ComNavOps has often lamented the loss of institutional memory from WWII regarding the conduct of amphibious assaults. On a closely related note, ComNavOps has also noted that our military has forgotten what real war is and just how destructive and indiscriminately destructive it is. As a reminder, here is what appears to be a detailed, contemporary report of the
Jima assault after action
report and lessons learned for the naval gunfire support component of the
assault (1). The source is not listed but
the report seems clearly to be a headquarter’s after action report.
As a brief reminder, the preparatory bombardment of the island lasted for 70 days and included the expenditure of 6800 tons of bombs and 22,000 shells. The Marines assaulted with three divisions (70,000 men) against around 20,000 Japanese. The invasion fleet consisted of around 500+ ships of all types.
Here is a partial list of major ships that provided bombardment support for the assault and the quantities of shells fired on D-1 (the day before the assault landing), alone.
Over 1400 14”-12” shells were fired, 1400 6”-8” shells, and around 5400 5” shells in just one day of pre-assault bombardment – and this is just a partial list of participating ships. Several other battleships and cruisers also participated. The immediate pre-assault bombardment lasted three days and the post-bombardment lasted for the rest of the ground combat. So, in just one day and in just a partial listing, the Navy fired over 1400 large caliber, high explosive shells. Given that each shell is loosely equivalent to a Tomahawk missile, the Navy expended the equivalent of a third of our total inventory of Tomahawk missiles in just one day of one island invasion and this is only a partial listing!
Here’s some data for a few of the bombardment ships for the three day period immediately prior to the invasion. Note the totals and note that those are for main battery rounds only.
Total ... 2,517
The report offers some interesting observations and conclusions about naval gun support.
a) Average expenditure for target destruction, at short ranges (under 3,500 yard's) = 9 rounds
b) Average time necessary to shift fire at short ranges from one target and identify the next target = 09 minutes
c) Average time for target destruction at short ranges (under 3,500 yards) = 15 minutes
d) From (b) and (c) above it may be concluded that a ship can execute maximum of 2.4 destructive missions per hour against sizeable material targets (blockhouses and pillboxes) at short ranges (under 3,500 yards).
The report also directly and indirectly discussed various fire support missions. We’ve forgotten exactly what fire support was supposed to accomplish. We’ve come to think that fire support is only a highly precise targeting of specific, known, clearly identified targets. That’s nice when it can happen but that’s not the main purpose of naval gunfire support as this report makes clear.
Night Harassment. Fire support was used to disrupt enemy night activities and prevent respite by enemy forces under the cover of darkness. Here is a sample of such a mission for the cruiser
. Santa Fe
harassing mission for the night by 4th Marine Division. Fire to be delivered on
234, bivouac area on road net, and cliffs in 216; 10 rounds main battery per
hour.” Santa Fe
Area Coverage. We’ve completely forgotten the value of area fire. Most targets are not readily detectable and area coverage with large caliber shells is required to destroy unseen targets, remove covering features, reshape terrain, and strip camouflage.
“It is realized that most of the firing on DOG MINUS THREE Day was directed toward area coverage because of lack of visibility, but such area coverage was of value to strip camouflage, a requirement in any preliminary bombardment.”
Night Illumination. Naval guns supplied vital night illumination.
"The old problem of demand exceeding supply in star shells was again prevalent.”
Suppression. Suppressive fire was conducted as the landing force approached the beach. Nothing keeps an enemy’s head down like 16” shells!
Reading reports like this makes us aware of just how much we’ve forgotten about amphibious assault conduct, in general, and naval gunfire support, specifically. The tiny handful of 5” guns on today’s surface ships are completely inadequate to support combat operations ashore. Even the Zumwalt’s few hundred 155 mm rocket shells are woefully insufficient to support ground combat in addition to the fact that they are intended as precision strike weapons rather than being large caliber, high explosive area munitions.
The Navy urgently needs to rethink its entire amphibious assault doctrine and reconsider the role that naval gunfire plays.