"Multiple Weapon Mounts - Am I missing something?" Topic

I'm building several forces for a near future SF campaign and picking and choosing from a number of excellent lines. One thing I have noticed is the large number of dual (and a few triple) weapon mounts. I'm not talking about a smaller coax machine gun or autocannon, but two identical large caliber guns. Is there a reason this would be advantageous? Or is it simply an aesthetic choice or a call back to the WWII era AA vehicles? I'm using what I consider plausible technology extrapolations in an attempt to have a "hard SF" game and I wondering if I'm missing some key consideration.

Aesthetic. "Moar shooty!"

The Russians (and Ukranians) have been doing some of this lately, with dual-barrel SP artillery for a higher RoF. Not quite the same are the large-caliber main guns w/ 30mm coax autocannon. A heck of a lot bigger than a coax MG …

Maybe in the future, they have quantum recoil suppression and turrets that act like the Tardis. Much bigger on the inside than they appear from the outside.

Another real life example is AMOS mortar system, which consists of two auto-fed breech-loading 120 mm mortars. This allows for dropping a pretty intense mortar barrage on a target – and against a moving target on foot, you want to get a lot of rounds going BOOM before the enemy manages to dive for cover. Never mind the psychological effect. Plus faster you shoot, the faster you can scoot to avoid counter-barrage.

As for anti-aircraft fire, multi-barrel guns are not just WWII nostalgy, but still in use today. When shooting at fast moving targets, you want to again put in a lot of dakka in a brief period of time to maximise your chances of hitting. Introduction of effective AA laser systems might change the requirements in future, though.

Speaking of energy weapons, if you have systems which require time to recharge, it might make sense to have two or more systems in parallel, so that operator can fire one of them while the other one recharges.

With rockets and missiles, reloading a launcher tube during combat might be so tricky that it makes sense to instead pack a lot of launcher tubes in parallel. The tubes themselves are relatively light and cheap, when it comes to vehicles.

The USMC's Ontos, used in the late 60s early 70s, may have been the ultimate example. It mounted 6 106mm recoiless rifles. The crew had to dismount to reload, so they had 6 shots to engage targets before reloading. It also had a .50 MG and a spotting rifle.

Dual main guns mostly seems to be aesthetics. Though I could make a good case for energy weapons that either need to cool down or recharge.

Cool-down is the reason given for the Aliens APC's top turret.

Multi-tube Artillery makes sense for getting the maximum weight of fire in a single Time-on-Target attack.

With rockets and missiles, reloading a launcher tube during combat might be so tricky that it makes sense to instead pack a lot of launcher tubes in parallel. The tubes themselves are relatively light and cheap, when it comes to vehicles.

That's definitely the case for the US's M270 MLRS. It takes some 15 minutes to reload the launcher box, which is why the MLRS batteries have two blocks of 6 tubes per launcher.

Not quite the same are the large-caliber main guns w/ 30mm coax autocannon. A heck of a lot bigger than a coax MG …

That's a different situation, it's packing a gun for every target. The BMP3 and BTR4 have a 100mm main gun for ATGMs and HE to blast infantry out of cover. Then there's the rapid-fire 30mm for light armor and softskins, and a coax 7.62mm MG for infantry in the open (though the 30mm works pretty well against infantry, too).

Couple of possible reasons:
1) Cooldown or Recharge- for energy weapons possibly, as others have mentioned.
2) More Rounds on Target- As others have mentioned, there are situations where this makes sense.
3) Better Fire Control- more of a hypothetical, but better fire control systems might make dual mounts more useful in some situations. Imagine a tank able to track and engage two targets in a couple of seconds for example; two weapons allows both shots to be taken. Or to quickly compensate for a missed shot the first time.

Overall though I'd suspect that such weapons would still be in the minority.

-Will

It looks cool :-)

Oh, reactive armor or something where you need to blast one layer off and then hit again immediately: HE to knock off the reactive armor blocks, followed almost immediately by a penetrator. I'm sure that you can think of more SF-y things, like a shield disruptor followed by an armor penetrator.

Oh, another similar idea, overwhelm any point-defense systems.

-Will

In a Sci-Fi setting, a six barreled ONTOs is designed to fire six guided missiles simultaneously, with two missiles being designed to track against as many as 3 separate targets. The two missile salvos are designed to defeat the enemy's automatic defenses, since they can only shoot down one missile at a time… The vehicle is designed to engage 3 targets at a time, since the enemy is organized into 3 vehicle platoons.

Navy ships now, can enter in multiple targets and launce the missiles simultaneously resulting in destruction of the targets before the initial rounds provide warning. If the target is valuable enough, multiple missiles will be volley fired to ensure destruction. The missiles from across a surface action group can by design be made to arrive simultaneously.

Multiple missle tubes makes sense to me. Twin 120mm cannon, not so much.

The West Germans experimented with some twin cannon tank destroyers in the Cold War.
link
en.wikipedia.org/wiki/VT_tank

My theories…

Targeting systems so advance the shots follow each other into the same point right behind the other.

Or truly higher rate of fire.

What I always want to know is where are the engines on sci-fi vehicles. :)

I've always thought they use smart shells that operate like the Royal Navy Seawolf missiles. . . The first missile feeds data on the target back to the few seconds behind second, and if the first misses, the second corrects and hits it dead on.

Mostly Rule Of Cool, though, or to improve RoF without other complications.

What I always want to know is where are the engines on sci-fi vehicles.

Given how big a 550hp Wankel rotary is (~20" wide and about 30" long), the engine kinda gets stuffed someplace out of the way and connected to a generator. Then you have electric motors in the wheel hubs or drive sprockets.

That is definitely the case for the GW Rhino and Chimera (engines inside the track loops) chassis.

The US Future Combat System put the engines (plural) and generators in the sponsons over the tracks, and had an electrical final drive unit at the front of the track that took up a volume about 15" deep. This left the entire rest of the hull open for the different vehicles in the back, from APC/IFV (and variants like ambulance or C3) to AFV to artillery.

Able to fire more bullets.

Imagine a weapon with 4-5 Vulcan cannons each with it own ammo capacity that is easy to reload as well.

You could put a lot of ammo down range very quickly.

Now imagine a Battery of 6-8 of them.