Air power has been the decisive factor in nearly every
major naval engagement since the beginning of the Second World War. Whether used by the
Allies or the Axis Powers, air power when systematically applied to naval warfare
annihilated naval surface forces and transport convoys not defended by friendly aircraft.
Some important examples bear examination. The battle of the Atlantic initially favoured
Germany, and the Luftwaffe's Focke Wulf Condors wreaked havoc upon Allied shipping convoys
on the high seas until countered by escort carriers and fighters. The infamous story of
convoy PQ-17, largely sunk by the Ju-88s and He-111s of the Luftwaffe, has been told many
times.
When the Allies gained the ascendancy in the Atlantic, it was again land based air power
which played the decisive role. Coastal Command's Liberators, Catalinas and Sunderlands
blocaded Germany and hunted down most of the Kriegsmarine's U-boat fleet. Mosquitos and
Beaufighters cut the shipping lanes in the North Sea.
The battle of the Mediterranean was dominated by air power, initially the Stukas and
He-111s of the Luftwaffe. Later RAF and USAAF aircraft cut Rommel's lifeline to North
Africa, seeing to the demise of the Afrika Korps (1).
Closer to home, the US-Australian executed Battle of the Bismarck Sea saw a major Japanese
invasion convoy annihilated off the coast of New Guinea (2). This came less than two years
after the Japanese Imperial Navy's land based torpedo and dive bombers sank the Repulse
and Prince of Wales off the Malaysian coast.
What is little known, is that Curtis LeMay's B-29 force in the Marianas, whilst bombing
Japan's cities to rubble, also conducted a major minelaying campaign against Japan's ports
and coastal shipping lanes. The B-29s, on the basis of statistics published by the US
Navy, sank more shipping through minelaying than the much vaunted USN submarine arm did
(3).
Whether we examine Luftwaffe performance in the Artic, or USAAF performance off the
Japanese coast, published statistics from many sources clearly indicate that land based
aircraft sunk more shipping than either the U-boats or the US Navy's submarines did, at a
fraction of the operating costs and loss rates of the latter. Whether shipping was
destroyed by direct attack or mining, aircraft did so far more efficiently.
More recently, RAF and RN Harriers and Sea Harriers played a decisive role in the retaking
of the Falklands, and Argentina's only useful opposition was provided by the Fuerza Aerea
Argentina (AAF), which sank four destroyers and frigates, and an important heavy container
ship using by modern standards a marginal capability (a handful of Exocets and WW2 vintage
USAAF dumb bombs). Were Argentine bombs fused properly, the losses would have been at
least twice as great (4).
US Navy operations against Iran in the late eighties saw the Iranian Navy annihilated when
faced by Harpoon firing A-6 bombers, while the heaviest US casualty of the period was an
FFG-7 which was nearly sunk by an accidentally targeted Iraqi air launched Exocet.
During the Gulf War, USN and RAF aircraft annihilated Iraq's naval capability in a matter
of days, using Harpoons, rockets, cannon and bombs. The Iraqi Navy suffered the maritime
equivalent of Khafji, their greatest contribution to the war being the decorating of
Allied aircraft with appropriate stencils. No less than 138 vessels were destroyed or
severely damaged, nearly all by Allied air power. The US surface fleet nearly lost two
ships to Iraqi naval mines.
The historical evidence is irrefutable. Aircraft are a vastly greater threat to shipping
and warships than submarines and surface warships are, moreover the latter are also highly
vulnerable to air attack.
What is the Primary Role of a Navy ?
The primary role of a navy is to control the seas (5). This is accomplished by engaging
shipping by direct attack and by mining, or the threat of doing so. The ascendancy of the
submarine and aircraft carrier during WW2, and the preeminent role performed by these
classes of vessel continue to this very day. The battleship, and conventional surface
combatants in general, have declined in importance since 1939. The primary role of the
surface combatant today is to provide a measure of air defence, defend other vessels from
submarines, and support amphibious landings with gunfire.
The evolution of the modern anti-shipping missile has led to a situation where shipping
must be defended from hostile missile firing aircraft at significant ranges, pushing up
the size and weight of carrier based fighters to the point where they can only be
effectively deployed on large carriers such as those used by the USN. The composition of a
CVBG today is largely defensive, with a single carrier needing to deploy many fighters,
multiple AEW aircraft, and be escorted by up to a dozen air defence cruisers (AAW), ASW
destroyers and light escorts such as frigates, as well as one or two attack submarines.
Such is the value of a carrier to opponent and user alike, that its deployment in
contested waters requires significant ASW and AAW support. The lightweight carrier is
simply not a viable proposition in contested waters (6).
In the context of a navy's primary role of sea control, unless the navy is able to deploy
one or more fully capable CVBGs, its primary tool for sea control will be the submarine.
The submarine will attack shipping with torpedoes and tube launched anti-shipping
missiles, and lay mines. It can also be deployed defensively to engage hostile submarines.
Mines are a particularly valuable weapon as they are
simple, cheap, reliable and persistent. Clever use of minefields can deny an opponent the
use of ports, shipping channels and lanes, as well as force shipping into kill zones
patrolled by submarines and aircraft. Modern mines are very difficult to find and remove,
and can be easily delivered by naval vessels and aircraft.
In a strategic war, sea control is usually employed offensively as a means of blockading
an opponent's shipping lanes or ports, or to enable amphibious forces to make a beachhead
on a contested coastline. Blockade can often starve an opponent of resources and war
material to the point where they are unable to sustain their war effort and collapse as a
result - Japan in 1945 is a good example.
The ability of any contemporary navy other than the USN to achieve even a degree of sea
control in the face of a well equipped modern air force is questionable. Whilst top of the
line submarines stand a reasonable chance of evading ASW aircraft, their ability to
sustain operations effectively whilst under constant aerial harassment must be questioned.
Every engagement with the enemy localises their position and increases their vulnerability
to attack.
Surface Action Groups (SAG) comprising cruisers, destroyers and frigates will not resist
sustained attack by state of the art air forces, which can saturate their SAM and AAA
defences with anti-shipping missiles and anti-radiation missiles. Once the SAG loses its
area defences (when the AAW cruisers are taken down with ARMs and ASMs), then they will be
picked off piecemeal with laser guided bombs and ASMs. The SAG is not survivable under
sustained and concentrated air attack, moreover attacking jets can usually stand-off from
outside area defence SAM range and keep lobbing ASMs at the SAG until its air defences
collapse.
The ability of a SAG to provide useful defence of convoys is also open to questioning. A
repeat of the PQ-17 fiasco, or the Bismarck Sea battle would be the most likely outcome.
Only the US CG-47 Aegis class cruiser has any chance of usefully defending a convoy. If
the air attack is sustained and concentrated, once the cruiser has exhausted its magazines
the battle is lost.
Sea Control and the ADF
The RAN is clearly aware of these circumstances, the building of six Collins class
submarines and recent lobbying for an additional two reflect a focus on using the
submarine, armed with Harpoons, torpedoes and mines, as its primary tool for sea control
(recent reports indicate the external mine carriage facility on the Collins will not be
used, and mines are thus to be carried at the expense of torpedoes and Harpoons). The
RAN's surface fleet, comprising in the early part of the next century a mix of lightweight
FFG-7 and ANZAC frigates, is simply not survivable without the support of RAAF fighters
and AEW&C aircraft. Since survivable and thus large carriers are simply beyond our
means as a nation, this situation will not change. The question which we must then ask is
whether a force of six to eight submarines can do a better job of performing the vital sea
control mission, than could be performed by the RAAF using its AP-3C, F-111 and F/A-18
wings.
 |
The Collins class submarine
represents the state of the art in conventional attack submarine capabilities. Due its
slow transit time and limited payload, it is an inferior sea control asset to tanker
supported tactical jets. The submarine can however play a vital role in supporting air
strikes, by driving shipping into kill zones, mopping up stragglers, carrying out Bomb
Damage Assessment and by providing Combat Search and Rescue if needed.
|
Several issues should be considered in
these circumstances:
flexibility - is a measure of how quickly an asset
can be retasked, rearmed, and redeployed to engage the opponent. The range of target types
which can be engaged is also an issue.
weight of fire - is a measure of how many weapons can
be launched in a saturation attack against an opponent's surface fleet or convoy.
survivability - is the ability to survive repeated
engagements with the opponent.
coverage - is a measure of what area of ocean can be
denied to the enemy by a single platform, or typical deployed unit of platforms.
operating radius - is a measure of how distant an
opponent can be blockaded or engaged effectively.
costs - acquisition, attrition and operating costs
should be considered.
persistence - is the ability to sustain control of
contested waters by maintaining a presence.
Flexibility favours air power, as aircraft can deploy
at hundreds of knots while submarines deploy at tens of knots. Submarines must return to
base to refuel and rearm, or rendezvous with submarine tenders, in either instance having
to do so from outside the coverage of hostile maritime aircraft. Aircraft can be reloaded
much faster than submarines, and can engage ships, submarines and other aircraft. Whilst a
submarine can dominate only the surface and subsurface medium under favourable
circumstances, aircraft can dominate the air, surface and subsurface media. An AP-3C can
engage shipping and submarines, while the F-111 and F/A-18 can engage aircraft and surface
vessels. All types can lay naval mines (the standard air delivered mine is a parachute
retarded Mk.80 series bomb warhead with a Mk.36/40/41 destructor kit attached (7),
released at low level). Air power is therefore a more flexible tool than submarines for
sea control
 |
The F/RF-111C strike aircraft can
attack shipping with Harpoons, Have Naps, Laser Guided Bombs, as well as lay naval mines.
This asset provides the RAAF with a tremendous capability to perform the sea control
mission, but requires tanker support to fully exploit its potential. |
Weight of fire favours air power, as six
or less aircraft can carry an equal load of Harpoons or mines to what a submarine can. A
squadron of twelve F-111s or F/A-18s can deliver the weight of fire of two submarines on a
single sortie, and several times the weight of fire if we allow the aircraft to fly home,
reload and re-engage, which the aircraft can do in much less time than it takes a
submarine to break contact, meet with a tender, and redeploy to regain contact with the
enemy. As an example, in the time it takes for a sub to transit 1,000 nautical miles at 20
kt to a kill zone, an F-111 can make no less than six trips with a 3 hr allowance for
reloading and refuelling on each sortie - in effect a single F-111 delivers about the same
aggregate weight of fire as a Collins class sub. Air power therefore delivers much greater
weight of fire than a submarine can.
| For the cost of a single
additional Collins submarine, the ADF could acquire a squadron of KC-135R tankers which
would allow the F-111 Wing to conduct sea control operations to greater radii than that of
the submarine force, as well as make all F-111G aircraft Harpoon capable. |
 |
Survivability favours air power, as
modern tactical jets can deal with hostile fighters, maritime aircraft and surface vessels
very effectively. Whereas a submarine must evade hostile ASW aircraft and vessels, and
submarines, in order to perform its mission, all of these threats are typically easy
targets for aircraft to successfully engage. The maritime patrol aircraft which is a
deadly threat to the submarine, is easy meat for an F-111 or F/A-18. The same is true of
surface vessels. Whilst a submarine can in theory engage an ASW aircraft with an
encapsulated SAM, the submarine is still the hunted party in the engagement. An aircraft
can always disengage and retreat much faster from an unfavourable engagement. Statistics
from WW2 suggest that submarines suffered much higher loss rates than aircraft in
sustained operations. Air power is thus more survivable than submarines are.
Coverage favours air power, as an aircraft using its ESM and radar can sweep a much larger
area much faster than a submarine using a towed sonar. In the sea control scenario, where
surface vessels are the target, aircraft offers substantially better coverage than
submarines, moreso if we can deploy several aircraft for each submarine.
Costs have and continue to favour air power across all three categories. A Collins class
submarine at $500M plus apiece is worth almost the cost of a squadron of state of the art
tactical jets, new. Losing a single submarine is a similar loss to that of a whole
squadron of tactical fighters, with a greater loss of life. In terms of bang for buck,
aircraft are therefore much better value as a sea control asset.
Persistence and operating radius favour the submarine, where air power lacks proper
inflight refuelling support. Where air power has proper inflight refuelling support, it
can match the operating radius of the submarine with no difficulty. The RAF's Nimrod
operations during the Falklands campaign are a good example.
 |
The plight of lightly armed
surface warships under sustained air attack is no better illustrated by the Royal Navy's
heavy losses during the Falklands campaign. The operationally marginal Argentine Air Force
and Naval Air Arm came very close to defeating the UK's armada using visually aimed dumb
bombs and a handful of Exocets, delivered by a motley collection of sixties technology
Mirages, Daggers, A-4 Skyhawks and Etendards, lacking even basic electronic warfare
capability and flying at the limit of their combat radius. |
This final point brings us to the
central issues for the ADF. Is it better to spend a billion dollars on a pair of
submarines, or invest less money in strengthening RAAF operating budgets, inflight
refuelling capability and the Strike Reconnaissance Wing ? Given the primacy of air power
as a sea control tool, should the RAN retain its responsibility and operating budgets as
the service primarily tasked with sea control, or should this activity become primarily a
RAAF responsibility ?
To explore the first issue, let us indulge in some basic arithmetic. The current SRW (82
WG) active complement comprises 22 F/RF-111C and 6 F-111G aircraft for a total of 28
aircraft with nine F-111Gs in reserve. Let us first assume that all aircraft are made
Harpoon capable, and all are available for use. With four Harpoons apiece this yields a
loadout of 4 x 36 = 144 rounds for 82 WG, which compares favourably with the total load of
6 x 23 = 138 rounds (Harpoon/torpedo) for the Collins force. Assuming that the aircraft
can deliver six or more sorties in the time a sub can deliver one sortie, the existing 82
WG inventory has more than six times the potency of the planned submarine force as a ship
killing asset.
These are interesting numbers. If we rate combat effectiveness by weight of fire alone,
the acquisition of one submarine increases our naval sea control combat effectiveness by a
factor of one in six (17%), the acquisition of two subs raises this to two in six (33%).
On the other hand, the current 22 Harpoon capable F-111s already have more than 400% the
combat effectiveness of the planned 6 strong submarine force. Subjecting the 15 F-111Gs to
an AUP upgrade to provide a Harpoon capability for all 36 operational airframes increases
this ratio beyond 625%.
Let us now make some comparisons. A Collins class sub costs about $500M. The cost of an
incremental AUP upgrade on the 15 F-111G aircraft has been estimated at between $80M and
$100M. This leaves a whole $400M dollar difference. Let us then assume that this money is
spent on buying 16 second hand KC-135R tankers, which yields $25M per tanker aircraft.
This is a generous allowance per airframe, as the USAF KC-135R cost about US$10M to
upgrade with CFM-56 engines from paid off KC-135As delivered prior to 1966, and zero timed
before 1980. It would allow for a glass cockpit, an electronic warfare fit and support
infrastructure.
For the cost of a single submarine the ADF could have not only a fully Harpoon capable 36
strong F-111 Wing, but also a squadron of tankers to provide this Wing with an operating
radius equal to or better than that of the submarine force. Not to speak of the other
benefits which accrue from having tankers, as I have argued in August issue AA. A single
submarine would thus improve the ADF's sea control combat effectiveness by 17%, whereas
its cost spent on an F-111G upgrade and 16 tankers would improve the ADF's sea control
combat effectiveness by something well in excess of 250% of the potency of the whole
submarine force.
Let us now assume a revised active wing size of 56 F-111 aircraft, assuming the existing
37 airframes are all made available. This would require the acquisition of an additional
19 F-111 airframes at about $90M for the package. Assuming then $5M per airframe for an
AUP upgrade on each and every aircraft amounts to about $95M. For half of the cost of an
additional submarine the ADF could double the size of the F-111 Wing, providing twelve
times the combat effectiveness of the six strong submarine force.
If the reason for acquiring two more submarines is to increase the ADF's capability in the
sea control role, we can do far better by spending three quarters of the money on tankers
and extra F-111s, and get vastly more capability for the dollars invested. Why bother with
more submarines ?
The second issue also bears some consideration. The existing arrangement is for the
conduct of joint operations between the RAN and the RAAF. What this really means is that
the RAAF is a service provider to the RAN, the joint force commander would almost
certainly be Navy and the RAN would develop the battle strategy, ostensibly with RAAF
advice on operations, and the RAAF would execute it.
Considering the previous analysis, we can argue a very strong case for the joint force
commander to be RAAF rather than RAN, and for the RAN to be the service provider to the
RAAF in sea control operations. The RAN would provide intelligence support and use its
submarines to assist the RAAF in its conduct of operations. RAN submarines could drive
hostile shipping into kill zones, mop up stragglers after air strikes, provide post strike
Bomb Damage Assessment, as well as provide Combat Search And Rescue if needed. This
arrangement reflects the weight of respective capabilities far better than the
Navy-lead-service-in-sea-control-operations model. The latter is an anachronism.
The government should give careful consideration to how it allocates both capital
investment and running costs in maritime surveillance and sea control capabilities.
Substantially better bang per buck can be achieved by shifting resources and
responsibilities from the RAN to the RAAF.
This discussion has simplified many of the issues, for instance by neglecting the
important capabilities of the AP-3C and F/A-18, but the essence would be no different were
the analysis much more thorough. Air power is the dominant weapon in strategic naval
operations and the ADF's ORBAT, operational running budgets and command and control
arrangements should reflect this. To do any less is to place tradition above the realities
of modern warfare.
 |
This plot illustrates the number
of sorties which could be flown by an F-111 during the time a submarine takes to transit
to the kill zone, against the distance to the kill zone. The calculation assumes a 3 hour
turnaround between sorties, and an average TAS of 430 kt assuming that the lower speed on
climbout and combat speed of 550 kt average out. Radii beyond 800 nautical miles require
inflight refuelling. Of interest is the fact that a single tanker supported F-111 can fit
up to 9 sorties in at 3300 NMI, allowing it to deliver 156% greater weight of fire than a
submarine can. |
References:
(1) Hallion R.P., Air Warfare and Maritime Operations, WP 45, RAAF Air Power Studies
Centre, 1996
(2) McAulay L., Battle of the Bismarck Sea, St. Martin's Press, NY 1991
(3) Chilstrom J.S., Maj, USAF, Mines Away ! The Significance of US Army Air Forces
Minelaying in WW II, USAF Air University Press, October 1993
(4) Middlebrook M., Operation Corporate, The Falklands War, 1982, Viking, 1985
(5) Wylie J.C., Rear Admiral USN, Military Strategy: A General Theory of Power Control,
Australian Naval Institute Press
(6) Spangenberg G.A., Naval Aviation Planning: A Retrospective View (and some lessons for
1995), in The Gold Book of Naval Aviation, Association of Naval Aviation, Inc, Virginia,
1985
(7) Jane's Air-Launched Weapons, Janes Information Group, 1990
