"Tank Machinegun Turrets effectiveness vs infantry?" Topic

How effective were extra machinegun turrets on a tank against infantry?

A number of early war tanks had them (Crusader I, T-28, T-35, the Neubaufahrzeug, and the twin-turreted T-26 come to mind). Obviously, they were determined to not be worth it. However, are there any anecdotes or situations in which these machinegun turrets were found to be effective? Were they less effective than Hull machineguns, or merely less efficient?

I'm just curious if there were any situations that occured in the early parts of the war in which these quickly obsolete turrets were effective in combat.

I'm just curious if there were any situations that occured in the early parts of the war in which these quickly obsolete turrets were effective in combat.

Probably pretty danged effective against infantry with no, or limited, anti-tank capabilities. However, this WW1-inspired multi-turret idea was premised upon tanks being used as infantry support weapons (heavy-medium tanks) or as light mechanized exploit/recon cavalry (tankettes and light tanks). Many heavy infantry support tanks, like the Matilda, were even designed to be slow, so the drivers wouldn't be tempted in battle to outpace the infantry too much.

But balanced against extra firepower, the extra turrets took up mass and space that could be devoted to larger weapons, more armor, better/larger engines, etc., and also added more points of failure to the tank. Just more stuff to go wrong, and another weak point in the tank's main armor.

This became quickly apparent early in the war as these multi-turret tanks matched up against new weapons -- AT guns and Dive Bombers, and new tactics -- massed tank formations, and a much faster pace of battle than WW1.

They were meant to suppress enemy MG's and scatter cavalry.

Let's start with the basics. MGs in armored turrets are effective against infantry. They kill infantry in the open, and they suppress infantry, MGs, and guns that are dug-in.

But the question is not whether an MG in a turret is effective, but rather whether the MG-mounted sub-turret was effective. The MG-mounted sub-turret had little to do with infantry with no, or limited, anti-tank capabilities. Any MG in any turret (or even pivot) mount, on any tank (or even any tankette), could be effective against infantry or cavalry in the open if there were no AT guns about. Sure, more MGs are better, but sub-turret is hardly any added value.

Sub-turrets were generally adopted not for addressing challenge of infantry in the open, but for the problem of infantry in well-developed trench systems.

The primary purpose for the extra MG mini-turret was to allow the tank to split it's MG fire, with the key desire being to split the fire at 90 and 270 degree angles from the tank. That's why you see the sub-turret generally located on one side or the other, with an unobstructed range of fire from the front to the side. If there are two sub-turrets, they are located on the two sides of the tank, to split their fire over both sides simultaneously. You don't see inter-designs with an MG sub-turret front-center to fire uniquely over the front arc of the tank.

This would allow a tank to straddle a trench and fire down the trench in both directions at the same time. British experience with tanks in WW1 showed this to be a very valuable capability.

It was pretty much a case of designing for the prior war's priorities. But by WW2, "infantry support" in a tank no longer meant clearing well developed trench systems.

Late inter-war experience (notably the Spanish Civil War, but also the Soviet/Finnish Winter War) showed that extensive trench lines were less of an issue, while bullet-proof armor was not enough to protect a tank on a modern battlefield. When it came to a question of putting weight into a sub-turret, or putting that weight into other things like heavier armor, the armor won out.

Some designers also hit upon the idea that firing out the front and back of one turret could achieve the same result, with minimum expense in space and weight. The Soviets kept the capability by putting rearward-firing MGs on their heavy tank turrets. Everyone else just gave up on split fire, as trenches never rose to the same magnitude of problem they had been in WW1.

-Mark
(aka: Mk 1)

I suspect that they were dropped mainly, or at least partly, because they were very vulnerable to AT fire.

Even the hull MG was eventually dropped (mostly post-war) for adding a point of vulnerability.

You don't see inter-designs with an MG sub-turret front-center to fire uniquely over the front arc of the tank.

Crusader 1.

In addition to all of the above.

While on paper it seemed like a good idea for clearing trenches and giving a larger arc of fire…

In addition to shot traps and weight taken up that could have been better used…

Extra manufacturing requirements would have been a factor in their disappearance as well. To rotate they would need to run on finely machined surfaces and use bearings of some sort. Something you may want to skip in a time of war.

Machine-guns are not that easy to make so it was likely better to employ it on the ground with a full crew and get maximum benefit from its use.

In most cases the sub turret gunners were isolated from the tank commander, working alone a weapon that normally needed 2 or 3 people to operate in a very cramped space (literally with no elbow room) with negligible visibility. And this lack of visibility not being compensated by useful direction from the tank commander who either had poor ability to communicate to the gunner or had his hands full with other problems (commanding rest of tank, co-ordinating with rest of the troop, etc), often both. With this in mind, it seems like a good idea on paper quickly turned into a "someone did not think this through" nightmare situation for the poor sub turret gunner. Who was probably puking his guts up because of the fumes from his weapon to worry too much anyway (what ventilation?)!

You could argue that the sub turrets of the early production Canadian Ram Cruiser became a virtue when it was converted into a troop carrier (Ram Kangeroo). But that was not a normal or planned situation or outcome.

That the M113 ACAV model was developed later shows that the idea was not entirely without merit or use. But moved onto a separate vehicle. There is also the Israeli habit of festooning the turret top with commander operated machine-guns to provide fire in many directions without the lag of traverse time to engage an enemy darting for cover. But here the speed of engaging a possibly RPG armed infantry team seems to be the reason (on the basis if you fire at them first, they has at least no immediate interest in shooting at you something that can take the whole tank out).

Were they less effective than Hull machineguns, or merely less efficient?

Considering the ability of the turret to traverse, I would presume that they would be somewhat more effective than bow (hull) machineguns. Not to mention that they had dedicated operators, where as the bow gunners might have other tasks to worry about, such taking care of the tank radio.

Whether it was efficient use of manpower to dedicate one tanker for crewing such a weapon is another issue, especially considering the difficulties he might have with coordinating the rest of the crew.

Agreed.

A lone crew man struck in an isolated turret is ineffective. While the commander is busy actually commanding the tank, main gun etc, what does this guy do? Wait to be told what to engage next? Decide to pop off a few rounds and then sit tight? Probably doing nothing most of the time waiting for an order that rarely comes.

Pretty ineffective all round.

DB

Usually set very low, almost hull height, limits vision and range of use.
Limited vision, no optical magnification or observation, strictly hand held, no mechanical controls to steady and adjust.
It adds weight to the vehicle and loses a crewmans' space and storage.

Additionally, at the start of the war most were using left over first war guns like the Vickers or the Maxim. Both incredibly bulky and complicated to operate inside a vehicle. Worse yet the pan fed Lewis or DPs. While the UK did switch over to the Besa soon enough, it was rather a new thing and took time to train up to proficiency, but was later renown for reliability and accuracy.

There is good reason why these went the way of the dodo.

The ability to see and adjust fire using the turret controls and magnified optics can not be ocer stressed enough. As an example, I was using an old Browning 1919 modified to take 7.62mm link in the early nineties still. Using ten power optics of the gun sight along with the turret controls and effects of the strike on the ground, i could hit targets out to 1,400 meters! Which is pretty good considering that the trace burns out between 800 and 1,100 meters out and the manuals stated the thing was only effective to 1,100m at max trace burn out.

However, if all you have between you and the enemy machine gun is nothing better than your cotton shirt,,,the thing is still a problem to you.

Given how many of the combatants kept multi-turreted tanks (none) I would say not many

Part of the issue was the debate as to the role of the tank in the Inter-war years; infantry support vehicle or the new age armoured cavalry. Hence the very different designs seen as the various countries experimented with what was the best battlefield role for their tanks

I remember reading somewhere the British in the desert using one of the turrets for storage.

Troopwo's experience is telling, and fairly consistent with what I have heard from other tankers and read in memoirs. A turretted MG with fire control … almost any form of fire control, can be a deadly accurate weapon against light targets.

This was not lost on tank forces and tank development teams in the post-war period. So we see various tanks with HMGs (12.7mm, 14.5mm and even 20mm) in the turret with the main gun, using the accuracy and effectiveness achieved by this mounting (but eventually judged to come at too high of a price on critical interior real estate).

So we also see turret-top externally mounted MGs and HMGs with fire controls and optics, in some cases even tied in to interior tank systems. Again … the effectiveness of a well controlled automatic weapon is obvious, the question is the cost of mounting it on the vehicle.

Part of the issue was the debate as to the role of the tank in the Inter-war years; infantry support vehicle or the new age armoured cavalry.

Yes and no. There was much debate of the role of tanks during the interwar period, and this did lead many designs down un-productive design paths. But the question of "infantry support vs. cavalry role" (perhaps better stated as breakthrough vs. maneuver role) had much more to do with armor and combat mobility than with weapons. In either role you might be required to engage infantry targets, dug-in positions, and hard (armored or concrete) targets. You might well prioritize the targets differently, but all were on your list. So all tanks that had enough room carried both MGs and cannons.

None of that addresses the question of secondary turrets mounting only MGs.

The question was not whether MGs were useful. By the mid- inter-war period pretty much every nation involved in tank design had concluded that MGs were useful. The question was not which doctrine the tank was designed for, infantry support or cavalry role, MGs were useful in both doctrines of tank warfare. The question was how to mount the MGs to effectively contribute to the doctrine and the tactics.

A lot of inter-war designs festooned MGs all over the tank. Some used fixed forward-firing MGs controlled by the driver, some used sponsons with MGs, like the guns on pre-dreadnaught armored cruisers on land, some put multi-MG mounts in the main turret, some provided turret-front MGs that were not linked co-axially to the main gun. There were lots of approaches to putting MGs on (in) tanks.

In the end, the most useful was an MG mounted co-axially with the main gun. This used space that was already paid for, used gun control mechanisms and optics that were already paid for, used crew members that were already paid for, and gave a very accurate, highly lethal weapon for use on soft targets.

The dedicated MG sub-turret went dis-appeared pretty quickly once combat experience showed the way. It's main incremental value, shooting down the side of the tank while the main turret shot the other way, was shown to be of very limited utility in WW2 combat.

So also sponson MGs quickly disappeared. Part of the reason for the sub-turret's demise also applied here. Sponsons, properly located, were also effective for simultaneously shooting down opposite sides of the tank. Combat experience showed this to be an uncommon requirement, and the cost of crew and interior space was beyond the value they provided.

Even the forward-firing hull MG went away, as combat experience showed that the space and weight were better used for other purposes. In this case it was not so much the cost of the mounting (an MG is cheap compared to the cost of a tank), but the cost of the extra crewman, both in terms of interior volume and in terms of manpower, that spelled the demise of the hull MG. So also, over time it became clear than any interruption in the continuous solid armored plate of the front slope added vulnerability and provided an aiming point for enemy AT weapons.

The British experience on this matter is an interesting study in learning and applying the lessons of combat.

Based on their experience in using tanks to break the trenches in WW1, the early interwar tanks all featured side-firing MGs. Sponson MGs that could ONLY fire to the sides in the Vickers Medium were replaced by twin MG sub-turrets (one each side) that could fire both to the sides and forward in the Vickers Medium Mk III. After flirting with the idea of the A1E1 Independent, also with two sub-turrets, the "breakthrough" role of early Infantry tanks shifted to an emphasis on heavier armor, and the sub-turrets were simply not important enough. One turret, one direction of fire, more armor.

But the cruisers still flirted with the MG sub-turret, with twin sub-turrets in the A9 Cruiser Mk 1, shifting to a single sub-turret to fire forward or to one side in the Crusader. Once combat experience showed the poor utility and high cost of the sub-turret on the Crusader, it was dropped, and by the time the Centurion was designed even the forward firing hull MG position was eliminated.

Or so I've read.

-Mark
(aka: Mk 1)

However interesting that today remote commander and loader weapon stations are back in favour in some MOUNT circumstances

You don't see inter-designs with an MG sub-turret front-center to fire uniquely over the front arc of the tank.

T-26 twin MG turret:

The M3 Lee as initially delivered came with something like seven machine-guns. They didn't last long and if memory serves the Grant version had no MGs at all.

Even the forward-firing hull MG went away, as combat experience showed that the space and weight were better used for other purposes. In this case it was not so much the cost of the mounting (an MG is cheap compared to the cost of a tank), but the cost of the extra crewman, both in terms of interior volume and in terms of manpower, that spelled the demise of the hull MG.

I think one of the reasons why the bow MG persisted so long was that this crew member tended to have other tasks, like maintaining the tank radio. So if he was needed on the ride anyway, he could as well be provided with an MG he could fire on his spare time. Once those other tasks declined (due to improvements in radio technology etc.) then it was no longer worth it to maintain that extra crew member for the bow MG alone.

Also some of the British designs made during the WWII eliminated the bow gunner position to make more space for other purposes – Sherman Firefly and Crusader with 6 pounder gun come to my mind.

On another note, I might want to mention that many of the inter-war tanks had relatively small caliber main guns (around 37 mm or so), with limited anti-personnel HE effect – maybe this could have encouraged the designers to pack in extra MGs for additional anti-infantry firepower? Then again, the Soviet T-28 featured both a larger calibre main gun (76.2 mm) and two MG sub-turrets…

As for the WWII tanks with lots of Dakka, I recall the early US M3 light tanks having up to five MGs (coaxial, bow, AA and two fixed forward), though later models reduced this to just three. And the experimental Bob Siemple tank from NZ had around six MGs pointing in various directions, though no main gun to complement them.

Mark stated it fairly nicely.

Strangely the turret machine gun persisted in one way on the developments of the top turret 0.50 cal mini turrets that plagued the M48 and later the M60 with its' mini turret on top of a ten foot tall turret already.

The M48 turrets were despised and most armies figured out ways to get rid of it in favour of a more flush design.

The M60 mg turrets were probably tolerated mostly because they served almost all their service in peacetime in Germany. The ability to get most of the tank commander out of a turret and more storage space it provided was probably why it was tolerated.

As Griefbringer mentioned, western armies tried to keep that fifth crewman. An extra man makes a massive difference in maintainance and guard duties.

The only other strange way that those mini turret development went, was in the fender mgs. If you see the early Stuart tanks, they had some five or more mgs. One on the turret top in a swing mount. One coaxially. One in the hull front. Then there were a machine gun literally in each the right and left front, or fenders as some might say. In North Africa, they were quickly dropped.

Strangely enough, they reappeared in of all things the Soviet BMD. Considering that they were aimed and aligned by the way the hull was pointed they were immpossible to aim. So the only good they were for was to creat noise and maybe crowd control.

However interesting that today remote commander and loader weapon stations are back in favour in some MOUNT circumstances

Well, we never really stopped mounting a commander's AAMG.

The remote weapons stations are to protect the shooter from snipers, while still allowing a fairly rapidly-swinging MG to deal with RPG shooters.

and sometimes you need a weapon that has less impact than the main gun, but more than the 7.62mm coax, so you end up mounting a .50cal on top of the main gun.

To say nothing of the various attempts to mount a 30mm chaingun or gas-operated MG in place of the .50cal on APCs, though a friend of mine insists that the minimum weapon for an ICV or IFV is one that has a useful anti-obstacle round, so probably 50mm minimum.