A.C.IV

2019-04-23T22:32:31Z

U34568764: /* Ammo racks */

{{Specs-Card|code=uk_ac4_thunderbolt}}

== Description ==

[[File:GarageImage_A.C.IV.jpg|420px|thumb|left]]
{{break}}
The '''{{Specs|name}}''', also known as the ''AC IV Thunderbolt'' or the ''AC IV Sentinel'', is a premium Rank {{Specs|rank}} British medium tank on the British tree {{Battle-rating}}. It was released some time after [[Update 1.55 "Royal Armour"]]. Armed with a [[Ordnance QF 17-pounder (76 mm)|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 [[M4A2|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.

== General info ==
=== Survivability and armour ===

'''Armour type:'''

* Cast homogeneous armour
* Rolled homogeneous armour (Hull roof)

{| class="wikitable"
|-
! Armour !! Front !! Sides !! Rear !! 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'' || 22.22 mm
|-
| 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
|-
! Armour !! Sides !! Roof
|-
| Cupola || 63.5 mm || 35 mm
|}
'''Notes:'''

* 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.

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 think, but due to the angle it is put at this tank is very fierce competition.

=== Mobility ===

{| class="wikitable" style="text-align:center"
|-
! colspan="3" | Mobility characteristic
|-
! Weight (tons)
! colspan="1" | Add-on Armour weight (tons)
! colspan="1" | Max speed (km/h)
|-
| rowspan="2" | 26.4 || colspan="1" rowspan="2" | N/A || colspan="1" | 53 (AB)
|-
|48 (RB/SB)
|-
! colspan="3" | Engine power (horsepower)
|-
! colspan="1" | Mode
!Stock
!Upgraded
|-
|''Arcade''
|615
|757
|-
|''Realistic/Simulator''
|351
|397
|-
! colspan="3" | Power-to-weight ratio (hp/ton)
|-
! colspan="1" | Mode
!Stock
!Upgraded
|-
|''Arcade''
|23.29
|28.67
|-
|''Realistic/Simulator''
|13.29
|15.04
|-
|}

== Armaments ==
=== Main armament ===

{{main|Ordnance QF 17-pounder (76 mm)}}

{| class="wikitable" style="text-align:center"
|-
! colspan="6" | [[Ordnance QF 17-pounder (76 mm)|76 mm OQF 17-pounder]]
|-
! colspan="3" rowspan="1" style="width:5em" |Capacity
! rowspan="1" | Vertical guidance
! rowspan="1" | Horizontal guidance
! rowspan="1" | Stabilizer
|-
| colspan="3" | 47 || -6°/+20° || ±180° || N/A
|-
! colspan="6" | Turret rotation speed (°/s)
|-
! style="width:4em" |Mode
! style="width:4em" |Stock
! style="width:4em" |Upgraded
! style="width:4em" |Prior + Full crew
! style="width:4em" |Prior + Expert qualif.
! style="width:4em" |Prior + Ace qualif.
|-
| ''Arcade'' || 10.7 || 14.8 || _.__ || _.__ || _.__
|-
| ''Realistic'' || 10.7 || 12.6 || _.__ || _.__ || _.__
|-
! colspan="4" | Reloading rate (seconds)
|-
! colspan="1" style="width:4em" |Stock
! colspan="1" style="width:4em" |Prior + Full crew
! colspan="1" style="width:4em" |Prior + Expert qualif.
! colspan="1" style="width:4em" |Prior + Ace qualif.
|-
| 7.60 || _.__ || _.__ || _.__
|-
|}

===== Ammunition =====
{| class="wikitable sortable" style="text-align:center" width="100%"
! colspan="8" | Penetration statistics
|-
! rowspan="2" data-sort-type="text" | Ammunition
! rowspan="2" class="unsortable" | Type of warhead
! colspan="6" | '''Penetration''' '''''in mm''''' '''@ 90°'''
|-
! 10m
! 100m
! 500m
! 1000m
! 1500m
! 2000m
|-
| Shot Mk.6 || AP || 160 || 157 || 133 || 112 || 96 || 86
|-
| Shell Mk.1 || HE || 9 || 9 || 9 || 9 || 9 || 9
|-
| Shot Mk.4 || APC || 165 || 160 || 138 || 108 || 94 || 81
|-
| Shot Mk.8 || APCBC || 171 || 168 || 156 || 143 || 130 || 120
|-
|}
{| class="wikitable sortable" style="text-align:center" width="100%"
! colspan="11" | Shell details
|-
! rowspan="2" data-sort-type="text" | Ammunition
! rowspan="2" class="unsortable" | Type of warhead
! rowspan="2" |Velocity in m/s
! rowspan="2" |Projectile Mass in kg
! rowspan="2" | ''Fuse delay''
''in m:''
! rowspan="2" | ''Fuse sensitivity''
''in mm:''
! rowspan="2" | ''Explosive Mass in g (TNT equivalent):''
! rowspan="2" | ''Normalization At 30° from horizontal:''
! colspan="3" | ''Ricochet:''
|-
! 0%
! 50%
! 100%
|-
| Shot Mk.6 || AP || 883 || 7.7 || N/A || N/A || N/A || -1° || 47° || 60° || 65°
|-
| Shell Mk.1 || HE || 883 || 7.0 || 0.4 || 0.5 || 580 || +0° || 79° || 80° || 81°
|-
| Shot Mk.4 || APC || 883 || 7.7 || N/A || N/A || N/A || -1° || 48° || 63° || 71°
|-
| Shot Mk.8 || APCBC || 883 || 7.7 || N/A || N/A || N/A || +4° || 48° || 63° || 71°
|-
|}
{| class="wikitable sortable" style="text-align:center"
! colspan="7" | Smoke characteristic
|-
! Ammunition
! Velocity in m/s
! Projectile Mass in kg
! ''Screen radius in m''
! ''Screen time in s''
! ''Screen hold time in s:''
! ''Explosive Mass in g (TNT equivalent):''
|-
| 17pdr Shell SS Mk.1 || 754 || 8.4 || 13 || 5 || 20 || 50
|-
|}

===== [[Ammo racks|Ammo racks]] =====
[[File:Ammoracks A.C.IV.png|right|thumbnail|x250px|[[Ammo racks|Ammo racks]] of the AC IV Thunderbolt]]
{| class="wikitable sortable" style="text-align:center"
|-
! class="wikitable unsortable" |Full ammo
! class="wikitable unsortable" |1st rack empty
! class="wikitable unsortable" |2nd rack empty
! class="wikitable unsortable" |3rd rack empty
! class="wikitable unsortable" |4th rack empty
! class="wikitable unsortable" |5th rack empty
! class="wikitable unsortable" |6th rack empty
! class="wikitable unsortable" |7th rack empty
! class="wikitable unsortable" |8th rack empty
! class="wikitable unsortable" |9th rack empty
! class="wikitable unsortable" |Visual discrepancy
|-
|| '''50''' || XX ''(+X)'' || XX ''(+X)'' || ''35 (+15)'' || ''45 (+5)'' || 10 ''(+40)'' || ''14 (+36)'' || 31 ''(+19)'' || 39 ''(+11)'' || 1 ''(+49)'' || style="text-align:center" | Yes
|-
|}

=== Machine guns ===

{{main|Vickers (7.7 mm)}}

{| class="wikitable" style="text-align:center"
|-
! colspan="7" | [[Vickers (7.7 mm)|7.7 mm Vickers]]
|-
! colspan="7" | ''Coaxial mount''
|-
! colspan="4" rowspan="1" style="width:5em" |Capacity (Belt capacity)
! rowspan="1" | Fire rate (shots/minute)
! rowspan="1" | Vertical guidance
! rowspan="1" | Horizontal guidance
|-
| colspan="4" | 4,250 (250) || 390 || N/A || N/A
|-
|}

== Usage in the 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 (1942)|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 ===

'''Pros:'''

*Good sloped armour.
*High penetration solid shot rounds.
*Good manoeuvrability.
*Fast reverse speed.
*Small profile.

'''Cons:'''

*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.

== History ==

===Development===
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 [[Ordnance QF 2-pounder (40 mm)|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 Lee|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 ''[[M4A5|Ram]]'' tank, being based off the the M3 Medium chassis and mated with a domestic design of their choice for the upper part. The Australian attached the chassis with a hull and turret with design similarities to the British [[Crusader Mk III|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. Though originally specified for a 2-pounder, it was then asked for a [[Ordnance QF 6-pounder Mk.III (57 mm)|6-pounder]] armament. Two Vickers machine gun were used as the coaxial and hull machine gun. 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.

===Termination===
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|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.

===Survivors===
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.

'''Trivia:''' 
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.

== Media ==
''An excellent addition to the article will be video guides, as well as screenshots from the game and photos.''

== Read also ==

* [https://warthunder.com/en/devblog/current/849/ [Devblog<nowiki>]</nowiki> AC IV Thunderbolt]

== Sources ==
''Paste links to sources and external resources, such as:''

* ''topic on the official game forum;''
* ''other literature.''

{{Britain medium tanks}}
{{Britain premium ground vehicles}}

War Thunder Wiki - User contributions [en]

A.C.IV