Hypervelocity cannons: Why not centrifugal?

[xpell]

-1- Do you really understand how much energy you are proposing putting into rotating a several meter diameter launch mechanism for a hypervelocity launch?

Calculating that was my next step, after checking if the concept was valid or not, as it happens to be and I expected but didn't know why. AFAIK, Engineering is also about not losing time or resources exploring invalid concepts.

-2- Do you really understand the damage that would be done by a simultaneous release of a reverse direction mass? Don't try to put it in the water at the rear of a battle group, what about on land?

I of course put it in the water because every weaponized hypervelocity gun project that I'm aware of is being studied for naval warfare (and marginally for high-altitude launches.) Actually, in the U.S., the main institution researching weaponized railguns and such is the Naval Surface Warfare Center with some help form NASA, to be deployed in USN vessels. And all of them are extended-range, indirect-fire weapons, meaning typical launch elevations 5º-45º. AFAIK, Engineering is also about knowing WTH one is talking about before considering an idea.

-3- Why wouldn't the large group of professional scientists who are working on hypervelocity weapons be testing your idea, if it had any merit? They are certainly testing and fielding other hypervelocity weapon launch technologies. Why are they fielding them, and not some spinning mechanism?

You certainly had to suffer lots of pain reading my messages to the point of not being able to read even the first one, because since the very first one I said:

Sure this is going to be impossible, unfeasible, far-fetched and/or plainly ridiculous by some reason(s), since nobody seems to be doing it and certainly I'm not smarter than the top military engineers around the world. But... would you help me to understand these reasons, please?

Again in #17:

There must be something that I'm not seeing if people way smarter and better educated than me like the top military engineers around the world are not exploring it. But I still don't know what is it.

And once more immediately after I was shown the problem which makes it impossible:

Now that's something! Thank you very much, seriously! I knew there had to be something wrong in my idea! (...)

Busted! Thanks to all!

Please take to heart that I'm fine with brainstorming (that's where my patents and much of my EE employment have come from), but in real life as an engineer you need to learn to look for existence/non-existence proofs early. Or you will waste your time and efforts on non-starter ideas, and not be much of an engineer. Hopefully that makes sense.

Well, I must say you certainly don't feel like it at all, since you hadn't even read my messages before deciding I'm a crank or something, or even checked what hypervelocity weapons are being designed for. But as you can see, I suspected that my idea was a non-starter from the beginning; I just wanted to know why. In my book, that's learning. This is an Internet forum, not an Engineering department.

 

[xpell]

But that's only a single angle. A real weapon would have to work at a range of different angles.

All of those weaponized railguns etc. that I'm aware of are being developed for naval extended-range indirect fire, not direct fire (you don't need hypervelocity for that at all.) That means typical elevation angles are going to be between 5º and 45º, so the "counter-shell" will splash into the water 50 to 572 meters away. In a real combat situation involving nothing less than super-long-range hypersonic weapons, no other friendly vessel is going to be so close by miles, and neither the coastline will be.

 

[Drakkith]

In a real combat situation involving nothing less than super-long-range hypersonic weapons, no other friendly vessel is going to be so close by miles, and neither the coastline will be.

Maybe. I'm not familiar with naval task group formations.

 

[Baluncore]

That means typical elevation angles are going to be between 5º and 45º, so the "counter-shell" will splash into the water 50 to 572 meters away.

Or hit the deck, superstructure or antennas. You certainly are persistent.

The only naval application I can see for a centrifugal cannon would be to spray a cloud of small projectiles at an incoming anti-ship missile.
That would require a very nimble aiming mechanism, something not found in a gyroscopically stable rotating systems.
So you must spin it all up after it is aimed, which will probably require the disc to be the rotor of a flat electric motor.
I expect the disc will still be spinning up, as the missiles strike.

 

[Loren]

That would be one hell of a gyroscope!

Try moving one of those!

 

[xpell]

Or hit the deck, superstructure or antennas. You certainly are persistent.

I have worked in robotics. Setting excluded angles / ranges is as easy as... setting them. You can do it via software or with hardware stops (usually both, a "soft" exclusion range via software, reprogrammable in real time as needed, and a "hard" exclusion with physical stops.) This is basic robotics, and you'd only need to exclude the thin angles pointing directly to your own ship (just as it's done with many other weapon systems.)

The only naval application I can see for a centrifugal cannon would be to spray a cloud of small projectiles at an incoming anti-ship missile.
That would require a very nimble aiming mechanism, something not found in a gyroscopically stable rotating systems.
So you must spin it all up after it is aimed, which will probably require the disc to be the rotor of a flat electric motor.
I expect the disc will still be spinning up, as the missiles strike.

All of these were calculations that I intended to do after checking if the concept had any chance to be viable. Since you kindly proved me wrong because the disk itself is not going to stand the stress of hypersonic circumferential speeds, as you said, I see no point in further exploring it and I thank you very much for it again.

 

[xpell]

Maybe. I'm not familiar with naval task group formations.

Trust me on that one. You don't want a friendly vessel or the coastline so close to you in a combat situation. There's a long list of reasons for that, including: high probability of collision if you need to hard maneuver at high speed; substandard sensor coverage area (there's an horizon, you know...); high probability of being hit by friendly fire in case one of the vessels needs to use its terminal defense systems against incoming threats; easy simultaneous detection of your entire task force (or a major part of it) by the enemy; becoming a closely-packed bunch of floating ducks for enemy submarines or naval aviation launching massive volleys of supersonic missiles; adding the noise of all packed vessels so much that the enemy's passive sonar operators will send flowers to your burial with a 'thank you' note; same with the unusual concentration of active or passive radar signals and electronic noise; a field day for enemy reconnaissance satellite operators with all those vessels and their large wakes "screaming" in their screens; if close to the coast, being attacked with hidden ground-launched missiles that will arrive very quickly (as it happened to the HMS Glamorgan during the Falklands War); general bad area coverage; and lots of etc.

 

[xpell]

That would be one hell of a gyroscope!

Try moving one of those!

It sure would be. As I said, my next step would have been calculating how much would it take to move it, but since I've been proven conceptually wrong, there's no reason to.

 

[mfb]

I have worked in robotics. Setting excluded angles / ranges is as easy as... setting them. You can do it via software or with hardware stops (usually both, a "soft" exclusion range via software, reprogrammable in real time as needed, and a "hard" exclusion with physical stops.) This is basic robotics.

"We cannot target that ship, Sir. Under the current angle we would also hit ourself. Why don't we wait a bit, maybe it changes its course?"

All of these were calculations that I intended to do after checking if the concept had any chance to be viable. Since you kindly proved me wrong because the disk itself is not going to stand the stress of hypersonic circumferential speeds, as you said, I see no point in further exploring it and I thank you very much for it again.

Then I guess the discussion is done.

 

[xpell]

"We cannot target that ship, Sir. Under the current angle we would also hit ourself. Why don't we wait a bit, maybe it changes its course?"

But this happens with every weapon system! You don't want your missiles, cannons or terminal defense systems to shoot against your own ship! All of them are limited in angle, sometimes highly limited (that's one of the reasons why VLS systems were developed.) Actually, with "my" cannon those angles would be way thinner than with most of these weapons if it's mounted on a high point of the vessel (which could be done if it was possible, which it isn't ---the reloading system wouldn't be as large and cumbersome as missile or heavy cannon reloading systems use to be, forcing them to be placed in lower positions.)

Furthermore, ships have a rudder for such cases, you know...

Then I guess the discussion is done.

Yes, it is. I anyway hate that it became so aggressive by so many people, especially that trigger-happy "Mentor". I don't think I did anything to be treated in such a way. I think I was totally polite and willing to learn and acknowledge my errors on the spot, as I did.

 

[Baluncore]

This is basic robotics, and you'd only need to exclude the thin angles pointing directly to your own ship (just as it's done with many other weapon systems.)

With a gun you can simply draw a line from the gun towards the target, the computation of exclusion angles is trivial. With a symmetrical system you have your “counter shell” on the reciprocal vector. But your centrifugal weapon system must be mounted somewhere on the vessel that has a wide field of fire. That “counter shell” on the reciprocal vector will shoot you in the foot. That will restrict your field of fire to a plane tangent with the local surface of the vessel, which makes it a really useless weapon. What you are arguing is akin to advocating standing behind an RPG launcher, because you seem to think you would be safe there.

I am surprised you haven’t yet stopped defending the indefensible.

 

[xpell]

With a gun you can simply draw a line from the gun towards the target, the computation of exclusion angles is trivial. With a symmetrical system you have your “counter shell” on the reciprocal vector. But your centrifugal weapon system must be mounted somewhere on the vessel that has a wide field of fire. That “counter shell” on the reciprocal vector will shoot you in the foot. That will restrict your field of fire to a plane tangent with the local surface of the vessel, which makes it a really useless weapon. What you are arguing is akin to advocating standing behind an RPG launcher, because you seem to think you would be safe there.

I am surprised you haven’t yet stopped defending the indefensible.

No, what I'm advocating is just changing course a few degrees exactly not to "stand behind the RPG launcher", just like warships have been doing for a better attacking angle since there're warships in recorded history, at least until VLS's were developed; and VLS don't apply to guns of any kind. But it doesn't mind, you proved me wrong on the disk resistance part, and I still thank you again for it.

Seriously, I'm shocked by this mindless degree of aggressivity (not specifically talking about you, but in general.)

 

[Baluncore]

Seriously, I'm shocked by this mindless degree of aggressivity (not specifically talking about you, but in general.)

Seriously, I am surprised that you keep coming back to defend the indefensible.

 

[xpell]

Seriously, I am surprised that you keep coming back to defend the indefensible.

What is indefensible in slightly changing course for a better or safer angle of attack just like every warship has been doing since there are warships?

Actually, most warships in history have been shooting their guns in close to a broadside position on the enemy. Since hypervelocity guns are always for long-range indirect fire (thus elevated, typically 5º-45º), if the gun is on top of the ship at about 50 m from the waterline, the "counterweight" would just harmlessly splash into the water at the other side of the ship, typically 50-600 meters away, possibly disintegrating upon impact and with most if not all of its energy going away from the launching vessel.

But once more, it doesn't mind. The concept is not viable with current technology and that's all.

BTW, do you notice how many "unusable firing angles" do those things have, both for cannons and missiles?