Korea: Naval air

Operation Strangle: Naval aviation in Korea.

by Fred Lane
Paper presented at the Aviation Historical Society of Australia, Sydney, 7 July 2004.

To understand naval aviation in the Korean War, it is necessary to understand the context. Before the Americans dropped the Hiroshima and Nagasaki atom bombs, a highly successful Pacific War had been waged between 1941 and 1945 when, following the lead of the British at Taranto, Japanese and American naval aircraft, dramatically demonstrated their overwhelming tactical and strategic worth. As well as enemy ships, naval aircraft routinely found and destroyed strategic military targets, including airfields and rail yards, in pure “strike” roles. Over time and sometimes at painful cost, the United States Navy, Marines and Army developed a highly successful “Cab Rank” Close Support system, independent of any Air Force component.

swordfish
Despite decades of neglect of the Fleet Air Arm a mere 21 “Stringbag” Fairey Swordfish demonstrated the worth of naval aviation when they single-handedly crippled the Italian battle fleet at Taranto in Operation Judgement on 11 November 1940, more than a year before Pearl Harbour.

Some authors claim that it was naval aviation that saved South Korea from falling to an aggressive North Korea. Others claim that, on the contrary, the Korean War saved naval aviation. In the face of the USAF’s powerful “Victory through Air Power” propaganda campaign in the late 1940s, the USN had been in real danger of losing its aviation component, just as the Royal Navy lost its Fleet Air Arm to the RAF in the 1920s and 1930s. Yet others argue that by late 1951 the Korean War had devolved into a boring military and political stalemate and that concomitant Washington machinations were much more important. There, as in London, the major war focus was on Europe, the Atlantic and nuclear weapons. Korea, they argued, was nothing much more than a sideshow to be fought by reservists and ad hoc forces. In fact, Korea was an important testing ground for the “limited war” concept waged by communist forces for the next half century. It was also correlated with a dramatic reversal of American naval aviation fortunes.

Post WW II evolution

In 1946 the USN’s authorised strength included 98 aircraft carriers and 29,125 aircraft. In 1947, even the perennially cash-strapped Australian Government purchased two British light fleet carriers, which led to HMAS Sydney and her carrier air group serving proudly in Korea from October 1951 to February 1952. The carrier had replaced the battleship as the premier capital ship but by June 1950, under the new US Department of Defence, the USN had a mere 15 carriers and 9,422 aircraft in commission, with nothing much of any substance in the pipeline.

For a number of reasons, not the least of which is the danger of trying to interpret biased historical records, this paper will focus initially on some of the better recorded political aspects that preceded the Korean War, examine how they might have influenced biased reporting and look at Sydney‘s part in Korea’s Operation Strangle, as seen by a very minor participant observer.

The vital contributions of naval aviation, particularly US Marine Corps aviation, to the defence of the Pusan Perimeter, the Inchon landings and the withdrawal of the 1st Marine Division from the Chosin Reservoir are acknowledged and are well known. The air transport contributions of USAF, Marine and other forces were novel, important and even vital in many Korean actions, but again they fall outside the immediate focus of this paper, as does the grinding and valiant work done by hundreds of Air Force aircrew, including those flying the F-51 Mustangs and the Meteors of RAAF 77 Squadron. Helicopters, especially US Marine Corps helicopters, revolutionised many aspects of land and sea warfare in Korea, but they too will only be briefly mentioned.

However, anyone researching hard data about the Korean War will find the library studded with minefields for the unwary, not the least of which are grossly biased enemy damage reports.

US Army assessment of aircrew damage claims

US Army historian Billy Mossman conservatively reports:

There must be a recognition that damage claims were overstated. In 1952, for instance, the Fifth Air Force in Korea noted that the experience of World War II had proved the validity of halving pilot claims, and that the need for a similar reduction of claims was being borne out by the Korean experience. The USN, in a study of close air support in Korea, went even further, concluding that pilot claims were of such questionable reliability as an index of performance that they should be omitted from consideration altogether.1

As will be discussed later, personal observations suggest that at least some so-called independent Army-source intelligence was also heavily exaggerated. This might be traced to bad habits condoned in WW II, but there was another reason in 1951, the intense rivalry at many levels between the USAF and USN that spawned, among other things, the “Revolt of the Admirals” in 1949. The author recommends a careful reading of all original data, including action reports backed up by pre- and post-action photographic evidence, before attempting to reach any conclusion regarding comparative Air Force versus Naval Aviation Korean War claims.

“Unified” Department of Defence

A serious bureaucratic bunfight raged in Washington between 1947-49 regarding the separation of the US Air Force from the US Army and a newly created “unified” Department of Defence that would oversee all the fighting services. Following the theories and leads of Guilio Douhet, Hugh Trenchard and Billy Mitchell, US Air Force advocates, ably led by Secretary of Defence Louis Johnson, claimed that sufficient numbers of the USAF’s grand new B-36 bomber, first flown in August 1946, would make large expensive navies and armies superfluous and therefore a waste of money.2 Their strongly held fallback position was that even if navy or army rumps insisted on keeping tiny little auxiliary air forces, simple economy of force and air safety considerations demanded a single authority to purchase all air-related assets and, importantly, to control all air operations in one geographical theatre. That authority, of course, rested with the USAF.

b-36

Bureaucratic fights for funds for the B-36 (H version, above) led to the cancellation and downgrading of many important USN projects, including the revolutionary flush-decked super carrier USS United States (below).

cv-usa


Carrier budget slashed

In the three years since WW II, the USN had its carrier fleet decimated. Despite this, Johnson slashed the carrier budget even more. A month after its keel was laid on 18 April, 1949, the Defence Secretary unilaterally cancelled the 65,000-ton super-carrier USS United States without consulting either the Secretary of the Navy or the Chief of Naval Operations (CNO). Forward planning for this ship had mollified USN aviators as they saw carrier after carrier decommissioned and squadron after squadron disbanded. This ship was seen as an essential step towards a nuclear-capable assured future. These and other actions elicited the resignation of the Secretary of the Navy John L. Sullivan, the “Revolt of the Admirals” and the undignified sacking of the CNO, ADML Louis E. Denfeld, by the end of October 1949.3

Unlike the Army, the USN was never keen on the idea of a separate Air Force concept. They were also concerned that “Army plus Air Force” votes would outweigh their lone voice in Joint Chiefs of Staff aviation-related decisions within the new Department of Defence.

The USN argued that no matter what WW II experiences in the European Theatre might suggest, a separate Air Force was not necessary. The recent Pacific War amply demonstrated how, given sufficient aircraft carriers and other aviation-related resources, strategic aims could be achieved without any Air Force assistance whatsoever. Never warming to GENL MacArthur, the USN had long argued that his USAF-assisted WW II coast-hopping strategy was far more costly than their direct thrust plan. They were dismayed at the profligate waste of landing craft and amphibious support ships in MacArthur-controlled side shows, including the Australian landings in Bougainville and Tarakan. They scoffed at the Air Force’s “daylight precision bombing” mantra as post-war bombing survey after survey confirmed the emptiness of the boast.

The USAF’s primary reliance on sledgehammer nuclear weapons, they argued, was costly, immoral and probably irrelevant in future limited wars. In any event, both the Army and the Air Force required a sizeable merchant fleet, and a navy to protect it, to mount and sustain operations anywhere in the world with anything other than nuclear bombs.

Unfortunately, logic and performance were not enough. The USN lost the public relations battle. A virtual media blitz in Congress, newspapers, magazines and even the cinema repeatedly trumpeted a “Victory through Air Power” theme.

Alongside all this Washington bureaucratic upheaval was the international political turmoil of the Berlin crisis of 1948 and communist successes in Czechoslovakia and China in 1948 and 1949. Closer to home, the Malayan Emergency was declared after communist terrorist attacks in 1948 and the French soon found themselves locked into a similar deadly struggle in Indo-China. Then the Soviets surprisingly exploded their first nuclear device on 29 August 1949. This contributed to an April 1950 US National Security Council (NSC) directive that warned of a Soviet Union bent on world domination and recommended sharp increases in US defence spending.

North Korea invades

Consistent with the NSC warnings, North Korea suddenly invaded South Korea on 25 June 1950 in the first stage of a war that was to last a little over three years. More than half the South Korean Army was destroyed within the first few weeks. By the end of July, UN ground reinforcements, chiefly under-strength American Army units fed piecemeal into the battle, found themselves pushed back into a small “Pusan Perimeter” pocket in the southeast corner of the peninsula.

Here was an opportunity for the first test in the cauldron of war of the Johnson-USAF domination-by-air strategy. If that strategy was sound, North Korea’s major communications centres and industrial bases would be bombed to a standstill within weeks. Its army would then fold and the ground forces would just mop up and take control of the civilian population.

korea
Korea

On 27 June the United Nations Security Council called on member nations to help South Korea. American B-26 Douglas Invader twin-engined tactical bombers and fighters of the Far East Air Force based in Japan commenced interdiction raids that night. B-29s followed up with heavier bombardments the next day.

Chiefly British Commonwealth warships initiated a highly successful naval blockade of the entire Korean coast within hours of the UN resolution. HMS Triumph, a British light fleet carrier with about 24 aircraft aboard, and USS Valley Forge, an American Essex class carrier with about 70 aircraft closed Korea. Triumph launched 12 Seafire Mk 47s and seven Fireflies to raid Haeju airfield at 0615, 3 July 1950. Valley Forge launched a series of raids against Pyongyang airfield using 12 AD Skyraiders, 16 F4U Corsairs and eight F9F-2 Panthers about the same time. The Panthers shot down two Yak-9Ps, a Spitfire-equivalent Russian-built fighter bomber.

triumph-seafire47s
Seafires Mk 47 aboard HMS
Triumph, in March 1950 off Subic Bay (above). An ASW Firefly (below) warming up for launch on Sydney‘s catapult, with a borrowed USN HO-3S1 (S-51) helicopter in the background.

firefly-sydney

 


First naval aircraft losses

However, the enemy was not responsible for the first naval aviation losses in Korea. The next day a Valley Forge AD Skyraider received flak damage. It made a flapless approach, hurdled the barriers, destroyed one AD and two F4Us, and damaged three other aircraft in the forward deck park.4 On 28 July, Triumph lost her first aircraft, a Seafire, shot down by a “friendly” B-29, in a classic communications failure and aircraft misidentification incident.5

valley-forge
Essex class CV USS Valley Forge (above) and a “Jeep” carrier the CVE USS Rendova (below) with USMC F4U Corsairs on deck.

rendova

One reason for the B-29/Seafire communications failure was a direct outcome outcome of the earlier Washington bunfight and a MacArthur-imposed command structure in Korea was that although a central command knew just about what was happening everywhere, there was little cross-information between the various commands in the same geographical area at the tactical level. From the start of the Korean War, as James Field notes:

For the conduct of the air campaign, control was centralized at the highest possible level and preplanned operations were the rule. From this structure had developed a communications system with large capacity for routine transmission of orders and reports between central command post and operating air bases, but with limited provision for tactical communications at the scene of action — Air Force verbosity swamped the less capacious naval circuits — an extreme example was the grandfather of all radio messages received by Task Force 77 in November 1950, which took 8,000 encrypted groups to set forth the air plan for one day, and which required over 30 man-hours for processing.6

Another well-forecast problem was that American navy and air force aircraft could not talk to each other or to opposite number close support controllers over the battlefield except on two VHF radio frequencies that were so overloaded that they were frequently unusable.

In the early days, many USN aircraft were forced to jettison their bombs before landing back on the carrier because they could not talk to ground controllers. Other very serious early problems included incompatible USN and USAF aeronautical charts and very poor target intelligence.7

Understanding the Australian naval aviation contribution to the Korean War is sometimes difficult because it is poorly recorded and there are many traps for the unwary in literature searches.8 For instance, the Americans who discuss naval aviation tend to focus on the 11 big and capable Seventh Fleet Essex class carriers that served in Korea from time to time. They tend to either ignore or lump in the contributions of the five reasonably capable British Commonwealth light fleet carriers, HMAS Sydney, HMS Triumph, HMS Theseus, HMS Glory and HMS Ocean, with the five frequently anonymous and usually single-role USN jeep carriers, such as USS Rendova and USS Sicily, that were significantly smaller and carried half their aircraft. More often, the RN and RAN carriers are ignored.

sea-fury
HMAS
Sydney carried 24 RAN Sea Furies, such as this one from 805 Squadron and 12 Fireflies.

When Sydney is not ignored, the associated data are frequently in error, even in Australian publications. For instance, the number of sorties flown by Sydney in Korea varies from 4,196 according to Eric Grove,9 to 2,366 according to the official RAN historian, Joe Straczek.10 The 2,366 figure is probably closer to the truth, but by the time Sydney’s tour ended, there was considerable internal inconsistency between Sydney’s catapult data, aircraft maintenance books and operations room logs.

Despite efforts to correct the error, the official RAN website said for years that Sydney carried 871 Squadron aboard.11 The RAN never had an 871 Squadron, it should read 817 Squadron. That was corrected after about 30 years. The modern website also nearly correctly says that 11 aircraft were lost and 77 damaged while delivering 802 bombs and 6,359 rocket projectiles.

Perhaps consolidated reports of United Nations aircraft casualties are least liable to error but it is sometimes difficult to determine exactly what losses were recorded by what command at what phase of the war. It is easy to be bewildered by the frequently changing alphabet soup systems that identified American carrier and amphibious forces, such as TF 77, TF 90, TF 95 and TF 96; also individual carrier types, such as CV, CVA, CVL, CVS and CVE; as well as aircraft squadrons and groups such as VMA, VMFS, CAG, ATG (from 1952), and 1st MAW versus MTACS-2.

Again, simple aircraft designators can be confusing. The B-26 was the Martin Marauder in WW II, but since 1948 and in the Korean War the B-26 was the Douglas Invader, which was called the A-26 in WW II. Helicopter designators were an almost indecipherable jumble, with virtually identical aircraft having totally different designators and type names according to the nation or service that flew them and the roles they performed. It is also frequently difficult to confirm whether RAAF, RAN, RN, South African Air Force and even US Marine Corps aircraft contribute to both USAF and USN consolidated data tables.

RAN aviation rarely mentioned

With rare exceptions, e.g. George Odgers (2000)12 Australian naval aviation contributions to the Korean War receive short shrift in the British, American and even Australian historical records, e.g. Ben Evans (2000),13 Cagle and Manson (1957),14 James Field (1962),15 Robert Futrell (1983)16 and Peter Firkins (1983).17 James Field mentions Sydney just twice in parts of six lines in his 457-page official USN history of Korea. Cagle and Manson award Sydney two lines in their 555 pages.

Even relatively careful and sympathetic authors like Odgers have been led astray. Although five were destroyed, only one, not four, aircraft were lost overboard from HMAS Sydney during Typhoon Ruth.18, 19 Odgers and many others also neglect an interesting international/interservice RAN-related rescue, discussed later, of the co-pilot of an American B-29 shot down in the Battle of Namsi on 23 October 1951.20

boxer
Just as the British and Americans misused their carriers early in WW II, USN carriers were also forced into an aircraft transport role. The very capable Essex class USS Boxer loads up USAF F-51 fighters for Korea in July 1950.

typhoon-ruth

Bad weather also interfered with aircraft carriers (and most land bases). Double-lashed Sea Furies and Fireflies ride out October 1951’s Typhoon Ruth in Sydney‘s deck park.

Misinformation

Finally, in a highly regarded book, BGEN Cyril Barclay either misidentifies his aircraft or the date when he says, in a footnote, that “Royal Navy and South African Air Force planes” contributed to Close Air Support of the Commonwealth Division between 31 October and 26 November 1951.21 There was no operational RN carrier within a thousand miles of Korea at that time. Sydney supplied the aircraft.

Some claims, never made by the aircrew or operating authority concerned, are later exaggerated by others. It is quite untrue that the Sea Fury recorded “many kills” of “Soviet MiG 15 fighters” as stated by Enzo Angelucci.22 Only one MiG 15 was ever shot down by Sea Furies. Six Sea Furies led by LEUT P. Carmichael, RN, 802 Squadron, HMS Glory, shot down a lone MiG 15 on 9 August 1952 off Korea.23

All this relates to weighing the efficacy of naval aviation in Korea. Whose data should be used? This is a difficult question.

Early USN claims were reasonably accurate when they were confirmed by hard photographic evidence, e.g. Valley Forge Action Report 16-31 July 1950.24 but personal experience suggests that later American reports might well be biased, perhaps for political reasons associated with the very survival of USN naval aviation and the attempted takeover of all things air by the USAF. It is dangerous trying to compare one set of “official” biased reports against another set of “official” biased reports.

Beware also of simple sortie number comparisons, even for similar-category aircraft. For instance, the USAF might have flown far more fighter-bomber sorties to the Pusan Perimeter than the USN, USMC and RN, but effect, in terms of weight of high explosive delivered on target on time, is what counts. Many early USAF fighter-bomber Close Support sorties were inappropriate. Jet aircraft with only two small rockets or just .5 machine guns sometimes monopolised the radios, air space and time over the front lines while more capable USN and USMC aircraft were forced to wait or even to jettison their more suitable bombs.25

Again, the USAF took great pride in their “daylight precision bombing”, particularly from B-29s. However, the USN cleaned up USAF B-29 failures many times, e.g. Wonsan oil refinery 13 July 1950 and the Seoul rail bridge 19 August 1950.26, 27 Many argue that the war was brought to a conclusion not because of USAF influence but because of the USN’s shifts to heavy air strikes on strategic targets, particularly power plants, in June-October 1952.

Conservative RAN claims

On the other hand, RAN aircrew claims were deliberately conservative. For instance, RAN aircrew claimed a North Korean Army divisional headquarters building destroyed in 6 October 1951 raid, but nothing else. An American Army ground-based intelligence source, “Leopard”, credited the same raid with not only destroying that building but also many troops, stores, vehicles, outlying shacks and other booty. RAN aircrew found this very hard to believe and it was never included in any formal RAN damage claims.

bridge-repairs-korea
RAN Firefly pilots became adept at dropping bridges. Unfortunately, Chinese and North Korean engineers became equally adept at repairing or bypassing them.

Conversely, reliable reports plus good photographic data led to Sydney claiming no rail or road bridge standing in the RAN sector on completion of one patrol in late November 1951. That included the important main rail line running south from Pyongyang. Days later, a major USAF intelligence summary reported rail traffic unhindered and operating at normal capacity throughout North Korea. Again, RAN aircrew found this hard to believe, at least for the sector they controlled.

It was perhaps no coincidence that about that time that even the USAF Fifth Air Force was trying to convince the CinCFE (GENL Ridgway, who had relieved the sacked GENL MacArthur in April 1951) that it was time to change its costly Operation Strangle strategy.

Operation Strangle

What was Operation Strangle? Following a similarly-named operation in Italy during WW II, Operation Strangle (Korea) was devised by the USAF Fifth Air Force Vice Commander, BGEN E.J. Timberlake, in May 1951, to interdict enemy road and rail traffic before it could resupply the front lines. Eight north-south routes were identified, 20 to 80 miles north of the foremost troops.28 There was some overlap, but generally the Fifth Air Force (including aircraft from West Coast carriers such as HMAS Sydney) was responsible for the two western routes. TF 77 targeted the two central routes from carriers normally deployed off the East Coast, while the mainly shore-based Marines took care of the three easternmost routes.29

The RAN chose Australian Fireflies for bridge-dropping and tunnel-blocking tasks. They usually carried two 500 lb bombs and 240 rounds of 20 mm. After shifting in late October 1951 from a 30-degree dive bomb to a 10-degree anti-submarine glide bomb profile, with 37-second delay fuses, Firefly pilots became expert at dropping bridge spans and blocking tunnels. For armed reconnaissance sorties of the road, rail and waterways networks, RAN Sea Furies typically carried eight three-inch ballistic rockets with 60 lb HE heads, 600 rounds of 20 mm and two 45-gallon drop tanks. Unlike the RAAF, USAF and USN, no RAN aircraft ever carried napalm in Korea.

a-26 invaders
The USAF contributed to the interdiction tasks with, for instance, day and night sorties from about 100 A-26 Invaders (above), but during
Sydney‘s tour, the USAF’s main interest after paying off their P-51 Mustangs lay in big B-29 Superfortress raids and F-86 Sabre fighter sweeps.

The USAF’s Far East Air Force (FEAF) allocated about 100 B-26 Douglas Invader medium bombers as night intruders and their entire F-84 Thunderjet fighter-bomber fleet to Operation Strangle. Despite some modest success in its early months, aircraft losses quickly mounted as the North Korean and Chinese displayed unexpected skills at camouflage, bridge repair, logistic flexibility and, particularly, shooting down aircraft with light weapons. Between August 1951 and March 1952 FEAF lost no fewer than 243 fighter bombers and another 290 sustained major damage. This was four times the aircraft replacement rate, if those aircraft with major damage are included. In human terms, 245 airmen were killed or missing and 34 wounded.30

Sydney‘s losses included three 805 Squadron pilots, 11 aircraft and another 77 damaged while making 2366 sorties and dropping 802 bombs and 6359 three-inch rockets.

Bridges were dropped, tunnels were blocked and virtually no traffic moved by day across the middle of North Korea during Sydney’s watch. Trucks and trains moved at night, but they were difficult to see. Operation Strangle reduced rail traffic to about five percent of its pre-war capacity during its first couple of months, but together with increased night road transport and even human A-frame back-pack porters, that limited capacity was sufficient to support the static enemy front line. Despite targets being sown randomly with up to 24 hours delay-fused bombs, most simple road and rail track cuts were repaired or by-passed within hours. Big bridges over fast-flowing rivers were harder to repair but, given time, nothing seemed to daunt the brilliant enemy engineers and their seemingly endless supply of labour and repair material. The enemy also quickly worked out what the next most likely target might be and redeployed their light anti-aircraft weapons accordingly.

Originally planned to last 45 days, Operation Strangle was extended continuously as it tried to meet its objectives. By December 1951, the Fifth Air Force had concluded that Operation Strangle was not working, but in the absence of an acceptable alternative, General Ridgway insisted that it continue.31

Not all of Sydney‘s sorties were pure Operation Strangle. There were self defence CAP sorties and two or three times a month a Sea Fury pilot might load up with 500 lb or 1000 lb bombs for pre-briefed strikes, sometimes on the East Coast. At other times Sydney‘s aircraft might conduct Naval Gunfire Support shoots (TARCAP) with anything from a battleship to a frigate. Other sorties included Photo Reconnaissance, Close Support, Rescue CAP (RESCAP), RAS convoy CAP (CONCAP) and rare anti-shipping strikes.

The Fireflies carried a pair of 250 lb depth charges on daylight anti-submarine patrols while CAP Sea Furies just had loaded guns. No submarine was ever found by Sydney‘s anti-submarine patrols and no enemy aircraft was ever intercepted by Sydney’s CAP.

The carriers operated in an environment that included riding out seasonal typhoons. Sydney was hit by a particularly severe Typhoon Ruth on 14-15 October 1951 that killed 500 Japanese ashore. Contrary to Odgers and Catchpole, only one Firefly (but also a motor boat and a forklift) were lost overboard and another four aircraft tied down on the flight deck were seriously damaged. Aircraft damage was caused mainly by double-tied chocks slipping out after failure to batten them with strips of wood. The Hangar Party battened their chocks and their aircraft remained undamaged, despite some heavy stores and equipment coming adrift.

Sydney typically spent about 10 days on patrol, with half to one day around the middle being devoted to Replenishment at Sea (RAS). Five to ten days in harbour followed, before repeating the cycle. Her 36 aircraft embarked (plus four spares) flew about 400 offensive sorties a month. A maximum of 89 Sydney sorties were flown in one day and 147 in two consecutive days.

For the data pedants, the author can vouch for the approximate accuracy of most of the following Sydney laundry list of claims by her CBALO section:

Sydney‘s aircraft, in total, killed 1428 troops, destroyed seven vehicles, seven field guns, and dropped 47 rail and four road bridges. Most of these bridges had, of course, been dropped more than once. The aircraft had demolished more than 1000 buildings or troop shelters, sunk 39 junks and 66 sampans or barges and destroyed 234 ox carts. Sixteen ammunition dumps and seven fuel dumps were blown up.

All this was achieved in 2366 sorties for the cost of three lives and 11 aircraft. Five more aircraft were lost to Typhoon Ruth. Nearly a third of those sorties were self-defensive, in the form of CAP or ASW patrols, or non-offensive (e.g., return from diversion Kimpo to carrier.) Sydney‘s aircraft had been hit by flak 87 times, an average of about once every 18 (operational) sorties.32

Because so few action photographs were ever published, it may be assumed by some that Sydney‘s aircraft rarely left the ship. Unfortunately, a mentally ill senior photography sailor ditched nearly all of Sydney’s camera gun and other film records into Hong Kong Harbour by after being told to clean up his section for Captain’s Rounds in February 1952. Only private snapshots and those few photographs sent on ahead remain.

The big USN carriers maintained a much higher work rate. They flew a total of about 2827 offensive sorties a month from about 70 aircraft in each of between one and four carriers deployed on station.33 Their AD Skyraiders carried a much heavier bombload than RAN aircraft: one 1,000 lb plus two 2000 lb bombs or half a dozen variations of rockets and smaller bombs plus four 20 mm guns. The F4U Corsairs also handled a bigger and more versatile bombload than the Sea Fury, but they mounted only .5 inch machine guns. The bigger USN carriers also conducted limited night operations.

The US Marines were Close Support experts and flew their F4U Corsairs from both their own dedicated carriers and ashore. Their intervention in the Pusan Perimeter in July and August 1950, their coverage of the Inchon invasion in September and their protection of the November-December 1950 withdrawal from the Yalu must be considered textbook Close Support. They also invented the forerunner of the aerial command centre. After experiencing severe communications problems with hard-pressed troops in the mountainous terrain around the Chosin Reservoir, they quickly threw a bunch of radio sets into a Douglas DC4 transport in December 1950 and preserved command and control during the withdrawal.


RESCAP

In the event of an aircraft being shot down, the Joint Operations Centre (JOC) had the theoretical ability to stop the whole air war and divert all airborne aircraft or launch others to aid aircrew survivors. A Sea Otter rescue by Triumph‘s amphibian of a Corsair pilot on 29 July 1950 was the first and last for that aircraft type in Korea.34 USAF Dumbos (Grumman SA-16 Albatross twin-engined flying boats) were also used throughout the Korean War to supplement the Angel (usually Sikorsky HO-3S1s or S-51) helicopters and smaller warships in this role.

An RAN Sea Fury spotted a USAF B-29 co-pilot who baled out into the Yellow Sea north of the Chinnampo Estuary after the Battle of Namsi on 23 October 1951. In a classic example of international and interservice cooperation, the survivor was spotted by Sea Furies, then Sydney scrambled a Firefly with a G-dropper dinghy. A motor boat from HMAS Murchison subsequently picked up the downed pilot from the middle of a minefield as he was being swept towards the shore.

murchison
Australian-built River class frigate HMAS
Murchison was a highly capable “maid of all work” in Korea.

Sydney’s SBLT Ian MacMillan crash-landed his Firefly in the Chaeryongang Waterways area on 26 October 1951 after being hit by AA fire. MacMillan and his observer, Hank Hancox, came under heavy automatic weapons fire from soldiers in the area. The enemy were initially kept at bay by orbiting RAN Fireflies and Sea Furies, but they were recalled when RAAF Meteors, tasked by JOC, arrived. Following hand signal directions from the Air Group Commander, who happened to be flying that day, the two Sea Furies with the best fuel states elected to suffer selective “radio failure” and failed to head the recall message, which was fortunate, because the Meteors had to leave some 20 minutes before the helicopter arrived.

The Sea Furies protected the pair until Sydney’s borrowed USN helicopter, piloted by USN CPO A.K. Babbitt, performed the longest helicopter rescue transit over enemy territory in the Korean War, courtesy of a convenient 25-30 knot tail wind on the long inbound leg. The helicopter and the Sea Furies landed safely near Seoul with all fuel gauges reading less than zero. This operation was successful in part because MacMillan and Hancox used RAN-introduced fluorescent panels to communicate with the RESCAP aircraft and to direct supporting fire towards enemy machine guns and other fire.

RAN Innovations

The RAN was responsible for a number of innovations in Korea. These included red and yellow fluorescent panels for RESCAP communications, worn as scarves. These were subsequently adopted by the USAF. Unlike the USN and many RN aircrew, all RAN aircrew trained thoroughly in Close Support, Naval Gunfire Support, Artillery Spotting and Photo Reconnaissance. Sydney was also the first to apply the seemingly simple “Lavender Line”, named after Sydney’s Flight Deck Officer. This line, painted on the flight deck, contributed to Sydney being the first carrier not to taxi an aircraft overboard from the forward deck park. Because of tighter drills, Sydney‘s single catapult launch rate was frequently as good as if not better than the twin-catapult USN carriers. Its landing rate was also usually better, but that was probably more a function of operating on a shorter deck than anything else.

As Sydney was leaving in February 1952 and possibly prompted by Sydney‘s urgings, MGEN Jacob Smart, the FEAF deputy operations commander, commissioned a study that counted massive Operation Strangle losses for little gain. The study recommended change to an Air Pressure Strategy that included some interdiction, but prioritised destruction that would cause “permanent loss to the enemy and…drain his strength”.35

USN major strikes, June-October 1952

Following the defection of North Korean BGEN Lee Il on 21 February 1952 and his debriefing by USN officers, it was learned that the enemy was delighted with the Washington policy of exempting the big Yalu River hydroelectric generating stations from attack. They supplied power to China as well as North Korea.36 Initiated by USN TF 77 staff officers, approval was eventually obtained to take out these targets with USN dive bombers. The naval aircraft had a better chance than B-29s of hitting the target without overflying China or, worse, accidentally bombing China. Between 23 and 27 June 1952, coordinated attacks by USN and USAF aircraft destroyed 11 of the 13 generating plants in North Korea, eliminating 90 per cent of their electrical power.37

mig-15
The MiG 15’s superior performance was a nasty surprise to all USAF-friendly forces in Korea.

The first target was the big Suiho plant, the fourth largest in the world. Antung, a big Chinese air complex housing 250 MiG-15s, was only 35 miles away, hence the large fighter cover for the strike aircraft. Also defending the target were 28 heavy AA guns and 43 lighter automatic weapons, many radar-controlled. On 23 June 1952, a three-carrier strike force of 35 AD Skyraider dive bombers, each loaded with one 1,000 lb and two 2,000 lb bombs, were protected by 84 USAF F-86 Sabres and 24 USN F-9F Panthers. The USAF followed up with coordinated attacks from 124 F-84 Thunderjets, but their tiny bombload made it doubtful that they contributed much. No aircraft was lost, although one diverted to Seoul to land wheels up after receiving flak damage. The Suiho bombing alone resulted in a 23 per cent loss of electrical power in northeast China and caused serious Chinese production shortfalls. The four-day campaign reduced power by 90 per cent in North Korea, causing a two-week blackout and serious disruptions to industry and agriculture.

However, Chinese and Soviet technicians rushed to repair the damage from these raids with small generating plants. Over time, these countermeasures, together with power-saving economies, successfully insulated the front lines from the effects of the raids.38

The policy of hitting power stations and other major military and industrial targets deep inside North Korea continued for six months or so but the USN had to jockey with the USAF for operational control of combined or single-service raids on the remaining few prime targets. These included massed USN/USAF raids on military targets in Pyongyang, the Sindok lead and zinc mine and the Aoji synthetic oil refinery. The latter target was up near the Russian border, way beyond the range of USAF dive bombers and could not be bombed by B-29s without them overflying Russia.

The 8 October 1952 raid on the rail centre of Kowan, a target with a bad flak reputation, was the last time USAF B-29 bombers were used in conjunction with USN aircraft in Korea. Ten B-29s suppressed flak very successfully with 500 lb VT-fused bombs, just before 89 USN aircraft bombed and rocketed the target. No aircraft was lost.
Subsequently, USAF policy was changed to permit B-29s to bomb only by night. It was perhaps no coincidence that this policy change was correlated not so much with MiG day fighter activity, the official reason, but to avoid the USAF being seen in a support role, like flak suppression, for USN strategic bombing, long regarded as the USAF’s sole prerogative.

Cherokee strikes

In the final six months, starting slowly from about mid-October 1952, Seventh Fleet naval aircraft primarily supported front line troops with another naval initiative, Cherokee strikes. These were concentrated attacks on pre-briefed targets, generally 20 to 40 miles from the front line but they had a chequered history. If they were regular Close Support, they should be closely controlled by the Fifth Air Force, said the USAF. The USN argued that these strikes were pre-briefed, they were heavy air-power missions outside the bomb line, they did not require mosquito direction and they might have flak suppression aircraft in company: therefore they were “strike”. After some negotiation between the respective commanders, it was agreed that the raids would be coordinated by the Fifth Air Force, the strike leader would check in and out with the ground Tactical Air Control party of the area and mosquito aircraft would mark the targets, just like Close Support.

In return, the Fifth Air Force was held solely responsible for any friendly fire incident. Data at the time suggested chiefly USAF and a few USMC, but no confirmed USN aircraft, had dropped ordnance on own troops. In February 1953 a USAF threat was made to relieve any air group commander whose aircraft was involved and to court-martial pilots responsible for inadvertent friendly fire. This dampened enthusiasm for a while, but by March 1953, as the weather improved and with ground radar assisting, Cherokee strikes regained momentum and continued until the end of the war in July.39


Naval Aviation outcome

Some claim that naval aviation saved South Korea from communist domination. Some others say it was the USAF. Yet others, particularly American naval aviators looking at a broader picture, claim that the converse might well have been true true: Korea saved naval aviation. Before anyone tries to weigh the contributions of naval aviation and other arms in saving South Korea, it should be noted that although the June-October 1952 USN air strikes were correlated with changing attitudes in the North Korean negotiators at the Truce Talks, perhaps the most important single factor that contributed to the signing of the armistice on 27 July 1953 was the death of Stalin on 5 March 1953.

Certainly, naval aviation was highly significant and maybe even decisive in a number of battles, including those around Pusan, Inchon and Chosin. Along with the USAF, however, naval aviation achieved little in expensive sideshows like Operation Strangle. Perhaps, above all, naval aviation, and particularly US Marine aviation, showed the USAF how to conduct Army Support, a skill the USAF initially ignored chiefly because it did not fit their overarching strategy and it was difficult. Naval aviation also spotlighted procedural and material weaknesses in their Joint Operations Center command system.

Did Korea save naval aviation? The failure of his USAF-dominated Korean strategy, together with other political machinations, led to Truman sacking Defense Secretary Johnson in September 1950. This alone was good news for the USN and naval aviation in general. This prefaced the approval of the first new carrier construction since Johnson cancelled the USS United States. The USS Forrestal‘s keel was laid on 14 July 1952.

However, it must be acknowledged that Korea was seen by many in 1950-53 to be a sideshow fought by the Reserves, not a real war. The “real war” was always Euro-centric and it kept America’s newest and biggest three Midway class carriers and the big British fleet carriers in the Atlantic or Mediterranean, far from Korea. Therefore it might be difficult to derive any important generalisation other than to note that Korea was the first of many little wars over the past half century. All were resolved with non-nuclear weapons. None validated the Douhet/Trenchard/Mitchell hard line position that victory could be achieved by air power alone. All American and British interventions employed aircraft carriers and sometimes Air Forces, but all depended on close cooperation with ground troops.

If causality is demanded, let us first remember that it was the British who invented the angled deck, the deck landing mirror and the steam catapult. These three very important components enabled jet aircraft and big bombload-carrying aircraft to operate safely from carriers. The British also invented the Harrier jump jet and ski ramp for medium and small carriers. The Royal Navy might argue persuasively that if naval aviation needed saving, it was these British inventions, rather than the Korean War, that did the job.

Certainly, naval aviation contributed significantly to the defence of South Korea and naval aviation has continued to be an essential element in America’s strategy in every war since then. Without naval aviation, especially the USMC intervention, the Pusan Perimeter might well have been lost and we might only conjecture whether there would have been enough political will to stage an Inchon-like invasion against a country not actively engaged in war. Close Support, long regarded as an irrelevant irritant by the USAF, resumed its rightful place, just as the USN, and especially the USMC, so ably demonstrated in Korea.

Contrary to USAF assertions back in 1948 that aircraft carriers would be quickly sunk in future conflicts, it has been not the carrier but the in-country airfield, such as Da Nang, that has proven vulnerable to enemy action. The carrier has also demonstrated a flexibility to attack targets virtually anywhere in the world without having to depend on sometimes convoluted overflight negotiations. Finally, the carrier also has the versatility to be used in many important roles other than war, ranging from disaster relief to space exploration.

References:

Angelucci, Enzo. Rand-McNally encyclopedia of military aircraft 1914-1980. Rand McNally: Chicago. 1981.
Appleman, Roy E. United States Army in the Korean War: South to the Naktong, North to the Yalu. Military History Department of the Army: Washington D.C. 1961.
Barclay Cyril N. The First Commonwealth Division: The story of the British Commonwealth forces in Korea. Gale and Polden: Aldershot. 1954.
Barlow, Jeffrey G. Revolt of the Admirals: The fight for naval aviation, 1945-1950. Naval Historical Center, Department of the Navy: Washington, D.C. 1994.
Bowdish, Randall G. Between Scylla and Charybdis: Discussion and dissent in the Navy. US Naval Institute Proceedings, 130/5 pp. 42-45. 2004.
Cagle, Malcolm. W. and Frank A. Manson. The Sea War in Korea. US Naval Institute Press: Annapolis. 1957. (Also on the CD: The sea services in the Korean War, US Naval Institute.)
Caraley, Demetrios. The politics of military unification: A study of conflict and the policy process. Columbia University Press: New York. 1966.
Catchpole, Brian. The Korean War, 1950-53. Robinson: London. 2000.
Denny, Norman.R. The Revolt of the Generals is coming. US Naval Institute Proceedings, 130/5. p. 78. 2004.
Douhet, Guilio. The command of the air. Tr D. Ferrari. Office of Air Force History: Washington, D.C. 1983.
Evans, Ben. Out in the cold: Australia’s involvement in the Korean War 1950-1953. Australian War Memorial and Department of Veterans Affairs: Canberra. 2000.
Field, James A. Jr. History of United States naval operations: Korea. Department of the Navy, Naval Historical Center: Washington, D.C. 1962. (Also http://www.history.navy.mil/books/field/ intro.htm and on the CD: The Sea Services in the Korean War, US Naval Institute.)
Firkins, Peter. Of nautilus and eagles: The history of the Royal Australian Navy. Hutchinson: Melbourne. 1983.
Flying Stations. Australian Naval Aviation Museum: Allen and Unwin. 1998.
Friedman, Norman. U.S. Aircraft Carriers. US Naval Institute Press: Annapolis. 1983.
Futrell, Robert F. The United States Air Force in Korea, 1950-1953, rev. ed. Office of Air Force History: Washington DC. 1983.
Futrell, Robert F. Tactical Employment of Strategic Air Power in Korea. Aerospace Power Journal – Winter 1988.
Griffith, Thomas E. Strategic Attack of National Electrical Systems. Air University Press: Maxwell Air Force Base, Alabama. 1944.
Grove, Eric. Policy in the Korean War era, in J.V.P. Goldrick and P.D. Jones (eds) Reflections on the Royal Australian Navy. Kangaroo Press: Kenthurst. 1991.
Hammond, P.Y. Super carriers and B-36 bombers: Appropriations, strategy and politics, in H. Stein ed., American civil-military decision. University of Alabama Press: Birmingham. 1963.
Hermes, Walter G. US Army in the Korean War: Truce tent and fighting front. Chief of Military History US Army: Washington D.C. 1966.
Jackson, Robert. The encyclopedia of military aircraft. Parragon: Bath. 2002.
Kirtland, Michael A. Planning air operations: Learning from Operation Strangle in the Korean War. Airpower Journal Vol 6/2, 37-42, 1992.
Lane, Fred. Revolt of the Admirals: B-36 versus the USS United States. Naval Officers Club Newsletter, 58 September 2004, p 27-29
Lane, Fred T. and Gerry Lane. Sea Furies in Korea, in J.V.P. Goldrick and P.D. Jones (eds) Reflections on the Royal Australian Navy. Kangaroo Press: Kenthurst. 1991.
Lewis, A.L. Revolt of the Admirals. A Research Report submitted in partial fulfilment of the graduation requirements. Maxwell Air Force Base: Alabama, April 1998. p16. 1998. (Also at: http://www.au.af.mil/au/awc/awcgate/acsc/98-166.pdf.)
McFarland, K.D. “The 1949 Revolt of the Admirals,” Parameters 11/2 (June 1981), p 56. 1981.
Mets, David R. Airpower and the sea services: Revolt of the Admirals. Aerospace Power Journal – Summer 1999.
Montross, Lynn et al. History of U.S. Marine operations in Korea, 1950-1953, 5 vols. Washington: Historical Branch, G-3, Headquarters, Marine Corps. 1954-1972.
Mossman, Billy C. The effectiveness of air interdiction during the Korean War. OCMH study prepared by the Histories Division, March 1966, Office of the Chief of Military History, Department of the Army. 1966. (Also at http://www.army.mil/cmh-pg/documents/237ADH.htm.)
Ogders, George. Remembering Korea: Australians in the war of 1950-53. Lansdown: Sydney. 2000.
Schnabel, James F. United States Army in the Korean War: Policy and direction: The first year. Washington: Office of the Chief of Military History. 1972.
Time magazine: Revolt of the Admirals, Time 54/16 (17 October 1949): 23.

Websites:

Bevilacqua, Allan C. (2004) Marine Corps Aviation in the Korean War, the First Year. At: mca-marines. org/Leather neck/Mayaviation.htm.
britains-smallwars. com/carriers/Glory.html.
britains-smallwars. com/carriers/Triumph.html.
britains-smallwars. com/korea/kwaircraft.html.
Field, James A. Jr. History of United States naval operations: Korea. At: history.navy.mil/books/field/ intro.htm.
history.navy.mil.htm. (About 220 declassified USN carrier and air group action reports in .pdf format are also on CD.)
Lewis, A.L. Revolt of the Admirals. http://www.au.af.mil/au/awc/awcgate/acsc/98-166.pdf.)
Mossman, Billy C. The effectiveness of air interdiction during the Korean War. At: www.army. mil/cmh-pg/documents/237ADH.htm.
Straczek, J.H. (Senior RAN Historical Officer.) At: navy.gov.au/spc/history/general/korea.htm.
USN carrier and air group action reports. http://www.history.navy.mil.htm. (About 220 declassified reports in .pdf format, also available on CD.)

Endnotes:

1. Mossman, Billy C. Mossman is the official US Army historian for Korea.
2. Douhet, Guilio. Douhet is recognized as the first to advance the theory that air power alone could win a war.
3. Barlow, Jeffrey G.; Lane, Fred 2004; Hammond, P.Y. p 493.
4. Cagle, Malcolm. W. and Frank A. Manson. pp 37-38. Cagle and Manson were experienced USN officers, with WW II combat experience. They served aboard Valley Forge in Korea chiefly to coordinate the dissemination of USN action information.
5. http://www.britains-smallwars. com/carriers/Triumph.html. This little website carries reliable-looking data about RN carriers in Korea.
6. Field, James A. Jr. p 387.
7. Cagle and Manson p 53.
8. Lane, Fred and Gerry Lane, 1991.
9. Grove, Eric.
10. navy.gov.au/spc/history/general/korea.htm. This official RAN website carries limited data, compared with its USN counterpart.
11. ibid.
12. Ogders, George. Odgers was a journalist and FltLt with RAAF 77 Squadron.
13. Evans, Ben. This is a Department of Veterans Affairs booklet about the Korean War.
14. Cagle and Manson op. cit. p 414.
15. Field, James op. cit.
16. Futrell, Robert F. Futrell wrote an encyclopaedic treatise, published in 1983, extolling USAF strategy and USAF operations in Korea.
17. Firkins, Peter.
18. Odgers op. cit. p 101;
19. Catchpole, Brian. p 203.
20. Odgers op. cit. p 115.
21. Barclay Cyril N. p 117.
22. Angelucci, Enzo. p 425.
23. britains-smallwars.com/carriers/Glory.html.
24. Valley Forge Action Report 16-31 July 1950. Korea action reports for carriers and air groups: history.navy.mil .htm; CV45-J50.pdf.
25. Cagle and Manson op. cit. p 45;
26. Futrell 1988 op. cit.
27. Cagle and Manson op. cit. p 49-74. Valley Forge Action report op. cit. Philippine Sea Action Report 22 December 1950, Korea action reports for carriers and air groups: history.navy. mil.htm; CV47-dec50.pdf.
28. Kirtland.
29. Cagle and Manson op. cit. p 241.
30. Catchpole op. cit., Kirtland op. cit.
31. Kirtland op. cit.
32. Flying Stations. The Australian Naval Aviation Museum: Allen and Unwin. 1998. p 100.
33. Cagle and Manson op. cit. p 523.
34. http://www.britains-smallwars.com/carriers/Triumph.html.
35. Griffith, Thomas E. Strategic Attack of National Electrical Systems. Air University Press: Maxwell Air Force Base, Alabama. 1944.
36. Cagle and Manson op. cit. p 442.
37. Griffith op. cit.
38. Cagle and Manson op. cit. p 441-454.
39. Cagle and Manson op. cit. p 460-469.

 


Armoured decks

The armoured flight deck controversy

The British armoured flight decks and enclosed hangars, as seen in their Illustrious class aircraft carriers, were vastly superior to the American Essex class that had open hangars, and an armoured main deck that supported an elevated flight deck, according to generations of RN and RAN fixed-wing pilots. There were pros and cons. Illustrious- and Essex-class total armour was comparable in terms of total weight, and the ships were of a similar size, but the British armoured flight deck design offered better protection than the American, so the argument went.

Examples

After all, look at the way Illustrious survived numerous bombs in January 1941 in the Mediterranean and Formidable survived two 500 kg bombs in the Med on 26 May 1941 and even a couple of kamikazes off Okinawa in early May 1945, all with minimal casualties. On the other hand, Essex class carriers, such as Franklin (CV-13) reported 989 casualties and severe damage on 19 March 1945 from two 250 kg bombs while Bunker Hill (CV-17) had 650 casualties and equally severe damage from two kamikaze hits on 11 May 1945.

Even modern internet comment is replete with the mantra that while British carriers “shrugged off kamikazes,” American carriers “had to retire for repairs.” Closer examination suggests this might not be quite so.

3carriers
The WW II experiences of the classes following USS Essex (top, hangar deck armour) HMS Illustrious (flight deck armour)and HIJMS Shokaku (hangar deck armour) provide interesting comparisons.

Stuart Eadon reiterated the mantra as late as 1991, saying that in contrast to the “vulnerable” wooden decks of American aircraft carriers, the armoured decks of the British Fleet carriers protected them to the extent that they frequently returned to flight operations within hours of being hit. He cites one oft-repeated comment by an observer watching a kamikaze attacker that “literally bounced along the deck and then slid off into the sea” (Eadon p. 266). Even more recently, in 2004, another source boasts, “The immense strength of the ships stood them in good stead … In the Pacific War most of the (Illustrious class) ships withstood one or even two kamikaze strikes without having to leave station” (Bishop and Chant p. 46).

Justification

Anthony Preston succinctly explains why the Illustrious class carriers were built with an armoured flight deck and enclosed hangar. The British specifications aimed to:

“Provide as much protection for the aircraft as possible. This meant … building an armoured box with 4.5-inch (114 mm) sides and a 3-inch (76.2 mm) roof,” (Preston, p.60).

The designers expected the air group to land on and be struck down in the face of air attack. Meanwhile the ship’s AA armament “welcomed the opportunity” to shoot down the attackers, he adds. This never happened.

Interestingly, the Japanese Shokaku class was also a purpose-built large aircraft carrier constructed around the same time. It had an American-style “open” hangar, with a 100 mm armoured hangar deck over the machinery spaces, much like the Essex class.

Multiple variables

Other authors, such as Stuart Slade and Richard Worth, point to a host of critically important variables that must be taken into account before coming to a reasoned conclusion. They make a convincing assertion that the different damage reported by British and American carriers can be explained chiefly by the amount of refuelled and rearmed aircraft on deck when the bomb or kamikaze hit. Put simply: the bigger and more volatile the deck park, British, American or Japanese, the heavier the damage, regardless of whether the flight deck was armoured or not. One corollary found proven was that if a bomb penetrated the British flight deck armour, the damage was likely to be long-lasting and severe. Another was that good damage control procedures were vitally important. A third potentially confounding factor, frequently overlooked in comment, is that there were only four British fleet carriers exposed to kamikazes and they were rarely subjected to the heavy sustained attacks experienced by American carriers. Except to prove an exception, even the dodgiest statistician could never rely on such a small number as four.

Illustrious

Essex Shokaku
Launched 5.4.1940 31.7.1942 12.12.1937
Displaced 28,661 tons 27,100 tons 26,675 tons
Dimensions 227 x 29 x 8.5 266 x 28.3 x 8.6 257.5 X 26 x 8.8
Speed 30.5 knots 33 knots 34.2 knots
Crew 1200 2600 1660
Propulsion 3 shafts, 110,000shp 4 shafts, 150,000shp 4 shafts, 160,000shp
Aircraft 45-65 90-100 84
A comparison of the Illustrious, Essex and Shokaku classes (dimensions in metres) in the table above shows that they were very similar in many respects as far as gross tonnage and dimensions are concerned. They all carried defensive armour to resist bombs, shells and torpedoes penetrating the vital machinery and magazine spaces. However, Slade makes a salient point, “The question is not so much whether armour is useful … but where the designer puts it,” he says. The British Illustrious class had the flight deck as the strength deck with three-inch amour, theoretically sufficient to resist 500-lb (226 kg) bombs and six-inch (15.2 cm) shells. Instead, the American Essex and the Japanese Shokaku classes both had 3.5 inches of armour on the hangar deck below a thinner flight deck that was nevertheless strong enough to take the punishment of five- to ten-ton aircraft landing on and taxying about.
Shokaku
Shokaku had a badly deformed flight deck after the Battle of the Coral Sea, but her armoured hangar deck allowed her to live to fight another day.

Perhaps there are two important and sometimes over-riding design considerations. The first is that all ship design is essentially a compromise between highly competing variables. The second is that unless the self-damage danger of aviation fuel and ordnance is not scrupulously controlled, then aircraft carriers are extremely vulnerable to secondary fires, regardless of where the armour might be sited.


More armour, more aircraft or more speed?

The Americans favoured large air groups and instead of striking them down into the protection of an armoured box, they depended on their aircraft to keep the enemy away. They also deliberately maximised their aircraft complement to the extent that they ran a permanent aircraft deck park. There was no other place to put them, even in their larger hangars. This was acceptable in most of the Pacific, but it was considered risky to delicate aircraft in the stormy North Atlantic and in action, according to RAF-advised RN 1930s-era thinking.

The British armoured box hangar design certainly protected aircraft from the elements, but it drastically reduced the number of aircraft, by maybe 40 per cent, that could be carried in hulls of similar displacement. This might not matter when there are plenty of aircraft carriers, but as the Pacific War quickly demonstrated there is almost invariably a scarcity of these vessels in the early stages.

Lift placement

The armoured box presented design difficulties in that it limited the size and placement of aircraft lifts. The centreline lifts demanded by the armoured box prevented the transfer of aircraft between the flight deck and hangar during flying operations. The open hangar concept and deck edge lift forward of the barriers permitted limited aircraft movements, even as aircraft were being flown on and off.

Illustrious
HMS Illustrious was limited to centreline lifts chiefly because of her “armoured box” construction.
Fire in an aircraft carrier, with all its volatile aircraft fuel and ordnance, is at the forefront of every carrier captain’s mind. The British were especially sensitive to this. As Anthony Preston notes, “As part of their fire precautions the British developed the concept of the ‘closed’ hangar, in which the ventilation of the hangar was sealed off from the rest of the ship” (Preston p. 44). Hangar access, other than by aircraft lift, was via air locks.

Aviation gasoline

Therefore the explosive aviation gasoline (AVGAS) fumes, including those vented by stowed aircraft in rough weather and during evasive manoeuvres, could be trapped inside a closed hangar and blown clear of the ship in a controlled manner. Open hangars risked sucking some of these fumes back into living spaces from random pathways. On the other hand, poor damage control might jeopardise the whole ship. For instance, the flight deck-armoured Japanese Taiho, after being hit by a submarine-fired torpedo at 0810 19 June 1944 looked relatively intact, she could make 26 knots and operate aircraft, but her forward lift was out of action and aviation fuel was sloshing about in the lift well for some hours. The vapour initially was restricted to the hangar but instead of venting this dangerous fuel/air mixture overboard in a controlled manner, an inexperienced damage control team vented it back into the ship. This set up a series of such large AVGAS-fed explosions, some more than six hours later, that the flight deck split longitudinally, virtually in two, and the hangar sides blew out before the entire ship was lost.

Taiho
HIJMS Taiho had an armoured flight deck, like Illustrious, but this had little to do with the manner of her sinking. She was destroyed by internal AVGAS explosions some six hours after a single torpedo hit.

Small fires in an armoured box hangar should be more easily controlled. Certainly, with both lifts up, fire curtains down and sprinklers operating, a single aircraft fire should be extinguished, promptly, within a couple of minutes. However, if reactions are slow or something goes awry, as it frequently does, the resulting fire or contained explosion could easily warp the armoured box to the detriment of the entire ship’s structure. Once this rigid structure is warped, repair becomes difficult, if not impossible.

After bombs distorted her hull on 10 January 1941, Illustrious had her centre propeller shaft cut away, with a concomitant speed reduction to 22 knots. Essex class carriers in similar situations tend to shrug off such potentially severe damage.

For instance, Oriskany’s extremely hot magnesium-fed magazine fire on the hangar deck in 1966 killed 44 people, but did not damage her main machinery or hull structure and she was back in the fleet five months later. Oriskany and other American aircraft carriers that experienced devastating ordnance-fed fires in recent times, such as USS Forrestal (29 July 1967) and USS Enterprise (14 January 1969), did not experience an AVGAS explosion, mainly because their jet aircraft no longer used high-volatile petrol as fuel, but a safer kerosene-based mixture with a much higher flash-point. Burning kerosene nevertheless spreads a very hot fire, but at normal atmospheric pressures it does not explode. None of the three carriers concerned reported structural defects, like Illustrious and Victorious, after similar fires.

Oriskanay
USS Oriskany (CV-34) burning fiercely, 26 October 1966, from a near-full magnesium flare stowage on the hangar deck.
Many better-armoured battleships were destroyed, by torpedo, bomb and shell, but no Essex or Illustrious class aircraft carrier was sunk in WW II. The Essex class USS Franklin was perhaps the most severely damaged. Three kamikaze hits, a bomb hit and a near miss between 9 and 30 October 1944 sent her back to the USA for a ten-week repair schedule. Another two 250 kg bombs plus internal fires and ordnance explosions on 19 March 1945 earned her a six-month sojourn in the Brooklyn Naval Yard. Importantly, she sailed home and was repairable after such severe damage.
Franklin
USS Franklin (CV-13), 19 March 1945, only 50 miles from the Japanese mainland , dead in the water, on fire and with a 15 degree list. She had taken two 250 kg bomb hits through the flight deck, one igniting ammunition stowed aft. Under tow, the crew quelled the fires and the ship eventually made her way home to the USA under her own power for repairs. The war ended before her repairs were completed.

Good aircraft fuel and ordnance handling practices mitigate aircraft carrier volatility. A number of big American and Japanese aircraft carriers were lost or heavily damaged by AVGAS explosions or fires following WW II action (e.g., American: Lexington CV-2 8 May 1942,Wasp CV-7 15 September 1942, Franklin CV-13 19 March 1945, Bunker Hill CV-17 11 May1945; Japanese: Soryu and Akagi 4 June 1942, Shokaku and Taiho 19 June1944.) Big British carriers also reported AVGAS-related fires (e.g. Formidable 12 August 1942 and 3 February 1951) but the British (and the Australians) tend to be much more conservative with their AVGAS and ordnance handling.

The RN insist that no aircraft be refuelled or rearmed during launch/land procedures. The entire AVGAS supply was routinely drained and even inert gas pumped into the lines when attack was expected. The Americans and Japanese, with their larger aircraft complement and complex deck parks had a greater demand for faster turn-around times. They frequently re-armed and refuelled aircraft during flying operations.

USS Forrestal
USS Forrestal CV-59 burning during the 26 July 1967 fire. Nine 450 kg bombs exploded on the 1.5 inch (38 mm) thick flight deck, killing 134 crewmembers and injuring 161. After seven months in a dockyard for repairs, Forrestal returned to the fleet and served out more than her originally planned life until decommissioned in 1993.

RN and RAN carriers routinely plugged rockets into the aircraft’s firing circuit on the catapult, with the aircraft pointing in a safe direction. USS Forrestal, to “save time” before its 29 July 1967 fire, plugged in rockets and removed quick-release circuit-breaker safety clips even before aircraft had completed their engine start­up procedures. It was suspected that a stray voltage surge, as an F-4 switched from ground to aircraft electrical supply, fired the Zuni rocket that initiated so much destruction.

USS Enterprise

USS Enterpise fire, 14 January 1968.

USS Enterprise CVN-65, the world’s first nuclear-powered aircraft carrier, had a similar fire, 14 January 1969. This time a Zuni rocket cooked off after heating by a huffer starter exhaust. It left 28 dead and 343 injured. There were 18 explosions, some of multiple simultaneous 227 kg bombs, leaving five holes up to 20 feet (six metres) in diameter in the flight deck. Most of the damage was repaired in eight weeks at Pearl Harbor.Enterprise is expected to serve out 50 years in harness, more than her original planned life.

British warship designer and well-known author David K. Brown asserts that the British armoured deck design never lived up to its reputation and concludes that “More fighters would have been better protection than armour” (Brown p. 56). He explains how the RN originally envisaged battles in comparatively restricted seas within the range of some land-based aircraft, such as the Mediterranean. This “narrow seas” concept was proven to be far removed from reality. Similarly, the idea that a 226 kg bomb would be the biggest that British carriers would need to resist was quickly refuted in practice. When a 500 kg bomb penetrated an Illustrious class carrier’s armoured deck (e.g. Illustrious 10 January 1941; Formidable 12 August 1942) it caused severe and frequently lasting damage.

 


Ship’s girder

The main reason for this was the structural consideration that the Illustrious class had the hangar as an integral part of the ship’s girder, while the Essex class had their hangar mounted outside this important structural design element. Ship designers see a large hangar space as essentially an unwelcome large open void. If the hangar is sited within the ship’s rigid girder and exposed to thermal or explosive shock, it might force this girder to deform.

Short of virtually rebuilding the entire ship, once deformed it stays that way. The Illustri­ous class carrier HMS Victorious, for instance, took nearly eight years from 1950 to re­build her from her hangar deck level up. This means that any damage wrought by fires or explosions on the seemingly more vulnerable Essex flight deck or armoured hangar deck might well be more extensive at first glance, but such damage need not easily compromise the ship’s rigid girder and therefore should be more easily repaired.

Damage control

Damage control in an aircraft carrier is a highly complex subject. There is a grave danger that an aircraft carrier will not be sunk by the simple explosion of a bomb, torpedo or shell, but by the fire  generated from that hit. Fully-fuelled and fully-armed aircraft on the flight deck or hangar deck frequently have the potential to cause more damage than a single well-directed bomb, torpedo or kamikaze, as the 1967 Forrestal (CV-59) and the 1969 Enterprise (CVN-65) fires demonstrated. The Forrestal fire claimed nearly 300 casualties. Nine 1000-pound (454 kg) bombs detonated, tearing holes in the flight deck through which flaming jet fuel poured into the spaces below. The fire was eventually extinguished but the ship had to return to Norfolk for extensive repairs that lasted ten months. Enterprise required 12 weeks in Pearl Harbor, but Forrestal served out her time and Enterprise is still serving; unlike the Illustrious class ships that tended to require longer repair periods or even pay off after lesser abuse.

The 1930s-era Lexington (CV-2) and Saratoga (CV-3) had the flight deck as the strength deck, but 1930s Japanese designs such as the Shokaku and even the German 23,000-­ton Graf Zeppelin all had the hangar deck carrying the main armour. Ark Royal and Eagle were the first two British carriers built after the Illustrious/Implacable classes and their 1942 designers opted for an armour distribution and hangar configuration more towards American lines. The heavily armoured flight deck and enclosed box hangar sacrifices were found to be just not worth the effort. By then it was also clear that no flight deck could ever be built that would protect the ship from the larger bombs becoming available, yet still keep topweight within manageable proportions.

The Forrestals and later big American carriers all have a solid flight deck, but this is not so much armour, as a necessary platform for the very heavy aircraft (30,000+ kg) they operate. Protective flight deck armour capability is a secondary consideration.

There are two design features that help these big ships. Firstly, they are incredibly large, so the void represented by the open hangar is proportionately smaller. Secondly, they are built with considerable redundancy to be remarkably tough: e.g. Oriskanay (CV-34) fire 26 Oc­tober 1966; Forrestal (CV-59) fire 29 July 1967; Enterprise (CVN-59) fire 14 January 1969.

Carrier design trend

Successful carrier design has been led chiefly by the British and Americans. The British contributed major improvements. Since WW II these include the angled deck, mirror, steam catapult, V/STOL and ski jump.

The Americans were right to insist on their faster 30+ knot carriers. The Americans also introduced air-to-air refuelling, Airborne Early Warning, auto­throttle and then auto-land systems. It must be concluded, however, that the British armoured deck and enclosed hangar concept, as built into the Illustrious class, never demonstrated the protection its designers sought. Additionally, the sacrifice in aircraft numbers and the difficulty of repair once the ship’s girder is distorted strongly militate against it ever being considered again.

All post-WW II trends, including the four British Malta class cancelled in late 1945 and the more recent American “super” carriers, tend to follow the Essex armoured hangar deck and open hangar principle over the Illustrious “armoured box” design.

References:

Bishop, C. and C. Chant. Aircraft carriers: The world’s greatest naval vessels and their aircraft. Silverdale Books: Wigston, 2004.
Brown, D.K. Nelson to Vanguard: Warship design 1923-1945. Naval Institute Press: Annapolis, 2006.
Eadon, S. (Ed.) Kamikaze: The story of the British Pacific Fleet. Square One publications: Worcester, 1991.
Foster, W. E. Fire on the hangar deck. Naval Institute Press: Annapolis, 2001.
Freeman, G.A. Sailors to the end: The deadly fire in the USS Forrestal and the heroes who fought it. Harper Collins: New York, 2004.
Friedman, N. British carrier aviation: The evolution of the ships and their aircraft. Naval Institute Press: Annapolis, 1988.
Hoyt, E.T. The kamikazes. Harper Collins: New York, 1985.
Preston, A. Aircraft carriers. Bison Books Corp.: Greenwich, 1979.

Websites:

Slade, S. Were armoured flight decks on British carriers worthwhile? (2002)
http://navweaps.com/index tech/tech030.htm.
Worth, R. The armoured box: The war’s verdict (2002) http:// navweaps.com/index_ tech/tech030.htm.


Carrier Fire: Oriskanay (Book)

Oriskanay fire

Fire in the Hangar

Book review by Fred Lane

Foster, W.F. (2001) Fire on the hangar deck: Ordeal of the Oriskany. Naval Institute Press: Annapolis. 175 pages including index, photographs and schematic drawings.US$26.95.

“Fire, fire, fire, fire in the hangar,” must be one of the most feared tannoy broadcasts ever in any ship that carries aircraft. It generates more anxiety in experienced aviators than the oft-called “Crash on deck”. With tonnes of volatile aircraft fuel, high explosives and aircraft oxygen nearby, it is almost axiomatic that more lives are about to be lost. The ship herself is in mortal danger. Only disciplined, fast and expert reactions can save a ship with a serious fire in the hangar. In the USS Oriskany fire, starting about 0720, 26 October 1966, many officers and sailors not only did the job they were trained to do, but also displayed superb individual and team initiative and bravery. This book by Wynn Foster should be required reading for every person in any ship operating an aircraft.

Wynn (Captain Hook) Foster, made two combat deployments in Vietnam aboard Oriskany, but was shot down in an A-4E Skyhawk and lost his right arm on 26 July, three months before the fire. His gripping account reflects his intimate knowledge of the ship, her systems and her crew. He also captures the drama of stark terror and confusion and the heroic responses to those challenges by his shipmates.

Essex class

Oriskany was an Essex class fleet carrier, modified to 27C standard, and nearly twice the size of the RAN Light Fleet carriers. She first saw action in Korea and in 1964, at the start of the Vietnam War, she was the youngest of the still-active WWII-era Essex class carriers.

In her 1966 Air Wing 16, she carried two squadrons of A-4 Skyhawks, one squadron of A-1 Skyraiders and two of F-8 Crusader aircraft. She also mounted detachments of E-1B Tracer AEW aircraft, A-3 Skywarrior tankers and UH-2 Seasprite SAR helicopters. She was on the second night shift, a midnight-to-noon operating cycle employing a 90-minute deck turnaround. At the time of the fire she was working up to launch her breakfast time 0730 strike.

Like the fires in Forrestal (134 dead, nine months later), and Enterprise (61 dead, 14 January 1969), the initial fire was probably caused by a breakdown in safety procedures, training and supervision. Bad weather cancelled Oriskany‘s scheduled night operations, so dozens of Mk 24 magnesium parachute flares and other ordnance were being unloaded from the night strike aircraft. A pair of young ordnance handlers were stowing the 25-pound flares into a ready use flare locker on the hangar deck when they inadvertently activated one. The seaman reflexively tossed the primed and hissing flare into the locker and slammed the door shut. Magnesium flares require no oxygen supply to burn, so the single flare ignited some 650 others in the ready use stowage locker.

Shared ventilation

The locker shared ventilation ducts with nearby officers’ cabins, so the resulting fireballs and explosions not only created havoc in the hangar, but also killed many officers in their cabin area. A total of 44 men died. At one stage the forward part of the ship, including the bridge, lost all electrical power (with 28 degrees of rudder on, of course).

“No great genius was required to deduce that under the pressures of round-the-clock combat operations, expedient departure from ordnance safety and handling was likely to occur,” says Foster (p 154).

Oriskanay fire
USS Oriskany on fire, 26 October 1966, off Vietnam.

The prescribed flare stowage in this essentially WWII carrier was unsuitable for the tempo demanded by Vietnam War operations. A ship-level decision to stow flares in a designated rocket-motor stowage was not unusual. However, this failed to take into sufficient account the increased danger of handling the more volatile flares and the shared ventilation trunk system that spread the fire.

Improper download

It was also likely that proper safety precautions, including making the flare safe for handling, had not been taken as it was downloaded from its aircraft. In this regard, the MK 24 flare design, its manuals, crew training and supervision all came in for criticism.

From the moment the flare’s fuse ignition sequence started, the handlers had some 18 seconds before the main charge ignited. This suggests that there was time to throw the flare overboard.

Forrestal fire
As the USS Forrestal was readying for a launch over Vietnam, on 29 July 1967, nine months
after the Oriskany fire, an even more serious fire claimed 134 lives and 62 injured (above, USN photo).

Damage to aircraft and the ship was severe. The primary cause, never conclusively established, was presumed to be a stray voltage input into a loaded F-4 Phantom’s firing circuit that fired a Zuni rocket into an A-4 Skyhawk’s drop tank. The A-4, incidentally, was hurriedly evacuated by the pilot, LCDR (later Senator and Presidential candidate) John S. McCain.

ADML J.S. Russell, a highly respected retired ex-aviator, headed a panel that reviewed the Oriskany and Forrestal fires. “Serious deficiencies (existed) in weapons technical publications and handbooks and munitions load-out specifications,” quotes Foster from this report (p160). “The problems were navy-wide,” summarises Foster. “(There are) dangers inherent in having to fight a full-time war with a peacetime manpower structure.”

However, there are two positive conclusions that must flow from these tragedies. Firstly, USN carriers can take a lot of punishment and still survive. Secondly, in an emergency, young sailors can be relied upon to distinguish themselves by unflinchingly risking their lives to save their shipmates and even the ship herself.

References:

Carlin, M.J. Trial: Ordeal of the USS Enterprise, 14 January 1969. Tuscarora Press: West Grove,1993.
Freeman, G.A. Sailors to the end: The deadly fire on the USS Forrestal and the heroes who fought it. Morrow William and Co.: New York, 2002.


HMS Glorious: Life span (Book)

Glorious

 

The Loss of HMS Glorious

Book review by John van Gelder

Winton, J. (1999) Carrier Glorious: The life and death of an aircraft carrier. Cassell Military Paperbacks: London. $16.95.

John Winton is a well-known author of many fiction and non-fiction books concerning the Royal Navy and naval subjects generally. In this book he has brought to life a fascinating story of a ship and many, perhaps unusual, people who served in her during a period of massive evolution in the Royal Navy. Regrettably, the end of the story is tragic in the extreme and controversial beyond belief.

Winton’s thoroughly researched book traces the history of Glorious from concept, building, service in World War I as a “big gun cruiser” to her conversion to an aircraft carrier and re-commissioning in 1930. Operation of the ship throughout the 1930s, primarily in the Mediterranean, provides great insight into the frustrations experienced by aviators, both RN and RAF, due to their perceived divided loyalties. The author does point out that the heavy RN/RAF battles were fought in the vicinity of Whitehall rather than at squadron level, where integration appeared to be on a happy note. In fact, during the 1930s Glorious had the reputation of being an efficient, well-run and happy ship.

The final two thirds of the book is concerned with the ship’s operations after the appointment of a new captain on 16 June 1939, until she was sunk twelve months later.

There is no doubt that the arrival of CAPT Guy D’Oyly-Hughes DSO DSC had a profound adverse effect, not so much on the ship’s company, but on the senior command structure of the vessel. The author treats this central character in a fairly even-handed manner in setting out the views of his supporters and detractors. On balance it would appear that the captain suffered from some very severe psychological problems. It is interesting to note that the remarks of the military historian Correlli Barnett, in his book Engage the enemy more closely, is far more forthright and scathing regarding D’Oyly-Hughes’s character. The reader, as in so many literary works, is left to ponder to what degree the captain’s mental state may have had on the subsequent tragic events.

Flawed aviation strategy?

For any person, with or without sea experience in the navy, this is a most absorbing story. The narrative raises many questions that beg answers as to why certain decisions were made in the operational area of Norway 62 years ago. Unfortunately, these questions can only now be answered in one’s imagination.

The evacuation of the two RAF squadrons, 263 Squadron Gladiators and 46 Squadron Hurricanes, from their bases in Norway and their landing on Glorious without arrestor hooks and without incident was a remarkable achievement and well described by Winton.

Leaving aside the issue of conflicts of personalities within Glorious, and there were many, there are two questions of utmost importance. Why was Glorious given permission from higher authority to proceed independently from the operational area back to Scapa Flow escorted by HMS Ardent and Acasta? Glorious had requested this course of action but for what reason? She was certainly not short of fuel.

gloriuos2
HMS Glorious, showing her 1930s-style “flying off deck” at hangar deck level.

Secondly, and perhaps more importantly, since the carrier was proceeding independently without any support from heavy surface vessels in good weather and excellent visibility, why was she not flying reconnaissance patrols? Apparently, one Swordfish and a flight of three Sea Gladiators were at ten minutes notice, but they were not even ranged on the flight deck.

The author provides a detailed account of the destruction of Glorious and her escorts by Scharnhorst and Gneisenau. There is a clear impression that the first inkling Glorious had of the presence of the German ships was when the first salvoes of 15-inch projectiles crashed around her from a range of 28,600 yards.

Gallant destroyers

The subsequent actions of Ardent and Acasta during the engagement were gallant beyond belief. There was only one survivor from both ships, making it difficult to imagine why posthumous awards for bravery were not made after the event.

In the sinking of Glorious, Ardent and Acasta the casualty list amounted to 1,519 killed, with only 34 survivors.

This is a well-written book. It is historically informative and contains lessons for both naval personnel and politicians, even in this missile age.

(Ed.note: Some of the blame for the reckless mishandling and almost criminal waste of RN aircraft carriers in the early stages of the war has been sheeted home to political interference, probably by Winston Churchill, and an ineffective, probably demented, First Sea Lord.)

Despite leading the world in some aspects, such as damage control and aircraft refuelling systems, the RN was woefully behind with modern aircraft and carrier employment strategies, Taranto notwithstanding. Before and even after the loss of Glorious it had long been argued by the RAF and supported by senior RN officers that modern aircraft were just too fast for the carriers.
 
The hookless RAF Hurricanes demonstrated convincingly that they could safely take off and land aboard Glorious. This was at a time when the Japanese were building their Zeroes and the USN was experimenting with a number of advanced fighter types.

Winton alludes to a “powerful force” supporting D’Oyly-Hughes and names Churchill as the probable ally. This “connection” might help to explain D’Oyly-Hughes’s arrogance based on ignorance and an evident reluctance of senior flag officers to curb his recklessness.

Churchill himself glosses over the tragedy, yet as he demolishes the “fuel shortage” straw man argument he offers no plausible alternative explanation.

“The Glorious had been detached early that morning to proceed home independently owing to a shortage of fuel, and by now was nearly 200 miles ahead of the main convoy. This explanation is not convincing. The Glorious presumably had enough fuel to steam at the speed of the convoy. All should have kept together.” (Churchill p. 516)

No British authority satisfactorily explains the apparent failure to act on Glorious‘s enemy report. One nearby cruiser, HMS Devonshire, heard her WT calls, but could take no action, such as relaying the message, for very good reasons. Hundreds of survivors needlessly succumbed to exposure after successfully abandoning ship because the Admiralty initiated no timely search and rescue operation.

References:

Barnett, C.  Engage the enemy more closely: The Royal Navy in WW II. Norton: New York, 1991.
Churchill W.S. The second world war, Vol 1. Cassel and Co: London, 1948.


Angled Deck origins

Origins of the Angled Deck

by Digger Bourke
 
The sketch of the proposed US Navy flush deck super carrier in the Naval Officers Club Newsletter 59 of l December, 2004, revived old memories of the original angled deck, or “canted deck” in the USN parlance of the time.

In the late 1940s the USN considered it vital to remain in the nuclear delivery business in competition with the US Air Force. Naval architects were considering twin-runway and flush deck layouts to handle the heavier and faster jet-age aircraft. HMS Warrior was even fitted with a rubber deck in 1948 to explore the weight-saving concept of operating aircraft without undercarriages.

A brilliant solution that solved many deck landing problems was proposed and developed by two officers of the Naval Section of the Royal Aircraft Establishment (RAE). CAPT (later RADM) D.R.F. Cambell DSO RN and Mr Lewis Boddington in late 1951 changed the whole concept of carrier design, solving the problems of handling the new aircraft and eliminating the crash barrier for routine operations. The ease of landing, compared with the old system, promised to make a great contribution to aircrew confidence and morale.

The revolutionary idea was first trialled in HMS Triumph in early 1952 with Attackers and a Meteor using a painted deck about eight degrees off centre to port. No deck machinery was altered, so only touch-and-go approaches were possible. Further trials were carried out in March 1952 in HMS Illustrious.

USS Antietam
USS
Antietam, seen here launching an F9F Panther from the angle, probably from a touch-and-go, conducted the first ever angled deck arrested landing trials between 12 and 16 January 1953. Note the pre-SCB125 open bow and five-inch turrets still in place. CAPT S.G. Mitchell USN, the commanding officer of USS Antietam, in an SNJ Texan/Harvard, is credited with the first angled deck arrested landing.

The concept was relayed to the USN, who were quick to act. They conducted simulated angle deck landings trials aboard USS Midway, 26-29 May 1952. Between September and December 1952, they also modified the USS Antietam, an Essex class carrier just emerging from reserve. Antietam had a ‘canted’ deck of eight degrees, later 10.5 degrees. The arrestor wires were realigned at right angles to the new centreline and they locked the port deck edge elevator in the up position. No regular barriers were fitted but an emergency barrier could be rigged in about two minutes in the event of a hook problem or other emergency. The carrier completed over 500 landings between 12 and 16 January 1953, day and night, with six types of jet and prop-driven aircraft, without incident.

Canted versus Angled

The USN “canted”, “slewed” and “slanted” versus “angled” deck argument was finally resolved 24 February 1955, when USN OPNAV 9020 directed that “angled” was the preferred usage.

Seahawk Hancock
An RN Seahawk conducts trials aboard USS
Antietam in July 1953.

Generously, Antietam crossed the Atlantic to allow experience by RN Attacker, Seahawk, Sea Vampire and Wyvern aircraft in late June and early July 1953. A total of 64 touch-and-go landings and 19 arrested landings were completed to the total satisfaction of all pilots taking part. The pilots were drawn from 806 Squadron (Seahawks) in RNAS Brawdy, the Service Trials Unit (STU) in RNAS Ford, the Naval Air Fighting Development Unit (NAFDU) and the Central Fighter Establishment (CFE) at RAF West Raynham, Norfolk. LCDR Freddy Sherborne RAN was on exchange with the STU and flew an Attacker in the trials. I was serving with NAFDU and flew a Seahawk. We were most fortunate to be included in these historic trials along with senior highly-regarded RN aviators.

Working with USS Antietam was a great success and cooperation was highly satisfactory, leading to complete approval by all participating aviators.

Aircrew morale was greatly boosted by removal of the crash barrier, by the opportunity to go around again, with the introduction of a “no-cut” technique until an arrestor wire was engaged and the relatively easy new circuit and landing procedures. A quantum decrease in deck landing accidents was promised and this proved to be true. USN hospitality continued after the completion of the flying program with a cocktail party in Portsmouth Dockyard Officers Mess, followed by a visit to the ship with our wives. There were some amusing reactions in some of our colleagues at RAF West Raynham when Aerodrome Dummy Deck Landings (ADDLS) were practised. Circuits were flown at 300 feet. A batsman on the runway monitored the last stages of the curved approaches, with the 100-yard straightaway offset ten degrees to port of the runway, and with no touch down. This was quite different from their standard 1000 feet high square circuits with slightly higher approach speeds.

Steam Catapult and Deck Landing Mirror

As the angled deck evolved, two other equally important British inventions appeared: the steam catapult by CMDR C.C. Mitchell OBE RNVR, and the Deck Landing Mirror by LCDR H.C.N. (Nick) Goodhart RN. Together, they give modem carriers the ability to operate without limits to aircraft design. The trials carrier HMS Perseus was the first to launch an aircraft by steam in 1952, but USS Hancock was the first operational ship with a steam catapult.

Hancock TrackerHMAS Melbourne
USS Hancock launches CMDR H.J. Jackson USN by steam in this S2F Tracker (left) on 1 June 1955. HMAS Melbourne (right) was the first operational carrier ever to commission with all three of the new jet-age systems, angled deck, steam catapult and mirror, on 28 October 1955.