Naval Bombardment Philosophy Recap

Well, our discussion wandered off into a land artillery discussion which is, admittedly, more than a bit related to naval bombardment.  The upshot of the discussion seemed to be that there are good reasons for the semi-standardization of land artillery on 155 mm guns.  The reasons include logistics, cost of the gun, ease of movement of the guns/munitions, munitions inventory, and general applicability/effectiveness of the 155 mm caliber.

I would note that most of those reasons don’t apply to naval guns in any significant way.  The cost of the naval gun is small compared to the overall cost of the ship, movement is effortless since the ship moves anyway, logistics are no more of a burden/challenge than for any other aspect of the ship’s logistical needs, and ships have relatively large magazines and sufficient inventory of munitions for their mission needs.

Beyond that, naval guns have a few advantages over land.  Modern naval gun loading is largely or totally automated which allows the rate of fire to be maintained indefinitely as opposed to hand loaded land artillery.  This allows the extended operation of larger caliber guns, if desired.  Being on ships, naval guns are inherently more survivable due to ‘stealth’, continual movement, and armor (well, guns used to be in armored mounts and ought to be today).

The conclusion seems to be that land artillery has settled on a reasonable compromise in the 155 mm gun but that naval guns are not bound by the same limitations.  Therefore, there is no reason not to have larger caliber naval guns.  Larger caliber guns produce bigger ‘booms’ and that is generally good.  For those cases where bigger is not better, ships, both individually and as a fleet, traditionally have a range of gun sizes and can choose the appropriate size. 

As with most things, a range of naval guns offers the best overall performance and value.  Too many people want to argue for one-or-the-other options when a mix is almost always best.  I don’t think anyone would argue that there are times when having a 16” gun available is highly desirable but that doesn’t mean the entire fleet should be armed with them.  A fleet mix of 5”, 8”, and 16” would seem reasonable. 

Some commenters have made the case for naval 155 mm guns and that’s a fair discussion.  Whether the benefits of moving to that size would be worth the disruption of the current 5” logistics, training, and support train is debatable.

In short, nothing about land artillery experience precludes larger caliber naval guns and I see no reason why they should not be part of the fleet gun mix.

AGS - DDG-1000 Gun System

The Advanced Gun System (AGS) developed for the DDG-1000 Zumwalt class destroyer is a 155 mm gun in a stealth mount.  The gun (and the ship, in a sense, since it was built around the gun) was developed in response to the retirement of the battleships and the resulting gap in naval gunfire support for troops ashore.



LRLAP 155 mm Round



While 155 mm is a NATO and US Army standard size, inexplicably, the Navy’s AGS will not be able to fire any of the existing rounds thus denying the Navy access to a huge inventory of ammunition.  Bear in mind that the AGS ammunition is the Long Range Land Attack Projectile (LRLAP) which is a rocket assisted projectile with extended glide capability for greater range.  Thus, the AGS is, essentially, a missile launching weapon rather than a standard naval gun.  The LRLAP has a reported range of around 70 miles and uses GPS guidance with canards for flight control.  Efforts are being made to achieve commonality with NATO/Army 155 rounds to the extent possible.  Hmm…  Seems like that should have been the first criteria?  Seeker heads are being investigated for future inclusion.



Other reports state that the AGS cannot be used in an anti-ship role though it is unclear why this is so (the GPS guided nature of the LRLAP, presumably?).  A naval vessel with guns that can’t be used against other ships seems short-sighted.

The AGS is a fully automated system from ammunition strike down and handling to loading and operation of the gun, itself.  While this reduces the crew requirements it also requires an inordinate amount of internal volume especially that devoted to ammunition storage and movement.  The AGS Intra-Ship Rearmament System (AIRS), which is the automated system for moving pallets from the flight deck to the magazine, consumes huge internal volumes.  Both the gun and ammunition handling are all-electric as opposed to previous hydraulic systems.  Power requirements are reported to be 800 kW per mount which precludes fitting the system to other classes of ship.



AGS



The rate of fire is 10 rds/min.  Magazine size has been reported as being 304 rounds per gun.  Rounds are stored on pallets of eight to facilitate the automated handling.

Defense Industry Daily reports that approximately $1.4B has been spent so far on the development of the AGS, AIRS, and LRLAP and work is nowhere near complete yet.  That is a lot of money to develop a gun system. 

In summary, what the Navy has is a dedicated land attack weapon with fair range compared to conventional naval guns.  This may well prove to be a very effective naval gunfire support weapon but the value relative to the cost seems suspect and, when the non-surface firing capability is factored in, the system seems overly restricted.  One can’t help but wonder if the already developed Mk71 8” gun wouldn’t have been a better starting point!