With restricted development funds for new aircraft projects and limited capacity in their carriers, the British favoured multi-role naval aircraft, often compromising all major characteristics to obtain this end. They were also forced for longer than the Japanese and Americans to retain biplane torpedo bombers: the Blackburn Shark, Fairey Swordfish and Fairey Albacore. That the brave Fleet Air Arm crews were able to achieve great successes with these last two obsolete types reflects greatly on their courage and professionalism.
And even when they moved on to an all-metal monoplane in the Fairey Barracuda, the Navy insisted on combining in one aircraft the characteristics of a dive-bomber and torpedo bomber. The enormous combined dive brakes and flaps certainly aided slow-speed deck landings, but their aerodynamic drag limited the range/endurance and climbing ability of these underpowered aircraft. And they were far from vice-free: retracting the dive brakes and applying rudder at the same time could result in an inverted dive, fatal on a low-altitude torpedo run; again the hydraulic system had a nasty habit of spraying ether in the pilot’s face, quickly rendering him unconscious. The luckier aircrews were glad to convert to the powerful and well-designed Grumman Avenger. The Avenger often carried bombs, but the specific dive-bomber role was taken over by the Curtiss Helldiver. The Avenger would be the torpedo bomber which sank both Japanese 70,000-ton super-battleships, Musashi and Yamato.
Many Second World War aircraft were fitted to drop torpedoes. German experiments went so far as to fit torpedo gear under a Focke-Wulf Fw-190 and even a Junkers Stuka, but normal Luftwaffe torpedo bombers were the Heinkel He-111 and He-115, and later the Junkers Ju-88. On the Italian side, their most successful torpedo bomber was the three-engined SM.79, which caused severe losses to British warships and transports in the Mediterranean.
RAF Wellington bombers operating out of Malta decimated Italian resupply convoys to North Africa, carrying two torpedoes apiece. And the reason the Avro Lancaster was able to carry such large bomb loads is because originally the bomb bay was intended to carry several torpedoes. The only USAAF twin-engined aircraft to carry a torpedo was the Martin B-26 Marauder, which flew from Midway to attack the Japanese carrier force, but the US Navy’s ‘Black Cat’ crews used Catalina flying boats armed with two torpedoes in night sorties against Japanese shipping.
Perhaps the most successful torpedo bomber concept was the Bristol Beaufighter. Following heavy losses of Bristol Beaufort torpedo bombers in attacks on Axis convoys in the Mediterranean, it was decided to clear the way for them by suppressing the flak defences with Beaufighters, heavily armed with four 20mm cannon, six.303 machine guns, and, later, rockets. The logical development was to add the torpedo under the belly of the Beaufighter itself, which could then carry out its own flak suppression on the attack run. The sturdily built Beaufighter could not only defend itself, but was capable of absorbing quite an amount of battle damage, and its twin air-cooled Hercules engines aided survivability.
US NAVY TORPEDO PLANE TACTICS
In 1945 the US Navy produced a training film which described the torpedo as ‘the most potent single weapon of destruction against enemy shipping’. Since Grumman Avenger torpedo bombers had just sunk the Yamato, they had good reason to be proud of their record. The purpose of the film was to explain the recent launch techniques, described in the film’s subtitle High Speed, High Altitude. The Americans had learned many lessons at the hands of their opponents in the Pacific, and the new techniques pioneered by Japanese naval pilots were eagerly taken up by the US Navy.
Although successful torpedo drops had been made from as high as 2000ft (610m) and 360 knots, repeated tests had shown that optimum torpedo performance and reliability called for 260 knots at 800ft (243m). Their experience had shown that out of 2000 torpedoes dropped correctly, 92 per cent ran hot, straight and normal, with a higher percentage of hits than any other form of aerial attack against shipping.
Every pilot trained by following the procedures laid down in the torpedo launching guide, in which he could read off combinations of height, speed, glide angle and range to target. The optimum, often stressed, of 260 knots at 800ft involved a torpedo water entry angle of about 28 degrees after a time of fall of 7 seconds, and a horizontal distance of 3000ft (914m) between point of release and water entry. He was advised to add at least 400yds (366m) for water run, meaning he released at a horizontal distance of 1400yds (1280m) from where the enemy ship would be when the torpedo hit.
Pilots executing power dives from high altitude needed to reduce speed and commence a shallow glide, dropping the torpedo at 800ft. Too steep a glide angle and the torpedo risked damaging itself or, in shallow water, even hitting the bottom. Conversely, too shallow a water entry, and the torpedo controls risked not functioning correctly. The comprehensive tables gave allowances to be made for cross-wind, and gave aim-off points for various ship lengths and speeds.
If a ship manoeuvred to try to avoid an initial attack, following pilots were trained in ship turning characteristics, such as the length of time for the rudder to take full effect, and the loss of speed of different types of ship when turning at full power. From this, with extensive practice they could estimate the correct aiming-off. The most common mistake was to underestimate ranges, as proved by post-combat analysis from the onboard camera. Dropping too far away gave the target time to evade, dropping too close could prevent the torpedo from arming. The Americans possessed a great advantage in that their torpedo bombers were large enough to carry onboard radar sets, and these were used to give slant ranges to target ships.
MODERN MARITIME PATROL AIRCRAFT
These still carry torpedoes, but normally in an antisubmarine role only. The Lockheed P-3 Orion, for example, is fitted to carry the Mk 44, Mk 46, Mk 50, Mk 54 and MU90 torpedoes.
The USA’s Cold War Soviet counterparts made good use for decades of the large Tupolev Tu-95, codenamed ‘Bear’ by NATO, whose four economical turboprops gave it a vast patrol range.
