First-Hand:No Damned Computer is Going to Tell Me What to DO - The Story of the Naval Tactical Data System, NTDS

INTRODUCTION

      It was 1962. Some of the prospective commanding officers of the new guided missile frigates, now on the building ways, had found out that the Naval Tactical Data System (NTDS) was going to be built into their new ship, and it did not set well with them. Some of them came in to our project office to let us know first hand that no damned computer was going to tell them what to do. For sure, no damned computer was going to fire their nuclear tipped guided missiles. They would take their new ship to sea, but they would not turn on our damned system with its new fangled electronic brain.

      We would try to explain to them that the new digital system, the first digitized weapon system in the US Navy, was designed to be an aid to their judgment in task force anti-air battle management, and would never, on its own, fire their weapons. We didn’t mention to them that if they refused to use the system, they would probably be instantly removed from their commands and maybe court martialed because the highest levels of Navy management wanted the new digital computer-driven system in the fleet as soon as possible, and for good reason.

      Secretary of the Navy John B. Connally, a former World War II task force fighter director officer, and Chief of Naval Operations Admiral Arleigh A. Burke were solidly behind the new system, and were pushing the small NTDS project office in the Bureau of Ships to accomplish in five years what would normally take fourteen years. The reason behind their push was Top Secret, and thus not known even by many naval officers and senior civil servants in the top hierarchy of the navy. Senior navy management did not want the Soviet Union to know that task force air defense exercises of the early 1950s had revealed that the US surface fleet could not cope with expected Soviet style massed air attacks using new high speed jet airplanes and high speed standoff missiles.

      As of 1954 the US Navy, as well as every other navy, tied their task force air defense together with a team wherein most of the moving parts were human beings. Radar blips of attacking aircraft, as well as friendly airplanes, were manually picked from radar scopes and manually plotted on backlit plotting tables, Course and speed of target aircraft was manually calculated from the plots of successive radar blips of a target aircraft, and then written in by hand near the target’s plotted track. If air target altitude had been measured by height finding radar, or estimated by “fade zone” techniques, the altitude was also penciled in near the track line. If the target was known hostile, known friendly, or unknown, that information was also penciled in. And, an assigned track number was also penciled in.

      No plotting team on any one ship in the task force could possibly measure and plot radar data on every raid in a massed air attack which might involve a few hundred raids coming at the task force from all points of the compass and at altitudes from sea level to 35,000 feet. Rather, as had been worked out in the great Pacific air battles of World War II, each ship in the task force measured and plotted the air targets in an assigned pie shaped wedge on their radar scopes, and their fighter director officers and gunnery coordinators controlled the fighter-interceptors and ship’s AA guns within that assigned piece of pie.

      The plotting team on each ship also reported the position of each air target they were tracking over a voice radio network to all other ships in the task force so that each ship could maintain a summary plot of all air targets so that an air target passing from one pie wedge to another could be instantly identified and it’s track maintained by a new reporting ship. This manual plot was done with grease pencil on a large transparent plexiglass screen in each ship’s combat Information center (CIC). The plexiglass was edge lighted so that the yellow grease penciled track plots glowed softly in the darkened CICs. Wearing radio headsets, the sailors doing the plotting, wrote the target information in a reverse, mirror image style, so that fighter directors and battle managers sitting on the other side of the vertical summary plot could read the annotated grease pencil markings.

      The fleet air defense management system had worked reasonably well during even the greatest ocean air battles of WW II. Secretary Connally did remember one massed Kamikaze air attack where the plotting teams were almost overwhelmed, and he had to forego his job as task force Fighter Director Officer and take control of a specific pair of interceptors to guide them to intercept a group of incoming Kamikazes.[Tillman, Barrett, “Coaching the Fighters,” U.S. Naval Institute Proceedings, Vol. 106/1/923, pp 39-45, Jan 1980, pp. 43-44]. The difference in the decade from 1944 to 1954 was new jet propelled aircraft that could travel almost twice as fast as their World War II counterparts. Manual plotting teams in post WW II shipboard combat information centers (CIC) just could not handle a massed attack of the new high speed jet aircraft, and in the minds of some senior Navy officials the future of the US surface fleet was in doubt. The radar plotting teams, the fighter directors, and the gunnery and missile coordinators needed some kind of automated help.

      The first attempts to solve the fleet air defense management problem used massive electromechanical analog computing devices, and they didn’t work very well; primarily because their high count of moving parts made them unreliable. Next, the Navy tried electronic vacuum tube-based analog computers which did not work much better because they needed so many tubes. The final solution came from the Navy’s codebreakers who had, in great secrecy, been using digital computers to decrypt encoded messages. A fortuitous combination of two young naval engineering duty officer commanders, one of whom was an expert in radar technology, and the other of whom was not only highly experienced in wartime operational use of radar, but also had been in charge of designing and building the Navy’s codebreaking computers, resulted in their conception of the digital computer based Naval Tactical Data System in 1955.

      In spite of the dependence upon three new immature technologies: digital computers, transistors, and large scale computer programming; and in spite of determined resistance by many senior naval officers, the NTDS project would later be acclaimed as one of the most successful projects ever undertaken by the US Navy. It would be the new science/art of computer programming that would almost bring the project to its knees, and it would be the reliability of the new digital equipment combined with a new breed of expert sailors, called Data System Technicians, that would save the project, and give the US Navy a powerful new capability it never had before .

FROM KAMIKAZES TO CODEBREAKERS, ORIGIN OF THE NAVAL TACTICAL DATA SYSTEM

Visions of Disaster at Sea

Legacy of the Divine Wind

For the most part they were just teenagers, they had been hastily trained, they were so vulnerable to the new American high performance fighters that more experienced fighter pilots were assigned to protect them. Also, many times their light Zero Fighters just bounced off their intended target ships, especially if they had forgotten to pull the arming lever of their 550 pound bomb. [Inoguchi, Capt. Rikihei & Nakajima, Cdr. Tadashi, The Divine Wind - Japan’s Kamikaze Force in World War II, Naval Institute Press, Annapolis, MD, 1958, Lib. Cong. Cat # 58-13974, pp 90-105] For example, on 16 April 1945, the destroyer USS Laffey was attacked by 22 Kamikazes and  sustained three direct Kamikaze hits, as well as bomb hits, but remained afloat to fight again at the Normandy Invasion. Among Laffey, her AA armed landing craft escort, and her overhead combat air patrol fighters, they shot down 16 of the 22 attackers; Laffey’s guns accounting for the bulk of the kills. [Becton, Radm. F. Julian, The Ship that Would Not Die, Pictorial Histories Publishing Co, Missoula, MT, 1980, ISBN 0-933126-87-5, p 245]

Even though the Allies destroyed the the Kamikaze airplanes in great numbers, they kept coming in great numbers, and they did considerable damage. By the end of WW II the estimate of Kamikaze damage was seventy one allied ships either sunk, or so damaged they could not be repaired, and these included a number of aircraft carriers. Another 150 ships had been so damaged that they had to be taken off the line for many months for shipyard repair. More than 6,600 Allied soldiers and sailors were killed in the Kamikaze attacks, and another 8,000 wounded. [Brown, David, Kamikaze, Gallery Books, New York,1990, ISBN 0-8317-2671-7, p 78]

More worrisome was the Japanese’s latest suicide weapon, the “Ohka” (cherry blossom) rocket boosted glide bomb. In its descent, it was much faster than the Zero Kamikaze fighter, and so, much harder to shoot down by fighters or ship’s guns. The Ohkas were “standoff weapons” slung under Mitsubishi G4M (Betty) twin engined bombers. On 12 April 1945 the first Ohka to be dropped in anger slammed into the US destroyer Mannert L. Abele, and broke its back. The ship went to the bottom in minutes. [Brown p 67]  The Ohkas were to be launched about 11 miles from their target ships, and the Allies concluded that the best way to defend against the Ohka was to shoot down the carrying mother plane before it reached launch point for its ‘standoff weapon.’ [Inoguchi p 141] 

The guidance mechanism in the Ohka was the most advanced mechanism in the history of the human race, a human being. In the years immediately following World War II, US Navy planners noted that even though future hostile nations might not resort to suicide weapons, great strides had been made in analog computing devices and precision guidance mechanisms, and that high speed, automatically guided, air launched standoff weapons could pose great danger to the US surface fleet.

 

The Postwar Fleet Air Defense Exercises

Even though in the years immediately preceding WW II the major warring powers had almost simultaneously, and secretly, developed rudimentary radar sets, Germany and Japan had not pressed their development. This seems to be primarily because the military leaders of both these nations believed in rapid, violent, aggressive conquests; whereas they considered radar to be a defensive weapon and not needed in their expected “short” wars of aggression. Furthermore, they expected their conquests to be completed before the time it would take to develop useful radar capability. It would not be until it was too late to significantly aid their war fighting that they realized they needed to put effort into radar development.

The Allies on the other hand, especially Great Britain and the United States, embraced radar and developed it to its fullest extent. By the end of hostilities the Allies not only had their original, but greatly improved, air search radars, but also precision surface search radars, and pencil beam fire control radars embedded in anti-surface and anti-air gunnery fire control systems. The biggest problem with U.S. naval radar in 1945 was that it produced an enormous amount of data but not enough information. The wartime U.S. Chief of Naval Operations, Admiral Earnest J. King, in October 1945 wrote a letter to the Chiefs of the Bureaus of Ordnance, Aeronautics and Ships expressing the fleet’s frustration regarding the prolific amount of data that radar was capable of providing. He noted that by the end of WW II;

“The display of information was slow, complicated and incomplete, rendering it difficult for the human mind to to grasp the entire situation either rapidly or correctly and resulting in the inability to handle more than a few raids simultaneously,. Weak communications prevented information from being properly collected or disseminated either internally aboard ships or externally between ships of a force.  He noted what is needed is; ”A method of presenting radar information automatically, instantaneously and continuously and in such a manner that the human mind ... may receive and act upon the information in the most convenient form; [plus] instantaneous dissemination of information within the ship and force.” [Bryant, William C., LT, USNR and Hermaine, Heath I., LT, USNR, History of Naval Fighter Direction, C.I.C. Magazine, U.S. Navy, Bureau of Aeronautics, April, May, and June 1946]

This charge from Admiral King to the bureau chiefs meant that they were authorized to spend a lot of time, money and effort on solving the radar data data handling problem, but as we will see, for a decade, due to the lack of the right technologies in the minds of men with the right imaginations, the solution would just not be in hand. In the mean time, due to new turbojet engine technology which enabled attacking aircraft to fly even faster, the problem only got worse. 

“Whereas a Lancaster taking off gives the impression of tremendous power hauling a ponderous weight triumphantly into the air, a Mosquito taking off rather suggests a bundle of ferocious energy that the pilot has to fight to keep down on to the runway. The place to watch is from the end just where the Mozzie gets airborne. You see her starting towards you along the flarepath, just a red and green wingtip light. Soon you can distinguish her shape, slim and somehow evil, and suddenly she is screaming toward you just like a gigantic cat. A moment later she is past and thirty feet up in the air”. [Bowyer, Chaz, Royal Air Force - The Aircraft in Service Since 1918, Temple Press, 1981, ISBN 0 600 34933 0, p 101]

Even though the de Havilland D.H. 98 Mosquito was classified as a light bomber, it could carry a heavier bomb load than the American Boeing B-17 heavy bomber, and it could outpace most models of the Supermarine Spitfire, powered by its two Rolls-Royce Merlin piston engines. In addition to the unarmed bomber version, other Mosquito configurations were built including heavily armed night fighters and unarmed photo-reconnaisance aircraft. The photo-recon version was especially fast so that it could outrun any pursuing fighter in the Luftwaffe. [Sweetman, Bill, Mosquito, Crown Publishers, Inc., New York, ISBN 0-517-548542, p 12, p 21] That was until 25 July 1944 when Flight Lieutenant A. E. Wall piloting a photo-rec. Mosquito over Munich was accosted by a fast moving german aircraft having no propellers. Wall could not outdistance the new jet propelled Messerschmitt Me 262 no matter how much power he applied, and he escaped only by diving into an obscuring cloud bank. [Boyne, Walter J., Messerschmitt Me 262, Smithsonian Institution Press , Washington, D.C., 1980, ISBN 0-87474-276-5, p. 41] The jet age had arrived. Soon there would be a new generation of jet propelled attack airplanes capable of traveling twice as fast as their World War II predecessors.

The increased speed of the new jet propelled attackers was enough to cause great alarm for specialists in fleet air defense, but there was one small comfort, aeronautical scientists of the mid 1940s questioned whether a manned aircraft could fly faster than the speed of sound, which is approximately 761 miles per hour at sea level, decreasing to about 660 mph at 36,000 feet altitude. The scientists knew that there were controllability problems as aircraft speed neared sonic speed, and there were questions whether airplane structures would hold up to the heavy buffeting encountered at these speeds due to the airflow around the craft transitioning unevenly at different places on the airplane from laminar subsonic flow to compressible supersonic flow.

On 14 October 1947 Captain Charles E. Yeager dispelled these concerns when, at  20 thousand feet above the National Advisory Committee for Aeronautics’ High Speed Flight Station in the Mojave Desert, he was released from the bomb bay of a modified B-29 ‘mother airplane’ piloting the Bell XS-1 research airplane. As soon as he was clear of the B-29, Yeager switched on two the four chambers of his XLR11 rocket engine and climbed to 40 thousand feet where he was to make his speed run. At the planned altitude he switched on a third rocket chamber and within seconds his mach meter registered 1.06 times the speed of sound. He then shut down all rocket chambers and glided the XS-1 down to the dry lake bed next to the High Speed Flight Station. Yeager reported no control problems and only minor transonic buffeting. [Miller, Jay, The X-Planes X-1 to X-31, Aerofax, Inc., Arlington, Texas, 1968, ISBN 0-517-56749-0, p. 19] Controlled, manned supersonic flight was now a reality, and manned supersonic attack aircraft would soon follow.

The Royal Navy had also made great strides in naval radar during WW II and had a radar-based fleet air defense organization similar to the US Navy’s wherein search radar information was used to coordinate ship’s guns and airborne fighter-interceptors against incoming attack aircraft. In 1948 both the Royal and US Navy’s fleet air defense organizations were manually intensive with no automated support. Aircraft tracks were still manually plotted on plotting boards, airplane speeds were still manually calculated from successive radar blips, and fighter intercept vectors were calculated on sheets of paper maneuvering boards. Details such as raid height, identification, and track number were manually entered on status boards.

The Royal Navy in 1948 ran fleet air defense exercises where task forces were ‘attacked’ by multiple high speed jet aircraft coming from different bearings and at different altitudes. They found that, because of the high speeds of the incoming aircraft, the manual fleet air defense organization could adequately and accurately plot about 12 simultaneous incoming raids and effectively assign interceptors or ship’s guns to engage them. When the number of attacking raids (wherein one raid can be just one attacker or many airplanes flying together) exceeded twenty the air defense organizations fell apart. The inter ship voice radio data passing personnel, the manual plotters, the fighter directors, and the gunnery coordinators were overwhelmed. It did not matter how experienced they were, or how many of them were working together, they just could not adequately handle the incoming flood of radar data on attackers and friendly interceptors, not to mention keeping track of which interceptor or ship’s guns was assigned to which attacker. [Bailey, Dennis M., Aegis Guided Missile Cruiser, Motorbooks International Publishers & Wholesalers, Osceola, WI, 1991, ISBN 0-87938-545-6, p. 39]

In 1950 the U.S. Navy conducted similar fleet air defense exercises which simulated the expected massive air attacks expected of the Soviet Union on U.S. fleet units. High speed air attackers again came in from all directions and altitudes. The attacks were planned out ahead of time so that attack plans could be compared with the fleet units actually saw and recorded. The results were devastating; one fourth of the attackers were never recorded by any of the shipboard combat information centers. Even worse, of the attacking planes which were detected and plotted, the gunnery coordinators and fighter directors only assigned about 75% to guns or interceptors. If it was unrealistically assumed that every assigned interceptor or gun made a kill, about half of the attackers would have made it through to the defended fleet center without having been engaged by a defensive weapon. [Bailey p. 39] In real life, the surface fleet units would have been annihilated. For good reason, the exercise results were not publicized, and considerable research and development was focused on trying to correct the U.S. Navy’s inability to adroitly use the massive amount of radar data on high speed attackers that was available, but not able to be turned into useful information in a timely manner by fleet units. There were concerns at the highest level of Navy management that the U.S. surface fleet was no longer a viable force in being.       

The Guided Missile Systems

TALOS

The principal US shipboard anti-aircraft weapons of World War II were the 5- inch 38 caliber and 3-inch 50 caliber guns and the 20 and 40 millimeter (MM) automatic cannons. (“38 caliber” means the barrel was 38 times as long as the 5-inch bore of the barrel) The 20 and 40 MM cannons had a maximum effective aerial range of about two miles, the three-inch gun an aerial range less then six miles, and the 5-inch gun could effectively bring down aircraft at a range of a little over six miles. A well trained five-inch gun crew could maintain a firing rate of one projectile every three seconds, prompting awed opposing Japanese forces to believe the USN had an automatic five-inch cannon. [Roscoe, Theodore, United States Destroyer Operations in World War II, United States Naval Institute, Annapolis, MD, 1953, Library of Congress card No. 53-4273, pp 15-18]

By mid 1944 the US Navy was experimenting with various air launched standoff weapons and senior navy officials had every reason to believe that the axis powers were doing the same, which they were, as exemplified by later German guided glide bombs, and the Japanese human guided rocket powered Ohka bomb. Bureau of Ordinance (BuOrd) managers realized that new shipboard anti-air defense weapons having much greater lethal ranges than the six miles of the 5-inch gun were needed to counter the expected air launched standoff weapons. In July 1944 BuOrd tasked the Applied Physics Laboratory (APL) of Johns Hopkins University to recommend solutions, 

The laboratory responded with the recommendation of a ship-launched guided supersonic missile powered by an air breathing ramjet engine. The missile would have a range of about 60 miles and would be guided by the launching ship using a precision fire control radar coupled to an analog fire control computer which would transmit steering commands to the missile. When the missile came within lethal range of its target a radar-based proximity fuse in the missile would detonate the warhead.

In January 1945 the Bureau tasked the Applied Physics Lab to begin work on developing a ramjet engine, the key unknown component of the proposed new guided missile. The project was given the code name “Bumblebee,” and on 19 October 1945 a Bumblebee ramjet test vehicle first exceeded the speed of sound. [Klingaman, William K., APL-Fifty Years of Service to the Nation - A History of The Johns Hopkins University Applied Physics Laboratory, The Johns Hopkins 

University Applied Physics Laboratory, Laurel, MD, 1993, ISBN 0-912025-04-2, pp 21-33]

Even though the Japanese surrender on 2 September 1945 had ended World War II, the navy asked Johns Hopkins to continue work on Bumblebee at an urgent pace because of continuing concern about the the perceived threat from supersonic attack aircraft combined with standoff weapons. In April 1948 the Chief of Naval Operations directed that the lessons learned in the Bumblebee project should be focused on developing a complete long range guided missile system. At this time the Applied Physics Laboratory was engaged in what was called a “Section T’ contract with the US Navy, and all missiles developed under the contract were given a name beginning with the letter “T.” History does not seem to record how, or who, thus came up with the name “Talos” for the new ramjet powered guided missile project.

TERRIER

The ramjet missiles were complex and expensive, and numerous flight tests were required to test the supersonic aerodynamic performance of the vehicles and their guidance systems. To save money APL had come up with a simpler, less expensive, two-stage solid rocket propelled test vehicle, designated STV-3, to gather flight test data. Its guidance system was relatively simple in that it follwed the center of a radar,beam locked on the target. The “beam-rider” guidance was found to be vey effective, and APL proposed to the navy that, given a warhead, the STV-3 test vehicle could be a lethal medium range (about 20 miles) guided missile. In April 1948 BuOrd was under intense pressure from the Chief of Naval Operations to accelerate develpment of shipboard guided missiles. The bureau therefore jumped at the chance and directed APL to begin turning the STV-3 into a weapon system in parallel with continued development of the longer range Talos missile. The APL manager, Richard Kershner, of the new branch-off project, following the “T” for-first-letter convention christened the new missile “Terrier” in recognition of its tenacity in clinging to the center of its radar guidance beam. The Bureau of Ordinance contracted with Convair Corporation to build a run of Terrier test missiles under the technical guidance of the Applied Physics Laboratory. [Klingman pp 62-64]