Fellow Contributors,
After some investigation I have some serious issues with the explanation on the Armoured Carriers site.
Any wire attached to the
nose of the torpedo would be IMHO a very poor idea. It is supposedly strong enough to support the weight (c1600 lbs) long enough to gain this preferred attitude on water entry yet manages to part exactly when required. Where "whiskers" for contact detonation are fitted, they might become entangled, and if the wire, once detached is still secured to the torpedo, it would stream back and become entangled in the rudders/propellers. Every other source I have found suggests the last thing required is a belly flop or worse still, first water impact on the delicate rudders. It is always emphasised that a nose first water entry is required to minimise shock to the gyro, pendulum mechanism and other delicate parts. Too high an impact in belly flop might even snap the torpedo in half.
Commonly used descriptions of the FAA Swordfish of WWII include “antique” or “flimsy” but as it only entered service in 1936 and its resistance to battle damage was legendary IMHO these are ill-informed. As a combat aircraft it had many shortcomings and against modern fighters or heavy AA defence it might have little chance of survival. It was out-evolved in the fighting role by more modern torpedo aircraft. What it could do, in addition to operating from flight decks in weather conditions which other aircraft could not consider, was use its slow speed stability to give its torpedo the most gentle possible water entry. At Taranto they were as low as 30ft off the water and some even kissed the surface with their wheels as they turned away. Darkness might allow the attackers some chance of survival, despite these tactics. In daylight such slow moving targets would likely be annihilated even before dropping their weapons since volume and accuracy of defensive fire had developed rapidly in just a few years. Faster, high performance aircraft needed to drop at higher speeds and for shallow harbours, techniques to minimise the dangers of high speed water impact and deep diving were required. The box tails and structures developed for the Pearl Harbor attack were necessary because the weapons were dropped from greater altitudes and faster speeds in daylight.
Reading Campbell’s Naval Weapons of WWII And Captain Sutton’s account on the FAA Museum website gives what I believe is the real picture on the “attached wire” story. Torpedoes need to be “vertical” in the cross sectional sense in the water, so as to apply gyro corrections to the vertical rudders and depth control to the horizontal. If the torpedo is not vertical, movement applied to the rudders may cause undesirable changes in depth and/or direction. Captain Sutton, a navigator/observer in one of the attacking aircraft described
Now the trouble with the torpedoes in those days was that they were converted ships’ torpedoes and had to be dropped extremely carefully into water. You had to fly - for a period after you had released it - easing it into the water - where there were two spools of wire attached to the aircraft which put it (the torpedo) nose down so it entered the water at the right angle and so we waited those few seconds - which seemed an immense period when you were doing it but a only few seconds after we released the torpedo.” The torpedo must be fired from at least 275m away.
Campbell says there was an air-tail which had limited aerodynamic capability, and fitted onto the horizontal rudders. This helped the torpedo enter the water nose first. Its main function however was to have two 18ft long wires attached to the outboard ends, which were wound on drums in the aircraft’s after fuselage, which payed out evenly as the torpedo dropped away, keeping it vertically orientated as it emerged from aircraft propwash and turbulence. The aircraft end of the wire was not secured and just ran off its drum. When the weapon entered the water, the air tail was torn off, complete with the wires, their job done. The torpedo was already correctly orientated for a relatively short run to the target.
The FAA had plenty of experience of harbour torpedo attacks, having used them against both Dunkerque at Mers-el-Kebir and Richelieu at Dakar. However, the bravery of the Taranto attackers in doing the same thing at night, through heavy AA fire and amongst barrage balloons is outstanding.
Faster aircraft, like the Beaufort and the Torbeau invariably used the Air Tail and later developments as they dropped their weapons from ever-greater heights and speeds. Since a torpedo is not aerodynamic, the enlarged unit Monotail was required to stabilise the weapon through a longer fall.
All the best
wadinga