Double barreled tanks?

[seadude]

Just curious, but has there been any designs, prototypes, production models, etc. of tanks with 2 barrels instead of one? I've kinda wondered from time to time why there has never been any tanks with 2 barrels? You see plenty of sci-fi tank designs with two barrels, but nothing in real life. Are there too many technical and mechanical problems to overcome for a two-barrel tank to become feasible?

[ChernayaAkula]

I suppose there simply hasn't been any need for a near-instantaneous second shot capability. You'd need a second gun, possibly a second loader or autoloader (or a more complex autoloader), all of which will make your tank bigger and heavier (and more expensive), while possibly making it less mobile (assuming engine and suspension are rated up as well) and harder to conceal. That is if both guns are aligned. To engage targets independently, it will need to be even more complex.
I reckon it will take a skilled loader about as long to load another round as the tank needs to right itself after the first shot and for the gunner to (re-)acquire a target. So rate of fire is not limited by the speed of the loader, but by the ability to (re-)acquire a target after the first shot in such a manner that it will be able to engage another target with precision.
If you are unsure your main gun will be able to take out a target with a single shot, it's probably more easier to devise a bigger or more precise gun than it is to cram in another gun of the same size.
It's probably a bit different for artillery pieces. You don't have to able to hit the same spot with the second shot (you don't want to, actually), so accuracy (paramount in an MBT) can be traded for increased rate of fire (in case you want to pop off a few rounds and get the hell outta Dodge before counter-battery fire can reach you) or longer sustained fire. See 2S35 Koalitsiya-SV prototype or AMOS 120mm twin-barrelled mortar.

I suppose multi-barrel turrets are feasible (and used to be the norm) in ships is because the can handle the recoil far better than an MBT could.

[kerick]

I don't see how a loader could reload the first gun while the second fired. He'd lose an arm.
I agree that a second barrel would be from mounting a second gun and that would lead to a much larger, more complex and expensive vehicle. Plus if one tank with two guns gets knocked out you just lost twice as much firepower. It does make a more dramatic looking game vehicle.

[rickshaw]

In the end, it comes down to how fast do you want to fire your gun.

In battle, the amount of dust and other crap that is thrown up at the end of the barrel is quite large and that has to clear before you can acquire or reacquire your target.   The Germans in the 1980s experimented with several leopard based hulls which carried twin 105mm or 120mm guns which were fixed in a casement structure.  They placed them on the outer edges of their vehicle to try and provide some way of minimising the obscuration which occurred on firing.  This was known as the "Leopard 3" but was primarily a defensive weapon (being fixed) and considered sub-optimum for the advance.  Something NATO had realised when it experimented with the Strv-103 back in the early 1970s.   As NATO was committed to defend and retake German territory in case of a Soviet attack, doctrinally they were opposed to the adoption of such a vehicle.   However the Cold War ended before a decision had to be reached on whether to adopt it or not.







I've often wondered if twin guns, mounted closely together in the centre of a vehicle might not be an excellent way of countering ERA.  You fire both, one slightly behind the other, with them mounted separately so that they don't interfere with each other's aim (and auto-correct for any recoil) and the first round strikes the ERA, setting off the tiles and the second round strikes through.   However, it would mean you'd fire half the rate of a normal tank in all likelihood because of the muzzle blast.

In the end, it is tactically better to utilise twice as many vehicles, which provide more options of defeating your enemy by firing at them from multiple different angles.

In the case of SPGs, multiple barrels offer tantalising ways of increasing your firepower by doubling the ROF.  The Russians have taken this idea on, with their double-barrelled SPG, the Koalitsija-SV.  The Americans have responded by utilising "time-on-target" shoots which utilise their vehicles auto-loaders (and human loaders) to fire more rounds quickly, on differing trajectories so they all arrive on the one target at approximately the same time.  Which is better?  No idea but I will note that the Koalitsija-SV is complex to build, maintain and operate.

[andrewj]

The German Maus "superheavy" tank had a main armament of a 12.8cm Pak 44 , with a coaxial 75 mm gun. Luckily for all concerned , only one prototype was built.

Andrew

[dadlamassu]

It all depends on what you want the tank to engage and what kind of gun you need to use.  If the gun is very slow to reload then a multiple gun mounting may be of use.  If the gun has a serious backblast and cannot be mounted inside then putting lots of guns on the outside is useful.  If there are disparate targets to engage - the Centurion 1 had a big gun to hit tanks and a 20mm cannon for soft or light armour. 

The Russians tried the KV-7-2 in 1941 with 2 guns


And KV-7-3 with 3 guns


The Americans used 6 guns on the M50 Ontos - but they had to loaded from outside.


There are numerous double barreled and quad barreled tanks in the Anti-Aircraft role. 

[perttime]

In the case of SPGs, ... The Americans have responded by utilising "time-on-target" shoots which utilise their vehicles auto-loaders (and human loaders) to fire more rounds quickly, on differing trajectories so they all arrive on the one target at approximately the same time.

We did something like that with mortars in early '80s - with manual calculations and laying. How many you could get on target depended on distance a bit.

[NARSES2]

The US designed a twin barrelled tank destroyer in the 50/60's ? Not sure of it's designation but Martin H has made a model of it. If you look at some of the UK show reports the pic will be there.

Was it the Poles prior to WWII who worked on the principle of two shots from a single AT gun in very quick succession in order to get through thicker armour ? Not commenting on the practicality of it but it seems that two barrels aimed at the same spot on the target with a fractional delay may be easier to achieve in practice then two quick shots ? Wouldn't be easy to design/manufacture at all but easier to use ?

[Dizzyfugu]

There was also a Japanese tank hunter with two recoilless 106mm guns, much like the ONTOS/M50. The selling point for these vehicles is/was that the crew had to leave the hull's shelter for reloading, so fining a quick salvo and retreat or have several shots ready was a conceptual necessity.

AFAIK, the German Kasematten design (as an alternative to the turret option) was rejected because it was too inflexible, or, the other way around, did not provide any tactical benefit under operating conditions.

[seadude]

I'm surprised a double barreled tank idea never really caught on, especially with NATO during the Cold War of the 70's and 80's when they had to face a numerically superior Soviet armored force, almost 3 to 1 I think? I'd love to try a double barreled tank design, but am not sure how to go about it yet as far as design and such. Was thinking about using an M1 Abrams tank model for starters.

[dadlamassu]

I'm surprised a double barreled tank dea never really caught on, especially with NATO during the Cold War of the 70's and 80's when they had to face a numerically superior Soviet armored force, almost 3 to 1 I think? I'd love to try a double barreled tank design, but am not sure how to go about it yet as far as design and such. Was thinking iabout using an M1 Abrams tank model for starters.

Why stop at 2 barrels?

[pyro-manic]

If you've got space for two guns, you also have space for one bigger and more powerful gun, which is usually better.

[seadude]

If a double barreled tank were ever to be produced, I'm betting it'll be a tank with railguns. But in order for that to happen, there needs to be a power source that is small enough and sufficient enough to power the tank/railguns. Probably won't see nuclear fusion reactors for at least another 50 years.

[sandiego89]

While not a traditional "tank" in the armor sense, I always thought the twin barrelled Sgt. York air defense system looked the buisiness.  Minor details of not working as advertised and being way over budget...

http://www.military-today.com/artillery/m247_sergeant_york.htm 

[ChernayaAkula]

I'm surprised a double barreled tank idea never really caught on, especially with NATO during the Cold War of the 70's and 80's when they had to face a numerically superior Soviet armored force, almost 3 to 1 I think? I'd love to try a double barreled tank design, but am not sure how to go about it yet as far as design and such. Was thinking about using an M1 Abrams tank model for starters.

Not surprising at all. As has been pointed out above rate of fire isn't limited by the speed of the loader, but rather by the ability to acquire a target after the first shot has left the tube. Tank rocking from the recoil, debris thrown up (in case of a resting tank) clearing, tank commander and gunner looking for a second target, actually laying the gun, all of that takes longer than it takes the loader to load a second round.
There is no point in having a near-instantaneous second shot capability if you can't actually hit the target. On the other hand, the second gun comes with some drawbacks such as size and weight. The resulting loss in mobility probably isn't worth a second gun that is of decidedly limited tactical value.

It's probably one of those 'slow is smooth and smooth is fast' things. Rather than being able to put lots of lead down the line, they thought that making every shot count is the better way to go.