Vickers for Interwar Tanks: The Class C/T Machine Gun

The Vickers company developed several versions of the Vickers machine gun for aircraft use during the 1920s and 1930s, but they also worked on armored vehicle versions of the gun in the 1930s. Between 1930 and 1936 these were adopted by the British military as the Mk IV through Mk VII guns, but the gun we are looking at today is the commercial export pattern, the Class C/T. This particular gun is one sold to Argentina.

The basic mechanics of the gun are unchanged from the standard Vickers heavy machine gun, but a bunch of adaptations were done to make the guns more suitable to use in armored vehicles. A pistol grip was developed to mount under the gun in place of the spade grips. Coupled with a large leather-covered buttpad and cheek pads, this allowed the gunner to hold the gun much like a rifle; essential in the tight confines of a turret. The barrel was shortened, and a new style of booster was designed which allowed the barrel to be removed from the rear of the gun, allowing the gun to be worked on from within the protection of the vehicle. The top cover was also give a hinge on the side, again for more compact use. The most complex change was the development of interchangeable feed blocks to allow left-hand or right-hand feeding with only the changing of that one unit.

One of the really interesting aspects of these tank guns was the experimentation around their cooling systems. For the British military, the goal was to have a gun capable of firing 3,000 rounds in 30 minutes. Normally this would be an easy bar for a Vickers to clear, but it would require refilling the water jacket – and that was a really clumsy exercise inside a tankette turret. Various types of circulating systems were tried out, but they all had problems with the need for the guns to be in flexible mounts. What would seem like a perfect idea of plumbing the gun into the vehicles existing radiator had the unfortunate consequence of rendering the whole vehicle immobile if the gun’s jacket took a bullet hit and leaked…

Overall production was low, and the guns were primarily used in vehicles that Vickers was building themselves. By the time World War Two began, the Vickers was clearly obsolescent in this role; there were much cheaper air-cooled options (like the Besa, which the British would choose for their own use).


  1. In your comments you mentioned the fact that by that time a .30 caliber machine gun was not an important part of a tanks armament. In the 60’s, the M-60 U.S. Army tank had the M-73, 7.62 NATO machine gun.
    Very interesting video, keep up the good work.

    • Yeah, I think that would better be phrased as rifle-caliber machine guns no longer being suitable as the *sole* armament of a tank. My understanding is that on the M-4 Sherman, and probably most tanks from 1940 on, the coaxial machine gun is used more often than any other weapon – there are a lot more soft targets on the battlefield than hard ones, and a rifle-caliber machine gun on a stable (or even stabilized) mount with a decent optical sight and a gunner firing from under armor is a very very good soft-target weapon at most combat ranges. So you need that weapon to be reliable and accurate. But *sometimes* you need hard-target capability, and when you need it you need it real bad, so the concept of a light tank or tankette with just the machine gun mostly went away when early WWII combat experience started coming in.

      If you have to squeeze both a hard-target gun and a rifle-caliber machine gun into a crowded turret, I can see the argument for making the machine gun something a bit slimmer than a classic Vickers. And with the big gun’s breech in the way, you aren’t going to be firing the MG by getting a cheek weld and squeezing a trigger under the receiver.

      • The only WW2 or Cold War era tank which didn’t have a 7.62mm or 8mm coaxial machine gun was the French AMX-30, which initially had a .50 cal coaxial and the upgraded AMX-30B had a 20mm coaxial. The French apparently believed that light armored vehicles and helicopters would be a greater threat than infantry for their tanks, although naturally the .50 cal or 20mm weapon could be used against infantry as well; the only problem with that would have been ammunition, which would be expended fairly rapidly against infantry. Even so, the AMX-30 did also have a 7.62mm machine on the roof and operated by the commander, although it could not be used when “buttoned up” against artillery or small arms fire.

        The successor of the AMX-30, Leclerc, also has a .50 cal coaxial machine gun. Return to the .50 cal was probably a compromise between ammunition stowage and anti-vehicular performance of the 20mm. Or as some people would probably say, the French just like to be different…

        Though not a tank, the German Puma IFV originally had a 5.56mm MG4 as the coaxial gun; a decision which raised a lot of eyebrows. However, the MG4s are currently being replaced by 7.62mm MG5 machine guns.

        • “(…)only WW2 or Cold War era tank which didn’t have a 7.62mm or 8mm coaxial machine gun was the French AMX-30(…)”
          False. Certain Valentine tanks has not coaxial guns

          The up-gunned Valentines: Mark VIII, IX and X
          Since the 2-pounder was found inadequate against the main German tanks of 1942, Vickers engineers worked frantically on a way to adapt the much more massive, long-barrel 6-pounder (57 mm/2.24 in) into the cramped Mark III turret. They succeeded, but at the expense of the coaxial Besa machine-gun. The Mark VIII received the British AEC A190 diesel, but the Mark IX, an upgunned Mark V, retained the US-built GMC 6004 diesel, which was upgraded towards the end of the production in 1942, now giving 160 hp. Both had somewhat downgraded armor. The Mark X was virtually identical to the IX, but at the start incorporated the new GMC diesel, a redesigned turret which reintroduced the coaxial machine-gun, and it used welded construction and some cast parts.

          • Yes, you are right, I forgot about certain WW2 exceptions to the rule. The Japanese also had some tanks, which did not have a coaxial machine gun, but a machine gun at the rear hemisphere of the turret (not necessarily directly in the opposite side of the main gun). The idea was that you could turn the machine gun to facing enemy infantry while having the main gun pointing to a different direction. Why this was considered better than a coaxial MG is a little unclear to me and apparently the Japanese also changed their minds, since their later designs did have a normal coaxial MG.

        • The Swiss Pz61 had a 20mm Oerlikon cannon co-axial with its 105mm main gun;

          It could be elevated to 70 degrees, independently of the main gun. This allowed it to be used against low-flying tactical aircraft, in addition to dealing with ground targets not considered worth a 105 round.

          When the Pz61s were upgraded in 1968-69 to the Pz68, the 20mm was replaced with a 7.5mm MG51 GPMG. By that time, the Swiss had concluded the same thing that most other armies had. That the co-ax MG was mainly for use against infantry, plus as a ranging gun for the main gun.

          Also, in their case, the tank’s turret was one of the smallest in internal volume since 1945. The 20mm took up too much space in it to be practical, and even a .50 Browning would have been a similar problem. The 7.5mm MG51, minus its shoulder stock, was overall only about half as big an “intrusion” as either of the heavier automatic guns.

          The real debate was, and to a certain extent still is, the usefulness or otherwise of the bow-mounted MG, generally a rifle-caliber, again for dealing with infantry and other “soft” targets out to roughly 400 meters. The bow gun could do that job in one direction while the co-ax or main gun was otherwise occupied. In case of an infantry “swarm” as seen in Korea, both MGs could concentrate fire in one direction.

          The present fashion for Remote Operated Weapon Stations (ROWS) atop tank turrets, mainly equipped with rifle-caliber GPMGs, would tend to indicate that in actual practice, tanks have become a bit deficient in MG capability for MOBUA even as they became highly efficient killers of other tanks in open-country warfare.



          • I should have known that making any categorical statements here would be an error and people would point out exceptions, but I almost expected that. It’s why this forum is so great compared to others (and YouTube comments in particular).

            The Israelis have traditionally put a lot of machine guns in and on their tanks, so definitely there appears to be deficit for MOBUA when it comes to anti-infantry firepower of the classic 1+1 MG configuration on most Cold War tanks. US tanks have usually had 1+2 machine guns though, with a weapons for both the commander and the loader on top of the turret.

            Modern Soviet/Russian tanks naturally can’t have more than two machine guns, because they have three man crews and the driver can’t possibly operate a weapon. Still, they do like their firepower, since the BMP-3 IFV has two bow machine gun positions in addition to a coaxial MG, 100mm low velocity gun AND a 30mm autocannon. However, the usefulness of the bow MG positions have been questioned in Western military press. Like most such positions the field of view of the gunners is very limited, which is also one of the reasons the bow machine guns disappeared from tanks soon after WW2. Another reason was that the machine gun opening created a weak spot in the frontal armor.

    • “(…).30 caliber machine gun was not an important part of a tanks armament(…)”
      This is function of enemy you have to fight against. If enemy does equip portable anti-tank launchers capable of defeating armour, then ability to prevent anyone from successfully using it is paramount.

      • Yeah, because using the large-caliber main gun to take out a single tank-hunter infantryman out in the open amounts to overkill.

        • That was the devil’s choice the IDF faced in the 1973 Yom Kippur War. When faced with coordinated infantry 9M14 Malyutka (AT-3 Sagger) ATGW teams working with Egyptian MBTs, did they load the main gun with HEAT or APDS for dealing with the T62s, or canister (“Beehive”) rounds for killing or at least dissuading the Sagger teams?

          The IDF’s solution was mounting a .50 BMG atop the main gun. While originally intended for target range practice to economize on HCG rounds, it was found to be an excellent “dissuader” for ATGW teams in actual combat, as unlike the rifle-caliber co-ax it was not outranged by a Sagger*. This is still the practice on the Merkava MBT today.

          (*The maximum effective range of the 9M14 is about 1,200 meters; the often-quoted 3,000 meter MER is questionable. Minimum range with SACLOS guidance is ~500m, so no Sagger operator with reasonable intelligence is going to open fire from within practical GPMG range of a tank if he can help it.)



          • For wire-guided missiles the maximum range quoted in sources is usually the length of the guidance wire. The practicality of launching the missile to maximum range is another thing. The Malyutka (AT-3) is a slow missile (110 m/s) a with flight time of nearly 30 seconds to the maximum range. If the target is free to maneuver, the is high chance it will be able to evade the missile by simply driving behind cover. It could even happen if the target is not aware of the approaching missile, unless we are talking about a completely flat “pool table” terrain. Also hitting the target at such ranges with s manually guided missile requires considerable skill with the 8x optic the guidance unit has.

            Still, I would say 1,200 meters is a somewhat low number for effective range. Certainly the hit probability goes down at longer ranges, but if we consider 50% hit probability as the cutoff point for effectiveness, the actual effective range depends greatly on the terrain and operator skill level. The later SACLOS variants should have a better effective range due to the lesser effect of operator skill.

  2. If only we had touched base with our ally, we could have made our MMG into an “LMG” without making it longer and bulkier!

  3. Here’s one of the dozen Vickers Carden-Lloyd M1934 light tanks purchased by Argentina

    564282538f049566d810ca23f8106a1a.jpg (540×673) (

    “Vickers Carden-Loyd Model 1934

    Arriving in 1937, twelve of these light tanks were intended as a stopgap solution before heavier more powerful tanks could be acquired. They performed admirably in military maneuvers near the Uruguayan border in 1938. In 1943, some models served in the communications section of the 2nd Infantry Regiment. However, they were soon relegated to purely training duties despite the unavailability of an adequate alternative, and by 1946, they may have been used by the police. Most vehicles survived until the early 50s, but were scrapped soon afterwards.”
    It as also worth noting that the entire series of interwar British light tanks (with the exception of the late Mark VIC, which had Besas) was armed with Vickers guns

    The Mark V had Vickers ,303 and .5 inch guns. The Mark VI, VIA and VIB duplicated this armament
    and the VIC had a 15mm Besa and 7.92mm Besa (I am going with Chamberlain and Ellis’ British and American Tanks of World War II in preference to the Encyclopedia as far a armament goes)

    PS – The “E” in the serial may stand for “Esercito” (Army) as opposed to “Armada” (Navy)

  4. Some of the British Vickers guns ended up in use by the LRDG in North Africa, replacing the Lewis gun on the pedestal mount in the back of the Chevrolet 20cwt truck.

    The Vickers offered more sustained-fire capability than the Lewis, and like the Lewis could be swung completely around on the “pipe” without fouling a hose down to a reserve water can.



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