A really big gun on a boat.

Apropos of a couple of threads in GD right now, I was thinking of this article I read awhile ago and never got around to asking about. The gist of the article is that the US navy is exploring guns capable of firing GPS-guided rounds 30 times more powerful than a current five inch gun at 6 rounds a minute, at speeds up to mach 16 and at a range of 250 miles.

My questions are these:

  1. To the engineering types, how feasible and/or imminent is this technology?

  2. Given that these shells will be fired clear out of the atmosphere, would the US need overfly rights the way they do now when sending in cruise missles/planes?

Navy 1, Air Force 0?

Seriously, though, if this pans out, it sounds like it could rewrite the book on current tactics, at least vis-a-vis hitting targets that are accessible by international waters but remain difficult to hit by air, perhaps because of denial of overflight rights or anti-aircraft defenses. :cool:

Presumably these proposed GPS-guided rounds would remain as vulnerable to line-of-sight problems as other GPS-guided ordinance, right? So that night, cloud cover, smoke, fog, etc. could still render them less usable or effective?

Could be wrong but I thought is was lazer guided ordance that had a problem with cloud cover and such where GPS devices are guided by known coordinates??

Actually, I’d be more concerned about the various treaties about not putting weapons into space. If these rounds are going out of the atmosphere, that might be a problem. (This is not to say that I think that keeping weaponry out of space is all that important, just that the question would have to be answered before the weapon could be used.)


That’s what I was thinking of… laser-guided ordinance.

Well. nowadays I hate to say anything is impossible. Still packing electronics like that into a cannon shell would be a challenge.

Imagine you are in a rocket flying to a target. The motor fires for several minutes, up to the peak where you begin to fall. Now picture the same trajectory in a cannon shell. All the energy needed to get you to the top of the arc, the same amount as was applied by your rocket motor in the first example, is passed onto the shell in one big wham.

That is a bucket load of G-forces. Many, many. You would need to have very robust electronics to survive that sort of punishment.

OK so we get you to the apex of your trajectory. Then what? What mechanism would we use to guide your shell to its target? Fins? Rockets? These would also have to be robust and would detract from the explosive payload.

So we have some really big company build us this shell. Would it have much use? Well, yes.

Unlike aircraft, gunfire can hit and keep hitting almost forever. Further, we might be able to get shells onto a target faster than we can brief pilots and get them there with the right load.

On the other hand, shells cannot look for targets and hit them as they appear. Also shell are smaller than most every aerial bomb.

Before we spend big bucks on a project like I would like to see a lot of simulations and studies of the number of targets that appear how far inland and their vulnerability.

Yes, but it’s been done at least on one scale - IIRC there was a round for the 16/50 battleship guns that was wire guided, and had an onboard optical camera. Expensive to manufacture, yes. Impossible, or even challenging, not really.

Frankly, I’m not sure how much of a ‘warhead’ package would really be needed. At the moment, the ultimate in AP loads is the DU saboted round - completely without any kind of explosive in the shell.

And, if we’re getting outside the atmosphere for weapons, I’d think THOR would be a better idea: the launch vehicle is completely out of the theatre of operations; no crew at risk; and I happen to like the idea of no DU dust, no chemical toxins from the ‘warhead.’

One of the big problems is versatility; another is manoeuverability.

Aircraft can perform multiple functions, a gun but one. Ships move slowly; aircraft move fast.

Aircraft can operate from sea or land; the gun is necessarily ship-borne - and likely ship-mounted - and ships are vulnerable to submarines and aircraft.

This sounds like an interesting weapon that could be really useful as part of a whole. Ivery much doubt that it will displace the carrier, but it might well bring back the battleship. We’ll see.

Still, a ship has an ability to linger offshore as a threat for a long time. It is the sort of thing that causes people’s minds to focus in a way that airpower does not seem to do.

Well, yes and no. I imagine using a rail gun allows you to spread out the acceleration over a slightly longer period than a chemical explosive round. So you could either use that longer period to lower the overall G forces on the projectile, or you could use it to produce higher velocities. I’d be more inclined to wonder whether the magnetic fields used in the rail gun would rip apart the payload’s sensitive electronics.