11 km/h back48 km/h forward
10 km/h backSpeed
The Cruiser tank A.C. Mark IV, also known as the AC IV Thunderbolt or the AC IV Sentinel, is a premium Rank III British medium tank on the British tree with a battle rating of 5.3 (AB/RB/SB). It was released some time after Update 1.55 "Royal Armour". Armed with a 17-pounder gun, it has a high firepower for the battle rating it is in, able to effectively fight any other tanks at the battle rating. The Thunderbolt is also a small and maneuverable tank able to exploit harsh terrain to target the enemy.
The AC IV is a relatively small medium tank in comparison to the common mainstay of the other countries, especially when compared to the American Sherman tanks. The Sentinel also has a good maneuverability and power-to-weight ratio for the propulsion, able to accelerate to its max speed of roughly 30 km/h quickly and stay there on stable terrain. The tank has a great advantage of a decent reverse speed in comparison to other medium tanks of its caliber, with a reverse speed almost the same speed as forward. The addition of the 17-pounder gun also gives this tank a whopping high firepower for the size, so it can stand a chance against tanks of the same tier despite being out of the league in terms of armour.
The tank in the game is the version planned for serial production, so it has the hull of the AC III; unlike the actual prototype design developed, which used the hull from the AC I version.
Survivability and armour
The AC IV Thunderbolt's armour have a high tendency to bounce shells. This is obvious with the extreme slope on the from of the tank, and turret design. The armour itself is not thick, but thanks to the angle of it this tank can be very fierce competition to enemy vehicles.
- Cast homogeneous armour
- Rolled homogeneous armour (Hull roof)
|Hull|| 50.8 mm (66-67°) Frontal glacis
50.8 mm (30°) Driver's port
50.8 mm (7-68°) Lower glacis
|44.45 mm (0-12°)|| 22.22 mm (78°) Top
44.45 mm (21-52°) Bottom
|Turret|| 63.5 mm (4-47°) Turret front
25.4-63.5 mm (1-68°) Gun mantlet
|63.5 mm (0-88°)||63.5 mm (1-53°)||35 mm|
|Cupola||63.5 mm||35 mm|
- Suspension wheels and bogies are 20 mm thick, tracks are 20 mm.
- The rear bottom area has a track placed there, providing 20 mm of extra armour.
- The commander cupola is extended outwards from the left side of the turret, creating a vulnerable unsloped area vulnerable to weaker guns.
|Weight (tons)|| Add-on Armour
|Max speed (km/h)|
|Engine power (horsepower)|
|Power-to-weight ratio (hp/ton)|
|76 mm OQF 17-pounder|
|Turret rotation speed (°/s)|
|Mode||Stock||Upgraded||Prior + Full crew||Prior + Expert qualif.||Prior + Ace qualif.|
|Reloading rate (seconds)|
|Stock||Prior + Full crew||Prior + Expert qualif.||Prior + Ace qualif.|
|Ammunition|| Type of
|Penetration in mm @ 90°|
|Ammunition|| Type of
Mass in kg
| Fuse delay
| Fuse sensitivity
| Explosive Mass in g
| Normalization At 30°
Mass in kg
| Screen radius
| Screen time
| Screen hold time
| Explosive Mass in g|
|17pdr Shell SS Mk.1||754||8.4||13||5||20||50|
|50||XX (+X)||XX (+X)||35 (+15)||45 (+5)||10 (+40)||14 (+36)||31 (+19)||39 (+11)||1 (+49)||Yes|
|Which ones||Default magnification||Maximum magnification|
|Main Gun optics||x1.85||x3.5|
Does not have improved zoom like other BR 5 Rank III British tanks, thus has worse zoom than many current opponents, which may have variable zooms up to X5. Do not unnecessarily provoke German SPG, as they have superior optics and are unlikely to miss.
In full up-tier, do not let japanese medium tanks ST-A1 get an upper hand at all costs, as they have optics eclipsing these entirely and might as well snipe A.C.IV from 2 km away, if have accuracy modifications.
|7.7 mm Vickers|
|Capacity (Belt capacity)|| Fire rate
| Horizontal |
Usage in battles
Exploit the A.C. IV's maneuverability against the heavier tanks, plus the 17-pounder tank allows for a penetration through the enemy's armour to cause internal damages. The fast reverse speed makes the "shoot-and-scoot" tactic a viable method against the enemy, and should be the prime one as the armour of the Sentinel is not exactly the most durable at only 50 mm flat. However, the sloping nature of the armour could give the bouncing capability of the tank comparable to the T-34, it's even arguably much better. So while the weight class is definitely against the Sentinel, a chance is always there to take out the opposition.
"Shoot-and-scoot" tactics are the best tactics to use with this vehicle. The Sentinel's armour does not let the tank be a brawler, so it must be more "sneaky" against the enemies. Another thing to note is the driver's hatch at the front of the tank. To avoid a frontally penetrating shot, always angle the driver's hatch away from the enemy.
Pros and cons
- Good sloped armour.
- High penetration solid shot rounds.
- Good manoeuvrability.
- Fast reverse speed.
- Small profile.
- Sloped armour only on the front.
- Susceptible to large caliber HE.
- Only 44mm (4.4cm) of side armour.
- Cannon lacks armour-piercing rounds with high-explosive filler.
- No APDS rounds, unlike other British medium tanks at this rank.
Australia began designing a tank in November 1940 as the AC I, and was intended to be a cruiser tank weighing between 16 to 20 tons with a 2-pounder gun. With no prior experience in producing a domestic tank, Australia sent a task force to the United States to study the M3 Medium design to understand the in-and-outs of a tank. They also received the aid of Colonel W.D. Watson MC in December 1940 from Britain, who has many years of tank designing experience. The overall mission ended up having the tank design to have a similar concept as the Canadian Ram tank, being based off the the M3 Medium chassis and mated with a domestic design of their choice for the upper part along with the incorporation of a suspension system of horizontal rubber cylinder springs seen on many early-war French tanks notably the H.39 and H.35. The Australian attached the chassis with a hull and turret with design similarities to the British Crusader tanks. The design started to become less of a cruiser tank and more of a medium tank by American specifications due to the attempt to up-armour and up-gun the tank to keep up with German armour development.
The first design was completed in February 1942 as the Cruiser Tank Mark 1 (AC I) and designated the "Sentinel". The design was simplified by using existing parts of current tanks and using a cast hull and turret. The entire hull being casted would be the first in history as many tanks of the era did not use such techniques. Although originally specified for a 2-pounder, it was then asked for a 6-pounder armament but due to the manufacturing of such guns not begining at the time in Australia they would have to use the 2 pounder for the first 65 produced. Two Vickers machine gun were used as the coaxial and hull machine gun the later having an armoured mount to protect its water sleeve resulting in a rather lewd looking front of which is made fun of to this day. With the power of three Cadillac V8 Petrol engines. It was unorthodox, but powerful enough to propel the vehicle. 65 of these tanks were made by June 1943 before being succeeded by a more advanced design known as AC III, also known as the "Thunderbolt". It had better armour and an improved firepower in the form of the 25-pounder howitzer. Despite the bigger gun, the 54-inch turret ring was never expanded to accommodate for the gun's larger size, so the crew experienced a slightly cramped turret interior for the benefit of having a better high-explosive charge and armour-piercing capability. Other differences in the design was the removal of the hull machine gun and a different set-up of the three Cadillac engines. One pilot model was built and plans were made for a production for 25 tanks for further trials, but the program was terminated.
Another attempt was made to increase Australian tank firepower with the AC IV design. It first started when the designers check to see if the turret could mount the massive 17-pounder in use by the British to fight the heavier and more protected German tanks. When the tests proved successful, the 17-pounder was chosen to be the gun for the AC IV, with a new and larger turret and 70-inch turret ring to improve crew comfort. These tanks were only made for evaluation purposes only and were never mass-produced for equipping the armoured units. However it would be the only commonwealth tank ever to mount such a gun.
The AC IV design, along with the entire Australian Cruiser tank program, was terminated in July 1943, ending with only 65 tanks produced and a few prototype models. The reason was that the funds were better spent improving the infrastructure than building new tanks due to the large number of American tanks such as the M4 Medium that were being supplied to Australia. The AC "Sentinel" were all put into storage and kept until the end of the war. The only use the Sentinel saw was in the film The Rats of Tobruk in 1943 when a squadron of AC I tanks were modified to resemble German tanks.
After the war, the Australian government disposed most of the tanks in 1945, most were sold off by the Commonwealth Disposals Commission. Today, about six Sentinels survive in intact conditions across the world. One notably in the Bovington Tank Museum, and three in Australia in the RAAC Tank Museum, Treloar Technology Centre, and one in the United States in the Collings Foundation.
Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:
- reference to the series of the vehicles;
- links to approximate analogues of other nations and research trees.
|Britain medium tanks|
|Cromwell||Cromwell I · Cromwell V · Cromwell V (RP-3)|
|Based on Cromwell||Challenger · Comet I · Comet I "Iron Duke IV"|
|Centurion||Centurion Mk 1 · Centurion Mk 3 · Centurion Mk.5 AVRE · Centurion Mk 10 · Centurion Action X · FV4202|
|Chieftain||Chieftain Mk 3 · Chieftain Mk 5 · Chieftain Mk 10|
|Challenger||Challenger Mk.2 · Challenger Mk.3 · Challenger 2 · Challenger 2 (2F)|
|Valentine||Valentine I · Valentine IX · Valentine XI|
|Vickers||Vickers MBT · Vickers Mk.7|
|Foreign||Grant I (USA) · Sherman IC "Trzyniec" (USA) · Sherman Firefly (USA) · Sherman II (USA)|
|A.C.IV (Australia) · Strv 81 (RB 52) (Sweden) · Sho't Kal Dalet (Israel)|
|Britain premium ground vehicles|
|Light tanks||A13 Mk I (3rd R.T.R.) · A13 Mk II 1939 · AEC Mk II · Crusader "The Saint"|
|Medium tanks||Grant I · Cromwell V (RP-3) · Sherman IC "Trzyniec" · A.C.IV · Comet I "Iron Duke IV"|
|Strv 81 (RB 52) · Centurion Mk.5 AVRE · Sho't Kal Dalet · Centurion Action X|
|Heavy tanks||Independent · Excelsior · Black Prince|
|Tank destroyers||Achilles (65 Rg.) · QF 3.7 Ram · Rooikat 105|