ComNavOps loves to look at weapons and systems and ask, “How will they be used?”, and see if the answer makes sense. We just did that for BAMS. Now, let’s take a look at the common USN 5” gun that is mounted on Burkes and Ticonderogas.
The gun is the Mk45 and comes in two calibers, 54 and 62, and is currently manufactured by BAE Systems. An automatic loader allows the gun to operate with no crew but the loader is limited to 20 rounds. A crew of six are required to operate the gun on a sustained basis. Navweaps website lists the rate of fire as 16 rounds per minute in sustained operation. It also gives the effective firing range as 15 miles (54 cal) or 23 miles (62 cal).
The common projectile is an HE round with various fuzing options and a burst charge of 7.7 lbs.
The Extended Range Guided Munition (ERGM) would have extended the range to 60 miles but was cancelled in 2008 after a protracted and troubled development.
Now that we know everything there is to know about the Mk45 5” gun, what roles does it perform?
The gun has an anti-ship capability although 5” guns are not considered capable of sinking a vessel of any size. Further, the gun is not considered effective as an anti-small boat (anti-swarm) weapon due to the slow rate of fire.
The gun is not considered effective in the AAW role.
The gun is somewhat useful in a shore gun support role against small or lightly protected targets. It is not considered to be particularly effective as an area bombardment weapon and is not effective against bunkers, fortifications or other hardened targets.
The major problem with the gun in the shore gun support role is that the Navy has doctrinally ruled out approaching within 25-50 miles of shore. That places the ship outside the gun’s range to even reach the shore let alone provide inland fire support.
|Mk 45 5" Gun - Too Limited For Modern Naval Combat?|
Considering the preceding, and given the size and weight of the gun and the internal ship’s volume consumed by the gun and its magazine, one can’t help but wonder about the limited utility of the gun. A 5” gun is an in-between weapon. It’s too small to be an effective shore gun support or anti-ship weapon and it’s too big and slow to be an effective anti-small boat or AAW weapon. If it were a Christmas cartoon weapon, it would be found on the
(for those of you who get the Christmas cartoon reference!) Island Of Misfit Toys
The Navy’s choice of the 5” gun as its mainstay projectile weapon has always been a bit puzzling.
ComNavOps also likes to examine history for precedents and lessons. In this case, I couldn’t help but wonder why the 5” gun of WWII was so ubiquitous and, presumably, useful whereas I’m drawing the conclusion that today’s 5” gun is of limited usefulness. What changed?
It wasn’t the gun that changed but, rather, the targets and doctrine. The 5” gun of WWII was inherently no more effective in the shore gun support role than today but the doctrine of the time allowed Navy ships to approach very closely to shore which allowed the gun to achieve its maximum capability and range. In the anti-surface role, the targets have changed. Small boat swarming was never a threat in WWII and most surface ships were relatively small. Consider the size of WWII destroyers compared to today’s versions or the size of WWII cargo ships compared to the supertanker size vessels of today. Finally, the 5” gun of WWII was an effective AAW weapon (to the extent that any WWII gun was an effective AAW weapon!) whereas today’s 5” gun is totally ineffective in the AAW role.
Thus, the 5” gun of WWII was a good general purpose gun, able to perform a variety of tasks at least reasonably well, and it was sized to fit on a wide range of ships. We see, then, that today’s gun isn’t all that much different but the targets it’s being asked to engage and the doctrine governing its use have changed markedly and have resulted in a gun that is no longer well suited as a general purpose weapon.
The Navy needs to rethink its selection of the 5” gun as the standard weapon of choice on its surface combatants. New construction Burkes (Flt III) might be better served with a modern 8” gun and a secondary 30-57mm gun.
As an historical sidenote, the Spruance class was designed and built to mount the 8” gun when the gun’s development was completed although the change never happened.