"And please, everybody, no suggestions of it-provides-umpteen-155mm-batteries-fire-support-capability, because a bigger gun has a bigger payload, meaning less shells need be fired (is there some kind of scientific ratio to justify a given caliber and more shells over a larger caliber with less shells?)." Well, that is exactly the case. I skimmed your post, but having done so I still fail to see your reasons for being so anti naval gunfire support. Naval gunfire support has proved its worth time and time again, and I expect it will continue to do so for many years to come. A ship is a far larger and more mobile platform than the best self propelled artillery gun and its associated logistis. If you give a ship a 155mm automatic gun with a range of 100NM's, you have a weapon which can shoot inland ~80NM's for the entire length of the war zones coast line, while keeping the weapons platform comparatively immune to enemy action. Of course this is only of use while the front lines (or enemy) are within ~80NM from the coast, but then consolidating the beach head is probably the most important part of an amphibious operation and well warrants the new gun in my opinion. You may well snear at the firepower of a ship board gun, however why do you think a modern warship only has one or two tubes compared to 6 or 8 tubes of old? Because the modern automatic guns have the firepower of six old semi-automatic guns. Land based guns have not evolved in the same way, they do not have the magazine capacity, neither do they have the sensor capacity without packing a lot of support assets, and they are an easier target for counter battery fire. At the end of the day, a guided missile costs more than a hail of 155mm shells, while it has a lower probability of making it to the target. As for your pondering why we dont use a larger gun, a larger gun would increase recoil on the ship and would reduce ammunition capacity, whereas a 155mm shell today packs the punch of a 203mm shell of the 70's.

Just a guess, but you've never been on a ship. A ship in the ocean, even close to shore is anything but stable. The entrance to the old Newport Navy Base by Bretton reef can come up with 8 foot swells without trying. The other thing about a ship, is that salt water gets into everything. Even completely secured objects. Our gun mounts rarely worked right after a few days at sea. Saltwater would get into something. Stored cannisters with missiles are extremely reliable. Our ASROCs never missfired, even though they were mounted right behind our main gun which was next to useless. The other thing, particularly at sea, is that automatic guns rarely are.

"Just a guess, but you've never been on a ship. A ship in the ocean, even close to shore is anything but stable." Well yes, yes I have been on ships before. Us Europeans are known to leave our own shores now and then. :D And these days we have these things called stabilisation systems, they stabalise things. If you can't get a reliable ship board gun by now, I would be rather disappointed. The simple answer would be to fit two tubes instead of the one.

If you can't get a reliable ship board gun by now, I would be rather disappointed. I guess you will be disappointed then. Remember that the moment the shell leaves the tube it's on a given path. Middle to small size ships can barely stay within 1 degree of roll. Imagine a 1 degree error in a flight path over 20nm. And yes they have compensators that can adjust for the changes in platform position, but they really are not capable of dealing with the vagaries of being at sea. The Abrahms tank is a good example, you can stablize for WVR targets, you also get to see where you missed and then correct. Fact is a 20nm shot has a long flightime and air currents will move it a bit one way or the other. Prefer one shot from a PGM, it won't miss and you can fire it from any platform regardless of size.

-> You may well snear at the firepower of a ship board gun, however why do you think a modern warship only has one or two tubes compared to 6 or 8 tubes of old? Because the modern automatic guns have the firepower of six old semi-automatic guns. That's interesting, because I thought it was the advent of the guided missile that removed multi-gun turrets from large vessels. And the realization that (aside from off-balanced we'll-put-all-our-faith-in-nuclear-cruise-missiles mentalities of the 1950-1960s) ships would not see much bombardment operations as compared to WW2 and earlier eras, especially when we consider the capabilities that aircraft were proving time and again battleships and the other heavily-armored ships of the fleet were no longer the queens of oceans. One need only observe the couple decades past WW2: after the war, how many multi-gun turret ships were built, as compared to guided missile ships? Gone were the days of inaccurate slugfests between ironclad battlewagons who had to rely on the shotgun effect of multiple barrels trying to throw downrange some ideal pattern of falling shot and shell, as one or two guided missiles could be precision-steered into any given target ship (as much precision as was possible back then, but still much more accurate than shell volleys). And it isn't a case of modern single mounting having greater rates of fire: there were single and twin 76mm heavy AA guns mounted on ships late in the war that could put up as lethal a hail of shells as can the USN's copy of the Italian 76 (USN's maxes at 85rpm, but only in bursts, not sustained. The Italians took it another step with developing the 120rpm SuperRapide, but did the USN adopt it on Perrys?), and the old twin 5/38 with semi-automatic loading could fire just as fast as the 20-30 rpm of these newer singles, and no current single barrel gun can put up as much fire as 6 of any WW2 naval guns >76mm (except solely in the case of the SuperRapide, whose 120rpm burst could compare to 3 US twin 76mm/50cal naval guns each firing at 20-30rpm per minute). The best 5" is again the Italian model, reportedly 45rpm. And the Russians claim that big twin 130mm/70cal can fire 80, but a majority of sources suggest only 45-60rpm (there is a big difference between maximum burst rate of fire and maximum sustained rate of fire: a WW2 USN Brooklyn class cruiser with its 5 triple 6" turrets would still be able to maintain a higher sustained rate of fire than 3 single-barrel AGS turrets: guns back then were made much thicker and heavier, not some modern-day lightweight alloys). So it isn't a case of automation relegating extra barrels to the scrap heap: it's about saving weight. And in the days when it was expected a few guided missiles would take out point targets, post-WW2 the USN slowly got away from massive shore bombardments, short of those few instances where re-commissioned battleships got to play Psychological warfare (how much ammunition was required to achieve the same results that less number of PGMs could've achieved? There is a practical line where you're just wasting too many unguided shells to get the same effect as one or two guided missiles). Sure, it can be argued that the price for even a number of guided artillery shells is cheaper than a given heavyweight cruise missile (which we don't always need). But an interesting case study could be, look at the German defenses during D-Day, and gauge just how many unguided shells it took to silence German opposition (which didn't entirely happen). Then gauge how few less rounds of precision guided missiles could've eliminated those defenses (yes I know they didn't have big PGMs back then. Humor me. But it generally compares to the USAF studies suggesting only a few precision bombs can achieve the same effect on taking out point targets as several tons of unguided saturation-tactic bombing. And yet still another issue of cost: until those guided AGS shells are coming off the production line cheaper, and with a lower dud rate, than any comparably-ranged missiles (NetFires LAM, G-MLRS), it's still a non-comparison. And as far as ships being more mobile than land artillery: there are tens of thousands of square miles of hot zone in Iraq and Afghanistan that no naval vessel could engage even with a 100nm AGS, yet land-based artillery can be airlifted or convoyed in and drive close enough to most of those areas to cover them. Just because someone suggests that the Earth is covered in 70-some percent open oceans, that doesn't mean 70-some percent of all your foreseeable battles will be fought in close proximity to all that water. WW2 is over. There are no more Atlantic Wall defenses to be conquered. No more entrenched island troops hiding out in the tropics. No more communist hoardes numbering in the several tens of thousands eagerly waiting out in the open to be shelled. No more heavily-reinforced coastal strongpoints with their railway guns needi

Keep in mind, a naval gun that can shoot 100nm is anything but useless, in fact, it is the most cost effective weapon aboard a ship. With precision guided capability this becomes even more so. Also remember, 75% of the population of planet earth lives within 100 miles of a coastline. I hope the Navy builds two DD(X) ships as technology demonstrators for the enormous number of new technologies being developed for the future fleet. I think it is important to build 2, one for each coast, each with a different design and different weapons capability, and hopefully both are nuclear powered even if it costs more. Use Sea Swap, test ballistic missile defense, the AGS, unmanned vehicles, and every other possible new piece of technology the Navy is developing on the two platforms. Only with actual testing instead of computer modeling will the Navy be able to determine if long range precision guns are the future, or if rocket style prcision weapons are the future, or a combination of both. This theoritical BS brought on by the computer age has its limitations, because when your dealing in theory everything goes right more often than it should, and capabilities that are achieved in computerized tactical simulation can be unbalanced to the strategical requirements that can only be evaluated by testing the real thing.

But can it hit anything from 100nm?

Doggtag, you are wrong in your assumption that guided missiles are what resulted in so few tubes on ships post WWII. Post WWII ships have fewer tubes, because the rate of fire is increased to a degree great enough to amount to the firepower of multiple tubes. Anti-ship missiles were only credable systems in the 70's onwards, while in the 60's ships still only had a couple of tubes at most.

But can it hit anything from 100nm? Lets build it and find out.

-> Doggtag, you are wrong in your assumption that guided missiles are what resulted in so few tubes on ships post WWII. Post WWII ships have fewer tubes, because the rate of fire is increased to a degree great enough to amount to the firepower of multiple tubes. Anti-ship missiles were only credable systems in the 70's onwards, while in the 60's ships still only had a couple of tubes at most. Are you absolutely positive about that, Yimmy (the "Post WWII ships have fewer tubes, because the rate of fire is increased to a degree great enough to amount to the firepower of multiple tubes" part)? When was the last USN 6" or 8" gun cruiser commissioned? 1950-something? (I mean new-build from the keel up, not reconstructed 50/50 ships with their aft gun turrets removed and replaced with SAM systems.) And where are all the automated 6" and 8" guns in single mountings that, by your reasoning, should have taken their place? Until the advent of the newer 5/62 Mk45Mod4 mount, 5-inchers didn't come close to the range that 6" and 8" guns of US cruisers could achieve, and automation aside, even less shell volume for a given barrage. Suggested reading: Norman Friedman's "U.S. Cruisers, an Illustrated Design History (Ship Plans by A.D. Baker III and Alan Raven), a rather thick book from the Naval Institute Press in Annapolis, MD (c 1984, ISBN 0-87021-718-6). I recommend close attention to chapter 13, "Into the Missile Age. Yes, I know it's a cruiser book, and the DDX is a destroyer (supposed to be, anyway). But still it brings up my point: when was the last USN 6" or 8" gun cruiser commissioned? And where are all the automated big guns above 5" caliber? The first 2 sentences of this chapter (13) sum it up: "With the end of WW2 both the role and the weaponry of the U.S. cruiser shifted dramatically to an emphasis on protection of the primary offensive unit of the fleet, the carrier, against air attack. Although interest in advanced defensive-gun systems continued for a time, the new and reconstructed cruisers were armed with antiaircraft missiles, which evolved through three generations, each with associated cruiser designs: the Terrier/Talos, the Typhon, and the current Aegis" (which is Standard SM-equipped). I don't have these following two books, but Friedman also suggests his "U.S. Destroyers, An Illustrated Design History" (c 1982, Annapolis , Naval Institute Press), and "U.S. Naval Weapons", (c 1983, Annapolis, Naval Institute Press, also London, Conway Maritime Press). He brings up the issue that in destroyer history, the Aegis Ticonderoga (CG-47) class cruiser was, under its original plan, DDG-47. Although I haven't yet acquired these other two books, I would be willing to bet there is little mention of using destroyers as primarily fire support and land attack vessels, and I doubt it was very long before the USN finally began to realize their 5" mountings were inadequate for shore bombardment (primary reasoning behind the 8" MCLWG program, and justification for re-activating the Iowas?), something that still hasn't fully been remedied, even with the slow development of extended range, gun-fired PGMs. And even if the truly effective anti-ship missiles didn't come about until the 1970s (Harpoon, Tomahawk, etc), multiple-gun turrets had begun to disappear years earlier, with the primary surface-strike capability being provided by carrier aviation, not cruisers and destroyers. The Navy has one hell of a Christmas wish list. But like every child, it will have to realize it isn't going to get everything it wants, and definitely not in the numbers it's asking for all of them. It can fuss and whine and complain and lobby to the politicians all they like, but it doesn't change the fact there is only so much defense budget to go around, so sacrifices will need to be made to keep worthwhile programs alive. The AGS/DDX program, although having much promise as a technology demontrator/test bed, isn't as deserving or necessary of a full production run (dozen+ hulls) as other programs. What the USN should be concentrating on is future upgrades to the current fleet, much of which will still be around 3 decades from now, to keep them frontline-capable for any foreseeable threats. If the USN is so hungry for adopting a more prevelant precision land attack role, then by all means, let them prove they can do it with current platforms, rather than demanding entirely new classes of ships laden with unproven, minimally tested technologies: god forbid we build a new class that spends most of its time non-mission-ready due to scores of mechanical failures in its rushed systems.