroyers, Elephant, JagdTiger, and JagdPanther. Tortoise might be regarded as the British answer to German monsters such as Jagtiger and King Tiger, but the concept seems to date back further to designs such as TOG. Even so, Tortoise was designed to be immune to all existing German anti-tank guns and had the largest gun (32pdr) on a British WW II AFV design.
The Tank, Heavy Assault, Tortoise (A39) was a British heavy assault tank design developed in late World War II but never put into mass production. It was developed for the task of clearing heavily fortified areas and as a result favoured armour protection (extremely thick armor) over mobility. Although heavy, at 79 tons, and not readily transported, it was considered reliable and a good gun platform.
As the tank was still in its trail stage when the project was terminated following the end of war, there were only 6 vehicles had been produced by the end of the war.
The Secretary of State for War and the Minister of Supply issued a Joint Memorandum in April 1943 that gave a vague specification for an Assault tank, classing it as a special purpose vehicle to operate in heavily defended areas as part of the specialist 79th Armoured Division.
The Nuffield Organisation responded with 18 separate designs. By February 1944, design AT16 was complete and was approved by the Tank Board, who proposed that month that 25 should be produced directly from the mockup stage without bothering with a prototype, to be available for operational service in September 1945. An order for 25 was placed by the War Office and work was begun.
Following the end of the war the order was reduced and only six vehicles were built. One example was sent to Germany for trials, where it was found to be mechanically reliable and a powerful and accurate gun platform. However, at a weight of 80 tons and a height of 10 feet (3.0 m) it was extremely slow and proved difficult to transport.
Since the Tortoise had a fixed casemate superstructure instead of a turret, it can be classified as a self-propelled gun or an assault gun and not a tank. The crew included a commander, driver, and gunner, with two loaders for the 32-pounder gun and two machine gunners.
The A39 Tortoise being towed on a trailer during trials in BAOR, 1948 [Via Wikipedia]
The main gun is a 3.7" anti aircraft gun converted to tank use that fired a 32 pdr round which was big enough to penetrate any german tank and ground target. The 32-pdr gun was in a power assisted limited traverse mounting (only the very first design AT1 had a turret). The gun barrel rather than being mounted on the more traditional trunions, protruded through a large ball mount. The ammunition for this weapon was two part with separate propellant and shell/shot and it’s shear weight and size required that Tortoise carried two loaders to service the gun. In tests, the gun was successful against a German Panther tank at nearly 1,000 yards.
A39 frontal view [Via Paul (Flickr)]
The secondary armament consisted of 2 mg's besa's. These originated from a czech design as was the bren gun but unlike the bren it was decided to keep the rimless cartridge instead of converting it to .303. The round was the mauser 7.92mm x 57mm which meant the besa fired totally different ammo from the rest of the british army but had the advantage of being able to use captured german ammo if the need should arise.
The Tortoise hull was divided into three compartments, the front containing the Meritt transmission, the rear containing the Meteor engine, fuel tanks and radiators, and the fighting compartment.
Tortoise at Bovington Tank Museum [Via Wikipedia]
The Tortoise had some unusual design features. The secondary armaments included a small turret mounted on top the hull which held twin Besa machine guns. The firing mechanisms of these guns had to be fitted with stops to prevent accidental firing at the hull fittings or crew hatches!
The heavy hull was supported by a torsion bar suspension system. The suspension consisted of four bogies on each side each containing two pairs of wheels each pair being linked to a transverse torsion bar. Each wheel could move independently from its partner and the suspension itself was said to have produced an excellent smooth ride. However the level of complication meant that there were in all over 200 separate greasing points - a maintenance nightmare!
A39 rear view [Via Paul (Flickr)]
The front and rear suspension units were of a different pattern with only on pair of return rollers and shock absorbers mounted on the foremost pair of road wheels.
- Weight: 78 long tons (87 short tons; 79 t)
- Crew: 7 (Commander, gunner, machine gunner, 2 loaders, driver, co-driver)
- Armor: 178–228 mm (7–9 in), 33 mm (1.3 in) top
- Main armament: Ordnance QF 32 pounder (94 mm gun)
- Secondary armament: 3 × 7.92 mm Besa machine guns
- Engine: Rolls-Royce Meteor V12 petrol 600 hp (450 kW)
- Power/weight: 7.7 hp/tonne
- Operational range: 140 km (87 miles) on road
- Speed: 19 km/h (12 mph) on road - 6 km/h (4 mph) off road
One of the six prototype Tortoises constructed of mild steel has been preserved at the The Tank Museum in Bovington, England. The vehicle is in running condition. A 2011 overhaul saw it running under its own power for the first time since the 1950s. It was shown to the public in June 2011 at Tankfest 2011, the Bovington museum's annual display of running vehicles.
Tortoise at Tankfest 2011 [Via War Relics Forum]
A Tortoise, without its gun, lies on the Kirkcudbright military training area near Kirkcudbright, Scotland. Other damage to the tank and the designation of the Kirkcudbright training area as a Site of Special Scientific Interestmean that removal of the Tortoise to a museum is now unlikely.
Tortoise at Kirkcudbright, Scotland [Via War Relics Forum]
Tortoise at Tankfest 2011. Heavy old beast got running again for this years show [Via lewran (Youtube)]