The Origins and Development of the American Escort Carrier

The USS Long Island as built, the first escort carrier

At the start of the Second World War with the German invasion of Poland in September 1939, the Kriegsmarine had fifty-seven U-boats in its fleet, but of those fifty-seven submarines, only twenty-two of them were suitable enough for carrying out combat patrols in the Atlantic and that small group consisted of the 626-ton Type VII boat and the larger 1,032 ton Type IX boat.  The Type VII was the most common U-boat used in the Battle of the Atlantic and with 703 hulls constructed, was the most widely built submarine class in naval history. The larger Type IX submarine was designed for extended long range patrols but lacked the maneuverability of the Type VII. Approximately 283 hulls of this larger class were built during the Second World War. Prior to the onset of the war, the head of the U-boat force, Rear Admiral Karl Doenitz, had stated that he would need at last ninety operational boats for the Atlantic at the start of hostilities and that eventually 300 would be needed to guarantee that he could choke off Great Britain's Atlantic supply routes. Fortunately for the Allies, Hitler didn't believe that the war would take long and dragged his feet on authorizing rapid expansion of the U-boat force for some time. The Atlantic U-boat menace is the context to understand the development of the escort carrier- in fact, as it would turn out, the escort carrier was one of the keys to victory in the Battle of the Atlantic. 

Led by the British construction of the HMS Argus which was commissioned in 1918 as the world's first aircraft carrier with a full-length deck (thereby setting the pattern of the aircraft carrier configuration) after conversion from a partially completed ocean liner, the United States Navy had the collier USS Jupiter converted to the first American aircraft carrier, the USS Langley, which was commissioned in 1922. Compared to the large fleet carriers that would become famous in the Second World War, both the HMS Argus and the USS Langley were much smaller vessels with the Argus coming in at 15,775 tons and the Langley at 11,050 tons. But both navies gained valuable experience in operating the ships, the US Navy in particular using the Langley to fine tune procedures for high tempo flight operations. The interwar period was a time of transition for both the US Navy and the Royal Navy as they transitioned from big gun warships to aircraft carriers- during the First World War, the first aircraft carrier in naval history, the HMS Furious, had started out as a cruiser converted with a partial flight deck before getting upgraded to a the pattern set by the HMS Argus with a full length deck. During it's time with a partial flight deck, though, the Furious did retain its aft gun turret, leading to some discussions in the Royal Navy about hybrid cruisers- vessels that had partial flight decks with cruiser guns. The ideas persisted into the 1920s and with the limits on battleship and aircraft carrier tonnage by the 1922 Washington Naval Treaty, the ideas of small aircraft carriers arose as a way of making better use of the allowed tonnage. A loophole in the treaty allowed the United States a chance to use up to 25% of its allotted cruiser tonnage for conversion to small aircraft carriers, but this was an idea that many "Big Gun" admirals were reticent to pursue. 

Bruce G. Leighton, early escort carrier advocate

In 1927, USN Lieutenant Commander Bruce G. Leighton wrote an influential paper on light carriers- he had presciently described roles for such carriers to include antisubmarine warfare, supporting larger fleet carriers, scouting and reconnaissance and support of amphibious landings while larger carriers could be freed up to hunt down the enemy's capital ships. He was also motivated by a concern that the loss of a large fleet carrier would be a bigger blow to the Navy's strength than the loss of a smaller carrier based on a cruiser hull. At the time of Leighton's paper, the USS Lexington and the USS Saratoga had just become operational and even though both vessels were much larger and more useful operationally than the USS Langley, they were still just the second and third aircraft carriers in the US fleet. 

With the clouds of war looming on the horizon and Japan pursuing an aggressive expansionist foreign policy in the Western Pacific, in 1935 the US Navy's Bureau of Construction and Repair had been considering conversion of ten fast passenger liners into light carriers. Conversion of an existing hull was believed to be the most expeditious way to get hulls into the fleet. The plans for light carriers might have died off had it not been for men like John S. McCain, the captain of the fourth US aircraft carrier built, the USS Ranger (the Ranger was first US carrier built from the keel up as an aircraft carrier; McCain was the grandfather of Arizona Senator John McCain). He and others in the fleet had wanted up until 1939 approximately eight "pocket-sized" aircraft carriers based on cruiser hulls that could act as outer defensive screens for the larger fleet carriers. The outbreak of the war in Europe furthered ideas of small aircraft carriers in the US Navy as observers watched the British battle the U-boats that were menacing their trans-Atlantic supply lines. Originally the USN thought that small aircraft carriers might have a dual role in providing air cover to the convoys in the Atlantic as well as delivering much-needed Lend-Lease aircraft to the Royal Air Force. As it would turn out, the cause of what would become the escort carrier got its biggest boost in October 1939 from President Franklin D. Roosevelt. He was a lifelong enthusiast and student of naval history and served as Assistant Secretary of the Navy from 1913-1918 under President Woodrow Wilson. Well-versed in naval affairs, Roosevelt instructed the US Navy to procure a merchant ship for conversion to an aircraft carrier. The ship was to displace 6,000 to 8,000 tons and have a speed of 15 knots and operate a unique air wing made up of either 12 helicopters or autogyros. The vessel would act as a convoy escort and perform antisubmarine warfare missions- the helicopters or autogyros wouldn't carry weapons, but use smoke bombs to mark U-boat locations for attack by destroyers.

Discussions with the Chief of Naval Operations, Admiral Harold Stark, in the weeks following Pearl Harbor led to the decision to obtain two diesel-powered C3-class merchant vessels from the Maritime Commission. The C3 class was designed by the US Maritime Commission as a 492-foot (150m) general purpose vessel that could be easily modified to a variety of roles. Helicopters and autogyros were ruled out as it was felt fixed-wing aircraft were more flexible and capable compared to the rotary winged aircraft of the day. This dictated the need for a full length flight deck. The Navy told the President that conversion to an escort carrier would take 18 months, but to Roosevelt, this was unacceptable. The speed of conversion was essential. He told Admiral Stark that the conversion should take no more than three months. At end of January 1940 two vessels were secured from the Moore-McCormick Line, the Mormacmail and the Mormacland. One ship after conversion would go to the US Navy and the other ship after conversion would go to the Royal Navy. The only organic air cover the British had at the time for the Atlantic convoys were Hawker Sea Hurricanes installed on CAM ships- catapult aircraft merchant ships. It was a one-way trip for the pilot who had no means of recovery other than ditching alongside a ship. Wholly unsuitable for antisubmarine warfare, the CAM ships were really geared towards going after the long-range Focke Wulf Fw 200 Condor maritime patrol aircraft that scouted the Atlantic for the U-boat fleet.

On 2 June 1940 just a few days before Roosevelt's three month deadline, the Mormacmail's conversion to an escort carrier was completed and she was commissioned as the USS Long Island at Newport News, Virginia and designated APV-1 but was soon changed to AVG-1 (Aircraft Escort Vessel). The designations changed two more times during the war as the value of the escort carrier was proven, to ACV (Auxiliary Aircraft Carrier) in August 1942 to CVE (Escort Carrier) in July 1943. As built, the USS Long Island was 492 feet (150m) and displaced 13,500 tons and could make 16.5 knots. The original flight deck was only 362 feet with the bridge below the forward edge of the flight deck. Testing showed the need for a longer flight deck, so in the summer after her commissioning the carrier went back into the yards to have a proper full length flight deck. There was one elevator aft and a single forward catapult on the port side. The opportunity was taken during the extension of the flight deck to make other improvements and when she came out of her refit, the ship now displaced 14,953 tons and was faster with a speed of just over 17 knots.

HMS Archer- note the small island not present on the Long Island

The Mormacland was converted a similar configuration but had a small island on the starboard side. She was transferred to the Royal Navy in November 1941 to become the HMS Archer. Despite the getting the second escort carrier built in the United States, the Royal Navy did set out to build an escort carrier of their own with the conversion of the German merchant vessel Hannover to become the HMS Audacity, commissioned in June 1941 to become the first British escort carrier with the HMS Archer as the second such ship. Compared to the USS Long Island and the HMS Archer, the HMS Audacity was very small escort carrier with a displacement of only 6,000 tons with an air wing of just six aircraft. The two escort carriers were a boon to British convoy operations and the Royal Navy ordered five more escort carriers from the United States based on the C3 class merchant vessel hull and based on the USS Long Island with further improvements. These four ships had a 440-foot flight deck and a small island on the starboard side (which the USS Long Island lacked)- they became the HMS Avenger, HMS Biter, HMS Dasher, and the HMS Charger. The last ship of the group was returned to the US Navy in 1942 and became the USS Charger which remained on the US East Coast as a training carrier.

USS Bogue

Much like how the USS Langley was used primarily for testing and experimentation, so too was the USS Long Island in its early career as the first American escort carrier. With the entry of the United States into the war in December 1941, Admiral Doenitz's U-boat fleet began to prosecute its attacks on the US East Coast with 400 ships sunk just in the first six months following Pearl Harbor. With the utmost urgency, a new class of escort carrier was ordered into production based on the experience with the USS Long Island. These vessels were converted from twenty four C3-class hulls as the Bogue-class. Because the Long Island and the first British escort carriers were diesel powered, they were thought to be too slow based on operational experience and the Bogue-class carriers would have steam turbines to drive them to 18 knots. The new escort carriers had a flight deck 442 feet long by 80 feet wide, bigger than the Long Island's flight deck. A single catapult was fitted on the forward port side but the ships had a larger hangar deck and two elevators instead of the Long Island's single elevator. A small island was located on the starboard side as well.

USS Sangamon

Of the twenty carriers based on C3-class hulls that became to Bogue-class, ten of them went to the Royal Navy. The new ships could carry twice the fuel of the Long Island/Archer-class ships and had an improved compartment layout in the hull. As the ships were four feet lower than the Long Island/Archer, they also had better seakeeping qualities. Since the 1942 escort carrier program called for twenty-four ships and only twenty C3-class hulls were available, four Cimarron-class fleet oilers were converted to escort carriers to become the Sangamon class. As these ships were based on larger hulls, they were longer at 553 feet with 23,250 tons displacement and could carry two squadrons of aircraft. Launched originally with just a single port side catapult, the four ships of the Sangamon class got a second catapult on the starboard side in 1944. Being former fleet oilers, the Sangamon class carried a significant amount of fuel which could also be used to top off the escorting destroyers in the task force. They were more stable at sea than the Bogue-class and could make 19 knots. The four ships of this class were the USS Sangamon (CVE-26), USS Suwanee (CVE-27), USS Chenango (CVE-28) and USS Santee (CVE-29). The Navy wanted more Sangamon-class carriers, but fleet oilers were also in demand for underway replenishment of the carrier battle groups in the Pacific.

Aware of the shortage of hulls for conversion to escort carriers, American shipbuilding magnate Henry J. Kaiser had proposed to President Roosevelt in 1942 the construction of an escort carrier design capable of 20 knots in quantity production from his shipyards which were turning out Liberty cargo ships at an impressive rate. Using prefabricated sections and mass production techniques used on the Liberty ships, the Casablanca-class escort carriers would become the most produced aircraft carrier class in naval history with fifty carriers built between July 1943 to the last Casablanca-class built in July 1944, an astounding achievement for the American wartime shipbuilding industry. The ships were built in Vancouver, Washington, and then delivered to Astoria, Oregon for final fitting-out before commissioning.

Schematic of the USS Casablanca

The Casablanca-class (the lead ship, USS Casablanca, was designated CVE-55) were 498 feet long with a 477-foot long by 80-feet wide flight deck that had two elevators and a single port side catapult. The engines were spaced apart to prevent a hit from taking out the engine room and the hangar deck was quite wide for an escort carrier. They were also the first all-welded carriers which made them lighter at 10,900 tons displacement but this gave the Casablanca-class superb maneuverability. Despite the quantity production and design features, the Casablancas weren't as good as the Sangamon-class carriers and the Navy insisted on something better if not as good as the Sangamon class. This resulted in the ultimate and final escort carrier class of the war, the Commencement Bay class.

USS Commencement Bay, the ultimate escort carrier

Based on all the operational experience of escort carriers so far, the Commencement Bay class ships were based on an improved Sangamon-class layout but longer with a length of 577 feet and a displacement of 24,900 tons. The flight deck was much stronger to operated heavier aircraft and the two elevators also operated faster to speed flight operations. Two forward catapults were standard with a bigger island as well. The ships could make 20 knots and had the heaviest defensive anti-aircraft armament of any escort carrier of the war. The lead ship, the USS Commencement Bay (CVE-105) was commissioned on 27 November 1944. Thirty-three ships were ordered but only nineteen were completed by war's end. Two of the completed carriers went straight into mothballs after completion. While the Commencement Bay-class carriers didn't see as much action as their predecessors, several of the ships did go on in the postwar period to become the first helicopter assault carriers and served until the arrival of the Iwo Jima-class LPH carriers in the 1960s.

Source: Hunter-Killer: U.S. Escort Carriers in the Battle of the Atlantic by William T. Y'Blood. Bluejacket Books/Naval Institute Press, 1983, pp 11-26. Photos: US Navy, National Archives, Wikipedia.

How the USS Wasp Helped Defeat Rommel's Afrika Corps

Spitfire Mk.V makes its takeoff run on the USS Wasp

From 1940 to 1942 the Italian Regia Aeronautica and the Luftwaffe mounted over 3,000 sorties against the British fortress island of Malta in the Mediterranean in an effort to secure their supply lines to Field Marshall Erwin Rommel's Afrika Korps in North Africa. Despite repeated attacks, the Allies managed to keep Malta supplied, even with Axis airfields only sixty miles to the north in Sicily. With the coming of the harsh Russian winter in 1941, poor flying conditions put a temporary hold on most air operations over the Eastern Front and Hitler decided once and for all to deal with Malta. Aircraft idled on the Eastern Front were temporarily moved to airfields in Sicily and southern Italy to begin an intensive aerial bombardment as a prelude to an invasion of the outpost. By the end of January 1942, Malta's defenses had been reduced only a few dozen Hawker Hurricanes which were far outclassed by the Messerschmitt Bf 109s that routinely prowled the skies around the British garrisons. The Hurricanes were delivered to Malta by a Royal Navy aircraft carrier- launching from a point 600 miles west of Malta off the coast of Algeria for the long flight to Malta. Now the British planned to send Supermarine Spitfires the same way to bolster the defenses of the island. Supermarine's engineers devised a 90 gallon external belly tank to extend the range of the Spitfire as well as the addition of a dust filter under the nose to keep the carburetor air relatively grit-free.

On 7 March 1942 the HMS Eagle delivered fifteen Spitfire Mk.Vs to the island and by the end of the month, the Eagle made two more deliveries. But the Luftwaffe and the Regia Aeronautica stepped up the pace of their attacks on the beleaguered island fortress and the bombers and torpedo bombers that were based on the island to harass Axis shipping had to be withdrawn, providing a much needed respite for the Afrika Korps who could now be supplied unmolested. The small Spitfire force suffered heavy attrition both in combat and due to air attacks on the island airfields and by the end of the month, the only carrier available to deliver Spitfires to the island, the HMS Eagle, had developed steering problems that would lay her up for four weeks in the dockyard at Gibraltar. As a result, on 1 April 2942 Prime Minster Winston Churchill contacted President Franklin D. Roosevelt for assistance in getting more Spitfires to Malta. No Spitfires were available in Egypt to be spared, and the other two available Royal Navy carriers weren't suitable- the HMS Argus was too small and the HMS Victorious' lifts were too small for Spitfires. The Luftwaffe hoped to knock Malta out before the late spring thaw in on the Eastern Front. 

Spitfires being craned aboard the USS Wasp

On 10 April 1942 President Roosevelt ordered Operation Calendar- on that day the USS Wasp docked in Glasgow and loaded forty-seven Spitfires while retaining twelve Grumman F4F Wildcats for self-defense. Nine days later the Wasp and her escorting force of British warships entered the Mediterranean. On 20 April 1942 at sunrise off the coast of Algeria, the Wasp launched her Wildcat combat air patrol first followed by the twelve Spitfires on the deck and then the thirty-five Spitfires that were brought up from the hangar deck. Alll but one of the Spitfires made it to Malta, greatly bolstering the defenses. Unfortunately the following day the Luftwaffe struck back at the island's airfields and by the end of the day, only seventeen Spitfires were left operational. RAF repair crews labored under constant air attack to cannibalize battle damaged Spitfires that were beyond repair to get the others operational to fight off the next attack. Once again, Churchill contacted Roosevelt and on 29 April the USS Wasp arrived back in Glasgow for Operation Bowery. This time not only did the Wasp take aboard forty-seven Spitfires, but she was joined by the newly-repaired HMS Eagle which took seventeen Spitfires. At dawn on 9 May 1942 a force of sixty-four Spitfires departed; one crashed on takeoff, killing its pilot and a second Spitfire flown by Royal Canadian Air Force pilot Jerry Smith found once airborne that he couldn't draw fuel from the 90-gallon drop tank. Once the deck of the Wasp was clear, he managed to land safely back aboard the carrier despite never having landed on a carrier and his Spitfire not having an arresting hook! No barriers were engaged either, and as result, the US Navy pilots aboard the Wasp "unofficially" awarded him a set of gold Navy pilot's wings. 

Spitfires share the deck with Wildcats with the HMS Eagle following

Of the sixty-two Spitfires that set out for Malta that day, two were lost along the way. As each Spitfire landed, it was immediately refueled and rearmed while a Malta-based pilot replaced the ferry pilot, all while the engine remained running. RAF ground crews had each Spitfire airborne and ready to meet the next Luftwaffe attack in only 15 minutes! Over the next two days, the Spitfires and remaining Hurricanes on Malta exacted a harsh price from the Luftwaffe attackers, but by this point, the weather was improving over the Eastern Front and Hitler ordered the aircraft transferred to the Mediterranean for the Malta operation moved back to Russia. The Regia Aeronautica was given responsibility for knocking out Malta's defenses but never came close to achieving the near-defeat of the fighter defenses of April and May of that year. Between 18 May and 8 June another seventy-six Spitfires were delivered to Malta, this time by Royal Navy carriers, but it never matched the effect of the USS Wasp making just two deliveries, leading Churchill to quip "Who says a wasp can't sting twice?"

The overall effect of having Malta as a base of operations against Axis shipping in the Mediterranean cannot be understated- of the Axis merchant ships that provided the lifeline to Erwin Rommel's Afrika Korps, 70% of Italian merchant shipping was sunk by Malta-based aircraft and 23% of German merchant shipping was sent to the bottom of the Mediterranean by the RAF on Malta. Had the British lost Malta, the outcome of the war in North Africa might have been very different.

Source: Military Aircraft Monthly International, Volume 10, Issue 1. "Air Wars: Spitfires to Malta" by Dr. Alfred Price, p4-11.

The British Knock Out the Italian Fleet with Biplanes

The Fairey Swordfish as marked/painted for the Taranto attack

The planning for the attack on the Italian fleet at the harbor of Taranto began in earnest in 1938 during the Munich Crisis when it seemed that Europe was headed for war. Though boasting a force of six battleships, five cruisers and twenty destroyers at the start of the conflict that could have caused significant headaches for the Royal Navy in the Mediterranean, Mussolini rarely ordered the fleet to sail far from the home port of Taranto and they would return at the earliest opportunity, failing to engage the British Mediterranean fleet. With the threat of war looming, captain of the HMS Glorious, Capt. Lumley Lyster, was asked to draw up an attack plan to knock out the Italian fleet while it sat in harbor. Essential to any attack given the strength of the defenses of the harbor would be surprise, necessitating a night attack. By the time 1940 had come around and maintaining the sea links with the British forces in North Africa took added importance, the need to proceed with the attack, codenamed "Operation Judgement", the trained Fairey Swordfish aircrews that trained aboard the HMS Glorious were now serving aboard the HMS Illustrious and under strict secrecy, the attack was planned for 12 October 1940 on Trafalgar Day. Unfortunately, a fire in the hangar deck of the Illustrious resulted in the Swordfish aircraft being drenched in saltwater, necessitating their clean up and repair. Also, the original attack plan called for the HMS Eagle to accompany the Illustrious on the attack, but Eagle had suffered damage from an accidental bomb explosion earlier in the year. As a result, some of Eagle's Swordfish and aircrew were transferred to the Illustrious. The attack was rescheduled for the night of 11/12 November 1940. 

Given the nature of the defenses based on the latest British reconnaissance, the first wave to attack Taranto would consist of twelve Swordfish, only six of which would carry torpedoes while the balance of aircraft carried bombs and flares. At the time, the conventional naval wisdom was that torpedoes were only usable in deep water, but the Royal Navy had modified their torpedoes to run in the shallow water of Taranto Harbor. The photos showed that the battleships were protected by torpedo nets, but they were standard keel-depth nets. The torpedoes used were configured to magnetically detonate below the ships' keels. 

Diagram of the attack on the Italian fleet

At 8:30pm the first wave took off from the HMS Illustrious. The gunners weren't carried, their place being taken by a supplemental fuel tank to allow a two-man crew to fly the 340-mile roundtrip mission. By 9:00pm the twelve aircraft were all airborne and they set off for Taranto. Several of the Swordfish became separated from the main formation and had to make their own way to the target- one pilot arrived at Taranto ahead of the main force and had to await the rest of the aircraft- some references indicate that this may have alerted the Italians. Arriving over the harbor at 11:00pm, the strike force immediately came under fire. One of the Swordfish peeled off from the group and dropped a series of flares at 7,500 feet along the eastern perimeter of Mar Grande, the outer harbor. A second Swordfish followed suit, illuminating the area for the rest of the strike force. Lt. Commander K. Williamson, the CO of No. 815 Squadron, made the first torpedo run against the battleship Conte di Cavour, blowing a hole in the side of the ship but getting shot down in the process. Two more Swordfish that accompanied Williamson then pressed their attack against the battleship Andrea Doria, which was unsuccessful. The last group of the first wave attacked two cruisers and four destroyers as well in Mar Piccolo, the inner harbor. The Swordfish's agility paid dividends as the seemingly archaic aircraft managed to weave around the barrage balloons and jink hard to throw off the anti-aircraft fire. 

HMS Illustrious with a Swordfish on the deck

With the first wave turning back for the Illustrious, the only aircraft shot down was that of their CO, Lt. Commander Williamson, who was taken prisoner along with his crewman. The second wave, under the lead of Lt. Commander J.W. Hale, the CO of No. 819 Squadron, had left the Illustrious thirty minutes after the first wave took off. Of the twelve Swordfish in the second wave, only eleven arrived at Taranto due to technical problem with the twelfth aircraft that forced it to return to the carrier. Arriving over the harbor at midnight, again the flare-dropping Swordfish lit up the area while the bomb and torpedo-armed aircraft set to work on the rest of the Italian battle fleet. Two aircraft attacked the battleship Littorio, but only one scored a hit. Another aircraft despite taking damage pressed an unsuccessful attack against the battleship Vittorio Veneto. The battleship Caio Duilio was also hit, and only one aircraft from the second wave was shot down, the two aircrew being killed. By 240am, the last of the Swordfish landed on the Illustrious. A third wave was planned the following night, but bad weather prevented a final blow to the Italian fleet. 

The attack was a stunning success by an aircraft that was older and slower than many of its contemporaries. Just 11 torpedoes and 48 bombs managed to knock out half of the Italian battle fleet at Taranto and while the defenders fired off over 22,000 rounds, only two aircraft were shot down, quite an impressive feat! The attack followed by the Battle of Cape Spartivento two weeks later and the Battle of Cape Matapan in March 1941 consolidated the Royal Navy's control of the Mediterranean, hastening the defeat of the Axis. The planning staff of the Imperial Japanese Navy, at the time putting together the plans for the attack on Pearl Harbor, studied the British attack at Taranto carefully and managed on 7 December 1941 to knock out more battleships in the process, but unlike the Mediterranean, the attack failed to shift the balance of power in the Pacific as the US Navy had shifted its fleet emphasis to the aircraft carrier as the new capital ship. 

Source: International Air Power Review, Volume 27, Winter 2010/11. "Warplane Classic- Fairey Swordfish- the Fleet Air Arm's enigmatic warrior" by Allan Laws, p125-129.

Grumman's Biggest Cat in World War II

In early 1941 the United States Navy issued a requirement to Grumman for development of a large twin-engined fighter powered by twin Pratt & Whitney R-2800 Double Wasp engines of 2,100 horsepower each. The Double Wasp was used on the Navy's other two fighters under development at the time, the Grumman F6F Hellcat and the Vought F4U Corsair- two such engines offered a tremendous leap in performance for what the Navy designated the F7F. The fighter would be heavily armed with four 20mm cannon in the wing roots and four 0.50-caliber machine guns in the nose with provision for carrying a torpedo under the fuselage or two 1,000 lb bombs under the wings. The large fighter would form the nucleus of the air wing of the new 45,000 ton Midway class aircraft carriers then under proposal. On 30 June 1941 the Navy authorized Grumman to begin work on the Tigercat. Two prototypes designated XF7F-1 were ordered on that day. As an interesting historical sidenote, five weeks earlier the US Army Air Force ordered two aircraft as well which were to be designated XP-65 but had lighter Wright R-1820 engines that would have been turbosupercharged to give the XP-65 even better peformance than the F7F. However, the differing specifications of the Navy and the Army were at odds as the USAAF wanted a lighter fighter than what the Navy desired. As a result, what might have been the first American joint-service fighter died quietly when the Army bowed out due to concerns about the design becoming overweight to meet Navy requirements. 

With the first F7F-1 Tigercats rolling off the Grumman production lines in April 1944, the Navy took the unusual step of having the Tigercat only operate with land-based squadrons of the US Marine Corps and skip  what promised to be a lengthy carrier qualification series of tests as the Navy had not previously operated large twin-engined fighters off its flight decks. The aircraft carrier it was intended for, the USS Midway, was still under construction at the time. At that point in the Pacific War the Navy felt that its fighter needs were being satisfied with the F6F Hellcat and the F4U Corsair. The Marines could operate the Tigercat as a fighter bomber which the Navy brass felt was more suited to the aircraft's design. Plans were set in motion to equip twelve Marine Corps fighter squadrons that were operating the Corsair at the time to re-equip with the Tigercat. The Corsairs would then be passed back to the Navy to meet fleet requirements in the Pacific. 

Production of the F7F-1 Tigercat came to sudden halt in December 1944 after only 35 aircraft were built. By this point in the war the Navy's carrier battle groups were gearing up for their first raids on the Japanese Home Islands themselves (Task Force 58 in February 1945) as a diversion for the assault on Iwo Jima. The Navy had a different role in mind for the Tigercat and the third F7F-1 was converted into the prototype XF7F-2N night fighter with an AN/APS-6 radar set in the nose, displacing the four 0.50-caliber machine guns, and a second seat for the radar operator over the wing behind the pilot. More powerful versions of the R-2800 radial were used to compensate for the increased weight of the second crewman and the additional radar equipment. However, changing requirements and technical issues meant that the F7F-2N was only an interim type, with only 65 being produced between December 1944 when F7F-1 production was stopped in favor of the night fighter and August 1945. Several of the -2Ns did go to sea, though, but for a series of comparison tests aboard the USS Antietam and the USS Shangri-La with the North American PBJ-1 Mitchell (the Navy version of the B-25 Mitchell). Both were being evaluated as night fighters by the Navy in April 1945 but it was soon found that both the Tigercat and the Mitchell were too large for the Essex-class fleet carriers and the Navy settled on radar-equipped variants of the F6F Hellcat and F4U Corsair instead. 

Only one Tigercat squadron made it to the Pacific before the end of the war with the Japanese surrender. Marine Corps squadron VMF(N)-533 was one of three Marine Corps night fighter squadrons established in 1943 operating the night fighter version of the Hellcat, the F6F-5N. Based in Okinawa at the time, the squadron was to convert to the night fighter Tigercat in theatre, but their new mounts arrived the day before the Japanese surrender. Patrols were made over China and Japan, but no operational engagements took place in the months following the Japanese surrender. Interestingly, the Royal Navy evaluated two F7F-2N Tigercats in the night fighter role, but decided to adopt the De Havilland Sea Hornet instead for the role. 

The most famous and most-produced version of the Tigercat, the F7F-3 and -3N, didn't arrive until March of 1946, too late for service in the Second World War. This variant was never carrier-qualified as well and by the time the Midway class carriers it was intended for were operational, the Navy's standard fighter was the Grumman F8F Bearcat and jets were just over the horizon. The F7F-4N was fully carrier capable and fully qualified unlike the previous versions, but only 14 of this model were built. In the Korean War, night fighting Tigercats in the hands of the Marine Corps finally drew blood and achieved fame that had eluded it during the Second World War. 

Source: United States Naval Fighters of World War II in Action by Michael O'Leary. Blandford Press, 1980, p136-141.

During times of war, operational necessities sometimes breed unusual solutions- in the Second World War the most famous of these was the Japanese kamikaze. Though no Allied airmen were ever committed to a formal suicide mission, the desperation of the in its first half did lead to one program that probably comes as close as can be to a suicide mission- the Catapult Armed Merchantmen (CAM ) ship program put in service by the British during the early days of the Battle of the Atlantic.

Being an island nation, Great Britain was dependent upon maritime trade and in particular, dependent upon the Atlantic convoys from the United States that delivered not just weapons and armaments, but also food staples and fuel. As the Battle of the Atlantic intensified in 1941, the German U-boat menace began taking its toll on merchant shipping that was Britain's wartime lifeline. However, the U-boats were only part of the problem as the Luftwaffe's long-range Focke Wulf Fw 200 Condor long range patrol bombers also preyed on the convoys and also provided eyes for the submerged U-boat wolfpacks.

The solution was the Catapult Armed Merchantmen and the Hawker Sea Hurricane. Approximately 36 cargo ships were fitted with a rocket-driven catapult mounted on the forecastle of the ships. The catapult was mounted in a fore-aft orientation and slightly offset to port to which the Sea Hurricane was mounted. The first Sea Hurricane variants only had local reinforcements and attachment points to the catapult trolley. Two pilots were assigned to each CAM ship and alternated 12 hour shifts. Once a Condor had been sighted, the alert pilot strapped into the Sea Hurricane and the rocket catapult fired, moving the Sea Hurricane and the expendable trolley at 3.5Gs while the pilot had the engine running at full power.

The CAM ship's forward structures were shielded to prevent damage caused by the rocket blast. Once committed to launch, the pilot had to use 1/3 starboard rudder to overcome the Hurricane's tendency to swing to port at full throttle. In addition, 1/3 flap was used to help get the Sea Hurricane airborne with the trim tabs set to neutral. If too much back pressure got applied during launch, the plane would stall and fall into the sea, so pilots would brace their right arm by shoving their right elbow against their hip to prevent inadvertent back pressure from the G-forces of the launch.

Launching the Sea Hurricane and engaging the Condor was the easy part of the mission. Since there was no way of returning to the ship, the pilot only had two choices- either ditch near the ship or hope there was enough fuel to head for land. Ditching a Sea Hurricane wasn't a great option- the bottom mounted radiator scoop easily flooded and the aircraft would sink quickly. If land was too far away to reach, the preferred option was to bail out rather than ditch the aircraft. Timing was of the essence, as exposure in the cold North Atlantic required an expeditious rescue out of the water. Later versions of the Sea Hurricane were fitted with two 44-gallon underwing tanks to extend the range and make reaching land more feasible.

As a result of the risks to the pilot in launching the Sea Hurricane, it was considered a last resort as most convoy captains didn't want the rocket flash to attract the attention of the Condors. By 1943, though, the CAM ships and their risky missions were superseded by the arrival of the first small escort carriers called MACs- Merchant Aircraft Carriers. The MACs were small escort carriers that lacked any hangar facilities and carried its Sea Hurricane complement (usually five) on the deck exposed to the elements. As a result, the Sea Hurricanes were only good for about 30 flying hours before saltwater corrosion took its toll. Although Sea Hurricanes were also deployed on the larger fleet carriers of the Royal Navy, handing idiosyncrasies on landing made them quickly superseded by purpose-built carrier fighters.

Source: Aeroplane Monthly, April 2010, Volume 38, No. 4. "Fierce Wind over the Deck" by Philip Jarrett, p36-40.

Development of the Harrier Ski-Jump

The development of the BAe Sea Harrier FRS.1 and the ski-jump are closely intertwined and the discussion one almost always leads to the discussion of the other. Hawker-Siddeley Aircraft, one of BAe's predecessor companies, had studied a naval Harrier variant as far back as 1969 as the P.1184 Maritime Harrier. When the Royal Navy awarded HSA a contract for naval Harrier variant in 1972, financial austerity was the watch word of the day in the British government and though based in part on the P.1184 Maritime Harrier, what would become the Sea Harrier FRS.1 would be a far less radical departure and minimum-change version of the land-based RAF Harrier GR.1.

In 1973 Royal Navy Lt. Commander David Taylor first formulated the ski-jump concept for V/STOL aircraft in the same class as the Harrier. His work was further developed in cooperation with the Hawker's Kingston division and the Ministry of Defence in sophisticated computer models followed by actual flight testing with an adjustable ski-jump built by HSA at the Royal Aircraft Establishment's main testing facility at Bedford.

One of the ski-jump's biggest proponents was John Farley, HSA's chief test pilot for the Harrier and Sea Harrier programs. During his test flights with early Harrier GR.1s off the aircraft carrier HMS Hermes, he found that there were certain moments in the pitching and heaving of a carrier deck in rough seas that could play havoc with a fully-loaded Sea Harrier making an STOL run off the carrier deck. In fact, tests had shown that in some sea conditions, as little as 5 degrees of deck angle up or down either at the stern or bow could shut down flight operations completely.

Farley also noted that in a pitching carrier deck, the most stable point to land in VTOL mode was the center of the deck as the ship virtually pivoted about that point in rough seas. Ideally, a fully-loaded Sea Harrier without a ski-jump would need the full-length of the deck to take off, but this meant that launching and recovery flight operations couldn't be simultaneously undertaken. Testing with the ground-based ski-jump at RAE Bedford showed that a shorter takeoff run would be needed, allowing the forward half of the deck to be used for launching aircraft off the ski-jump and from the midpoint back used for recovery of Sea Harriers.

Farley himself made the first takeoff from the ski-jump at RAE Bedford on 5 August 1977 with the sixth production Harrier GR.1. The first series of tests had the ramp set at 6 degrees, then moved it up to 12 degrees and then finally to 20 degrees. With the ramp at its steepest 20 degree setting, Farley could get a Harrier airborne with as little as 42 knots of airspeed as the ramp provided a significant upward velocity vector that allowed the pilot time to pivot the nozzles back, clean up the aircraft and depart in nearly all but the worst sea conditions. In addition, should an emergency occur on takeoff from a ski-jump, there was valuable time to either jettison the stores or eject.

Testing further showed that the ski-jump reduced required wind-over-deck speed. As the upcoming Invincible class "Harrier carriers" were gas turbine powered, not needing higher speeds to achieve ideal wind-over-deck speeds meant a more inexpensive and less powerful powerplant would be needed for the ship, an added bonus in the atmosphere of financial austerity of the day.

It was also found that as the aircraft reached the ski-jump, there was a rapid increase in loading on the undercarriage and as a result, the design of the Sea Harrier was modified to incorporate structural reinforcement around the aft main undercarriage just below the blast deflectors of the aft nozzles.

The trials at RAE Bedford were tremendously successful and a 7 degree ski-jump was added to the already-completed HMS Invincible and to the HMS Illustrious. The lower-than-ideal angle was due to the presence of the forward Sea Dart SAM launcher on the bow. The last ship of the class, HMS Ark Royal, wasn't finished until 1985 an as such, it got a 40-foot deck extension and a 12 degree ski-jump, allowing it to launch a fully-loaded Sea Harrier. In 1986 the Invincible and Illustrious had their ski-jumps refitted to the same standard as the Ark Royal. In addition, when the HMS Hermes underwent its refit in 1979 from an assault carrier to one compatible with the Sea Harrier, it got a 12 degree ski-jump as well. The ski-jumps were crucial to Harrier GR.3 and Sea Harrier FRS.1 operations in the Falklands campaign in 1982.

The sea trials for the Sea Harrier FRS.1 began in October 1979 aboard the HMS Hermes and the first operational sea deployment took place in May 1980 aboard the HMS Invincible.

Source: BAe Sea Harrier (Warpaint Series No. 75) by Kev Darling. Warpaint Books Ltd, 2010, p1-8.

The First Torpedo Bomber: The Shorts 184 of the First World War

Captain Murray F. Sueter, Director of the Air Department of the Admiralty of the Royal Navy, was one of the most enthusiastic proponents of British naval aviation during the First World War. One of his most passionate causes was championing naval torpedo bombers, though in those days a "proper" torpedo bomber was felt to be a seaplane. Working with the Short Brothers, a large two-seat biplane called the Short Type 184 was produced in significant numbers (650 in all) during the First World War. With a pilot and observer and floats, the 225-horsepower Short 184 was the first reliable torpedo bomber to not only go into production, but to prove itself in combat.

Despite successful tests showing that it was possible to air drop a torpedo against a surface vessel, Captain Sueter's ideas got little support within the Admiralty. However, he was given a chance to prove his theories with the Short 184 during the disastrous Dardenelles Campaign on the Gallipoli Peninsula against Turkey in 1915. Four Short 184s were embarked aboard a converted steam packet to serve as a seaplane tender, arriving on station in the northern Aegean Sea in June 1915.

On 12 August 1915, Flight Commander C.H.K. Edmonds and his observer flew a Short 184 carrying a single torpedo toward the Straits of the Dardanelles. Sighting a Turkish freighter in the Sea of Marmara that was carrying 3,000 Turkish troops to reinforce the Gallipoli Peninsula, Edmonds slowly descended from 800 feet to only 15 feet and closed within 300 feet of the vessel before releasing his torpedo, which struck the troop transport amidships, making the world's first successful combat aerial torpedo attack.

Five days later Edmonds and his observer again sortied in their torpedo-armed Short 184 along with a second Short 184 piloted by Flight Lieutenant G.B. Dacre. Approaching the Turkish coast at low altitude, both aircraft came under ground fire from Turkish gun batteries on the coast. Weaving at low altitude, Edmonds sighted three Turkish merchant ships and homed in on the largest of the three vessels, again descending to near-wavetop height for torpedo release, scoring a direct hit that set the vessel ablaze.

Edmonds' wingman found himself forced down due to an engine failure. While on the water getting his engine re-started, Dacre noticed a Turkish steam tug cross his nose and he fired his torpedo while still sitting in the water. The torpedo hit the tug squarely and sank it immediately. Having finally gotten his engine restarted, Dacre nursed his Short 184 into the air under heavy fire.

Despite this success, the Admiralty remained lukewarm to Sueter's ideas. He had requested a force of 200 torpedo bombers to act in conjunction with the Grand Fleet in the North Sea in action against the German High Seas Fleet, but his ideas were considered too radical and risky for the Royal Navy. Sueter then proposed using the Short 184 to attack the High Seas Fleet at anchor at Wilhelmshaven, but again was rejected. He then proposed an attack on the Austro-Hungarian fleet at its naval bases on the Adriatic- he managed to win over the First Sea Lord, Earl Jellicoe, who approved the deployment of Short 184s to a seaplane base in Italy to attack the Austro-Hungarian fleet at anchor at its main harbor base in Pola.

The attack was to take place on 2 September 1917 but on the eve of the operation a storm arose and the aircraft were unable to depart. The attack was postponed indefinitely and not resurrected before the war ended in 1918 as many in the Royal Navy felt that the seaplanes were better used for scouting and reconnaissance than for attacks on surface vessels.

Source: Ship Strike: The History of Air-to-Sea Weapons Systems by Peter C. Smith. Airlife Publishing, 1998, p9-12.