The Regia Marina (Royal Italian Navy) explored various projects for adding one or more aircraft carriers to the fleet in the 1930s but took no action beyond developing a basic design for constructing a new vessel and identifying suitable candidate merchant ships for conversion. In mid-1940, as Italy prepared to enter the war as an ally of Germany, a design was prepared for a simple conversion of the fast liner Roma into an aircraft carrier, but again was deemed less of a priority than other construction and set aside in January 1941.

It took the shock of defeat at Cape Matapan (March 28, 1941), which the Italians largely attributed to effective British deployment of its carrier Formidable, to revive demands for a carrier as an urgent requirement. In July 1941 the Undersecretary of the Navy authorized the conversion of the Roma into a carrier, using the design studies of the previous year as a basis. In the event, the project became much more ambitious and required a major transformation of the relatively elderly liner into the carrier Aquila.

Initially, the Regia Marina planned the Aquila (“Eagle”), as the new carrier was to be called, as bare-bones, minimum-effort conversion that would get aircraft to sea in minimal time. However, unanticipated minor problems and the navy’s understandable desire for the maximum possible capability in what might prove its only aircraft carrier led to a spiralling of new features, greater complexity, and mounting delays. To improve the hydrodynamics of the hull, increase fuel capacity, and provide the underwater protection naturally lacking in a merchant hull, large bulges were installed on either side of the hull at the waterline. The interior of the ship was completely gutted to make room for a large hanger with space for 40 airplanes, aviation stores, workshops, and accommodation for a crew of 1165 naval personnel and 243 pilots and support personnel from the Regia Aeronautica. A full-length flight deck topped the hanger, with a large island on a sponson to starboard. For protection against surface threats, the ship received eight 135-mm (5.3-in) L45 guns in single mounts along either side of the deck. Antiaircraft defense was supplied by twelve 65-mm L64 guns in single mounts along the deck edges and 132 x 20-mm L65 Breda machine guns in 22 sextuple mounts along the deck edges and fore and aft of the island. A small amount of armor—some in the form of concrete—was distributed around vital areas of the ship. On the whole, a well thought out, state of the art carrier thus emerged from all of this effort, but, as we shall see, at a fatal cost in time.

Displacement: 23,350 tons (standard), 27,800 tons (full load)

Dimensions: 759’2″ (oa) x 96’6″ x 24’0″

Flight deck: 700’0″ x 83’0″

Machinery: Belluzzo geared turbines, 8 Thornycroft boilers, 4 shafts, 140,000 shp = 30 knots

Bunkerage: 2,800 tons = 4,000 nm @ 18 knots

Aircraft: 36; some sources say Aquila’s air group would have been fifty-one Re2001’s, some of which were to be modified to carry a torpedo.

Armament: 8 x 5.3″, 12 x 65mm AA, 22 x 6-barrel 20mm AA

Complement: 1,420

The superstructure was razed completely and a large hangar 525 feet long and 59 feet wide was erected beneath the steel flight deck. The Roma’s original power plant was replaced completely with two sets of machinery originally intended for light cruisers of the Capitani Romani class, raising the carrier’s speed from 21 knots to 30 knots. The furnace uptakes were trunked to starboard into a very large stack that was incorporated into a substantial island structure. Two elevators connected the hangar and flight deck, which carried two catapults and full arresting gear. All armament was fitted on platforms sponsoned out from the ship’s side. Magazines and aviation fuel stowage were created and protected by 3-inch armor decks. To ensure stability and provide effective defense against torpedo attack, the hull was fitted with deep bulges on each side.

When Italy surrendered on September 8, 1943, the Aquila was virtually complete. The Germans seized the ship but it was heavily damaged by United States Army Air Force bombing on June 16, 1944 and a human torpedo attack on April 19, 1945. On April 24, 1945, the ship was scuttled at Genoa. After World War II the ship was raised and taken to La Spezia in 1949. Initially the Italian Navy considered refitting the Aquila for service as a carrier but this plan was abandoned and the ship broken up in 1952. In late 1942 the Regia Marina decided to add a second carrier to the fleet and began a simple conversion of the liner Augustus along the lines originally proposed for the Roma.

Slow progress on the extensive Aquila conversion and the obvious need for additional carriers led the navy to revive the idea of an austere, minimum-change liner conversion in 1942. The liner Augustus was selected for conversion as the Sparviero (“Kestrel”). It was designed to be, essentially, a large escort carrier. Sparviero was to have a continuous flight deck surmounting a simple, hull-top hanger, but no island. Torpedo bulges were fitted to the hull, but no other major modifications were considered. The air group was to be limited to 20 aircraft. Gun armament would consist of six 152-mm (6-in) single-purpose guns and four 102-mm (4-in) antiaircraft guns. With a waterline length of 664 ft (202 m), a beam of 83 ft (25 m), a draft of 30 ft (9 m), she was roughly the same size as Aquila. But her original, tired diesel machinery would give only a fraction of the earlier carrier’s power—28,000 hp on 4 shafts—and a maximum speed of only 18 knots.

When the ship, by then renamed the Sparviero, was seized by Germany after Italy surrendered only the superstructure had been razed. The hulk was scuttled on April 24, 1945, in an attempt to block the entrance to the harbor at Genoa. It was raised in 1947 and scrapped.

The air groups for these carriers were particularly well-conceived. Rather than developing the plethora of limited-production, specialist types that typified the opposing Royal Navy Fleet Air Arm, the Regia Aeronautica standardized on a single type and adapted it to fulfill all the roles required of a naval strike aircraft. This would simplify the provision of spares and the training of naval pilots. It would maximize the number of aircraft that could be accommodated (51, including the deck park), and it would give the air group unparalleled flexibility. For strikes against enemy naval units, all aircraft could carry antiship ordnance, because each of the strike aircraft was capable of defending itself against combat air patrols. At the same time, in the event of an attack on the Aquila, all available aircraft could be used as fighters. There were no clumsy dive bombers or torpedo planes to be cleared from the deck in such a crisis.

For this one, multirole aircraft, the navy settled on the Reggiane Re.2001, the higher-performance, inline-engined version of the familiar Re.2000. The Re.2001 closely resembled the Re.2000 in almost all respects. But the bulky, trouble-prone Piaggio P.IX radial engine gave way to a liquid-cooled, Alfa Romeo RA.1000 RC.41a Monsone V-12, a license-built Daimler-Benz DB 601 offering 1175 hp for takeoff. At same time, the the Re.2000’s wing structure was redesigned to replace the leak- and fire-prone integral wing fuel tanks with more conventional armored fuel tanks, supplemented, when required, by a large torpedo-shaped drop tank under the fuselage. The Falco’s twin, nose-mounted, 12.7-mm Breda-SAFAT machine guns were supplemented by a 7.7-mm gun in each wing. Maximum speed increased to 339 mph (545 kmh) at 17,946 ft (5470 m) and range, on internal fuel, was 684 mi (1100 km).

Difficulties with license production of the DB 601 engine limited initial orders for the Re.2001 to only 120 aircraft. But, of these, fully 50 were Re.2001OR (Organizzazione Roma) models, specifically intended for the carrier project. The Re.2000OR incorporated strengthened landing gear and airframe components to cater to the higher loads anticipated during shipboard landings. A large, A-frame arrestor hook was fitted to the reinforced rear fuselage, and the airframe was finished in the elegant, overall pale grey-blue first seen on the Re.2000 catapult fighters. The naval aircraft retained the bomb shackle standard on land-based Re.2000 fighter bombers and could thus handle the naval bomber role. Weapons would probably have included a standard 551-lb (250 kg) demolition bomb and a special, 1389-lb (630-kg) armor-piercing antiship bomb.

While the Re.2001OR was admirably suited to the naval fighter and bomber roles, it could not fulfil the vital torpedo carrying mission as built. While bombs might cripple a ship, the torpedo was still the only weapon that could reliably strike below the waterline and sink ships. Accordingly Reggiane modified one of the Re.2001ORs (MM.9921) to carry a light torpedo as the Re.2001G. This was ready for flight tests in June of 1943, but crashed before torpedo trials could begin.


USN Fire-Control Interwar I

The competitive system of target practice repeatedly exposed limitations in the fire-control system. Range finders often gave inaccurate initial estimates, leading to erroneous range rates and poor shooting. It took time to correct these errors and bring the salvoes onto the target. Because the exercises were timed—reflecting the need to hit the target quickly in battle—they could end before some ships scored any hits. Fire-control officers faced a lot of pressure. They had to be able to rapidly synthesize many data points (estimates of target range, range rate, spotting corrections) from a variety of sources (range finders, plotting and tracking boards, electronic telephones) to determine how to bring the guns on target. In some practices, they were not up to the task. There was too much information to process and synthesize in too little time.

The Navy needed to augment the system with a device that could gather together all these different sources of information, process them, and build a model of the target’s movements in real time. With a more comprehensive model, officers could focus on bringing the guns onto the predicted point and then refining the model based on feedback from spotting, range-finder ranges, and observations of target bearing. Rear Adm. Joseph Strauss, chief of BuOrd, spoke to this goal in his annual report for 1915: “As the fighting ranges increase, the necessity of a simple yet efficient means of keeping the range becomes more pressing, and the bureau has experimental instruments under construction which it is hoped will aid materially in the solution of this problem.” He addressed the same theme the next year: “Increased attention is . . . being devoted to the development of instruments that will get and keep the range with the greatest precision possible, having in mind conditions as they will probably exist in battle as indicated by reports of naval engagements in the present war.”

Reports from World War I suggested the Navy was behind British and German standards; they were opening fire at 20,000 yards and fighting beyond 15,000. The Navy’s 1914 practice firings were only from 10,000 to 12,000 yards. Greater ranges would require better tools. The fire-control board of 1916 was more specific in its recommendations: move away from the Mark II Plotting Board, which was then in general use.

The rate of change board (Mark II plotting board) . . . provides a sample method of plotting a curve of rate of change, using range finders and spots. With sufficiently good observations the past rate of change can be obtained and used in connection with the sight-bar range while “straddling” for holding the range. Excellent results have thus been obtained on long range target practices. Such practices however, are necessarily restricted, both in rate of change practicable and, more particularly, in changes in the rate of change,—as compared with what may be expected with own ship and target running at high speed and on varying courses,—as they both may do in station keeping and . . . in attempting to evade fire. For these latter conditions, results from the rate of change board are likely to lag too seriously for efficient range keeping.

The board recommended keeping the range automatically with a mechanical “range keeper” that could model the movements of the target and maintain the firing range through a variety of complex maneuvers. The board argued that the system should work in such a way that “changes in range due to own ship’s movements may be applied as nearly as automatically as practicable, to the end that the ship may be free to change course and speed without loss of accuracy.” Its members thought that true-course plotters could allow for this but that what was needed was a new device, a mechanical, rangekeeping computer.

The Ford rangekeeper was the solution. It was the brainchild of Hannibal C. Ford, an extremely talented mechanical engineer who had been introduced to the challenges of fire control by Elmer Sperry. Ford joined Sperry’s company in 1909, helping to develop the gyrocompass and becoming the lead engineer for Sperry’s battle tracer. In 1915, Ford resigned from Sperry’s company and founded the Ford Marine Appliance Corporation, later renamed the Ford Instrument Company. In 1916, Lt. Cdr. F. C. Martin, responsible for the Fire Control Section in BuOrd, began discussing the idea of a rangekeeping device with Ford.39 These discussions led to Ford’s first product, the Navy’s Rangekeeper Mark I.

Ford’s rangekeeper sought to address two critical problems with the Navy’s existing system. The first was that the tracking and plotting mechanisms were manual, slow to develop a solution, and error-prone; their feedback loop took too long. The second problem was that there was no automated means of controlling for the movements of the firing ship; if it turned or maneuvered, the fire-control solution—the range rates that had been developed—had to be recalculated. Ford solved these issues with an automatic calculation mechanism that provided more rapid feedback to the fire-control officer. The rangekeeper reduced his cognitive burden, allowing him to devote more concentration to the model and the corrections necessary to bring the guns onto the target.

The rangekeeper integrated two separate internal models, one for the motion of the firing ship and another for the target. From these models, it continuously generated a series of outputs required by the fire-control system, including the range and deflection (or bearing) settings for the guns. It integrated well into the existing fire-control system, providing a much more accurate model without the need for redesign. The required inputs were readily available (like firing-ship course from the gyrocompass) or already being gathered by the system (like target range and speed). Some of the inputs, like target bearing, could be provided automatically using the data-transmission system. Because of the smoothness with which the rangekeeper integrated into the existing system, plotting devices could continue to serve as a backup if it failed, and established practices—like spotting—did not have to change.

What did change, and changed significantly, was the way the fire-control officer assessed the accuracy of the model of the target’s movements. Ford designed his machine to provide a great deal of feedback about the quality of its internal model. On its face was a graphical representation of the target. This representation built on the approach Reeves and White introduced in the change-of-range projector. A disk representing the target rotated to reflect its estimated course, and a “button” along its length indicated its estimated speed, just as the projector’s “pin” had done. Two wires were placed over this representation. One wire indicated the observed range to the target and the other the observed bearing. If the rangekeeper’s model was accurate, these two wires would intersect over the target speed “button.” If they did not, the operator knew immediately that corrections were necessary; he could get a sense of what they might need to be by which wires were off and by how far.

This level of feedback was possible because Ford’s design separated the motion of the firing ship and that of the target. Although similar computing devices were developed in the early years of the twentieth century, Ford’s was the only one to maintain this separation. It allowed fire-control officers to check and refine the accuracy of their solutions before opening fire. Previously, spotting was the only real feedback loop in the system. With the rangekeeper, observations of the target provided a constant check of the developing model, allowing it to be enhanced continually and permitting more accurate fire. Ford’s decision was likely influenced by his discussions with Martin and his work with Sperry’s battle tracer, which also separated the motion of the firing ship and the target. Regardless, the choice was crucial and one of the most valuable features of the rangekeeper.

The value of feedback was reflected in the initial revisions to the instrument. The first models automatically took in target-bearing information from the data-transmission system. This was quickly replaced by a follow-the-pointer mechanism allowing a manual check. The rangekeeper generated its own prediction of target bearing and displayed it on the face of the instrument alongside the observed bearing. If the generated bearing and observed bearing did not agree, the solution could quickly be corrected. A second modification added a graphical plotter that automatically recorded observed ranges. These could be compared with ranges generated by the instrument, giving the operator a quantitative sense of necessary corrections and augmenting the information from the horizontal wire in the instrument’s face. Rapid feedback was an integral aspect of the rangekeeper’s design and a core reason why the Navy considered the Ford superior to other candidate devices.

The rangekeeper was initially tested on the battleship Texas in 1916, and a board was assigned to assess the results. The board’s report was very positive; it considered the rangekeeper superior to any other method and recommended installation on every battleship. Production versions started being installed in 1917. The first ships to receive rangekeepers were the most modern battleships. By early 1918, each of the Navy’s dreadnoughts had at least one system. By the spring of the same year, eleven of the older predreadnoughts had them as well.

However, the reception in the fleet was not as enthusiastic as might have been expected. Although the rangekeeper offered a dramatic improvement in potential accuracy, the simplistic conditions of gunnery exercises did not always require such a sophisticated tool. BuOrd was compelled to respond to criticism from the fleet and justify its decision to adopt the new device: “The machine was designed to deal with difficult conditions we expect to arise in battle, where changes of course and speed will be frequent and vision poor. It is impossible to reproduce anything well like this in target practice, and, therefore, not an easy matter to get people to realize the importance of taking these conditions into consideration.” Experience in World War I and exposure to the rigorous gunnery practices of the RN led to more challenging exercises. Combined with increasing familiarity with the rangekeeper, these helped the fleet embrace its use.

The introduction of the rangekeeper gave the fire-control system a sophisticated brain; self-synchronous data-transmission systems gave it a more effective nervous system. Sperry’s systems had two specific limitations. They lacked the precision for transmitting range data, and because they transmitted information in a series of steps from a “zero” level, they had to be periodically synchronized—set back to zero—to ensure alignment. If they became misaligned in battle, the ship would have to revert to telephonic communications. In 1918, BuOrd began looking for a solution that supported automatic synchronization and increased precision.45 By this time, Cdr. W. R. Van Auken had replaced Lieutenant Commander Martin in the bureau’s Fire Control Section. Van Auken discussed the problem with Ford. The bureau’s history of World War I describes what happened next:

When the elevation system was discussed, all thought was expended toward a design using synchronous motors. About January, 1918, Mr. Ford was called into conference by Commander Van Auken and the manufacture of this system was placed in his hands. In May the first unit, the range converter, was accepted. This was modified as required and in September, 1918, the New Mexico obtained the first synchronous follow-the-pointer elevation installation. This Bureau-Ford system is now being installed on all major ships.46

The introduction of self-synchronous systems allowed the Navy to reconfigure the transmission of data the same way it did telephonic communications, dramatically increasing the flexibility and safe-to-fail characteristics of the system. Switchboards were expanded to allow the dynamic reconfiguration of data-transmission systems. Through the switchboard, any director could become the primary source of target bearings; if two targets were being engaged, the system could be divided and two directors used simultaneously, each driving a separate rangekeeper. Different turrets could be connected to different directors and rangekeepers, depending on the circumstances. The ability to self-synchronize allowed the system to be reconfigured on the fly. The advantages were so great that self-synchronous systems for elevation and bearing became the standard in new ships and were retrofitted into existing ones.

The ability to reconfigure the system dynamically and cross-connect components created new opportunities. A feature known as the “stable vertical” capitalized on this potential and addressed a major source of human error. Even if the solution developed by the rangekeeper was correct, the accuracy of individual salvoes could vary because of the reaction time of the director operator. He had to fire the guns at the right time in the ship’s roll, usually when the horizontal wire of his telescope was parallel to the horizon. If he pressed the firing key too early or too late, the shells would miss the target. If the horizon was obscured, either by smoke or poor visibility, this was much more likely. The stable vertical solved these problems. It was a gyroscopically stabilized artificial horizon that could be used when the actual horizon was obscured. When connected to the fire-control system, the stable vertical could fire the guns automatically when the ship’s deck passed through the horizontal plane, eliminating errors due to the director operator’s reaction time or view of the horizon.

Introduced on the Navy’s Colorado-class battleships, the stable vertical increased the accuracy of fire, particularly at longer ranges—where minor errors had a greater influence—and in conditions of poor visibility. Because the fire-control system could be easily reconfigured through the switchboard, it was simple to incorporate the stable vertical into the system and have it fire the guns. The stable vertical was a modular upgrade made possible through the system’s open architecture. As older ships were modernized, it was retrofitted into them, and once sufficient experience had been gained, it became the primary indicator of the ship’s inclination for fire-control purposes, replacing the eyes of the director operator.

The final ingredient in the Navy’s standardized fire-control system was the creation of a specific language for communicating information between and among the various stations. Precise details had to be communicated quickly, clearly, and succinctly over the telephone circuits. Each circuit was a party line, meaning every station connected to the line could hear all the others and transmit information over the circuit to any. On a battleship, there could be as many as twenty-one stations patched into the captain’s battle circuit. It was essential to keep communication brief and convey as much information as possible in a short amount of time, as explained by a 1940 manual:

The development of efficient communications is one of the most important problems in the training of a fire control organization. . . . Successful communication requires, first . . . a satisfactory system of telephones and other transmitting instruments, and second, properly trained personnel. . . . The second requirement, however, is not one that can be met by mechanical perfection of instruments, or by prescribing hard and fast rules for personnel. It demands careful indoctrination and training so that every individual is familiar with the problem at least as it concerns his immediate station and those with which he is in communication, and is prepared to act intelligently in any contingency.

The fire-control system required a communication method with a very high signal-to-noise ratio. Existing English-language structures were insufficient to meet the need; the manual continued, “The demand for brevity has resulted in the development of numerous stereotyped phrases and modes of expression. They constitute what may be termed a ‘fire control language.’”

Specific rules—representing an increased level of constraint—were developed to guide communications. Numeric values were transmitted by enunciating each digit separately, except in cases when the last two digits were zero, said as “double oh.” A range of 13,350 yards, for example, was communicated as “Range one-three-three-five-oh.” A range of 29,000 yards was, “Range two-nine-oh-double-oh.” Spotting corrections were similarly constrained. “Up” increased the range; “down” decreased it. Deflection corrections were “left” and “right.” To prevent confusion between the two, “oh” was always added immediately after the word “right.”

This language significantly reduced the length of communications and the time necessary to convey information. Additional rules governed how to address specific stations, how to acknowledge information, and how to transfer responsibilities from one station to another. The development of this language triggered a new level of complexity and standardization within the Navy’s fire-control system. It was a new enabling constraint that enhanced the capabilities of the system and broke symmetry with what came before.

USN Fire-Control Interwar II


The Navy’s complete fire-control system, as it emerged in the years immediately after World War I and installed on its most modern battleships, the 16-inch-gunned Colorado class, was the most sophisticated in the world. The various elements of the system—the Ford rangekeeper, the stable vertical, reconfigurable connections, data-transmission systems, and a standard vocabulary—had come together to form a cohesive whole that dramatically increased the effectiveness of the officers and men responsible for bringing the guns onto the target. This had several important implications for the development of tactical doctrine in the interwar period.

The system enabled the “very rapid postwar development of U.S. naval gunnery,” which increasingly emphasized long-range gunfire using aerial spotting. It triggered the development of more sophisticated battle tactics designed to seize the initiative from opponents and keep them off balance. The system also provided a solid foundation for future investment; alone among the world’s major navies, the U.S. Navy emerged from World War I satisfied with its fire-control system. This meant that future research and development could focus on enhancing it while other navies struggled to bring their systems up to the new standard.

Wartime experience illustrated that seizing the initiative in a modern naval battle could be decisive. The Navy hoped that it could use aggressive offensive action and accurate long-range gunfire at the start of an engagement to control its pace and gain an advantage over the enemy. The War Instructions of 1923 clearly made this point, stressing that victory could best be obtained through the “assumption of the offensive, which confers the advantage of the initiative and enables us to impose our plan on the enemy.” By opening fire at extreme range, the Navy hoped to force an enemy formation to maneuver, possibly disrupting its transition from approach to battle formation. This would put the enemy on the defensive and prevent him from executing his plans. Having obtained the initiative from the outset, the Navy expected to be able to fight a decisive battle and secure victory.

A second advantage of firing at long-range was the increased likelihood of scoring a hit on the deck of an enemy ship. This had important implications. First, it increased the probability that a hit would penetrate vital areas—like machinery spaces or magazines—of the target. Second, the chances of a penetrating hit would be the same regardless of the target angle presented by the enemy (the firing ship’s relative bearing from the enemy). At closer ranges, hits would strike the hull and be less likely to penetrate at certain angles.

Finally, as Norman Friedman’s numerous design studies have shown, the Navy’s battleships enjoyed a relatively high level of protection against “plunging fire.” Beginning with the ships of the Nevada class, authorized in 1911 and designed under the new General Board process, all of the Navy’s battleships had featured the “all-or-nothing” armor scheme. Employing only the heaviest armor over the most vital portions of the ship and only light plating elsewhere, “all or nothing” was the first battleship armor scheme specifically intended to protect the ship in combat beyond ten thousand yards. The Navy’s twelve most modern battleships featured this scheme. The battleships of other navies had been designed with “incremental” armor schemes, patchworks of varied thicknesses with much less deck protection, designed for battle at significantly shorter ranges.

Long-range fire introduced a challenge for spotting. To make corrections effectively, spotters had to be able to see the impact of shells that missed the target. They had to be able to observe the target’s waterline and thereby gauge the distance between the target ship’s hull and the splashes of missing shells. At longer ranges, when the target’s hull was below the horizon, it was nearly impossible to adjust the fire-control solution accurately. This effectively limited the maximum range of battleship gunfire to between 22,000 and 26,000 yards. The only way to increase this distance was to increase the height of the spotting position. Masts could only be built so high; aircraft proved an ideal solution.

On 17 February 1919, the battleship Texas conducted a long-range firing exercise using aerial spotting. Radio was used to relay spotting data back to Texas, and observations from the plane proved much more effective than spotting from the masts of the ship. Lt. Cdr. Kenneth Whiting, in testimony before the General Board, estimated the increase in effectiveness to be as large as 200 percent. The Navy embraced aerial spotting as the key to long-range gunfire. Gunnery lectures and war games at the Naval War College reflected assumptions about its effectiveness, and as early as 1922, the Bureau of Aeronautics was advocating increased elevation for battleship guns (to allow firing at longer range) because of the greater accuracy aerial spotting made possible.

The capabilities of the Ford rangekeeper created new tactical possibilities. Because it could accurately model continuously changing range rates, the Navy began to consider using maneuver to gain an advantage in battle. Manual plotting approaches, like the Mark II Plotting Board, depended on keeping a steady course with relatively consistent range rates. This is one reason why opposing lines of battleships tended to settle on parallel courses. With the rangekeeper, the Navy had a system that could model the challenging situation of a target steaming on an opposite course. This was a significant potential advantage.

Beginning in the late 1920s, the Navy began to experiment with the concept of fighting on a course reciprocal to that of the enemy, what it called “reverse action.” The evidence suggests that the Navy assumed that the more primitive fire-control systems of the most likely opponent—the Imperial Japanese Navy (IJN)—would be unable to deal adequately with the rapidly changing range rates. The enemy would be forced to fight at a disadvantage or to reverse course, a dangerous maneuver in battle. Either way, the Navy expected to gain a tactical advantage.

Accuracy of Battleship Gunfire at Long Ranges

Source: Capt. W. C. Watts, “Lecture on Gunnery for War College Class of 1923,” 22 September 1922, table E, 46, Strategic, box 13.

Immediately after World War I, there was a global emphasis on reducing military expenditures. National governments participated in a treaty system that reduced the sizes of all major navies and restricted the ships they could build. Large wartime budgets evaporated, and critical decisions about how best to invest the limited available funds had to be made. Because the Navy had already developed an effective fire-control system, investment in this area could be kept relatively low. This was a major advantage. The RN, in contrast, had concentrated on a less sophisticated system, the Dryer Table. Substantial investment was made in the development of an entirely new system in the early 1920s. The resulting Admiralty Fire Control Table was extremely capable, but it was large and costly. Insufficient resources were available to install it in all the RN’s battleships before World War II.

The U.S. Navy, having an effective fire-control system already in place, could concentrate on incrementally improving it and applying similar approaches to other areas. More advanced versions of the rangekeeper accounted for more variables and improved accuracy. Automatic remote control of guns and turrets eliminated another source of human error. Sophisticated computing devices for antiaircraft fire control were built to solve the same basic problem in three dimensions. The torpedo data computer gave submarines a fire-control system for their torpedoes. These new developments were ready by World War II and had a profound influence on it.

The emergence of the Navy’s fire-control system had important and long-running effects. It influenced battle tactics and doctrine; it provided a solid basis for improvement; and it allowed future efforts to focus on new features and functions. Specific characteristics of the system ensured that it could meet future needs effectively; the most important of these was its open architecture. This made it possible for new technologies—like the stable vertical and radar—to be integrated relatively easily, so that the capabilities of the system could be upgraded incrementally. In the language of complexity, the system had significant emergent potential.


The development of the Navy’s fire-control system offers insight into effective approaches to learning and innovation. One of the most important of these was the system of learning and feedback that focused attention on a specific objective: accurate gunfire, at long range, in battle. Sims created the initial version of that learning system, by introducing standardized approaches and competitive evaluation of ships and gunners. That system became an enabling constraint that fostered improvements as individual officers and men took it upon themselves to refine their skills and achieve better scores. The system of learning and feedback was augmented by the regular fire-control boards that examined current practices and recommended improvements. This incorporated a second level of feedback into the system; it identified the most effective approaches for further exploitation, eliminated the worst deficiencies, and fostered increasing standardization.

BuOrd sat above both of these feedback loops, taking in recommendations from the boards and the fleet and combining them with its own view as to what was possible. It sought new approaches to address deficiencies, often by farming out the invention of new technologies to specialists. The bureau consistently reserved the responsibility of system integration for itself, ensuring that the system met the Navy’s needs. Ultimately, the new fire-control system emerged from this interplay of individuals, their organizations, and these cycles of feedback.

The seed of the first innovative step came from Sims, triggered by his interaction with Scott and his system of continuous aim. Sims played the role of the reformer. He recognized the value of the new approach and agitated for its introduction. In this effort, Sims had powerful allies. Without the sponsorship of Rear Admiral Taylor, Sims never would have been appointed inspector of target practice. The connections Sims established with President Theodore Roosevelt also served him well, and they ensured protection for his methods and ideas, even when they disrupted existing approaches and institutions.

This was because Roosevelt and Taylor sought institutional realignment; they pushed the Navy toward a new era of professionalism, where evidence and data would trump anecdote and tradition. This contrasts with the traditional view of Sims as the enlightened radical who pushed for innovation against a tide of fierce resistance. Resistance there certainly was, but Sims did not operate alone. He was the willing foil of the president and more senior officers who wanted to bring about a revolutionary transformation.

Sims played the part well. Not satisfied with continuous aim, he sought to introduce a more radical change—an expectation of continual improvement that would provide the basis for the Navy’s advancements in fire control over the next forty years. This was the promise Sims brought when he assumed the role of inspector of target practice in 1902. Upon the introduction of the concept of fire control in 1905, he fulfilled it. Sims proved an able choice and impressed upon a willing generation of like-minded younger officers the need to continually refine and improve their work.

Technical expertise was also required to create the fire-control system. New technologies had to be invented to allow the system to deliver its potential. Sperry’s gyrocompass and his data-transmission systems were essential first steps. Ford’s rangekeeper was vital and became the heart of the new system, but it would not have been as effective without the self-synchronous transmission systems that came soon after.

The Navy recognized that outside expertise was necessary to create the components of the new system. BuOrd effectively harnessed the skills of Sperry, Ford, and their businesses to build a series of new technologies that made the innovative system possible. As the fire-control system developed, additional firms provided components, including General Electric and Arma. The importance of bringing in outside ideas—either of a technical nature, as in this case, or from some other field—should not be underestimated.

Variability played a key role. After the introduction of the constraint—Sims’ competitive system of target practice—and standardized approaches to continuous aim, ships were left to develop their own procedures for improving the accuracy of their fire. The variation in procedures from ship to ship led to multiple, parallel, safe-to-fail experiments as different officers trialed new ideas to enhance their scores. The decentralized climate of experimentation fostered new ideas, such as the range clock and range projector; accelerated overall learning; prevented the Navy from coalescing too rapidly around a single solution; and ultimately led to a more effective system. The fire-control boards tied these lessons together and ensured the whole Navy could learn from them.

Throughout the development of the fire-control system, the Navy remained in control of the overall system and chose to play the role of system integrator. Suppliers like Sperry and Ford contributed to it, but their parts were just components in a broader architecture. Neither vendor could obtain control of the system. That was a critical decision. By maintaining overall responsibility and assuming the role of system architect, BuOrd ensured that the system would perform correctly in battle. A secondary consequence of this decision was the emergence of open architecture; because the Navy contracted for pieces of the solution, the result was loosely coupled through well-defined interfaces. This made it possible to replace the plotting and tracking boards with the rangekeeper quickly and easily. It also made it possible to plug in new technologies, like the stable vertical and the director, as they became available.

The development of the Navy’s fire-control system is an excellent case study of how innovation can occur. There are numerous essential ingredients—a new idea, a champion to drive it, and a fertile environment in which the idea can take root. Most case studies stop with a similar list. What the history of the fire-control system illustrates is that more is needed: a system of feedback. Feedback is required to allow the other members of the organization to pursue actively the end goals established by the champion and his sponsors. Without this, the improvement efforts will not “scale” and grow throughout the organization; they will fade when the champion is not there to drive them. If the system can foster learning and experimentation, as the Navy’s fire-control exercises did, it will be more effective at identifying ideas that will enhance the initial concept.

Technical expertise is a given when discussing innovation. What the Navy’s experience shows, however, is that it is only a narrow aspect of the problem. Technical brilliance must be effectively integrated into a broader system. Ways to use the new technologies must be found; this can entail many challenges, such as new methods of communication, organization, and visualization. To make it all effective, system integration is required, and integration must be achieved with a clear eye to the end goal. For the Navy, this goal was success in battle, and the officers of BuOrd and the fleet focused their work on it; the exercises gave them regular feedback on their progress.

The open architecture was critical. Without the ability to reconfigure the system and improve it incrementally, improved technologies could not have been integrated so rapidly. This would have slowed progress, increased expense, and potentially inhibited innovation. The Navy might have been forced to use less effective solutions longer had the architecture not maintained the emergent potential of the system.

Finally, complexity suggests that the time immediately following a symmetry break can be a turbulent one. The Navy experienced this. The decision was made to move to fire control in 1905, but the existing procedures and equipment were insufficient. The Navy leveraged this uncertainty advantageously by patiently allowing individual experimentation and effective approaches to emerge. The Navy avoided a common problem for organizations pursuing innovation: premature convergence. It did not attempt to identify a “good” approach quickly; instead, it allowed time for an excellent approach to emerge from the collective work of many individuals.

First British Polaris Submarines

HMS Resolution breaking the surface of the sea.

On 26 February 1964, about a year after the project started, the keel for the first Ship Submersible Ballistic Nuclear (SSBN) was laid at the Vickers yard at Barrow, but it was not quite the normal keel-laying ceremony in this case. A 250-ton section of the pressure hull was moved from the welding bay in the massive construction shed to the slipway where eventually it would be joined by the other sections required to build the submarine. Also on the same day, the Government finally approved the building of the fifth Polaris submarine.

As if CPE didn’t have enough on his plate, in April 1964 the three separate armed service ministries were combined into a new organisation, the Ministry of Defence. Despite the turmoil caused by the move across Whitehall from the old Admiralty Building to the new MoD main building, there were several advantages. At last CPE had ample dedicated office space and conference facilities, security was much improved and his team finally got its own teleprinter network. As an added bonus, Mackenzie got his own official car; before this he had been using public transport. On the downside, the new organisation made getting things done more difficult for CPE; in the old Admiralty organisation he had direct access to the ‘board’. Now the path was longer and certainly more tortuous.

The keel for the second Polaris submarine was laid at Cammell Laird on 26 June 1964, exactly on time as detailed in the Longcast. A shortage of suitably qualified specialised welders who could work with the QT35 steel used for the submarine hulls caused concern. This was only partially relieved after a nationwide recruiting campaign. Added to this was a series of strikes or threatened stoppages that jeopardised the overall programme. Also, CPE felt that the fitting out of Valiant was not progressing satisfactorily and the shipyard needed to allocate more manpower to the task. There was no easy solution to this, the specialised skills required to meet the very high cleanliness and quality standards that were required in both the SSBN and SSN build programmes were in short supply. A great deal of time and money was expended on rectifying this problem.

Within a few days of the General Election on 15 October 1964 CPE and his staff gave a presentation on the Polaris programme to the victorious Labour ministers who might have any involvement with the Polaris programme. Among them was Denis Healey, the newly appointed Secretary of State for Defence. Although CPE did not receive the hostile reception he had been expecting, the Labour Party had made no secret of its opposition to the project prior to the election, pledging that it intended to renegotiate the Polaris Arrangement or cancel the project outright. However, no decision was forthcoming. When Healey first examined the ‘accounts’, he could not believe the cost of Polaris; he could not understand why it was so cheap. He also recalls that certain senior naval officers expected him or actively encouraged him to cancel Polaris. They told him that although two submarines were laid down, they could be converted to hunter-killer submarines at no extra cost. Wilson told Healey not to brief the Cabinet as he intended to continue with the Polaris project on the grounds that the financial penalties would be colossal if the Government cancelled at this stage.

By mid-November both shipyards were reporting that the political uncertainty was causing key workers to leave the project. Regardless of the Government’s dithering, work continued on major parts of the project, the proposed home port for the submarines at Faslane and the armaments depot at Coulport. Suitable terms of reference and pay had to be agreed for the Coulport staff, many of whom would be very highly qualified technicians the likes of whom had not been seen in the civil service. They were men who would soon be undergoing training on the new systems in America; these would require the necessary increases in pay to allow for the higher cost of living in that country. In both these cases the Treasury was not particularly helpful and CPE was involved in long and difficult discussions.

After a weekend at Chequers at the end of the year, at which defence matters were top of the agenda, the Government announced it intended to keep Polaris as the national deterrent, although it failed to mention the size of the force. For CPE this meant that the programme was to remain as it was and the first submarine was to be operational by mid-1968, with the remainder following at six-monthly intervals. The Government finally seemed to have grasped the enormity of the task when in early 1965 the Minister for the Navy, when announcing the naval estimates, acknowledged that the Polaris project was the most challenging peace-time task the Navy could have been given.

In January 1965, CPE addressed a meeting of the Defence Council chaired by the Secretary of State for Defence. He stressed that five submarines were required to ensure that one would always be available on patrol. He also stressed that he felt that five submarines would not overstretch the crews or the personnel required to maintain the submarines; morale was a very important factor in the admiral’s eyes. After his presentation, CPE was thanked by Healey but was told that his views were largely immaterial. The Treasury had demanded that the Polaris force be cut to three submarines, but after a meeting between the Cabinet’s Overseas Policy and Defence Committees a compromise was reached and it was agreed that the force should consist of four.

As a result of this all, work and contracts associated with the fifth submarine were cancelled. Where contracts could not be cancelled the parts concerned became spares.

One has to agree with Mackenzie, who was never convinced that the cancellation was a Treasury-driven decision. He felt that it was a move to appease the left wing of the Labour Party, and it had the potential to have a detrimental effect on crew welfare. He later wrote: ‘All that their (the Labour Party) clamour achieved was to lay an almost intolerable burden on the men, and the women, responsible for the efficiency of the deterrent.’

Finding the manpower to crew the new submarines was going to be a major problem because many of the posts would require highly specialised technicians. This would require a 40 per cent increase in submarine manpower during the mid-1960s, not the easiest of tasks as Healey was busily reducing the overall naval manpower by 10 per cent. Although there were many volunteers for the Polaris Squadron from both serving submariners and general service to meet the growing requirement, for the first time since the Second World War personnel were drafted into the Submarine Service. The number of volunteers had remained remarkably constant from the 1950s at around 450. While this number could meet the requirements of the conventional submarine squadrons and the rapidly expanding nuclear fleet. Also, new accommodation blocks at HMS Dolphin were built.

With the election out of the way and the project, admittedly now a smaller project, the future was secure and life in the CPE became more routine. All the major requirements of the programme were identified, milestones were defined and work was progressing well on building the submarines and their new base on the Clyde. Admiral Mackenzie and his team now found themselves monitoring progress and, although not everything ran smoothly, the management systems that were put in place highlighted areas of concern and allowed them to be addressed at the earliest opportunity. Despite the new Government’s aversion to nuclear weapons, CPE found the newly installed ministers generally helpful and willing to assist. Notwithstanding this, the Polaris project remained a somewhat delicate subject with the Government, as Mackenzie was to discover. At the launching of HMS Resolution at Barrow in October 1967 the admiral was asked by a member of the press what he thought about the decision not to build the fifth submarine. Mackenzie was rather blunt and truthful in his reply; he was told to keep his mouth shut in future. On 8 December 1967, Frank Allaun, the MP for Salford East, asked the Secretary of State for Defence in the House of Commons whether Mackenzie’s public speech was made with his authority, and if he would give an assurance that there not be an expansion of the Polaris programme. Healey replied that Mackenzie had not made a speech but had answered questions from the press at a briefing arranged by the shipbuilders. He added that decision not to proceed with the construction of a fifth Polaris submarine, of which he had informed the House on 15 February 1965, was unchanged.

Although there was still much work to be done, 1966 saw the first major milestones of the programme achieved. The Royal Navy Polaris School at Faslane was completed and formally opened on 30 June; at the end of the following month HMS Valiant was accepted into the Fleet; the first Polaris submarine, HMS Resolution, was launched on 15 September; and by the end of year the reactor test bed HMS Warspite had successfully completed her contractor’s sea trials.

Meanwhile, Cammell Laird was falling behind schedule with its two submarines and there were still problems with procuring the steel for the hulls of the Fleet submarines. However, these problems were to fade into insignificance when hair-line cracks were found in the welds in the pressure hull of HMS Dreadnought. This had the potential to be disastrous and seriously disrupt the whole nuclear submarine building programme. A comprehensive ultrasonic survey of the affected welds was quickly implemented and fortunately showed that this was not a significant or generic problem.

During the year there were several changes in the management team. Admiral Mackenzie was more than aware that both naval personnel and civil servants normally changed post every two or three years and not to do so might affect their future careers. It says a lot about the admiral’s generosity of spirit that he allowed his very successful team to be broken up to allow people to pursue their careers. Captain McKaig was relieved by Captain P. Higham as Deputy CPE; the Chief Administrative Officer, Bob Lewin, was replaced by Peter Nailor; and Captain La Niece was relieved by Captain C.H. Hammer in Washington. CPE made an exception to this with Charles Shepard, who was Head of the Polaris Weapon Section, and who, Mackenzie felt, was irreplaceable and should remain in post until the project was completed.

In the 1966 Defence Review the Wilson Government made significant cuts in the defence budget, and the review saw inter-service rivalries reach a new height. In the early 1960s the Navy had started planning the replacement for its aging aircraft carrier fleet, which was designated CVA-01. The RAF submitted a paper to the Treasury that compared the histories of carrier-borne and land-based bomber campaigns. Needless to say, the paper suggested that the new carriers and their supporting escort, the Type 82 destroyers, should be cancelled and the RAF could supply all the required support from land bases. There were also substantial reductions in the country’s worldwide commitments but the Polaris project remained unaffected.

On 9 November 1967 Healey told the Commons: ‘We have no intention of increasing the Polaris Force beyond its present planned strength of four submarines,’ and on 6 December 1967, he emphasised that, ‘the decision not to proceed with the construction at the fifth submarine … is unchanged’. On 14 February 1968 Healey said that he was quite satisfied that the Polaris submarines would provide an effective contribution to the Western nuclear strategic deterrent and reiterated, in answer to a supplementary question, that the contribution made by the four Polaris boats ‘was a very substantial one indeed’.

During 1967 both HMS Renown and HMS Repulse were launched. Unfortunately, Repulse ran aground in the Walney Channel. Several CND anti-nuclear protesters had wedged themselves into the lock gates, delaying the launch by half an hour, which left insufficient clearance for Repulse to clear the mud. The launch was carried out by Lady Joan Zuckerman; wife of Sir Solly Zuckerman, Chief Scientific Advisor to the Government, who was also caught up in the CND demonstration. Despite this unfavourable start, Repulse went on to be the longest active survivor of the class; finally being decommissioned in 1996.

On 10 August 1967, the Clyde Submarine Base was officially commissioned (the formal opening was held on 10 May 1968 by HM Queen Elizabeth, where it became officially known as the Clyde Submarine Base, HMS Neptune). HMS Resolution successfully completed contractor’s sea trials and was accepted into service in October 1967. She then commenced a work-up period that culminated in her demonstration and shakedown operation (DASO), which involved the live firing of a missile in February 1968. Both HMS Resolution crews successfully completed DASO and the submarine was ‘handed over’ to her operating authority, C-in-C Home Fleet in June. Towards the end of the year it became apparent that the progress on the fourth submarine at Barrow, HMS Repulse, was so advanced that she would be completed before the third boat, HMS Renown, at Birkenhead. The programme was adjusted to take account of this. Also during 1967, as a consequence of the accidental flooding of SSBN02, the future HMS Renown, a further major readjustment of PMPs had to be undertaken in order to achieve recovery of the programme.

In August 1968 Admiral Mackenzie handed over to Rear Admiral A.F. Trewby, who became Assistant Controller (Polaris). He would ensure that the original build programme was completed and the submarines once in service had the necessary resources and facilities needed to keep them operational.

After an amazing five-and-a-half years of development, on 30 June 1969 the RAF formally handed over the responsibility for the nuclear deterrent to the Royal Navy.

In late 1973, Edward Heath’s Conservative Government approved an upgrade to the Polaris missile. The early beginnings of studies to increase the likelihood of successful penetration of the Polaris warheads to Moscow began in 1964, even before the Polaris system was deployed, in order to preserve this capability in the face of anti-ballistic missile batteries around Moscow. This very secret project became known as ‘Chevaline’ and was the culmination of a year-long project that explored various possible solutions. These were to build more Polaris submarines; use a hardened missile, use a hardened missile with penetration aids, use an MIV warhead option, or – the Navy’s preferred option – adopt the new American Poseidon missile, which had a greater range and carried more warheads than Polaris. Chevaline used a variety of penetration aids and decoys so that an enemy ABM system would be overwhelmed attempting to deal with them all, ensuring that enough warheads would get through and thereby guaranteeing an acceptable level of deterrence. This project remained secret through four different governments and was not disclosed until 24 January 1980 when Francis Pym, Secretary of State for Defence, speaking in a House of Commons debate on nuclear weapons, announced the existence of the Chevaline programme.

In 1982 Thatcher and Reagan reached an agreement to replace the British Polaris fleet with American-supplied Trident missiles. This was the culmination of a process started by the Callaghan Government a few years previously. It is interesting to note that during this period the same arguments that were raised during the Polaris project surfaced again, including how many boats would be required. David Owen, Defence Secretary in the Callaghan Government, wrote a paper that suggested, much to the horror of the Navy chiefs, that Fleet submarines could carry nuclear-armed cruise missiles, thereby doing away with the need for a dedicated missile submarine.

As the newer Vanguard-class submarines entered service, the Resolution-class vessels were gradually decommissioned. After 229 patrols, the Polaris fleet was finally decommissioned. HMS Repulse carried out the final Polaris patrol and was decommissioned at the End of Polaris Ceremony at Faslane on 28 August 1996. The Polaris Stone was dedicated and placed at the entrance to the Northern Area.

On 22 and 23 April 2013, a ceremony was held at Faslane to mark the fiftieth anniversary of the signing of the Polaris Agreement. During this ceremony, the Polaris Stone was moved to its new position in front of the Tyne Building and rededicated; perhaps to make room for a Trident Stone. Gerry McFeely’s recalled the ceremony:

Having arrived in the Base in August ’87, Resolution Class ‘bombers’ were a fairly common sight to me from that time through to the final decommissioning of HMS Repulse in August ’96. Whilst my main focus, by far, was the installation of Trident Vanguard as part of the Directorate of Naval Infrastructure & Environment (DNIE), which had emerged from Directorate of Quartering (Navy) subsequently to materialise as NBSA, and then reinvented as WSA; Reso Class was never far from my office window. Between the morning brief and the Wardroom back-bar scuttlebutt they kept me very much abreast of the ‘ongoings’ of our mutual affection and respect for the United Kingdom Independent Nuclear Deterrent. Reso with Polaris, if not a direct part of my desk work, was most definitely part of my life.

I fully supported their move from the Southern Berths at 1 & 2, which had been their natural home for so many years, from 1968 I think, to 10, 11 & 12 Berths in the Northern Area. I believe I was instrumental in identifying and establishing the Squadron in Belmore House as the new Squadron HQ. The hardest part of that exercise was persuading Captain JWR (JOHN) Harris RN to leave the Command Building in Red Square and move north to Belmore House. John left the Base in late November 1996 and since he invited me to his RPC (leaving drinks) I must have been forgiven! This was just some four months after the end of Polaris with the decommissioning of HMS Repulse and the unveiling of the ‘Polaris Monument’ in the largely completed Northern Area of the Base.

Ten years after I retired, in April 2013 I was absolutely delighted to receive an invitation from the Squadron Cdr to attend the 50th Anniversary of the signing of Polaris Sales Agreement between the governments of the United States and our United Kingdom. I was honoured to accept as I saw it as a pleasant opportunity to catch up with some former colleagues, friends and RN stalwarts. The important event was scheduled to take place at Faslane (in the Supermess) over the Tues/Wed 22nd and 23rd April 2013. Transport was to be generously provided and Base access organised, but as I was an Hon Member of the Wardroom HMS Neptune, I did not need to avail myself of these essentials.

The two-day event was largely funded (95 per cent at least) and sponsored by the main and involved contractors over the last fifty years, with such illustrious names as AWE, Babcock, BAE Systems, Lockheed Martin, Mass, Qinetiq and Rolls-Royce. I understand that these industry partners were ‘proud to support’ the event. To balance the scales on that particular point I can state with some confidence that CSB/HMNB Clyde Staff were equally proud to have programmed, maintained and managed the unbroken Deterrent Patrol, which had brought us to the present date. The Polaris Sales Agreement event was well organised throughout the two days and executed with military precision. The first evening, a superb buffet supper was provided in the Neptune Supermess from 1900–2200 and presented an ideal opportunity to seek out and catch up. In fact, for most of the guests the evening passed too quickly. Among the luminaries I met up with, bearing in mind I had been away for some ten years, included John Howie of Babcock, Ashley Lane of Mass, Cdr Don Milton of Coulport, Cdr J.H. Leatherby RN; Ron Laley and Ivor Jones, both of the Squadron, as well as Richard ‘Taff’ Evans [1st boat 1st patrol in Resolution] and many, many more of the ‘Trade’. Cdr James ‘Revenge’ Richards RN was one of the many who could not appear due to operational commitments – a sense of duty!

We as Neptune Guests, all did our bit on the ‘circulation front’, ensuring none of the USN guests were abandoned and were completely at ease in the Neptune environment. Throughout the evening DVDs of the history of Polaris were viewed and ‘thank you’ speeches made with the evening concluding with the issue of commemorative tokens (very posh!) being issued to all attendees.

The following day, under the guidance of Lt Cdr (later Cdr) Simon McCleary RN the plan was to marshal at the Chief’s Mess and travel by Base Bus [310] along Maidstone Road to Belmore House for the rededication of the resited ‘Polaris Monument’. The Service was conducted by the Rev Chaplain Richard Rowe with Cdre Steve Garrett Comfasflot escorting Rear Admiral Mark A. Beverstock Chief Strategic Systems Executive and his American counterpart T.J. Benedict USN Dir SSP. Several long retired Naval personnel including Cdre F.G. Thompson (with Dany) and COs both ashore and afloat also in attendance ‘in full rig’.

If I have praised the organisers of the event highly enough and the buffet providers likewise, my compliments must be recorded for the balanced and thoughtful Rededication Service. It included, along with Readings from Psalm 107 etc, the Polaris Prayer, the Naval Prayer and the Prayer for World Peace, concluding with the Benediction and the joint unveiling of the Polaris Monument by CSSE & Dir SSP.

A moving ‘moment of silence’ finalised the ceremony and all moved off to admire the ‘stone’, say fond farewells and leave to meet their transport arrangements for the journey home. For my own part I was honoured to be present on such an important occasion in the history of the Base – proud to be part of it, a lifelong memory.

The Kobukson or “Turtle Ship

Korean fleet led by Yi Sun Sin. The Battle of Noryang, 18 November 1598, occurred when a Japanese fleet led by the Shimazu clan tried to break through the blockade. Although the Shimazu fleet was severely damaged by the combined Chinese-Korean fleet, the Japanese Sunch’on garrison was evacuated. Yi Sun Sin was killed in the battle.

Throughout the two campaigns, in contrast to the fighting on land, the Korean navy was always superior. This was in part because of the splendid leadership of Admiral Yi Sun Sin, who nearly always led the entire Korean fleet. In contrast, the Japanese fleet lacked strong leadership and was little better than a combination of small coastal/inland water navies. The Koreans also enjoyed a technological advantage in the form of their armored Kobukson (turtle ships). These formed the core of the Korean fleet and inflicted serious damage on the Japanese fleet. The Korean victories at sea constantly threatened the Japanese supply lines and were one of the major causes of Japan’s abandonment of the campaign.

The Kobukson, also known as the Turtle Ship, was the first ironclad warship in the world.

Boasting unparalleled firepower and mobility, it proved a pivotal instrument for victory in the sea battles under Admiral Yi. Effectively a sea tank, it was capable of sinking large numbers of enemy vessels, and so did much to maintain the morale of Korean sailors, so often outnumbered by the vast fleets of the Japanese navy.

It should not be supposed that Admiral Yi designed and built the Turtle Ship entirely by himself. The planning and the actual construction of the Kobukson required the combined efforts of a large number of people, both craftsmen and naval officers. On the practical side of the work, for instance, Na Dae-yong (1556-1612) played one of the most important roles in bringing the plans for the first ship to fruition.

An Overview of Kobukson:

The following are the main features of Kobukson, as recorded by Yi Sun-sin’s nephew, Yi Boon, in his book, Haeng Rok.

– Its dimensions are 34.2m in length, 6.4m in height, and 10.3m in width; it is thus roughly the same size as a Panokseon (the standard warship of the Korean Navy at the time of the Seven Years War).

– The prow is fashioned in the shape of a dragon’s head; cannon balls are fired through the mouth.

– The stern is in the shape of a turtle’s tail. Additional gun ports are stationed beneath it.

– The turtle’s ‘back’ is a roof made with planks, and is covered with iron spikes. Amid the spikes is a narrow, cross-shaped alley that serves as a passageway along the roof for the crew to use.

– Six gun ports are positioned on each side of the deck.

– During combat the spikes on the roof are concealed with straw mats, on which an unsuspecting enemy will be impaled if he tries to board.

– Any attack from port or starboard is repelled by arrows and cannon-fire, which can be launched from every part of the ship.

– From the inside, the outside can be seen, but the inside cannot be seen from the outside.

– It employs every variety of projectile-based weapon, including long-ranging cannon such as Chon (Heaven), Chi (Earth), Hyon (Black) and Hwang (Yellow).

– As such, it is able to roam freely and unopposed amid many hundreds of  enemy ships.

Detailed Description:

The Kobukson was mounted with a dragon’s head at the bow, and a turtle’s tail at the stern. It had two decks, a lower deck for oarsmen and the storage of supplies, and an upper deck for archers and gunners. It was specially designed so that its sailors could see their enemies outside while themselves remaining invisible.

In the naval warfare of the day, it was usual to attempt to board an opponent’s ship and engage him in hand to hand combat. The Kobukson was designed with a view to making this kind of assault particularly difficult. Not only was the ship roofed over, protecting both combat(45) and non-combat(80) personnel alike, but the roof itself was fitted with deadly iron spikes, often concealed beneath innocent-looking straw mats.

Unlike other warships, the Kobukson had guns stationed not only along its sides, but also in the bow and in the stern, allowing it unprecedented accuracy and flexibility of range in fire power. The dragon head was designed not only to ‘breathe out’ flaming arrows and cannon balls, but also sulphurous fumes and clouds of smoke, which provided the Korean Navy with cover for tactical maneuvers, as well as frightening the more superstitious of the Japanese sailors.

A little below the bow, there protruded the head of a gargoyle, which served as a charging device, and together with the dragon head constituted the secret of the Kobukson’s tactic of ramming. In battle, the Kobukson would charge an enemy ship and, once the gargoyle’s head had breached its hull, cannon balls would be fired from the dragon’s head into the breach as the ship withdrew. The gargoyle had the further effect of improving the ship’s hydrodynamic performance by cutting the waves as the ship sped along, thus increasing its ramming speed.

Two further features of the Kobukson made it particularly serviceable for the execution of this tactic. First, it was built with Red Pine timbers no less than 12cm in diameter; the advantage offered by this type of wood was that its relative density of 0.73 was much higher than that of average timber, which lay typically between 0.41-0.47. Secondly, wooden nails were used in the construction of the Kobukson; unlike metal, which was quick to rust, the wooden nails absorbed water and expanded, and thus over time the joints became more secure. Indeed, the Kobukson as a whole was constructed on this principle: support beams were fitted to the roofs by means of a system of matching indentations and interlocking teeth, thus making the entire structure of the vessel stronger and more resilient.

The Japanese ships, built out of wood with a low density, were light and swift, but the relative weakness of the wood to withstand the recoil of a cannon put a restriction on the number of heavy fire-arms that could be carried on one ship, and consequently they normally preferred to use muskets, which had a maximum range of 100 meters. The Kobukson, on the other hand, were able to carry a whole array of different cannons on board, including long-distance cannons such as the Chon (Heaven) with a range of over 500 meters, the Chi (Earth), its slightly smaller companion, which had a range of 350 meters, and the Seung (Victory), a portable cannon, with a range of up to 200 meters.

Kobukson had 8 oars on either side, with a team of five men – a leader and four regular oarsmen – assigned to each oar, making a total rowing crew of 80. During combat every oarsman was expected to be on duty, but at other times they would take turns at the oar in pairs. The leader would direct his colleagues to row forward or backward, to increase or decrease speed, to halt or turn about, according to the changing circumstances of the battle. This innovative division of duties thus gave the Kobukson superior potential of movement not only in terms of speed but also in terms of the range of its possible maneuvers.

The combat personnel on board the Kobukson were divided into three groups: Gunners, Chargers, responsible for the loading of cannons with shells and gunpowder, and Archers. It was thus possible for the Kobukson to produce an uninterrupted shower of cannon balls and fire-arrows, wreaking havoc on everything that came within its range.

The number of gun ports generally varied from ship to ship, but the Tong Je Young Kobukson which we find described in the Complete Works of Yi Sun-sin, had a total of 74: 12 ports on either side of the turtle’s back, 44 on either side of the shielded boards underneath, 2 above and below dragon’s head, and so on.

Invented late in the 16th century, Kobukson was a unique warship, the like of which cannot be found used anywhere else in world naval history. Planned with meticulous care, and the result of much detailed scientific research, it boasted unsurpassed structure and performance. Above all, much meaning lies in the fact that Kobukson was a refinement and a remodeling of P’anokson, the existing warship of Korea, based on careful investigation of the primary Japanese tactic of grappling and boarding.

Replicas of Kobukson are on display in various national museums, such as the War Memorial of Korea, as well as in other museums throughout the world, such as the Wasington D.C. War Memorial Museum in North America, the Maritime Museum of Great Britain, and in many other countries including China, Japan, Germany, France, Canada and so on.


Stealth U-Boats

U-480 with Olt z S Hans-Joachim Förster saluting.

In order to prevent being detected either by acoustic or visual means, the submarine fleets had to employ a range of counter-measures to either thwart the penetrative gaze of radar and the sono-buoy or reduce the amount of time the individual U-boats spent on the surface to make it far more difficult for reconnaissance planes to discover their whereabouts. Unfortunately for the Germans none of the main radar warning receivers they developed (Borkum, Metox, Naxos, Tunis and Wanze) operated flawlessly against aircraft; their own active radar sets (Gema, Hohentwiel and Lessing) though effective went into service tardily; what radar and sonar decoys (Aphrodite and Thetis for the former and Bold, Sieglinde and Siegmund for the latter) they produced failed to achieve any lasting success; and the anti-sonar synthetic rubber Oppanol coating they used on the hulls of the U-boats to disguise their acoustic signature (known by the codename Alberich) had major adhesive problems that restricted its application. In addition, it was soon discovered that the use of schnorchel air induction tube, which enabled submarines to run their air-breathing diesel engines and recharge their batteries while still submerged, was not quite all that it seemed at the outset. Quite apart from the health risks (specifically, oxygen-deprivation) that the early non-fully automated models posed for the U-boat crews, a schnorchel boat could also be detected even if its mast was coated with the camouflage antiradar coating of synthetic rubber and iron oxide powder (Tarnmatte).


This was a textured synthetic rubber called OPPANOL. The idea behind this 4MM thick rubber was to cover the entire U-boat in this textured rubber. In reality this OPPANAL only reduced the sonar pulse by about 15 per cent when the boat was at periscope depth. Absorption varied with depth, temp and salinity. The big problem with this system was that of adhesion. There was just no glue at the time that would keep the rubber panels in place. Over time wave action etc. made the rubber panels come lose and actually create more noise than a boat that did not have the coating. It was also found to decrease the speed of the boat by about 1.1/2 knots. The hull and tower were also occasionally covered. For this purpose a black, rubber-like material was used “Alberich”. It served however only for the camouflage against ASDIC, not against radar.

This material reduced the detectable engine noise from the powerplant, and also the sound-echo reflected from the submarine by some 15 per cent. The patented material was a polyisobutene known as Oppanol; in the form used by the U-Bootwaffe it was made in 4mm-thick sheets, to be glued to the steel structure of the submarine. Initial tests on a Type II boat seemed promising, and it was decided to apply the coating to a new Type IXC, U-67, before she entered service.

Although the concept was sound (and is widely used today), the problem in 1941 was that a suitable adhesive had not been perfected. During U-67’s short voyage to her first operational base with 2. Unterseebootsflotille at Lorient that August, it is estimated that at least 60 per cent of her Alberich coating was lost. Once the Alberich `tiles’ had loosened, the turbulence caused by the loose ends of partially detached panels flapping around in the current caused increased drag, and in fact a treated and `peeling’ submarine could end up more `noisy’ than an untreated one.

A suitable adhesive was only found in 1944, and when this was used to coat the Type VII boat U-480 with Alberich it was judged to be effective. On 25 August 1944, U-480 (Olt z S Hans-Joachim Förster) made an attack on convoy BTC-78 off the English coast near Lands End, sinking the freighter Orminster. By this late in the war very few boats would escape once detected by Allied surface ships, but although the escorts began a determined hunt they had to give up after seven hours, and the Alberich-treated U-boat escaped unscathed. Of course, it was not possible to determine to what degree her escape was due to the Alberich rather than simply to the skill of her commander, but it was ordered that in future all new Type XXIII and Type XXVI boats should be treated with Alberich. In the event, only one Type XXIII, U-4709, had been treated before the war ended, and she was scuttled before undertaking any combat patrols.

Type XXIII, U-4709

Type XXI

Anti-Radar Coatings

Tarnmatte (camouflage mat)

A more successful attempt at improving stealth characteristics was the use of a synthetic rubber coating for the exposed head of the U-boat schnorkel or air intake/exhaust tube. The installation of this device was one of the German responses to the introduction in spring 1943 of Allied centimetric radar capable of detecting boats running on the surface day or night, which thereafter forced them to spend most of their time `in the cellar’. This not only seriously degraded their ability to intercept Allied targets, but made the unavoidable periods spent running the diesel engines on the surface to recharge the electrical batteries extremely hazardous. The retractable schnorkel came into widespread use only in May 1944; it provided an air intake and exhaust for the diesels, so that boats could theoretically stay underwater 24 hours a day, not only charging batteries but cruising submerged (very slowly) on diesel power. However, not only was it difficult and even dangerous to operate, but its head above the surface could easily be detected by radar-equipped Allied aircraft.

The synthetic material used to coat the head was known as Buna; the thickness of the coating was dependent on the wavelength of the specific Allied radar emission, and to defeat the 9.7cm-wavelength ASV Mk III set the Tarnmatte was applied 2cm thick. It was very flexible and used on KUGEL-SCHWIMMER SNORKELS etc. Its thickness dictated the frequency of radar radiation that was absorbed. It was much more successful than Alberich, and was reported to be 90 per cent effective.

Despite claiming that Tarnmatte could absorb 90% of the waves emitted by the Allied airborne Mark III radar sets, schnorchel boats could be let down on occasion by the wake left by their mast on the surface of the sea or by a telltale cloud of diesel exhaust fumes that revealed their presence to the eyes of a trained aerial observer hunting for them.


This was far better at absorbing radar radiation but due to difficult manufacturing it was not flexible and could only be made in flat sheets or in round forms (it could not be made to cover the various shapes of a U-boats hull). It was made up of 7 layers of conductive material (paper or plastic with carbon black) separated by layers of di-electric material (rigid synthetic called IGELIT, which is a polyvinylchloride foam that was 70 per cent air by volume). The total thickness was about 8CM thick. This material absorbed radiation between 2 and 50 CM.

D-Day caused U-Boat Command to order an evacuation. Within the French bases, eight U-boats newly fitted with schnorchel gear were approaching readiness as the evacuation gathered pace. With the decision to stop sending boats against the D-Day traffic in the Seine area, they instead were despatched to the Bristol and North Channels on Britain’s west coast. U667 had been operational within the Bristol Channel since the end of July and had reported sinking a destroyer and 15,000 tons of enemy shipping.3 Kapitänleutnant Hardo Rodler von Roithberg’s U989 also scored surprise successes in late August when he damaged the American freighter SS Louis Kossuth and sank the British SS Ashmun J Clough southwest of the Isle of Wight, before being ordered to head for Norway as part of the general evacuation. Another 9th U-Flotilla boat U480 that had left Brest in early August for the English Channel sank corvette HMCS Alberni, minesweeper HMS Loyalty and badly damaged SS Fort Yale northeast of Barfleur, before moving on to attack convoy FTM74 on the afternoon of 25 August. The convoy had overrun the submerged U-boat, the din of propellers easily audible throughout the German hull. The 5,712-ton straggler SS Orminster was torpedoed thirty-five miles northwest of Cap d’Antifer by Oberleutnant zur See Hans-Joachim Förster after which U480 was hunted for seven hours but escaped, his ability to avoid detection enhanced by the Alberich covering – an early form of stealth technology – that had been applied during the previous May:

25 August 1944. 1508hrs. Am being pursued by four anti-submarine vessels, two of which are operating ASDICs; the third, which apparently acts as depth-charge dropper, approaches at intervals of from five to ten minutes and drops charges; the fourth can be heard to be running her engines at very low speed. Listening conditions are particularly good.

2140hrs. Beginning of dusk. Pursuit lasts until 2200 during which time we have covered five miles over the ground … I maintain my depth by shifting the crew. One of the A/S vessels frequently lies directly above us with her engines just ticking over, when the least sound aboard her is clearly audible and ASDIC impulses are extremely loud … The depth-charge dropper, which has lately been lying stopped, approaches and drops five or six depth charges at intervals. These cause such trivial damage that I am convinced that the enemy is unable to locate us with ASDIC … I attribute the enemy’s failure to locate me mainly to the protection afforded by Alberich …

Alberich, named after the guardian of the Rhinegold treasure from Wagner’s Der Ring des Nibelungen, consisted of 4mm-thick sheets of synthetic rubber, Oppanol, which possessed sound absorbing properties. The sheets were secured to the outer hull with adhesive, claiming a 15 per cent reduction in sonar echo reflection, as well as acting as sound insulation for the internal machinery of the U-boat. While Alberich itself was reliable, the adhesive used to secure its place on the hull was less so and experiments continued until the war’s end to prevent sheets from being partially washed off and so flapping in the water stream creating both drag and noise.

The first U-boat to receive Alberich was the Type II U11, covered in the sheeting for initial trials with the 5th U-Flotilla during 1940. In 1941 a larger boat, the Type IX U67 and then UD4 were similarly tested, though the adhesive problem prevented its widespread use amongst combat boats. Not until the dawn of the ‘schnorchel war’ was Alberich used on patrol, U480 being the first U-boat to enter combat clad in the rubber sheeting. After Förster’s enthusiastic appraisal of the material the decision was made to attempt to cover numerous Type XXIII U-boats with Alberich, though the first was not ready for service until February 1945 when U4709 was commissioned. It was suggested that the huge unfinished ‘Valentin’ bunker in Bremen be given over to Alberich fitting, though the plan was shelved. In total there were more Type VIICs that ended the war with Alberich coatings, despite the fact that for every one of its type covered, two and a half Type XXIIIs could be so treated.

More commonly used was Tarnmatte, a compound synthetic rubber and iron-oxide powder that coated the head of a U-boat’s schnorchel to absorb enemy radar waves, and which was claimed to absorb 90 per cent of waves emitted by the ASV Mk III airborne radar.

Förster and U480 would not make landfall until October, and his War Diary provides an interesting glimpse at the difficulties faced by U-boats compelled to remain submerged for long periods of time in transit to, from and within the combat zone:

12 September: 0511hrs. 300 miles west of Ireland. Surfaced for the first time in 40 days. The boat stinks. Everything is covered with phosphorescent particles. One’s footmarks on the bridge show up fluorescently … Schnorchel fittings and flooding slots also glow brightly in the darkness. Because of a high stern sea the bridge is constantly awash and the men cannot stand up on the slippery wooden deck; it is therefore impossible either to change or to dismantle the AA guns. The shields of the twin AA guns cannot be opened; the hinges appear to have rusted up and cannot be attended to in the dark. The 3.7cm gun is out of action; so shall first transmit my situation report and then proceed on schnorchel until the state of the sea permits me either to change the AA guns or dismantle them for overhaul below.

2nd October: 1710hrs. Off the west coast of Norway. Surfaced. The whole flak armament is unserviceable. The gun shields have been torn away from their mountings and are fouling the guns. Everything, including the 3.7cm gun, is corroded and covered with growth.

Balkon-Gerät – The Balkon-Gerät (Balcony Apparatus) was an improved version of (‘’Gruppenhorchgerät’’) GHG. The GHG fitted to early U-boats could not be used effectively at periscope depth. To solve this, a new listening device, known as ‘balkon’ (balcony) fitted to a second, lower hull, was successfully tested on U-194 in January 1943. Where the previous had 24 hydrophones, the Balkon had 48 hydrophones and improved electronics, which enabled more accurate readings to be taken. It was standard on XXIs but was fitted to some VIICs and VIIC/41s in 1944 and 1945.

The Sinking of the Szent Istvan

Death at Dawn – The Emperor’s Last Battleship. Szent Istvan. from Stephan Mussil on Vimeo.

The Austro-Hungarian Navy in late WWI had suffered a consistent decline and severe setbacks. Since 1917, the Allies had begun to use large convoys in the Mediterranean and the Adriatic in order to maintain their supplies to the Middle East, as well as to Italy and the Salonika front, in a similar way as in the Atlantic. While escorting these convoys took up a large capacity of the naval forces, the effort was worth it. Following the entry into the war by the USA, American destroyers were incorporated into these escort operations, alongside the British, French and Italian naval forces. However, the Allies were aware that this protection was only a conditional one and that, ultimately, it came down to hitting the German and Austro-Hungarian surface and submarine vessels in such a damaging way that the threat to Allied shipping would be reduced. Attempts were made at improving the fight against the naval forces of the Central Powers in that – in the second half of 1917 in particular – everything possible was done in order to precisely monitor the radio traffic and to decipher the code words whenever expedient.

Germans, Austrians and Hungarians had long ago become dissatisfied with the development of the naval war in the Mediterranean, despite sporadic successes. German statisticians had calculated that the tonnage figures of the ships sunk by the submarines were decreasing constantly per boat and per day. Even the numbers of Austro-Hungarian sinkings since the autumn of 1917 alone were cause for concern. In October 1917, an outstanding 12,000 tons of shipping space had still been destroyed, but in November only 4,000, and in December 1917 not a single sinking. The Germans were also becoming increasingly concerned due to the Allied aerial threat to Pula (Pola) and Kotor.

On 12 November 1917, Kaiser Wilhelm had visited Pula and had made a vain attempt to convince the Commander of the Fleet, Admiral Njegovan, to decommission the capital ships and to use the crew for other purposes. The visit by Kaiser Wilhelm took place at a time when the breakthrough Battle of Flitsch-Tolmein had been fought, and Austro-Hungarian and German troops had crossed the Tagliamento River and advanced to the Piave.

For the Allied fleet presence in the Mediterranean, this naturally did not remain without consequences. Italy had requested additional support from its allies, and wanted it to be transported across the sea in particular. The first to react were the British, who had two monitors enter the lagoons of Venice. However, Italy had also requested that Japan send additional destroyers. This request could not be met, while instead, the British and French gave the Italians the good advice of using their own naval forces more actively. British destroyers spent 70 per cent of their time at sea, while the Italians lay in the ports for a larger proportion of the time. However, the Entente powers had naturally understood Italy’s concern that the Austro-Hungarian troops might perhaps still wish to expand on the successes of the Twelfth Battle of the Isonzo by landing in the Rimini area, or attacking Venice. The Allies were also concerned that Italy might be forced to withdraw from Albania. If Italy were to retire from the war, it was even considered how the Allies might take possession of the Italian fleet. But all these worries had been groundless.

The situation in Italy had continued to occupy the minds of the Allies. At a naval war conference at the end of November and the beginning of December 1917, the Italian Prime Minister Orlando pointed out that the Italian armaments industry could no longer function due to a lack of coal, and hoped that additional coal supplies from the Allied marines of at least 100,000 tons could be provided. The British and French were not in a position to fulfill the Italian requests, but they could do nothing else but assume additional tasks in the leadership of the naval war, transport more supplies across the sea and protect the convoys as best they could. Here, the Imperial and Royal Navy no longer appeared to represent a significant danger.

The activities of the Fleet continued to be reduced. Like the land army, the crews on the ships and the entire naval personnel were forced to acknowledge that the hardships were now being felt everywhere, and that the shortages caused significant limitations. In the short term, a measure appeared to take effect that had in fact seemed obvious: Vice Admiral Richard von Barry organised a fishing fleet of 650 boats and 4,500 sea men, most of them former fishermen, who were to provide additional food supplies. However, ultimately, this was also not the solution. Morale continued to sink, and lethal boredom became rife. In 1916, the Naval District Commander of Trieste, Vice Admiral Alfred von Koudelka, suggested deploying the sailors with the land army according to a type of rotation principle. This would surely stave off the boredom. He then received the inmates of the naval prison in Pula, who did indeed serve at the front, but who after completing their sentences returned to their ships. The experiment was not repeated.

Aside from more minor activities, Njegovan failed to disrupt the Allied fleets in the Adriatic. Neither were connections interrupted, nor were there larger naval battles com parable to the one in the Strait of Otranto, for example. With the sinking of the Wien, however, the calamity had already begun to descend upon the Imperial and Royal Navy. Next came the mutiny in Kotor, then Njegovan was dismissed and replaced by Rear Admiral Miklos von Horthy. His nomination as Commander of the Fleet was accompanied by a full shake-up of the command authorities in Vienna, new appointments and reassignment of posts. Horthy began to prepare the Fleet for action, even if it was not aimed at achieving much more than keeping the people busy, and thus counteracting at least one reason for the mutiny. And when, in May, another mutiny occurred on a torpedo boat in Pula, Horthy decided to make an example of those involved, and had the two ringleaders, a Czech and a Croat, shot as a public warning. Twenty men from each ship lying in Pula were required to attend the execution.

Clearly, the measure had an effect, since until the autumn the Commander of the Fleet no longer had substantial cause for concern with regard to the discipline of his ships’ crews. However, this altered nothing when it came to the lack of activity of the Fleet. Older ships were taken out of service and disarmed. Particular attention was paid to Kotor, where there had been fears of an Allied attack since the autumn of 1917. In April 1918, Emperor Karl asked Horthy whether an Austrian submarine might be sent to the Black Sea. Horthy refused; he referred not least to the fact that the Austro-Hungarian flag was already present in the Black Sea, since the Danube Flotilla units had arrived there.

In the spring of 1918, the naval war in the Adriatic had begun to take on other forms. Italians and Austrians attempted to cause damage through small forays, landing operations and penetration into the naval ports. The Allied measures for protecting their shipping, particularly the convoy system and the intensification of the fight against submarines, were taking effect. In January 1918, the Germans lost more submarines in the Mediterranean than throughout the entire year of 1917. In May 1918, German submarine losses in the Mediterranean again increased sharply. The British intensified their air attacks on Kotor, which had a greater effect than the British themselves were aware. The necessity of taking protective measures, and only being able to depart and come in to port under highly specific conditions had an enormous deceleration effect on the naval warfare and also obstructed the submarines in particular.

In this situation, Rear Admiral Horthy wanted to repeat his raid on the Otranto barrier. This time, however, not only a relatively small squadron was to take part, but also the 1st Battleship Division. The campaign was planned for 11 June. On the evening of 8 June, the first battleship group, with two ‘Tegetthoff’ class ships, left Pula. Horthy himself travelled on the flagship of the Fleet, the Viribus Unitis. The second group of battleships, with Szent Istvan and Tegetthoff, left Pula on the evening of 9 June. However, the Allies had been warned. The increase in radio traffic and aviation activity had drawn their attention to the fact that an operation was being planned. Even before dawn on 10 June, Italian torpedo boats (MAS = Motoscafi Antisomergibile) fired two torpedoes at the Szent Istvan. The battleship was so severely hit that it sank in less than three hours. Then Horthy abandoned the operation, since the element of surprise had without doubt been lost. Thus, the final turning point in the naval war had been only too obvious. Of less significance was the fact that the Americans had also sent a submarine fighter unit to the Mediterranean, in order to participate in the blockade of the Strait of Otranto. The ships, the majority of which were manned by volunteers and crews who had no experience of naval war at all, were now no more than an outward extension of the Allied presence. Until the end of the war, they failed to sink even a single submarine.

Following the failure of the Piave Offensive, the situation also deteriorated week by week, indeed almost daily, for the Imperial and Royal Navy. The transport of supplies by sea for the Imperial and Royal XIX Corps, which was then renamed `Army Group Albania’, was already very highly at risk. No other supply and evacuation opportunities were available. Loyalty among the troops was diminishing continuously. The submarines were achieving almost no further successes. The Germans were now nowhere near being able to make good the loss of the Austro-Hungarian vessels, and an increase in their number to 28 in total in the Mediterranean in August 1918 (including the submarine UB 128 under the command of Lieutenant Wilhelm Canaris) remained without impact, since the number of vessels that were suitable for action was decreasing steadily. Horthy described the Fleet as still ready for service, and also claimed that the consequences of the revolt in Kotor had been overcome. However, he pointed out that the continuous escorts provided for the convoys sailing up and down the Adriatic coast, which were attempting to reach Albania in particular, were making extremely high demands on the torpedo boat flotilla. Since the construction of fourteen submarines and nine torpedo boats had been ordered, and that it could still not be predicted when they could be put into service, the collapse of the Fleet within a foreseeable period of time appeared to be inevitable. On 17 October, the Army High Command ordered the Austro-Hungarian submarines to end the commercial warfare and instructed them to restrict themselves from then on to standing ready to defend the Dalmatian ports. At this time, the Allied fleet formations were already more or less sailing freely in the waters of the Mediterranean. They even used their battleships to attack the Albanian coast and to block the Austrian ports. The last major operation conducted by the Imperial and Royal naval forces was to fire at the port of Durazzo on 2 October, which, while having no significant effect on the port itself, gave an Imperial and Royal submarine under Ship-of-the-Line Lieutenant Hermann Rigele the opportunity to torpedo a British cruiser. Thus, the end had also come for the Imperial and Royal Navy.