The US Navy is building a fleet of small unmanned vessels to
act as pickets and outer escorts for carrier and surface groups despite having
no evidence, whatsoever, that the unmanned vessels can effectively carry out
their task. Since the Navy refuses to
conduct any actual experimentation to validate the concept prior to committing
to production, is there any other source of information that might allow us to
assess the concept? Of course there is
and it’s our most reliable source … history!
Specifically, it’s the battle for Okinawa and the role of the Kamikaze
and the US Navy picket ships.
Okinawa was a major battle for both the US and Japan. US losses during the 3 month battle were steep
with 768 aircraft lost in addition to staggering naval losses.(5) From Wikipedia:
At
sea, 368 Allied ships—including 120 amphibious craft—were damaged while another
36—including 15 amphibious ships and 12 destroyers—were sunk during the Okinawa
campaign. The US Navy's dead exceeded its wounded, with 4,907 killed and 4,874
wounded, primarily from kamikaze attacks. (5)
Just as astounding to us, today, was the magnitude of the
forces assembled for the battle. Consider
this partial Allied naval order of battle at Okinawa (1)
US Navy combat ships:
11 fleet
carriers
6 light
carriers
22 escort
carriers
8 fast battleships
10 old battleships
2 large cruisers,
12 heavy
cruisers
13 light
cruisers
4 anti-aircraft light cruisers
132 destroyers
45 destroyer
escorts
Amphibious assault vessels:
84 attack
transports
29 attack cargo
ships
LCIs, LSMs, LSTs,
LSVs, etc.
Auxiliaries:
52 submarine
chasers
23 fast minesweepers
69 minesweepers
11 minelayers
49 oilers
Royal Navy combat ships:
5 fleet carriers
2 battleships
7 light cruisers
14 destroyers
The 265 US combat ships, alone, nearly equals the size of
our entire present day fleet and that was just the force for a single
operation. We’ve truly forgotten the size of the force necessary to wage total
war.
Japan, too, fielded a large force, mainly aerial, along with
the battleship Yamato, a cruiser, and several destroyers. During the course of the battle, Japan
launched 10 large scale kamikaze attacks against the US Navy Fifth Fleet
guarding the Okinawa amphibious invasion fleet.
Each attack consisted of hundreds of aircraft. For example, the first attack consisted of
355 kamikaze aircraft and 344 escort fighters and lasted for five hours. The US Combat Air Patrol (CAP) did an amazing
job but could not stop every attacker.
Twenty-two
kamikazes penetrated the combat air patrol shield on April 6, sinking six ships
and damaging 18 others. Three hundred fifty U.S. crewmen died. (2)
Only 22 attacking aircraft managed to penetrate the aerial
defenses but the damage they did was enormous.
What was the overall result of the kamikaze attacks?
The
Japanese fell short of their goal of “one plane one ship,” but sank 36 American
warships, and damaged 368 other vessels at Okinawa. The Navy’s losses were the
highest of the Pacific war: 4,907 sailors and officers killed, and 4,824
wounded. Japan lost an estimated 1,600 suicide and conventional planes at
Okinawa. (2)
The sheer number of attacking aircraft represented what we
would, today, call a saturation attack intended to overwhelm the defensive
capacity of the US fleet.
The Navy’s answer to the kamikaze saturation attacks was to
establish a ring of radar picket ships around the island and the invasion fleet
extending out as far as 80 miles. The
pickets provided early warning, fighter direction, and direct engagement. Each picket ship was tied to a circular
station of 5000 yds radius.
Wikipedia describes the Okinawa radar picket system.
A
ring of 15 radar picket stations was established around Okinawa to cover all
possible approaches to the island and the attacking fleet. Initially, a typical
picket station had one or two destroyers supported by two landing ships,
usually landing craft
support (large) (LCS(L))
or landing ship
medium (rocket) (LSM(R)),
for additional AA firepower. Eventually, the number of destroyers and supporting
ships were doubled at the most threatened stations, and combat air patrols were provided as well. In early 1945, 26 new construction Gearing-class
destroyers were ordered as
radar pickets without torpedo tubes, to allow for extra radar and AA equipment,
but only some of these were ready in time to serve off Okinawa. Seven destroyer escorts were also completed as radar pickets. The radar picket mission was
vital, but it was also costly to the ships performing it. Out of 101 destroyers
assigned to radar picket stations, 10 were sunk and 32 were damaged by kamikaze
attacks. The 88 LCS(L)s assigned to picket stations had two sunk and 11 damaged
by kamikazes, while the 11 LSM(R)s had three sunk and two damaged. (3)
 |
Okinawa Picket Stations
|
Note: Some picket diagrams show a 16th
station located near station 12.
Understanding the basics of the situation at Okinawa, what
can we learn that is applicable to today’s Navy? The foundation of any analysis is the
recognition that the Kamikaze was the functional equivalent of a guided anti-ship
missile. The guidance, obviously, was in
the form of a human pilot and the ‘missile’ was very powerful, rivaling a
modern guided missile in terms of destructive impact. This functional equivalency allows us to
assess the attacks and defense in modern terms.
Further, the dynamic of the Kamikaze and the picket ships gives us
insight into the Navy’s plans regarding its unmanned picket/escort vessels.
As you recall from previous posts, the Navy intends to
procure two types of unmanned vessels.
One will be a small version which is intended to act as a picket for a
larger group by providing surveillance and reconnaissance – much the same as
the picket ships did at Okinawa. The
second will be a somewhat larger vessel which is intended to stay with the main
group and act as a missile barge.
So, what does the Okinawa Kamikaze and picket ship scenario
tell us about the Navy’s plans for its unmanned vessels today? There are several lessons, factors, and
considerations for us.
Lethality – We
need to recognize that today’s anti-ship missile will be every bit as lethal,
if not more so, than the Kamikazes. In
fact, the situation is far worse today due to the complete absence of armor on
modern ships. The Okinawa picket ships
routinely absorbed multiple hits, kept fighting, and often survived. Does anyone seriously believe that a Burke,
FFG(X), or LCS can take multiple hits and not sink? Astonishingly, one of those ships is actually
designed to be abandoned at the first hit!
A missile attack against our ships will be devastating and we need to
factor that into our ship designs and cost and we need to accept that naval
battles will involve a significant degree of attrition. The lethality will absolutely stun us.
Saturation – The Kamikaze
was used as a saturation attack with each of ten major attacks consisting of several
hundred aircraft. This is a lesson we
have completely forgotten. Peer warfare
requires huge numbers of munitions – dwarfing any estimates we may have. This was demonstrated time and again in WWII
and Korea where munition expenditures far exceeded predictions. We’ve become so used to the small Tomahawk
strikes against unresisting targets that we’ve come to believe that peer warfare
will involve the same minimal usage of weapons.
Nothing could be further from the truth.
We’ll see unimaginably massive expenditures of weapons against us and
unbelievable salvos launched against our fleets. We absolutely must come to terms with this
reality because it drives our ship design sensor and weapons density, fire
control capacities, sensor design, armor considerations, etc. Ships with one CIWS will not survive
saturation attacks. We must heavily arm
our ships – far beyond anything imagined by today’s designers.
Defensive Guidance/Sensors
- Defending ships at Okinawa did not possess any weapon guidance comparable to
the Kamikaze pilots and this put them at a huge disadvantage. The defending weapons were optically (and
radar, to a degree) aimed and fuzed to a marginally successful degree. The mismatch in technology between the advanced
[human] guidance of the Kamikazes and the unguided defensive weapons mimics and
demonstrates the consequences of a loss of defensive sensors and fire control
in modern engagements. Given the very limited
number of sensors and fire controls on modern ships, it is all too easy to
imagine a ship being blinded early in an engagement and being unable to
continue fighting even though the weapons, themselves, might still be
available. We desperately need to
increase the number of sensors (redundancy) and types of sensors on our ships. For example, we should have much more
extensive, physically distributed EO/IR sensors tied into the fire control
system as well as a separate, technologically dissimilar type of radar as a
backup to the Aegis arrays. The Aegis
arrays are large, exposed targets and likely to be seriously damaged and
degraded from almost any hit. Consider
the Burke destroyer that was involved in the collision with a commercial ship. One of its radar arrays was, apparently,
rendered completely inoperative and that was from a waterline collision, not a
missile hit. In like fashion, the Port
Royal’s arrays were reportedly rendered inoperative when it gently nosed
aground off Pearl Harbor. That doesn’t
bode well for the combat resilience of the Aegis system. We need sensor redundancy and backups.
Armament – The use
of picket ships mimics the Navy’s desire for advanced screens of unmanned
vessels. The pickets succeeded in their
mission but were devastated – what does that suggest for today’s unmanned
vessel screens? The picket ships were
heavily armed and armored but were still devastated. The Navy, in contrast, envisions the unmanned
escorts being unarmed. They’ll be
quickly eliminated in any combat which will transfer the burden of their
functions back to the manned escorts who won’t be trained or proficient at the
functions and certainly won’t be properly positioned.
Armor – The
Okinawa picket ships were all armored to varying degrees. Again, the Navy envisions completely
unarmored, unmanned vessels as pickets.
Not only will the unmanned vessels be quickly eliminated but the absence
of armor ensures that weapon expenditure by the enemy to do so will be
absolutely minimal. One of the major
benefits of the Okinawa pickets was that they soaked up so many of the
Kamikazes. Imagine if each picket had
instantly sunk from a single hit. The
remaining Kamikazes would have been able to continue on to the amphibious
ships, the true targets of the Kamikazes, instead of being wasted against the
pickets.
 |
| USS Aaron Ward After 6 Kamikaze and 2 Bombs |
Weapon Density –
The number of weapons on the picket ships was incredible and that redundancy
allowed the pickets to keep fighting even after taking multiple hits. The USS Aaron Ward is an outstanding example
of a ship that was able to keep firing despite taking half a dozen or so
Kamikaze strikes and a couple of bomb hits.
Even the ships that would make up today’s core group have very limited
numbers of defensive weapons. While the
VLS numbers are large, and quad packing makes the missile inventory numbers
even larger, we’ve shown that the number of VLS weapons that are actually
usable in an engagement is limited to around four. Beyond that, the number of close in weapons
is nearly non-existent. Burkes have a
single CIWS. Many ships have a single
RAM/SeaRAM. We need to greatly increase
the number of defensive weapons installed on our ships.
Picket Spacing –
One of the aspects that jumps out from looking at the diagrams of the picket
locations is the distances involved. For
those of us who have grown up looking at Navy PR photos of ships sailing side
by side, the idea of spacing is foreign to us.
The Okinawa pickets were located 20-80 miles (mostly 50-80 miles) from
the center of the defended area.
Translating that to modern terms is difficult but one way to sort of get
a handle on it is to compare the Okinawa distancing to the speed of the
incoming attackers. Obviously, the
faster the attacker, the farther out the picket has to be located in order to
provide sufficient warning. At Okinawa,
the pickets were, generally, 50-80 miles from the center point of the defended
area which puts them at distance equivalent to 25% - 40% of the attacking
aircraft’s speed (assuming 200 mph). For
a modern high subsonic (assume 500 mph), anti-ship missile that would,
proportionally, place pickets at 125 miles – 200 miles. That seems unbelievable to us, today, but
facing supersonic or high subsonic missiles, those are the kinds of distances
required to provide sufficient early warning and engagement.
If the Navy intends, as they say, to place unmanned vessels
as escort pickets for the main groups, the pickets will need to be 50-200 miles
out which places them well beyond any AAW support from the core group. As we stated earlier, being unarmed and
unarmored, they’ll die quickly and easily.
I’m pretty sure the Navy hasn’t thought this through.
The Okinawa picket stations were positioned close enough to
allow continuous tracking of attacking aircraft but were too far apart to
provide mutual gun support. Given
today’s longer ranged anti-air missiles, mutual support may be possible but
only if many, many more pickets are used due to the greater required distancing
from the escorted group and only if the pickets are armed. Again, this reminds us that we’ve completely
forgotten just how many ships are required to form a survivable group. We’ve grown up seeing a carrier escorted by
three ships when the combat-reality is that we will need 30+ ships and that’s
before we factor in any distant picket requirements.
Countermeasures -
Japan did attempt radar countermeasures, employing chaff and radar reflective
kites, though with limited success.
Today, sophisticated radar countermeasures would, undoubtedly, be
employed and would greatly decrease the effectiveness of radar pickets.
Expendability -
It was understood that the pickets would be spotted and attacked. Recommendations were made that the picket
ships be the smallest possible ship that could perform the function so as to
make losses ‘acceptable’.(4) This is a
concern for us, today, given that our smallest surface ship is the
multi-billion dollar Burke. Even the
future frigate is a billion-plus dollar ship and cannot be considered
expendable. The Navy’s vision of small
unmanned vessels may be appropriate in terms of cost, if they can resist the
temptation to gold plate them.
Summary
Future naval warfare will, without a doubt, feature massive,
saturation missile attacks and the US Navy has not devoted any attention to the
problem. The Chinese Type 055 destroyer/cruiser,
for example, has 112 VLS cells that can be loaded with anti-ship missiles. Okinawa offers historical lessons that we can
apply to our defensive efforts. The Navy
plans to employ unmanned picket vessels to accompany and escort carriers and
surface groups but the pickets are going to be unarmed and unarmored. A peer enemy will have hundreds or thousands
of missiles available for attacks and unarmed/unarmored pickets won’t stand a
chance and will be quickly eliminated leaving the core group with no early
warning and no early engagement.
The Okinawa pickets provided early warning but also early
engagement and fighter direction assistance.
In other words, the pickets were not just passive observers, they were
active combatants and, as such, managed to tie up many of Kamikaze aircraft
that penetrated the CAP screen. We need
to give serious thought to reconfiguring our pickets beyond their purely
passive sensing role and make them combatants.
That requires arming them with short/medium AAW weapons and building
them with an appropriate degree of armor.
The Okinawa pickets clearly demonstrated the value of armor.
Given the relatively small number of kamikaze aircraft that
penetrated the CAP, the damage and destruction they wrought was stunning and
modern anti-ship missiles are likely to be even more destructive given the
unarmored and weakly built ships that make up today’s fleet. We need to alter our ship design philosophy
and start designing ships for combat, not peacetime cruises.
The Okinawa example pointed up the need for massive numbers
of ships to stand up to high end saturation attacks and to compensate for sunk
and damaged ships. Okinawa, alone,
involved over 600 ships, not counting hundreds of additional, lesser craft such
as LCIs, LSMs, LSTs,
LSVs, etc.
This one operation used 2-3 times more ships than the entire current US
Navy. We’ve forgotten what is required
to wage high end war.
Frankly, the Navy’s vision of unmanned, unarmed, unarmored
picket/escort ships is ludicrous and combat-useless. They’ll be instantly eliminated in any attack
without accomplishing anything. Only if
we can make them powerful enough and tough enough to survive long enough to
accomplish their purpose will they be combat-useful. However, this requires a complete rethink of
the entire concept. Unfortunately, just
like the LCS, the Navy has already committed to the design and acquisition of a
fleet of unmanned vessels without any understanding of their capabilities and
vulnerabilities. As with the LCS, we’re
committed to buying a fleet of worthless vessels. Is the Navy truly incapable of learning from
their mistakes? It would seem so.
____________________________
Related side note:
The radar picket system was established to provide early
warning and early defense against the kamikaze saturation attacks. The ultimate development of radar picket
ships was the high speed, nuclear powered submarine USS Triton which could
perform picket duty and dive when threatened.
The obvious problem with this tactic is that the pickets could be kept
underwater and ‘mission killed’ by a single aircraft. In addition, a submarine has no anti-air
capability and cannot engage the attack, only warn of its approach.
____________________________________
(1)https://en.wikipedia.org/wiki/Okinawa_naval_order_of_battle
(2)History News Network website, “Kamikazes at the Battle of
Okinawa”, Joseph Wheelan, 6-Mar-2020,
https://historynewsnetwork.org/article/174496
(3)https://en.wikipedia.org/wiki/Radar_picket
(4)Naval History and Heritage Command website, “Battle
Experience Radar Pickets and Methods of Combating Suicide Attacks Off Okinawa”,
https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/b/battle-experience-radar-pickets.html
(5)https://en.wikipedia.org/wiki/Battle_of_Okinawa#Military_losses
