Difference between revisions of "Tortoise"

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Revision as of 15:14, 27 October 2022

Tortoise
uk_a39_tortoise.png
GarageImage Tortoise.jpg
ArtImage Tortoise.png
Tortoise
AB RB SB
6.7 6.7 6.3
Research:63 000 Specs-Card-Exp.png
Purchase:200 000 Specs-Card-Lion.png
Show in game

Description

The A39 Tortoise is a rank IV British tank destroyer with a battle rating of 6.7 (AB/RB) and 6.3 (SB). It was introduced in Update 1.55 "Royal Armour" along with the initial British ground tree. A huge casemate structure made as an assault vehicle akin to the American's T95, the Tortoise presents thick raw sloped armour with a unique heavy punching 94 mm cannon.

General info

Survivability and armour

Smoke grenades
Creation of a smoke screen in front of the vehicle
Armourfront / side / back
Hull170 / 110 / 100
Turret215 / 152 / 110
Crew7 people
Visibility129 %

The Tortoise, as its name suggests, sacrifices speed to survivability.. With its cast 152 mm sloped armour, the Tortoise can survive most head on encounters. The area around the gun mantlet is 215 mm thick with a flat surface under the gunner's optics. It has a 55 mm plate (75°) under the gun and a 170 mm semi-rounded LFP. Sides are 152 mm thick. The engine deck's side armour is 101.6 mm thick with an asymmetry on the left. Rear armour is 100-110 mm thick flat plates. At this BR, there are not many tanks that can penetrate such thick material from the front. If used correctly, this vehicle should only get out of battles with a few 75, 88 and 122 mm scratches.

If, by any chance, an enemy gets through this massive steel casing, there is no less than 7 spaced out crew members to soak up damage. Most of the time, the AA gunner's cupola gets penetrated, since it is only 100 mm flat armour. AP (and APDS) shells will only disable the AA defences while any APHE shell may incapacitate the driver and 1 or 2 loaders. If unlucky, it will detonate the massive ammo rack lying on the floor. Another common angle of attack is the machine gunner's port. Once again, AP shots will knock-out 2-3 non-essential crew members (machine gunner, commander, loader) and APHE shells may even eliminate the gunner. Sometimes, when getting too exposed, the 170 mm almost flat LFP gets shot at. This will usually disable the gunner, transmission and even ignite an ammo rack if there's enough explosive. A few highly penetrating tanks may shoot through the flat 215 mm surface underneath the gunner's optics. This usually means an instant knock-out for the Tortoise if it happens to be an IS-2, Tiger II (H) since there are ammo racks all around the gunner. Any penetrating hit to the side usually means an instant elimination (if not immediate, the following shot should be the last). The cannon barrel is often targeted by players: its large and thin muzzle brake tends to be damaged easily. Note that some large HE shells may tear through the top armour, wrecking havoc in the crew compartment.

Armour type:

  • Cast homogeneous armour
  • Rolled homogeneous armour (Side hull, Rear hull, Hull roof, Superstructure roof)
Armour Front Sides Rear Roof
Hull 55 mm (75°) Front glacis
170 mm (3-71°) Lower glacis
110 + 50.8 mm 100 mm (10-45°) 25 mm
Superstructure 215 mm (0-59°), 152 mm (0-45°) Front armour
96 + 80 + 152 mm Gun mantlet
152 mm 110 mm (0-7°) 50.8 mm
Cupola 101.6 mm 101.6 mm 101.6 mm 25 mm

Notes:

  • Suspension wheels and bogies are 20 mm thick while tracks are 30 mm thick.
  • Tracks on the side of the Tortoise give an additional 30 mm of armour.
  • The steel boxes on the side of the rear of the Tortoise grant only an extra 5 mm of armour.

Mobility

Reverse gearbox
Forward and backward movement is possible at the same maximum speed
Speedforward / back
AB21 / 21 km/h
RB and SB20 / 20 km/h
Number of gears6 forward
6 back
Weight81.3 t
Engine power
AB1 240 hp
RB and SB650 hp
Power-to-weight ratio
AB15.3 hp/t
RB and SB8.0 hp/t
Game Mode Max Speed (km/h) Weight (tons) Engine power (horsepower) Power-to-weight ratio (hp/ton)
Forward Reverse Stock Upgraded Stock Upgraded
Arcade 21 21 81.3 923 1,240 11.35 15.25
Realistic 20 20 575 650 7.07 8

Such a great armour plays heavily on mobility. With a max speed of 20 km/h in both directions, neutral steering and wide tracks, this tank has good enough mobility to get into position and fire on the enemy. It is not advised to travel up to the frontlines since it will only expose weak spots, make flanking easier, and take a really long time due to poor max speed.

Modifications and economy

Repair costBasic → Reference
AB3 599 → 4 671 Sl icon.png
RB4 092 → 5 311 Sl icon.png
SB5 376 → 6 978 Sl icon.png
Total cost of modifications52 800 Rp icon.png
91 000 Sl icon.png
Talisman cost1 700 Ge icon.png
Crew training57 000 Sl icon.png
Experts200 000 Sl icon.png
Aces800 Ge icon.png
Research Aces520 000 Rp icon.png
Reward for battleAB / RB / SB
120 / 200 / 250 % Sl icon.png
172 / 172 / 172 % Rp icon.png
Modifications
Mobility Protection Firepower
Mods new tank traks.png
Tracks
Research:
3 500 Rp icon.png
Cost:
6 000 Sl icon.png
160 Ge icon.png
Mods new tank suspension.png
Suspension
Research:
3 000 Rp icon.png
Cost:
5 200 Sl icon.png
135 Ge icon.png
Mods new tank break.png
Brake System
Research:
3 000 Rp icon.png
Cost:
5 200 Sl icon.png
135 Ge icon.png
Mods new tank filter.png
Filters
Research:
4 400 Rp icon.png
Cost:
7 600 Sl icon.png
200 Ge icon.png
Mods new tank transmission.png
Transmission
Research:
5 700 Rp icon.png
Cost:
9 800 Sl icon.png
260 Ge icon.png
Mods new tank engine.png
Engine
Research:
5 700 Rp icon.png
Cost:
9 800 Sl icon.png
260 Ge icon.png
Mods tank tool kit.png
Improved Parts
Research:
3 500 Rp icon.png
Cost:
6 000 Sl icon.png
160 Ge icon.png
Mods extinguisher.png
Improved FPE
Research:
3 000 Rp icon.png
Cost:
5 200 Sl icon.png
135 Ge icon.png
Mods tank reinforcement uk.png
Crew Replenishment
Research:
4 400 Rp icon.png
Cost:
7 600 Sl icon.png
200 Ge icon.png
Mods new tank horizontal aiming.png
Horizontal Drive
Research:
3 500 Rp icon.png
Cost:
6 000 Sl icon.png
160 Ge icon.png
Mods tank cannon.png
Adjustment of Fire
Research:
3 000 Rp icon.png
Cost:
5 200 Sl icon.png
135 Ge icon.png
Mods new tank vertical aiming.png
Elevation Mechanism
Research:
4 400 Rp icon.png
Cost:
7 600 Sl icon.png
200 Ge icon.png
Mods smoke screen.png
Smoke grenade
Research:
5 700 Rp icon.png
Cost:
9 800 Sl icon.png
260 Ge icon.png

Armaments

Main armament

Ammunition60 rounds
Reloadbasic crew → aces
11.1 → 8.6 s
Vertical guidance-10° / 18°
Horizontal guidance-20° / 20°
Main article: 32pdr OQF (94 mm)

Unlike other British Rank IV tanks, the Tortoise does not have access to APDS or HESH ammunition, it relies on pure AP solid shots. Fortunately, these large calibre rounds are roughly similar to the 20-pounder cannon's APDS rounds, meaning the learning curve from the Charioteer Mk VII is not too steep. Plus, these 94 mm shells are stock rounds in the Tortoise.

The main APCBC round for the Tortoise features superb penetration with 250+ mm at close range. While some other opponents might sport a better penetration, the ~10 seconds reload and incredible accuracy means you will usually be able to get a shot off before the enemy at this BR since a lot of tanks make use of large calibre guns with long reload times (Tiger II, IS-2, FV4005, etc.). The Shot Mk.1 also features excellent post-penetration damage thanks to its large calibre.

Due to the stable gun platform provided by an incredibly heavy chassis, as well as the decent gun traverse, the Tortoise is able to halt, stabilize and fire its gun before enemies are able to.

94 mm 32pdr OQF Turret rotation speed (°/s) Reloading rate (seconds)
Mode Capacity Vertical Horizontal Stabilizer Stock Upgraded Full Expert Aced Stock Full Expert Aced
Arcade 60 -10°/+18° ±20° N/A 8.81 12.19 14.80 16.37 17.41 11.18 9.89 9.12 8.60
Realistic 5.95 7.00 8.50 9.40 10.00

Ammunition

Penetration statistics
Ammunition Type of
warhead
Penetration @ 0° Angle of Attack (mm)
10 m 100 m 500 m 1,000 m 1,500 m 2,000 m
Shell Mk.1 HE 13 13 13 13 13 13
Shot Mk.1 APCBC 256 253 241 226 212 199
Shell details
Ammunition Type of
warhead
Velocity
(m/s)
Projectile
Mass (kg)
Fuse delay
(m)
Fuse sensitivity
(mm)
Explosive Mass
(TNT equivalent) (g)
Ricochet
0% 50% 100%
Shell Mk.1 HE 1,043 12.7 0.4 0.5 920 79° 80° 81°
Shot Mk.1 APCBC 929 14.5 N/A N/A N/A 48° 63° 71°

Ammo racks

Ammo racks of the Tortoise
Full
ammo
Ammo
part
1st
rack empty
2nd
rack empty
3rd
rack empty
4th
rack empty
5th
rack empty
Visual
discrepancy
60 Projectiles
Propellants
41 (+19)
59 (+1)
31 (+29)
35 (+25)
21 (+39)
31 (+29)
11 (+49)
1 (+59)
(+59)
N/A
No

Note:

  • As they are modeled by sets of 2, shells disappear from the rack only after you fire both shells in the set.

Machine guns

Ammunition6 750 rounds
Belt capacity225 rounds
Reloadbasic crew → aces
10.4 → 8.0 s
Fire rate600 shots/min
Main article: BESA (7.92 mm)

The secondary armament on this tank is a MG turret with twin-mounted BESA machine guns, good for dealing with low-flying planes and even some bombers, although these MGs lack the power of cannons for aircraft encountered in mixed battles at this BR. Since this turret is the main weak spot on this tank's frontal armour, it is often disabled in the first few shots.

Six of the vehicle's smoke grenades are located on the machine gun turret, and even if it's disabled (locking it in the direction it was facing) the grenades will still fire like normal.

7.92 mm BESA
Mount Capacity (Belt) Fire rate Vertical Horizontal
Cupola 3,375 (225) 600 -6°/+20° ±180°
Cupola 3,375 (225) 600 -6°/+20° ±180°

Usage in battles

The A39 Tortoise was created with the intention of serving as a "heavy assault tank" to break through the Siegfried Line. It plays more as a tank destroyer that's best used at long range. Therefore, to maximize the potential of the Tortoise, one must stay at long distances and snipe enemies with the very accurate 32 pdr OQF cannon, while making sure to choose good cover, so as to not allow the enemy to target the Tortoise's weak spots: the MG turret and gunner's cupola, the flat areas of the mantlet armour, and the lower front plate (LFP) if it is left exposed. With its slow speed and reload rate, this is not a frontline tank; it will easily be outflanked if used in shorter range engagements. In summary, the Tortoise is best used in a defensive capacity - either to defend capture points, or important strategic areas on the map (i.e. areas where enemies love to camp).

The Tortoise is a true sniper tank destroyer: the farther, the better. Its biggest vulnerability is that it moves extremely slowly, so it's not recommended for frontline combat. It plays much better as an entrenched shooter that can change a game by picking cover with a good field of fire, and then denying enemy entry or egress of an area. The cannon lacks an AP shell with HE filler, making general knowledge of tank internals a must. With good gun depression, it can be near-invincible when taking a good hull-down position, and can retreat back into cover easily enough due to its good reverse speed.

Some tips for specific combat environments:

Plains

This type of terrain is mostly devoid of any structures that could possibly provide cover. The terrain itself will provide the main form of cover. Maps such as Kursk, Mozdok and Jungle can be described as such. Find decent cover that provides a good view of the battlefield and field of fire, then set up a kill zone to deny entry into an area. Scout with binoculars so as to not needlessly expose yourself, then pop out at the right time to fire at any worthwhile targets of opportunity. Overextend tactics work well with this tank: line up a shot, take it, and fall back behind cover. Do not bother to move from a good position if possible: the Tortoise can take many shots before going down, and its dreadful top speed make it counterintuitive to play in an offensive capacity. Reposition the tank only if the enemy line gets too close or if there is a flanker in the vicinity.

Urban

These kind of grounds are all about buildings, terrain variation is almost nonexistent. Maps such as Abandoned Factory, Port Novorossiysk and Advance to the Rhine are urban battlefields. This is the most tricky scenario to face with the Tortoise. Pick an alley and cover it from one end or ambush near a capture point, if feeling lucky. Always try to stay near allied cover.

Rural

Rural maps are a mix of the two former: a small urban map surrounded by plains. Maps such as Fields of Poland, Eastern Europe and Normandy are rural environments. Stay around the town and never get in, cover alleys from afar, make the enemy fear to turn any corner. Try to get as far as possible to the town and keep an eye for flankers.

Hilly terrain

These maps feature high terrain deformation with steep hills and even walls. Maps such as Ash River, Karelia and Frozen Pass falls under this designation. Use the same tactics as with plains while being extra careful since flanking is easier on these kind of maps. Stick to the rear of allied armour or play as a bullet magnet, leaving light tanks a way to flank the enemy without getting too much attention. Make sure to hide weak spots behind props such as rocks or walls, leaving only the gun mantlet exposed.

Pros and cons

Pros:

  • Good frontal armour and adequately thick side armour
  • Angling the tank at near-45 degrees increases protection
  • 94 mm 32-pdr OQF cannon offers both high penetration power and post-penetration spalling damage
  • Highest penetrating round (Shot Mk. 1 APCBC) has a forgiving and predictable trajectory
  • 7-man crew means that it will usually take several HEAT or APDS rounds to knock out the Tortoise (even penetrating APHE shells likely will not destroy the tank in a single hit)
  • Goes as fast in reverse as it does when travelling forward

Cons:

  • Given its enormous size, the tank is nearly impossible to fully conceal.
  • Lack of speed and manoeuvrability: it is extremely slow given its enormous weight. You will not be able to run away from threats.
  • The Tortoise lacks AP shells with any explosive filler. However, unlike most other British tanks at this battle rating, no APDS shells are available for the 32-pounder.
  • Obvious weak spot: The MG turret on top of the tank is massive and is weakly armoured, which players will readily take advantage of: if an APHE round were to penetrate, it would likely kill the loader (and possibly the driver).
  • The top left corner of the tank is big and flat; APHE rounds with high penetration can punch right through, killing the commander and gunner.
  • Due to the casemate design, cover and fields of fire must be chosen carefully to minimize exposition of the Tortoise's weaknesses.
  • The lower front plate (LFP) is somewhat flat and presents a possible weak spot for enemies to shoot at if exposed.

History

Development

Years before the invasion of Normandy, there were men among the Allied planners worrying about the heavily-defended fortification lines such as the Siegfried Line blocking the path from France to Germany. One of the proposed methods was to develop extremely heavily armoured vehicles capable of destroying any fortification it comes across and any resistance the German had. Britain and America both worked on this project in order to develop these super-heavy tanks.

The British began to develop a new type of vehicle to counter this threat, the Assault Tanks that focuses all effort on armour. The first development for such a tank began in 1943 as the A33 Excelsior tank, though this was cancelled with better reliability of the Churchill infantry tank. The Secretary of State for War and the Minister of Supply sent out specifications for the Assault Tanks in April 1943, to which the Nuffield Organisation react with 18 designs for the specifications between May 1943 to February 1944, named AT1 to AT18. Each design was more armoured than its predecessor, but design AT16 was approved by the Tank Board in February 1944. It was proposed that 25 vehicles would be produced and thus work began throughout the rest of the war. Six units were produced before production came to an end.

Design

The AT16 was renamed the A39 Tortoise Heavy Assault Tank during its production life. The Tortoise is a fixed casemate design. Though classified as an Assault Tank, it was in reality a self-propelled/assault gun. The fixed casemate superstructure limited the gun traverse, but the front armour is very thick at 225 mm. This large amount of armour came at the increased weight of 80 tons and a height of 10 feet. The gun is the 96 mm 32-pounder gun that provided effective explosive and armour-piercing capabilities, good enough to destroy a Panther tank at 1,000 yards away. The Tortoise is powered by a Meteor engine with an all-speed transmission system for equal speed forward and reverse. The suspension is a bogie system, with each bogie having a pair of wheels that are linked to a transverse torsion bar. The vehicle holds a crew of six people, two of which are loaders for the 32-pounder gun.

Cancellation

By the time the few prototypes of the vehicles were made, World War II in Europe ended in May 1945. The rapid demilitarization and lack of need for such a vehicle reduced the original order amount to just 6 vehicles, which were built. One was sent to Germany for evaluation trials, where the Tortoise proved itself as being mechanically reliable and its 32-pounder a great asset on the battlefield. Its undoing was its 80 ton weight, which gave it a low speed and a logistical nightmare to transport around the region.

In the end, the super heavy tanks designs made by the Americans (T28) and the British (Tortoise) only proved that such needs for tanks were unnecessary. The Siegfried Line and other such fortifications were taken out by use of the standard issued medium tanks such as the M4 Shermans, proving that affordable, mass-produced vehicles could dominate the modern battlefield. The only positive note that these heavy tanks provided was that it showed the true extent of American and British industrial capabilities, being able to produce these massive monsters.

Media

Skins
Videos

See also

External links

Paste links to sources and external resources, such as:

  • topic on the official game forum;
  • other literature.


Nuffield Mechanizations and Aero Limited
Cruiser Tanks 
Tank, Cruiser, Mk III (A13 Mk I)  A13 Mk I · A13 Mk I (3rd R.T.R.)
Tank, Cruiser, Mk IV (A13 Mk II)  A13 Mk II · A13 Mk II 1939
Tank, Cruiser, Mk VI, Crusader (A15)  Crusader II · Crusader "The Saint" · Crusader III
Tank Destroyers  Tortoise
SPAAs  Crusader AA Mk I · Crusader AA Mk II
Export  ▄Crusader Mk.II

Britain tank destroyers
Infantry tank derivatives  Archer · Gun Carrier (3-in)
Light tank derivatives  Alecto I
M10 Achilles  Achilles · Achilles (65 Rg.)
Centurion derivatives  FV4005 · Conway
ATGM  Swingfire · Striker
Other  Tortoise · ▄M109A1
Canada  QF 3.7 Ram
South Africa  G6 · ZT3A2