Analog Computers Used in WW2

Hi and a dumb question here...Are you any kind of an expert on analog computers?

Chatgpt:

I wouldn’t say I’m an expert on analog computers, but I have a solid understanding of how they work and their applications, especially in historical contexts. They were mainly used before digital computers became dominant, for tasks involving continuous data like simulating systems in real-time (e.g., flight simulators, process control, etc.). They often rely on components like operational amplifiers, resistors, and capacitors to model complex mathematical operations, rather than binary logic.

What specifically would you like to know about analog computers? Maybe we can dive into the details you're curious about.

Holden:

I'm a little bit curious about the way such things were being used during WW2. What weapon systems would you say involved such analog computers?

Chatgpt:

Analog computers played a significant role during World War II, especially in the realm of fire control systems and targeting solutions. These devices were crucial for calculating firing solutions for ships, planes, and artillery. Here are some of the key weapon systems and applications where analog computers were used: 1. Naval Fire Control Systems:

U.S. Navy's Mark I Fire Control Computer (Ford Mk 1A): One of the most famous examples of an analog computer during WWII was the Mark I fire control computer, which was used on U.S. battleships and cruisers. It was responsible for calculating the complex ballistics needed to accurately fire naval guns at moving targets (such as enemy ships or aircraft) while accounting for factors like wind, ship movement, target movement, and the Coriolis effect. The Mk 1A was an electro-mechanical analog computer that could rapidly compute firing solutions.

British Admiralty Fire Control Table (AFCT): The British had their own version of naval fire control computers, which were used to direct their big-gun ships. These computers performed similar functions to the U.S. Navy's Mark I, calculating firing solutions for long-range naval engagements.

2. Anti-Aircraft Fire Control:

M9 Gun Director: Used by the U.S. Army, the M9 was an analog computer system that helped aim anti-aircraft artillery. It could predict the future position of an enemy aircraft based on its current speed, direction, and altitude, helping anti-aircraft guns fire ahead of the target. The M9 played a significant role in defending against enemy bombers.

Kerrison Predictor: The British Kerrison Predictor was another analog computer that helped anti-aircraft guns track and hit moving aircraft. It used mechanical and electrical systems to calculate the lead required to hit fast-moving planes.

3. Torpedo Data Computer (TDC):

U.S. Submarine Torpedo Fire Control System: U.S. submarines used the Torpedo Data Computer, which was a type of mechanical analog computer designed to calculate the proper firing angle for torpedoes. This system took into account the target's course, speed, and distance, as well as the submarine’s own position, to optimize the torpedo's path. It allowed for more precise torpedo attacks against enemy ships.

4. Bombsights:

Norden Bombsight: One of the most well-known analog devices from WWII, the Norden bombsight was used by American bomber aircraft, such as the B-17 Flying Fortress. This mechanical analog computer allowed bombers to accurately drop bombs from high altitudes. It calculated the aircraft's speed, altitude, wind speed, and direction to guide the bombers in releasing bombs with greater accuracy.

Lotfernrohr 7 (Lotfe 7): The Luftwaffe’s equivalent to the Norden bombsight was the Lotfe 7, another type of analog computer used for calculating bomb trajectories.

5. Artillery Fire Control:

Field Artillery Analog Computers: Analog computers were also used in ground-based artillery to calculate firing solutions for indirect fire. These devices, like the U.S. M1 Field Artillery Computing Sight, helped artillery crews determine the angle and charge needed to accurately hit distant targets based on input such as range, wind, elevation, and air density.

Key Functions of Analog Computers in Weapon Systems:

Real-time calculations: The advantage of analog computers in military systems was their ability to perform continuous real-time calculations without the need for discrete digital inputs, making them ideal for rapidly changing battlefield conditions.

Ballistics: Computing complex ballistic trajectories, especially when both the target and the firing platform were in motion, was a common and critical use. Prediction: Predictive firing, particularly for anti-aircraft and naval engagements, where targets moved quickly and unpredictably, required rapid computations of future positions.

Limitations:

While analog computers were invaluable during WWII, their accuracy was limited by mechanical tolerances and wear and tear. As the war progressed, there were continuous improvements, but these systems were eventually replaced by digital computers post-war due to their greater accuracy, flexibility, and reliability.

These analog systems were an impressive feat of engineering and were critical to the effectiveness of many WWII-era weapon systems. Holden:

Thanks! Was something like that being used for the defensive guns on the B29?

Chatgpt:

Yes, the defensive gun system on the B-29 Superfortress did indeed use an early form of analog computing for aiming and controlling its remote-controlled gun turrets. The system was quite advanced for its time and incorporated analog computers to provide accurate firing solutions against fast-moving enemy aircraft. B-29 Defensive Gun System:

The B-29 had an innovative, centralized fire control system for its defensive guns, which was one of the most sophisticated gun control systems of WWII. Here’s how it worked: 1. Centralized Fire Control (CFC) System:

The B-29 had a network of remote-controlled turrets (four gun turrets and a tail gun position), which were operated by five gunners using sighting stations located inside the aircraft. The gunners didn’t directly aim the guns; instead, they used sighting devices (gun directors), and the actual firing solution was computed by analog fire control computers.

2. Analog Computing for Aiming:

The B-29's system used General Electric's Central Fire Control System, which relied on analog computers to calculate the proper lead and aiming adjustments based on the movement of the aircraft and the target. These computers factored in variables like the B-29’s own speed and altitude, the target’s speed and trajectory, and environmental conditions.

The system employed electro-mechanical analog computing to calculate the necessary angles for firing the guns so that they could lead a moving enemy aircraft. This allowed the gunners to hit fast-moving fighters that were attempting to intercept or attack the bomber.

3. Remote-Controlled Turrets:

Each of the four turrets was equipped with twin .50 caliber machine guns (and some had an additional 20mm cannon). These turrets were operated remotely from gunner stations inside the pressurized cabin, a design choice that helped reduce the need for gunners to be stationed in unpressurized areas, increasing crew safety and comfort at high altitudes.

The turret system was electrically operated and synchronized with the analog computers to ensure that all guns aimed and fired correctly based on the computed solutions.

4. Gunners’ Sights:

The gunners used advanced optical sights linked to the fire control computers. These sights provided input to the analog computer, which would then calculate where to aim the guns. The computers handled the com

plexity of aiming and adjusting for the speed of both the bomber and the attacking aircraft, ensuring more accurate fire.

1. Coordination Between Multiple Turrets:

The B-29's fire control system allowed multiple turrets to be directed by a single gunner if necessary, enhancing the bomber's defensive capabilities. For example, if one gunner spotted an enemy fighter, they could take control of more than one turret to concentrate firepower on the attacking plane. The analog computers managed the coordination of the turrets, making it one of the first aircraft to use a "networked" gun system.

Advantages of the System:

Increased Accuracy: The analog computing system was able to calculate and adjust for lead, bullet drop, and aircraft movement in real time, making the B-29’s defensive fire more accurate compared to manually aimed guns.

Reduced Crew Fatigue: By automating many of the calculations and remotely controlling the turrets, the B-29 system allowed the gunners to focus more on observation and firing, reducing the strain and workload during combat.

Survivability at High Altitude: The B-29 flew at high altitudes where enemy fighters had a harder time reaching them, and the pressurized cabin, along with the remote gun system, allowed the gunners to operate in relative safety and comfort.

Comparison with Previous Systems:

This system was a major advancement compared to earlier bomber designs where gunners directly controlled the guns and manually adjusted for the aircraft's movement and target trajectory. On aircraft like the B-17, for example, gunners had to physically move the guns and manually estimate lead and distance, which was much less precise than the B-29’s system. Legacy:

The B-29’s gun control system, with its use of analog computing for gun aiming, was one of the precursors to more modern, automated weapons systems. After the war, the principles behind the B-29’s fire control system were further developed, eventually leading to fully digital and radar-guided systems.

In short, the B-29’s use of analog computers for its defensive gun system was a key technological leap during WWII, showcasing early computer-aided targeting in aerial warfare. Holden:

Thanks! Was the success of that system against Japanese fighter planes ever analyzed and documented?

Chatgpt:

Yes, the success of the B-29's centralized fire control system, which used analog computing for its defensive guns, was analyzed and documented both during and after World War II. The system proved to be highly effective, though it was not without its challenges and limitations. Here’s an overview of its documented performance against Japanese fighter planes:

1. Effectiveness Against Japanese Fighters:

High Kill Rate: The B-29’s remote-controlled, centralized fire control system was successful in defending against Japanese fighter planes, particularly during the bombing campaigns over Japan in 1944-1945. U.S. Army Air Forces records indicate that B-29 gunners shot down a significant number of Japanese fighters, with some reports estimating the system was responsible for the destruction of hundreds of enemy aircraft by the end of the war.

High Altitude Advantage: B-29s often operated at high altitudes (30,000 feet and above), which provided an advantage against Japanese aircraft that struggled to intercept bombers at such heights. This gave B-29 crews more time to react, and the centralized fire control system’s predictive capabilities allowed gunners to engage enemy fighters before they could close in on the bomber formation.

Concentration of Fire: One key advantage of the system was that multiple turrets could be directed at a single target. When a Japanese fighter approached, gunners could take control of several turrets to concentrate fire on a single target, increasing the likelihood of a hit. This made the B-29 a formidable opponent for lightly armored Japanese aircraft.

2. Analysis of the System’s Strengths:

Accurate Targeting: Post-war analysis showed that the analog computers provided a significant improvement in accuracy compared to previous bomber defensive systems. The ability to calculate the lead necessary to hit fast-moving, often erratically maneuvering enemy planes made the B-29 much more dangerous to approaching fighters.

Reduced Gunner Fatigue: The use of remote-controlled gun turrets and analog computers to automate targeting reduced the workload on gunners. This was especially important on long missions, such as the raids on Tokyo, where gunners might otherwise have become fatigued from manually tracking and firing at enemy aircraft.

Effectiveness Against Kamikaze Attacks: Late in the war, Japanese kamikaze tactics presented a unique challenge. The B-29's fire control system, while not foolproof, provided an effective defense against these attacks. The system allowed gunners to engage kamikaze planes at greater distances and with more concentrated firepower than traditional bomber defenses.

3. Limitations and Challenges:

Jamming and Mechanical Issues: Despite its sophistication, the system was not without technical difficulties. The analog computers were complex electro-mechanical devices that required regular maintenance and calibration. There were instances of mechanical failure or jamming, particularly in the harsh conditions of high-altitude combat.

Learning Curve for Crews: The system was advanced for its time, and there was a learning curve for the crews who operated it. Early in its deployment, some gunners struggled to adapt to the remote-controlled nature of the system and the reliance on analog computing for targeting, which led to lower accuracy rates in the initial stages of combat.

Vulnerability in Low-Altitude Missions: As the war progressed, the B-29s transitioned to lower-altitude bombing raids, especially during nighttime firebombing campaigns over Japanese cities. In these lower-altitude scenarios, Japanese fighters and anti-aircraft fire posed a greater threat, and the B-29's defensive system, designed primarily for high-altitude engagements, was somewhat less effective. The centralized system was still useful but wasn’t as optimized for lower-altitude, high-speed combat.

4. Post-War Analysis and Documentation:

Reports and Debriefings: After the war, extensive debriefings and reports from aircrew highlighted the successes and shortcomings of the B-29’s defensive system. These reports generally confirmed the system’s effectiveness in shooting down a high number of enemy aircraft and protecting the bombers from attack. However, they also noted the complexity of maintaining the system and the occasional mechanical failures.

Comparisons with Other Bombers: The B-29’s centralized fire control system was compared favorably to the more manual systems used on earlier bombers like the B-17 and B-24. While those bombers had effective defensive armaments, the B-29’s system provided a higher level of automation and accuracy, which was seen as a clear technological step forward in bomber defense.

5. Lessons for Future Aircraft:

The success of the B-29’s defensive system had a lasting impact on the development of aircraft weaponry and defensive measures. Many of the principles used in the B-29—such as centralized control, predictive aiming using analog computers, and remote operation of turrets—were later refined and incorporated into early jet bombers and even some modern systems that use digital computing.

Summary:

In conclusion, the B-29’s analog computer-driven gun control system was largely successful in defending the aircraft from Japanese fighters. While not without its issues, it was a significant leap in technology compared to previous systems. Its effectiveness was well-documented and analyzed both during and after the war, with the system being credited for many kills against enemy fighters. The B-29’s defensive gun system is considered one of the most advanced of its era, providing valuable lessons for future air combat systems.