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.



At the Cold War peak in the 1980s, the deployment of weapons and defence systems from space (or at least, extremely high altitude) became the new playthings for both Communist and Western governments. On the US side of the Atlantic, president Ronald Reagan’s opposition to the doctrine of mutually assured destruction meant that the US military was investing time into researching the means of defending America against a nuclear strike, rather than the weapons required for a retaliatory attack. Cue the Homing Overlay Experiment (HOE).

In 1984, the US Army launched two missiles at each other from either side of the Pacific. One was launched from California with a dummy warhead and a trajectory that would take it 7,242 kilometres (4,500 miles) away to a spot near Kwajalein Atoll. The army waited for the missile to pop up on Kwajalein’s radar before launching their experimental counter-measure to intercept it. This was a kinetic weapon that looked much like another missile, until it approached the nuclear dummy outside Earth’s atmosphere at more than 185 kilometres (114 miles) altitude. Here, it unfurled a huge, ribbed aluminium net to increase its lethal radius and made directly for the dummy, striking it at such speed that both were practically vaporised. This fourth test was the first to be considered a success and was likened to shooting a bullet out of the air in mid-flight with another bullet.

This was the first non-nuclear missile defence technology: prior to HOE, the only means any country had of defending against a nuclear strike was to detonate another warhead in the air to destroy everything in its blast radius. Obviously, the subsequent radioactive fallout from this method could have had dire consequences for the world. While HOE itself was, thankfully, never needed, the force-of-impact technology it pioneered has been passed down to today’s US missile defence systems.



Wickersham Land Torpedo (USA 1918)

The foundations then were laid for remote-controlled vehicles and weapons just as the First World War began. World War I proved to be an odd, tragic mix of outmoded generalship combined with deadly new technologies. From the machine gun and radio to the airplane and tank, transformational weapons were introduced in the war, but the generals could not figure out just how to use them. Instead, they clung to nineteenth-century strategies and tactics and the conflict was characterized by brave but senseless charges back and forth across a no-man’s-land of machine guns and trenches.

With war becoming less heroic and more deadly, unmanned weapons began to gain some appeal. On land, there was the “electric dog,” a three-wheeled cart (really just a converted tricycle) designed to carry supplies up to the trenches. A precursor to laser control, it followed the lights of a lantern. More deadly was the “land torpedo,” a remotely controlled armored tractor, loaded up with one thousand pounds of explosives, designed to drive up to enemy trenches and explode. It was patented in 1917 (appearing in Popular Science magazine) and a prototype was built by Caterpillar Tractors just before the war ended.

Suicide bombing, supply carrier

Operated by wire

Developer – Elmer E. Wickersham

Manufacturer – C. L. Best Tractor Company

Loading capacity – 50kg

Article translated from Russian []

PTS amphibious vehicle

Soviet-made tracked amphibious transport PTS-M of Serbian River Flotilla 1st Pontoon Battalion.

PTS amphibious vehicle

The PTS has been in Egyptian service for some years, its amphibious carrying capacity having been used to good effect during the Yom Kippur war of 1973.

The PTS amphibian entered service with the Soviet army in the mid-1960s, and in comparison with the earlier K- 61 amphibian has a greatly increased load-carrying capability, slightly higher speed on both land and water, and can also tow a trailer when afloat. The PTS has a steel hull with the crew compartment at the very front of the hull and the cargo area stretching back right to the rear. The crew compartment, unlike those on the earlier K-61 and BAV-485, is fully enclosed, the two-man crew entering via two circular roof hatches An NBC system is provided to enable the vehicle to operate in an NBC-contaminated area, The engine is beneath the vehicle, with the exhaust pipes on top of the cargo compartment on each side, a configuration which in certain conditions could permit exhaust fumes to be blown back into the cargo area, an unfortunate situation when troops are being carried. The PTS can carry a maximum of 5000kg (11,023lb) of cargo on land and 10000kg (22,0461b) on water, or up to 70 or so fully equipped troops. Cargo and vehicles such as a Ural- 375D 6×6 4000-ks (B, B1B-lb) truck can be loaded into the PTS via the rear tailgate, which has two integral loading ramps. The suspension of the vehicle is of the torsion-bar type with six dual rubber tyred road wheels, plus a drive sprocket at the front and an idler at the rear; there are no track-return rollers. The vehicle is driven in the water by two propellers mounted in tunnels under the rear of the hull, and steered by two rudders, Before the vehicle enters the water a trim vane is erected at the front to stop water swamping the forward part of the vehicle, and the bilge pumps are switched on. AII vehicles have a front-mounted winch (to recover other vehicles and equipment, or to assist in self-recovery), night driving equipment, a searchlight mounted on top of the crew compartment, radios and an intercom.

The PTS can also tow the specially developed PKP boat shaped two- wheel trailer, which is provided with ramps to enable cargo to be loaded, This has two sponsons, one on each side: for land travel these are folded on top of the trailer but before entering the water they are swung through 180* and locked in positron to provide additional buoyancy, The trailer is used to carry a 122-mm (4 8-in) D-30 howitzer while the PTS vehicle carries the truck, ammunition and crew. The latest production version is the PTS-M, which has minor differences including increased fuel capacity.

The PTS-M is found in the surveillance equipment, radio communication, an intercom system, and high of motorized rifle and tank divisions. It is capacity bilge pump. The cabin fully enclosed also found in engineer amphibious units at and the PTS-M is capable of operating in an Army and Front level, nuclear and chemical environment and in amphibious company of engineer battalions.

In assault operations, it is used to ferry troops and cargo. In bridging operations, it is used as a floating crane, an expedient for a shore deadman, and cable anchorage transporter. In ice-crossing operations, it is fitted with special attachments and used to clear lanes from broken ice. And finally, in bridge destruction operations, it is used to ferry demolition crews and equipment water-15 km/h (9.3 mph).

The only known variant is one used by Poland, which has a rocket-propelled mine-clearing system mounted in the rear. In addition to being used by most members of the Warsaw Pact, the PTS is also operated by Egypt, Iraq and Syria.


Year into service:          1965

Manufacturer:               Kurganmashzavod

Crew:                               2

Engine Type:                  V46-5 Quad Valve

Eng Layout:                      V 12

Eng Starting Primary:        Air

Engine Displacement:      38,880 cc

Engine BHP:                       710 BHP

Engine Torque:                  880 ft lbs

Engine Bore x Stroke:       150 mm x 150 mm

Dimensions Length:          11,500 mm

Dimensions Width:           3,300 mm

Dimensions Height:          2,650 mm

Cargo area length:            8,000 mm

Carge area width:             2,900 mm

Cargo area height:            Enc 1,700 mm Exc 4,000 mm

Fuel consumption:            N/A

Fuel Multi:                         Yes

Fuel Quantity:                   860 Ltr

Fuel range:                         300 km

Trench clearance:             2,500 mm

Max Road Speed:              60 kph

Max Off-Road Speed:       45 kph

Amphibious:                       Yes

Amphibious type:              Screw Jet

Amphibious speed:           12 kph

Amphibious time:              18 Hours

Amphibious bearing:        12,000 kg

Max ascent angle:             60 Degrees

Max descent angle:          52 Degrees

Side slope:                          35 Degrees

Vertical obstacle:              650 mm

Ground clearance:            400 mm

Ground pressure:              0.56 kg / cm2

Weight Combat:                34,000 kg

Weight Empty:                   24,000 kg


The PTS-4 has a total weight of 33 tons with a payload of 12 tons on land and 18 tons on water. The vehicle is able to reach a maximum speed on road of 60 km/h and 15 km/h on water.

Developed since 2007 by the Russian Defense Company Uralvagonzavod, the PTS-4 is based on the suspension of main battle tank T-80 and gears of main battle tank T-72. The PTS-4 can carry infantry fighting vehicles, armoured personnel carrier and trucks.

The PTS-4 will be ready to enter in production. In 2011, the vehicle has passed a series of qualification tests. The PTS-4 has a fully-enclosed armored cab. It provides protection against small arms fire and artillery shell splinters.



BAV-485 amphibious carrier

Derived directly from the wartime 6 x 6 DUKW provided under Lend-Lease, the BAV-485 is a watertight boat-like body on a Soviet truck chassis.

Following the successful use of American-supplied DUKW 6×6 amphibious vehicles by the Soviet army during World War II, it was decided to build a similar vehicle but based on a Soviet truck chassis. This finally appeared in the early 195Os as the BAV-485, sometimes called the ZIL-485, The layout of the BAV-485 is similar to that of. the American DUKW with the engine and transmission at the front, crew seats to the rear of the engine compartment, and the cargo area at the rear. A maximum of 2500 kg (5,511-lb) of cargo or 25 fully equipped troops can be carried. The crew at the front are provided with a windscreen which can be folded forwards, and if required bows and a tarpaulin cover can be erected over the crew and troop compartments. A major improvement over the original American DUKW is the installation of a drop-down tailgate at the very rear of the cargo compartment, which enables light vehicles, mortars and light artillery weapons to be loaded very quickly. The engine is coupled to a manual gearbox with five forward and one reverse gear, and a two-speed transfer case,- The main brakes are pneumatic, with a mechanical parking brake that operates on the rear wheels only. The BAV-485 is powered in the water by a single three-blade propeller mounted under the rear of the hull, and before the vehicle enters the water bilge pumps must be switched on.

The basic BAV-485 was based on the ZIL-151 6×6 2500-ks (5,511-1b) truck chassis built by the Likhachev Motor Vehicle Plant ln Moscow between 1947 and 1958. Later production vehicles were based on the ZIL-157 6×6 2500-kg (5,511-1b) truck chassis built at the same plant between l95B and 1961, this model being designated the BAV-485A. The major difference between the BAV-485 and the later BAV-485A is that the former has external air lines for the central tyre pressure-regulation system while the latter has internal air lines which are less easily damaged. The central tyre pressure-regulation system is a common feature on Soviet wheeled armoured vehicles and military trucks, and enables the driver to adjust the ground pressure to suit the ground being crossed. It is by no means a new idea, however, as the Americans had a similar system on their DUKWs during World War II. Some BAV-4BSs have been observed with a 12.7-mm (0.5-in) DShKM heavy machine-gun for anti-aircraft defence, this being mounted on the forward right side of the troop compartment.

Specification BAV-485

Crew: 1+ 1

Combat weight: on land and on water 9650 kg (21,275-lb)

Powerplant: one ZIL- 123 6-cylinder petrol engine developing 110 hp (82 kW)

Dimensions: length 9.54 m (31 ft 3.6 in) width 2.845 m (9 ft 4 in): height 2.66 m(8 ft 8.7 in)

Performance: maximum road speed 60 km/h (37.3 mph); maximum water speed 10 km/h (6.2 mph) maximum road range 480 km (298 miles); fording amphibious; gradient 60 per cent; vertical obstacle 0.4 m (1 ft 4 in); trench not applicable


More DUKWs

Pronounced “duck,” this 2.5-ton, six-wheel-drive amphibious vehicle was put into service with the USMC and U. S. Army in 1942. Built on a truck chassis, the DUKW could carry 25 fully equipped troops. Clumsy and slow, DUKWs were little used by the USMC in the Pacific during WORLD W AR II, although a USMC DUKW company saw action at IWO JIMA. Most DUKWs were used by the army in the European theater. Operation HUSKY was also the first Allied invasion of the war in which the specially designed amphibious DUKW truck was employed.


The Army Rescues the Navy. There was some objection to the DUKWs as a waste of resources. The first were shipped to Cape Cod, where they joined the U. S. Army’s 1st Engineer Amphibian Brigade. That winter when a Coast Guard boat foundered in high winds and a DUKW rescued its seven-man crew, Secretary of War Henry L. Stimson informed President Franklin D. Roosevelt at a cabinet meeting that “Two nights ago on Cape Cod, an army truck rescued the men from a stranded naval vessel.” This ended any opposition to the new vehicle, which was then sent to war.

The DUKW amphibian truck was one of the most innovative logistical developments of World War II. Based on the highly successful Yellow Truck 2.5-ton truck, the new vehicle was developed to meet the need for an amphibian vehicle capable of delivering men and supplies over the beaches on remote islands without dock facilities in the Pacific theater. DUKW production was 37,000 units during the war.

When approached about the possibility, General Motors, which had bought out Yellow Truck, took little more than a month to produce four pilot models. The new vehicle took its name from the company code of D for the year (1942), U for utility, K for four-wheel drive, and W for two rear-driving axles. The “Duck,” as it became known, weighed 7.5 tons empty; was 31 feet long and 8 feet wide; was powered by an 8-cylinder, 91-horsepower engine; and could transport up to 50 troops or 2.5 tons of supplies.

Buoyancy was provided by giving it a body composed largely of sealed, empty tanks. On land the DUKW employed its six driving wheels, while in the water it used its marine propeller and rudder. On land it could reach road speeds of 45 miles per hour, while its maximum water speed was 5 miles per hour. In order to prevent the DUKW from becoming bogged down in sand, tire pressure was kept low. Once the vehicle was on a solid surface, the driver used a device to inflate the tires from an air compressor and air storage tank. The DUKW entered the U. S. military inventory in October 1942. The DUKWs entered the Pacific fighting in operations against Nouméa in New Caledonia. In the European theater, DUKWs were employed most notably in the Sicily landings and at Normandy, where in the first 90 days after the initial landings they moved ashore 18 million tons of supplies.

A number of DUKWs remain in service to transport tourists. They have also been used to rescue civilians stranded by natural disasters, such as flooding.