247: Plans and Preparations

Description

The Italian Navy’s fleet-in-being strategy kept it safe from traditional surface engagements but left it vulnerable to an approach no one had tried in wartime: a nighttime carrier strike against ships at anchor. Admiral Cunningham’s plan, Operation Judgement, relied on the seemingly antiquated Fairey Swordfish biplane’s ability to conduct low-level night torpedo runs — a capability no other carrier aircraft of the era could match.

The target, the naval base at Taranto, was ringed with anti-aircraft guns, searchlights, barrage balloons, and torpedo nets — yet gaps in the Italian defenses, particularly the shallow and incomplete netting, gave the British a genuine chance. The episode lays out the full scope of the operation, which was just one element of the larger Operation MB8 flooding the Mediterranean with simultaneous British movements.

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Transcript

Hello everyone and welcome to History of the Second World War episode 247 - Taranto Pt. 1 - Planning and Preparations. This week a big thank you goes out to abcd, Siege Art, Hayden, Jim, Matt, Christopher, Trina for supporting the podcast by becoming members. Members get access to ad-free versions of all of the podcast’s episode plus special member only episodes roughly once a month. Head on over to historyofthesecondworldwar.com/members to find out more. The Mediterranean Sea was a critical area of naval operations for both the Italians and the British during the first years of the war. For the Italians they had to have some level of control over the Sea so that they could move troops and supplies to their various units in North Africa and the Balkans. For the British it was a way of protecting their ability to move their own forces around the Eastern Mediterranean, at least before the invasion of Crete, to protect the coasts around the Mediterranean from possible Italian action, and to support their continued defense of Malta in the central Mediterranean. From the very beginning of the war the British Mediterranean fleet, based in Alexandria Egypt had played an active role in attempting to curtail Italian operations within the Mediterranean and in North Africa. The commander of the fleet, Admiral Cunningham, had executed multiple fleet operations with the goal of engaging the Italian fleet in battle and destroying it. In these efforts Cunningham would experience the same issues that would have to be overcome by every naval commander throughout history, how to find a way to get an enemy to engage while maintaining a fleet of superior strength. Cunningham found this to be quite difficult in the Mediterranean because the Italians were generally pretty good at finding his ships with aircraft and then simply disengaging with their fleet if they felt they would be at a disadvantage. But while aircraft posed challenges for trying to ambush the Italian fleet while it was out at sea, they also presented some interesting opportunities for how the Royal Navy could use airpower to its advantage. In mid November 1940 the possibilities of that air power would be put on display when two groups of Swordfish bombers took off from the Royal Navy carrier Illustrious and attacked the Italian fleet at anchor at Taranto. They would use a mixture of bombs and torpedoes to attack the Italian battleships and shore facilities at Taranto, and they would be for the most part quite successful. For the months that followed the raid the balance of power in the Mediterranean would shift towards the British, which was fortunate for the Royal Navy because it would be asked to utilize most of its strength to assist in operations and evacuations from Greece and Crete in early 1941.

Before the Second World War the Italian Navy was seen as one of the premier navies of the world. Due to the restrictions placed on it by the treaty system that began with the Washington Naval Treaty, and the economic realities of Italy, it would never be as large or as powerful as the Royal Navy, but it also had a far more limited geographical scope to worry about. The Italian Navy only needed to concern itself with the Mediterranean, while the British would have to spread their forces out all over the world. And for most of the interwar period, the British and Italians were cooperating together and were far from enemies, at least until the late 1930s when Italian interests began to converge with that of Germany. When Italy entered the war it had a modern and very capable fleet made up of both modernized and modern battleships, including the new Littorio class battleships which were just entering into service in 1940. They were joined by a fleet of cruisers which were considered to be on par with anything the Royal Navy possessed and then many smaller destroyers and other vessels . Because of the emphasis placed on naval construction during the 1930s, when they entered the war Italian naval strength was greater than the Royal Navy complement in the Mediterranean, although the balance did shift as the British brought more ships into play. But the Italian fleet would always be a threat, and the Italian leaders knew it which is why they were far more concerned with keeping the fleet together than risking it in some kind of major fleet action. Using a fleet in being strategy, as long as the Italian Navy had its ships it could influence how the Royal Navy acted in the Mediterranean, even if the two groups of ships never actually met in combat. But there were things that the Italian fleet had to do, it could not just sit in port the entire war, and during 1940 one of its major tasks was convoy escorts, getting Italian men and supplies to North Africa and the Balkans. Each of these escort tasks put ships at risk, but everything in war is a risk.

On the Royal Navy side, they would be aggressive in the Mediterranean during the early part of the war, trying to use their strength to chip away at the Italian forces. The Royal Navy was never able to concentrate its forces in the Mediterranean though, and large portions of the Navy would always be retained in waters closer to home primarily to counteract possible German surface raiders. This meant that Cunningham was often dealing with a set of older ships, particularly in the battleship arena, where the best he received was a few of the modernized Queen Elizabeth class battleships. Importantly for the raid on Taranto, Cunningham would also have under his command at least one aircraft carrier during 1940, and they were the key to the attack on Taranto. The British carriers at this time carried what at first glance appeared to be an obsolete aircraft, the Fairey Swordfish. It was a biplane with rigid linen used instead of the all metal skin of many of its contemporaries. The Swordfish had been introduced into fleet service in 1936 and was generally well liked by the Royal Navy for its stability and reliability. It was not fast, with a top speed of just 143 miles per hour, over 100 miles per hour slower than the Stuka dive bomber which was already seen as too slow by the standards of 1940. But what the Swordfish could do was maneuver incredibly well especially at the very low altitudes where it would do its torpedo bombing missions. The Swordfish was, in general, the perfect example of reliable function over flashy form and if it could get into position, and if it could achieve some level of surprise it could be very effective. It is interesting that Swordfish torpedo bombers would feature in two of the most important early war successes of the Royal Navy, with the attack at Taranto and the hunt for the Bismarck both featuring the biplane. If you are wondering what a Swordfish looks like, I recommend looking up almost any book on the Taranto attack, because I think it is some sort of international law that any book about Taranto must feature a Swordfish on the cover.

Just as important as the aircraft used in the Taranto operation were the torpedoes that they would use to do most of their damage. The one in use at the time was the Mark XII torpedo which carried 388 pounds of explosives and if it was able to explode on or under a ship it would cause serious damage. Like many torpedoes at this time it did not need to actually hit the enemy ship to explode, but would also explode as it went under the ship due to the magnetic field generated by the giant hunk of steel that was a warship in 1940. This magnetic field disrupted a detonator which caused the explosion, and in some ways this type of detonation was actually preferred to the more basic contact explosion because the location of the explosion, and the way that water amplified the explosion could cause far more damage than a contact explosion . Importantly for the Taranto operation, the torpedo had to be dropped from under 200 feet, which meant that the Swordfish would have to be very close to the water on their attack runs. But this limitation was well understood and had been trained for, the Swordfish pilots knew what they were doing.

The city of Taranto is located on the western side of the heel of the Italian boot which meant it was perfectly positioned as a port that would allow the Italian fleet to control the central Mediterranean. The port facilities contained two anchorages, Mar Grande and Mar Piccolo. Piccolo was only suitable for smaller naval vessels, destroyers up to heavy cruisers, simply due to the depth and access to the anchorage. But Mar Grande was able to hold much larger ships and this is where the Italian battleships would be moored at the time of the attack. There had been work done over the years to build up breakwaters around Mar Grande to improve its ability to hold ships. There were also multiple moles, or piers that could be used by even the largest Italian ships. It was seen as the home base for the Italian battle fleet, which also meant that there had been a lot of thought put into its defenses in the years before the war. Just the breakwaters and the moles added some challenge to any attack, particularly from submarines or aircraft, but that was mostly just a side effect of those structures, they were primarily built to improve the harbor facilities. The dedicated defenses came in two different forms, active and passive. The core of the active defenses was of course anti-aircraft guns, of which many had been put in place in the years before 1940. There were a total of 21 batteries of 10.2cm or 4 inch guns, with some of them mounted alongside shore guns while others were on barges in the harbor to provide all around defenses. There were also a large number of smaller guns, 2cm and then even just machine guns which were mounted at various points around the ships. To assist these guns in finding and identifying targets there was a series of sound detection stations that were built so that any approaching aircraft would be heard far before it could launch its attacks. These sound detection systems had a range of around 25 miles under optimal conditions, which was more than enough to allow the gun crews to be put on alert and to prepare to meet any enemy attack. Once the aircraft were over the harbor they would have to try and dodge the 22 searchlights which were put in place with the goal of spotting an enemy aircraft and then keeping it illuminated to allow every gun in the vicinity to fire on the intruder. While the guns and the searchlights were active defenses, more importantly for defense against airborne torpedo attacks was the large amount of anti-torpedo netting that was designed to be placed around the harbor. There were around 4,550 yards which is just over 4,100 meters of anti torpedo netting available at the time of the attack. There was also around 3,000 yards, or just under 3,000 meters, of additional netting available that had simply not been deployed by late 1940. This lack of effort in the deployment of this netting was important because to be fully secure the harbor needed almost 14,000 yards of netting, or almost 3 times more than was actually in the water at the time of the attack. But the Italians were not overly concerned about air dropped torpedoes because they believed that they could not be used in the relatively shallow water of Taranto, with 40 feet of depth in many areas. In some ways it would not have mattered if there was more netting because it was also poorly designed to meet the British attack . The Italians were almost exclusively concerned with torpedoes with contact triggers, which meant that they had to actually hit the ships to detonate their warhead. Because of this the nets were quite shallow, they did not go to the bottom of the water and instead were just deep enough to ensure that for a torpedo to go under them they would also pass under the ships. The Royal Navy wanted to go under the ships to utilize the magnetic triggers, even if they were not always successful in doing so. The final type of passive defensive system was a series of barrage balloons. I think barrage balloons get a bad rap when it comes to their utility, but in the case of protecting against a night time attack by torpedo bombers they were quite useful. Any attacker would have to fly below the elevation of the balloons to launch their attacks, and at night there was no way for the pilots to see the cables that connected the balloons to the ground. Touching a cable could instantly take a wing off of an aircraft sending it quickly to the ground. Much like with the netting though, while they were a good idea, there simply was not enough of them to provide the level of defense required. The primary problem was that there was not enough hydrogen available to keep them aloft all of the time, and many of them would not be in the air at the time of the attack. Overall, the Italian defenses were nothing to scoff at, and the strength of particularly the anti-aircraft armament had to be taken into account by the British plan.

The beginnings of the Taranto plan started simply with the goal of utilizing an attack on Taranto as a way to damage the Italian Navy’s ability to protect the troop convoys that were shuttling reinforcements to North Africa, with the bonus that any damage done would also reduce the ability of the Italians to attack the Malta convoys. Right from the beginning a standard bombardment of the positions at Taranto was discarded, as the Italian Naval forces were simply too strong in the area, and Cunningham simply did not have enough capital ships to stage the attack. But an air attack did seem possible. In the mid 1930s the Royal Navy commanders at that time had put together an attack plan for Taranto, at a time when Italy and Britain appeared to be headed towards war during the Abyssinian Crisis. This plan was referenced but of course heavily updated for the new requirements. The job of updating the earlier draft was given to Captain Lyster, who was at that time in command of the carrier Glorious, which would not be used for the operation as it would be lost during the Norwegian campaign. While many of the specific details would change, there were many things that would remain the same. First and foremost, the attack would happen at night to increase the likelihood that the attack would be a surprise while also providing the British aircraft with at least some protection due to darkness. Airborne interception of aircraft at night was very challenging, almost impossible with the technology available to the Italians in 1940, and so using the darkness as cover for the Swordfish would remove the very real possibility of being intercepted and shot down by Italian aircraft. However, it was important that the operation not happen on a night without some moonlight, otherwise the Swordfish aircrew would not be able to actually see anything to launch their torpedoes at. The best situation would be for a relatively calm night with a good amount of moonlight that could be used for target identification and attack. It is worth noting that the Royal Navy’s aviators were probably the best airmen in the world for night time carrier operations at this point in the war. Being able to launch, attack, and recover all under the cover of darkness was an ability that other nations would either discard entirely or never be particularly good at. Even under perfect conditions there was still some concern about the ability of the Swordfish crews to see their targets and so part of the plan would involve several Swordfish which would play the role of pathfinders. They would drop flares over the port for illumination so that the other aircraft would have an easier job finding their targets. In each wave of 15 aircraft 1 Swordfish would have the important job of dropping these flares. Speaking of waves, a total of 30 Swordfish were planned, with 2 waves of 15 aircraft that would arrive at slightly different times. Not all of the aircraft would be armed with torpedoes though, and instead a total of 10, or 5 in each wave, would be equipped with bombs that they would try to use to attack any cruisers or destroyers that they found in the port. This would later be seen as a mistake, but at the time the idea was that the bombing aircraft would cause at least some confusion among the defenders due to their different attack profiles. If everything came in low and launched torpedoes the defenders might be able to concentrate too much fire on them, whereas if there were also dive bombing attacks happening it would at least split Italian focus. Then once the aircraft launched their attacks they would head back out to the carriers, where they would land and be prepared for the next attack. One interesting feature of these plans was that next attack, because in the action that would happen at Taranto there would only be one night of attacks, however in the plan as it was written there was supposed to be a second attack the following night. This would involve a single wave of 15 aircraft, again with the mix of torpedo and bombing aircraft to clean up any Italian ships that were found to be still floating. Launching a two night operation would have required the carriers and their escorts to stay within attack range, which is why this second night did not end up happening. The greatest concern was the possibility of an Italian air attack, or some kind of surface action, even though the carriers involved would be escorted by a strong force of cruisers and destroyers, with four of both being detailed as the screening force. While this type of operation had never really been attempted during wartime, it was not some sort of completely wild idea, and even from the very beginning it seemed very likely that it could be successful.

The original plan involved the participation of two carriers, the Eagle and the Illustrious. However, there were some problems with the Eagle which caused it to be removed from the operation. The problem revolved around the carrier’s fuel system due to a near miss during an Italian air attack. The end result is that there would be fewer Swordfish available than the plan called for, simply because they would not be present. 6 Swordfish would be flown over from Eagle to Illustrious, but this could not make up for an entire carrier worth of aircraft. This was the latest in the list of challenges experienced by the carriers, with the operation originally delayed from the October 21st start date due to a fire in one of Illustrious’ hangars. Then it had to be delayed again due to weather concerns before finally being rescheduled for the second week of November. All of this date shifting was important because the raid on Taranto was actually just one part of a much larger operation called MB8. These operations would involve multiple convoys of merchant ships moving all over the Mediterranean, from the west, the north, and the south. There were also multiple different attacks on Italian military facilities, including one from Force H based in Gibraltar in the form of an air attack against an Italian air field on Sardinia and another attack by British cruisers on the Italian forces in the Strait of Otranto. The Taranto raid would be named Operation Judgement and was just one part of this larger endeavor. All of this was being done at one time for two complementary reasons. The first was that by launching a large number of naval operations at one time the Italians would hopefully be quite confused and the movement of the ships for Operation Judgement in particular would be lost in a sea of noise. But also, all of those convoys did need to move, and by doing them near the same time, and with other operations also occurring, it just limited the possible Italian response. There were only so many Italian resources, and with 4 convoys and 4 military operations all happening at the same time they could not react to all of them. The most important of these operations was Judgement though, it was the only one that had the chance of meaningfully changing the course of the war. I hope you will join me for the next episode, which will cover the momentous events in the skies over Taranto on the night of November 11/12 1940