Tetrarch I

Tetrarch I

Daimler Mk II

Tetrarch I

Daimler Mk II

Britain

I Rank

Battle rating:

AB	RB	SB
1.0	1.0	1.0

Class:

Light tank

Research:Free

Purchase:Free

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Description

The Tank, Light Mk VII, Tetrarch I (A17) (or just Tetrarch) is a rank I British light tank with a battle rating of 1.0 (AB/RB/SB). It was introduced in Update 1.55 "Royal Armour" along with the initial British ground tree. A light tank with a 2-pounder, it fits the British light line of a fast tank with a powerful gun but weak armour.

The Tetrarch plays like any other Rank I vehicle in the game. Zip around with high speed to the destination and get a first shot off on the enemy tank (preferably the gunner). The 2-pounder can penetrate most enemy tanks at close range and the 40 mm shells can cause a decent amount of shrapnel that can damage most of the internals at the area of the penetration. The mobility is great with the adequate horsepower to propel the 7 ton tank around. The armour is barely adequate for Rank I, with its flat surfaces encouraging penetration with the cramped interiors making one-hit destruction a worrying situation for the Tetrarch.

General info

Survivability and armour

The armour of the Tetrarch I is of a typical light tank style. Topping at 16mm on the front of the hull and turret, its frontal armour is insufficent to stop even heavy MG bullets. It can only resist rifle caliber MG bullets or shrapnel, which significantly decreases its protection in any engagements. The side and rear armour is worse, at 14-10mm. This means that even rifle caliber MG have a chance of penetrating it when close enough. Thus you should avoid absolutely every vehicle, including the seemingly harmless ones like GAZ-AAA 4M. The roof thickness of 7-4mm is also not enough to stop aircraft bullets from above. Overall the armour values of the Tetrarch I is very poor and should never be relied upon. 

Given the thin armour, any penetrating rounds will easily damage the interior. The 3 crew of the Tetrarch are very closely packed, and can be knocked out easily by a frontal penetration, regardless of whether the round has explosive fillers. The thin armour also means that the crew are vulnerable to over pressure damage. Vehicles like the Ho-Ro or even the M8 HMC can trigger a deadly over pressure easily. 

The Tetrarch I does get 2 smoke grenades which can be used to create chances for escape. 

Smoke grenades

Creation of a smoke screen in front of the vehicle

Armourfront / side / back

Hull16 / 14 / 10

Turret16 / 14 / 10

Crew3 people

Visibility72 %

Armour type:

• Rolled homogeneous armour
• Cast homogeneous armour (Gun mantlet)

Armour	Front	Sides	Rear	Roof
Hull	16 mm (15°) Driver's port 16 mm (2°) Front plate 10 mm (72°) Front glacis 16 mm (19-43°) Lower glacis	14 mm (0-1°)	10 mm (22-51°)	7 mm (79-88°)
Turret	14 mm (18°) Turret front 16 mm (10-80°) Gun mantlet	14 mm (13-15°)	10 mm (2°)	4 mm

Notes:

• Suspension wheels and tracks are 15 mm thick.
• A little glimpse of the 4mm roof can be see from the front. A well placed HE round will penetrate and result in a knock-out.

Mobility

The Tetrarch I makes up for its lack of protection with a wonderful mobility. It is quite a light tank and has a 165hp engine powering it, giving it a rather high power-to-weight ratio of 21.7 meaning gread acceleration across all types of terrains. It can reach its top speed of ~65 km/h quite quickly on hard surfaces like concrete road or grass plain. The off road speed is also not disappointing, being around ~40 km/h on mountainous terrains. The brakes are effective too and can stop the vehicle properly at high speed. With this speed, the Tetrarch can get to crucial locations very quickly at the start of the match alongisde other fast vehicles from both teams which is beneficial to cap a point and/or set up ambushes on a chokepoint. 

However, just like most of the WW2 tanks, the Tetrarch suffers from a slow reverse speed of only -7 km/h, which will not be able to reverse you out of danger in time. Its hull traverse also feels "sticky", both turning on the move and when stationary will be quite slow when comparing to light tanks like the BT-5. This and the slow reverse prevent the Tetrarch I from maneuvering freely in confined environments like a town, limiting its mobility. 

Speedforward / back

AB75 / 7 km/h

RB and SB67 / 7 km/h

Number of gears5 forward

1 back

Weight7.6 t

Engine power

AB315 hp

RB and SB165 hp

Power-to-weight ratio

AB41.4 hp/t

RB and SB21.7 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	75	7	7.6	256	315	33.68	41.45
Realistic	67	7		146	165	19.21	21.71

Modifications and economy

Repair cost

ABfree

RBfree

SBfree

Total cost of modifications3 770

170

Talisman cost190

Crew trainingfree

Experts1 000

Aces10

Research Aces80 000

Reward for battleAB / RB / SB

10 / 10 / 10 %

100 / 100 / 100 %

Modifications

Mobility	Protection	Firepower
Tracks Research: 330 Cost: 15 45 Suspension Brake System Research: 300 Cost: 13 40 Filters Transmission Engine	Improved Parts Improved FPE Crew Replenishment	Horizontal Drive Research: 330 Cost: 15 45 40mm_uk_2pdr_APHV_ammo_pack Research: 330 Cost: 15 45 Adjustment of Fire Research: 300 Cost: 13 40 40mm_uk_2pdr_APHE_ammo_pack Research: 300 Cost: 13 40 Elevation Mechanism Research: 410 Cost: 18 55 Smoke grenade Research: 410 Cost: 18 55 Artillery Support Research: 530 Cost: 25 70 40mm_uk_2pdr_APCBC_ammo_pack Research: 530 Cost: 25 70

Armaments

Main armament

40 mm QF 2-pounder cannon

Shoulder stabilizer

Reduces the swing of the gun in one plane while moving

Ammunition50 rounds

Reloadbasic crew → aces

3.6 → 2.8 s

Vertical guidance-15° / 25°

40 mm QF 2-pounder					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	50	-15°/+25°	±180°	Vertical	6.66	9.22	11.20	12.39	13.18	3.64	3.22	2.97	2.80
Realistic					4.17	4.90	5.95	6.58	7.00

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
Shot Mk.1 AP/T	AP	72	68	52	37	27	19
Shot Mk.IXB APCBC/T	APCBC	89	86	77	66	57	50
Shot Mk.1 APHV/T	AP	80	75	58	41	30	21
Shell Mk.1 AP/T	APHE	66	62	49	36	26	20

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%
Shot Mk.1 AP/T	AP	792	1.08	N/A	N/A	N/A	47°	60°	65°
Shot Mk.IXB APCBC/T	APCBC	792	1.24	N/A	N/A	N/A	48°	63°	71°
Shot Mk.1 APHV/T	AP	853	1.08	N/A	N/A	N/A	47°	60°	65°
Shell Mk.1 AP/T	APHE	792	1.08	1.2	9	20.9	47°	60°	65°

Ammo racks

Ammo racks of the Tetrarch I

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	Visual discrepancy
50	38 (+12)	25 (+25)	13 (+27)	1 (+49)	No

Optics

Tetrarch I Optics
	Default magnification	Maximum magnification
Main Gun optics	x1.8	x3.5
Comparable optics	AMR.35 ZT3

Machine guns

7.92 mm BESA machine gun (coaxial)

Ammunition2 025 rounds

Belt capacity225 rounds

Reloadbasic crew → aces

10.4 → 8.0 s

Fire rate600 shots/min

7.92 mm BESA
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
Coaxial	2,025 (225)	600	N/A	N/A

Usage in battles

This tank is all about mobility: it can nearly go anywhere fast, surprising the enemy. Being one of the smallest vehicles in game, the Tetrarch will be able to roll through the thinnest passages at high speed. Its short hull enables it to cross hilly woods and rocky ground without ditching. On gear 1, it can climb any hill, as long as it sticks to the ground, thus reaching advantageous spots from where it can snipe using its good gun depression, showing only its tiny turret. Although, it is recommended to change position often since anyone knowing where the Tetrarch is can pin it down easily (remember that the Tetrarch only have 3 crew members and thin armour). Consider flanking with this vehicle since it has such a good speed but beware the Tetrarch's slow turret slewing rate, so pre-aim the cannon in the expected direction of the enemy.

Target isolated enemies since the 2-pounder gun does not have significant post-penetration damage. Shoot the gunner first to disable it from returning fire, then, stop it from moving by shooting the driver, engine or transmission. Et voilà ! then, disable every crewmen one by one. Make sure to shoot at the gunner's and driver's position every 3-4 shots since it takes roughly 15 seconds to replace them.

Use the Tetrarch's awesome off-road mobility and climbing to get into an unusual position behind enemy lines, fire a few shot and disappear in the shadows. If the Tetrarch gets spotted before finishing an enemy, flee: staying alive is more important than destroying someone, finish the enemy off later, when they have forgotten about the Tetrarch's presence.

Otherwise, anyone playing the Tetrarch should get back behind friendly lines if two or more enemies are approaching since it's cannon can only take down enemies one by one, patiently shooting down each crewman.

As with any tank equipped with the QF 2-pounder, little post-penetration damage makes large and crowded tanks a nightmare, thus, LVT(A)(1), T-28 and the less common T-35 should be avoided, although the Tetrarch's APHE shell can be rather quite effective against these vehicles.

Pros and cons

Pros:

• Powerful gun with piercing shells and fast reload
• Awesome mobility: high top speed, great acceleration, and good climbing ability
• Vertical stabilizer available for the 2-pounder, an advantage in CQC
• Small profile, is harder to get spotted and hit
• Large gun depression of -15 degrees

Cons:

• Rather slow turret traverse
• High speed often makes the vehicle hard to control
• Low survivability: incredibly thin armour, low crew count, and is vulnerable to overpressure or even ramming damage
• Only reaches max speed when going down a slope
• Does not have good post-penetration damage, often requiring follow-up shots to finish off the enemy
• High shell dispersion at longer ranges
• Short hull, has difficulty crossing ditches/trenches

History

Development

Development for this tank started in 1937 by Vickers-Armstrongs privately as the Light Tank Mk VII and nicknamed the Purdah.. The intention was for the tank to be sold to either the British Army or foreign countries as the latest light tank of the company. It's predecessor, the Mk VIB Light Tank, was considered insufficient in firepower, armed with only machine guns. The new design would use the new 2-pounder gun along with a coaxial machine gun. The Mk VII design was finished around 1938, and the British War Office (government administrating the British Army) took up the design for trials in May 1938 that lasted until June. The trials tested the Mk VII's ability to act as a "light cruiser", but this failed as the A13 cruiser was much better at the task. Thus, it was suggested that the Mk VII be tested as a light tank instead and production to be started for the trials. During the trials, the War Office gave the Mk VII the specification number A17 for identification and was put into limited production in November 1938 with a few design changes. It was initially known as the "Purdah" from its standardization date, but in September 22, 1941, the Mk VII Light Tank also received the name 'Tetrarch' as part of an order to distinguish tanks by chosen names.

Demand for the tank fluctuated depending on the War Office demand for the tank. In July 1938, the first order came for 70 tanks, then 100, then 120 in November, then back to 70 in July 1940. This order then jumped back to 100, then finally settled on 220 after Metropolitan Cammell Carriage and Wagon, a part of Vickers-Armstrong, had enough armour plating to create that many tanks. Production was suppose to start in July 1940, but was delayed due to many factors, especially with World War II now on full swing against Germany. Light tank also soon fell out of War Office use after the poor performance they showed in the Battle of France, so military production was focused on the infantry and cruiser tanks rather than light tanks. Bombing raids by the Luftwaffe in the Blitz also disrupted the production of the tanks when the factories intended for their production were targeted. These delays due to waning military interest, the pressure of war, and enemy attacks caused only a small number of Tetrarch light tanks to be produced, with 177 units produced from 1938 to 1942.

Design

The Tetrarch featured armour only about 16 mm thick and the whole design weighed about 7.6 tonnes. The vehicle moved on a eight road wheel (four on each side) suspension system and there were no other driver or idler wheel present. The engine powering the vehicle was a 165 hp Meadows Type 30 engine that can propel the vehicle up to a speed of 64 km/h. The vehicle functions on a steering mechanism and mechanical system taken from earlier Vickers tanks, the unique steering mechanism allowed for turning by bending the tracks on each side of the tank rather than by braking a set of track, but the latter was still involved when making sharper turns and low speed turns.

However, the Tetrarch presented many faults in its design during its time with the British military. The small size of the tank only allowed a crew of three for the tank to operate, making it a very cramped and the crew overworked. Also, the Tetrarch's cooling system was faulty, enough so that the Tetrarch was an unsuitable tank for the North Africa campaign due to the hot climate at the area.

Combat usage

The Tetrarch was first issued in November 1940 to the 1st and 6th Armoured Division, the 1st had lost most of their equipment in the Battle of France and the 6th was a newly formed unit. While these units were sent to North Africa, the defects in the engine cooling system forced the Tetrarchs to stay behind, until they were taken out of armoured divisions due to the "light tank" concept becoming obsolete, though they were still used as training vehicles.

The Tetrarchs still saw use overseas as part of the Lend-Lease program, and 20 were supplied to the Soviet Union in 1942 to fight back the invading German Army. In the cold Russian weather, it was noted that the cooling problem was still present and the cold also caused damages to the tank's suspension and tracks. The vehicle was well-liked for its handling, manoeuvrability, and speed, plus was compatible with low-octane fuel the Soviets used in their diesel-powered tanks. The Soviets compared the Tetrarch's capabilities to their T-70 light tank and employed the Tetrarch in the same roles. Some were used for training, other as propaganda purposes, and combat, with a notable event where two were assigned to the 132nd Separated Tank Battalion in September 1943. Both Tetrarchs were destroyed in combat.

Back to the British, in mid-1941, the Tetrarch was still integrated in the Royal Armoured Corps as part of tank squadrons that would be sent to overseas operations. The three Special Service Squadrons exist as "A", "B", and "C"; "A" and "B" were armed with the older Mk VI light tank and the Valentine tank, but the "C" squadron was equipped with 12 Tetrarchs in its ranks. These squadrons were first used in Freetown, West Africa in order to ensure Spain does not enter the conflict on Germany's side, then the squadrons were withdrawn to Operation Ironclad, the invasion of Madagascar. Six Tetrarchs were deployed alongside Valentines in "B" Special Service Squadron, which took elements of "B" and "C" squadron. The invasion commenced on May 5, 1942 and "B" Squadron encountered difficulty after a Tetrarch became stuck in the beach after coming loose from a landing craft. The Tetrarch and Valentine were still able to assist the infantry after that delay, but the rocky terrain in the region made tank manoeuvring difficult. After two days of combat, the forces on the island formally surrendered, the losses experienced by the squadron were 8 tanks knocked out, with only four tanks (1 Valentine and 3 Tetrarchs) left functional.

After Operation Ironclad, the Tetrarchs were shifted in their roles to become part of the airborne forces after War Office and the Army decided that the light tanks of the day were not capable of competing against other tanks. It was in mid-1941 when the Airborne forces decided to use gliders as part of their landing equipment and the General Aircraft Hamilcar glider can carry one Tetrarch tank and its crew in the storage compartment. By 1942, the War Office had redesignated the Tetrarch as an "airborne" tank and the essential unit with the Tetrarch on hand was the "C" Squadron, converted into an independent tank unit and brought to the airborne forces in June 1942. Though intentionally in 1st Airborne Division and primed for the invasion of Sicily, not enough gliders for the Tetrarchs were available so they were left behind, the "C" squadron was transferred to 6th Airborne Division in April 1943. The squadron was expanded into a regiment by bringing in more light tanks and other reconnaissance vehicles, the regiment has at least 21 Tetrarchs on hand in its three squadrons in May 1944, some modified with a 76.2 mm howitzer for close support (CS) and others retaining the 2-pounder that has Littlejohn adaptors that increased its penetration capabilities. A consistent problem for the airborne forces was the low number of tanks available to them; with only 50 available Tetrarchs reported in December 1942, the demand could not be met, thus a new airborne tank design must be made to fill this demand, which the specifications was sent to the United States for manufacturing.

The next British operation using the Tetrarch was Operation Tonga, which was an airborne operation that took place alongside D-Day with the objective to capture two bridges over the Caen Canal and Orne River. This began in June 5, 1944 with only parachute brigades landing first to clear anti-glider obstacles on the landing zones, which then allowed the gliders to land on the next day, carrying the tanks with them. As they landed, the tank force of about twenty tanks became depleted by four tanks from glider incidents, the remaining Tetrarchs still operational were ordered to link-up with 8th Parachute Battalion to preform reconnaissance. The general notion with the Tetrarch was for it to avoid any contact with German armour as even the most typical German unit like the Panzer III can destroy the Tetrarch, so the tank was relegated to infantry support. By August 1944, the majority of the Tetrarchs in the squadron were replaced with Cromwells and only three Tetrarchs remained with the Headquarters troop of the Regiment.

Operation Tonga was the last World War II conflict involving the Tetrarch, and it was replaced by the M22 Locust in October 1944. Though declared obsolete in January 1946, the Tetrarchs stayed with a few units like the 3rd Hussars until 1949. The Tetrarch in every military branch, even in training exercises, were formally removed from service by 1950.

Media

Skins

• Skins and camouflages for the Tetrarch I from live.warthunder.com.

Videos

Airmobile tanks discusses the Tetrarch I at 0:31 - War Thunder Official Channel

See also

Other vehicles of similar configuration and role

• M22

External links

• [Devblog] Tetrarch Mk I