WWI and WWII Sonar in Naval Warfare

Sonar Research and Naval Warfare: 1914-1954

During both World War I and World War II, there were a number of informational tactics used by the Navy in order to gain ground on enemy troops. One of those was sonar research, because it provided them with knowledge they would not have otherwise had (Hackmann, 1984). Sonar is not perfect, but a great deal of work has gone into it since its creation, and that has helped it to become a more valuable tool for Naval operations. Sonar is used for navigation, but also for communication and the detection of objects, primarily underwater (Urick, 1983). There are two types of sonar: passive and active. In active sonar, pings are sent out to search for other objects (Hackmann, 1984). Passive sonar does not send out a signal, but only listens for the pings and signals of others (Hackmann, 1984). Both have their place, and can be highly effective. Additionally, both were used by the Navy during WWI and WWII, in an effort to protect vessels from enemies and also locate enemy vessels that may become targets (Hackmann, 1984; Hackmann, 1986).

This paper seeks to provide information about sonar and how it was used in both WWI and WWII. It also addresses some specific questions that need to be answered about the use of sonar, including:

How did sonar use and quality differ between WWI and WWII when it came to active and passive options?

What type of effect did sonar actually have on WWI and WWII in the sense of gathering information?

Did the use of sonar change the course of either war and, if so, how was that change created and measured?

Because sonar is so often used for intelligence and because it can easily be used to gather certain types of information, it is not surprising that it was popular in both WWI and WWII (Hackmann, 1984). In between those wars, advancements were made in sonar. It will be vital to this paper's conclusions to explore not only how sonar was used in both wars, but how much different it was and how that affected the value of it for Naval operations. It is to be expected that the sonar available in WWI was not as good as the sonar available in WWII, simply because of the time between wars and the way that technology continues to advance. However, the extent to which sonar changed and how that may or may not have affected what took place during both wars is also an important consideration that will be addressed. Without clear knowledge of how sonar works and what it had to offer to Naval operations in both WWI and WWII, it is not possible to understand the value of it and/or how it may have helped a particular side or country win either war. If there were problems with sonar or reasons why it may have hindered the cause of Naval operations at the time, those also have to be considered and discussed in order to provide complete information.

Concepts and Theories

The prevailing theory considered here is that sonar was vital to intelligence gathering in both wars, and that it was significantly more valuable in WWII than it was in WWI, simply because of the advancement of technology that occurred during that time period. While that is the theory proposed, there are no guarantees that it is the correct one, or that there are not other considerations that have to be addressed and/or are being overlooked. There may be other components to the issue that are not a part of the use of sonar but that may have been affected by it or may have affected its outcome in either one or both of the wars. If this were to be the case, it would be important to be aware of this so that any studies into the wars and the use of sonar by Naval operations can be as accurate as possible. When a theory is presented, it is necessary to provide backing for that theory, in order for it to be accepted and in order for it to be studied in the right way.

The concept being addressed throughout this paper is that sonar was a necessary and valuable component for the Navy in both WWI and WWII, and that the outcome of one or both of those wars could have been drastically different had sonar not been employed. This is something that can be studied, and a conclusion regarding it can be reached, but only with a proper understanding of what sonar could and could not do. It was not the same then as it is today, and could not offer as much information that would allow for the gathering of intelligence, especially in underwater situations. That does not mean it was not valuable to the Navy, however, and there is a strong belief that sonar could have been what actually won both of the wars. Whether this can be proven with any degree of certainty is debatable, but that does not mean that information cannot be provided that will shed strong light on the value of sonar when it comes to Naval operations during the wars.

Hypotheses and Variables

Having a hypothesis to consider is an important part of the study and discovery process. For the purposes here, there is more than one hypothesis because there is more than one significant event (war) being discussed. To that end, the hypotheses under consideration are as follows:

In World War I, the use of sonar in Naval operations played a significant role in which country ended up victorious.

In World War II, the use of -- and advancements in -- sonar in Naval operations played a significant role in which country ended up victorious.

Hypotheses are important, but they are not all that has to be considered here. There are also variable that are a large part of the study, and that, if not taken into account, could easily skew the results of the study. The variables here include a number of things that are not related to sonar, such as the number of ships used in the war, the location of the fighting, the number of troops sent to fight, the length of the war, and the other ways in which intelligence was gathered, in addition to sonar. There are many variables, which can make it difficult for a study to control for all of the reasons that something took place. In this case, having a number of variables could make it more difficult to determine exactly how much of an influence sonar had on which country won the war, and how successful they were based on the length of time it took for a victory. Naturally, that is a problem. It is not possible to remove or ignore these variables, however. They must be considered.

Since the variables cannot be removed, it is important to control for them as much as possible. This will be done through an examination of the conditions at the time the sonar was used, in order to determine how different the variables were and how much of an influence they may have had on the ultimate outcome. It is also possible to study the sonar more directly, by determining when (and if) it specifically affected something that was related to the outcome of either of the wars. Sonar is not just used for fighting a battle or winning a war. It is also used for the gathering of intelligence in order to determine enemy movements and other factors that have to be considered when a war is taking place (Hackmann, 1984). Understanding what types of intelligence could be collected and in what quantities can go a long way toward determining the true value of sonar in both WWI and WWII. That can allow conclusions to be drawn that are based on as much knowledge of the time period as is possible given the length of time that has passed since the wars took place.

Cases

One of the ways a study can provide detailed, valuable information about a specific event or period in history is through the use of case studies. These are certain things that happened, and that are used as examples of what the author is attempting to convey. They can help conclusions to be drawn, and they can also offer insight in ways that are more difficult to get across or understand without direction information that can be used for comparison. For this paper, each war will be its own case. That means there will be two cases explored. Case One will be WWI, and Case Two will be WWII. It is not realistically possible to divide these events much further, because there were so many different -- and often ongoing -- battles fought during both wars. Attempting to break the wars down into individuals battles would results in being required to study numerous, small cases, some of which have very little information provided about them. That would be detrimental to the study, and would also be confusing. Larger cases make more sense for this study, and will be used to provide insight about, and examples of, how sonar made a difference in Naval operations.

Case One: World War I

World War I, or the First World War, was also called "The Great War" (Abbatiello, 2005). Centered in Europe, it was actually a global war that brought in a number of countries, including the United States and its Naval operations (Price, 2004). These Naval operations used sonar in order to find other ships and determine where to position themselves in order to have the best opportunities to protect their crews and stop enemy troops from gaining any ground. The main use of sonar during this time was from surface vessels, and it was only passive sonar (Abbatiello, 2005). Using active sonar can be risky, because it also lets others in the area who are also using sonar find the vessel more easily (Abbatiello, 2005). Sending out a signal is not always a good choice in wartime, when a vessel is attempting to remain stealthy and avoid detection (Price, 2004). That does not mean that passive sonar used by other vessels would not still find that vessel, but only that it would be more difficult to do so and the vessel would not be making itself obvious to others.

When WWI occurred, that actually led to a relatively rapid development of sonar. There was a need to detect submarines, because they could hide under the water and get close to intended targets before anyone knew they were coming (Howard, 2007). Naturally, that was a problem for those who were targeted by these submarines. There needed to be a way to stop them, or at least know where they were so people could have some kind of warning (Abbatiello, 2005). Because of that concern, more research was done into ways to use sound to find things under the ocean. This was not the first development or use of sonar, but it was among the first times that it was used in that manner and for an important purpose such as the protection of life and limb (Abbatiello, 2005). Without the use of sonar and without working to develop it as quickly as possible, many more lives could have been lost in WWI and in future battles. The development of sonar was a game changer for WWI, as it was able to find submarines before they got too close (Abbatiello, 2005). That gave people time to get away or prepare, as well as time to retaliate.

The British were among the first to place a focus on sound and how to get more value from it for the purpose of detecting enemy submarines (Howard, 2007). They created devices for listening underwater and called them hydrophones (Abbatiello, 2005). During that same time, Paul Langevin, a French physicist, was working with Russian immigrant and electrical engineer Constantin Chilowski on developing devices that could detect a submarine (Price, 2004). These were active devices based on sound, and they used quartz as a method of detection because of its vibrational properties (Price, 2004). This was taking place in 1915, long before the sonar that is used today was created or envisioned (Howard, 2007). Despite the fact that it was relatively primitive, both the French and the British were clearly onto something with the directions they were taking (Abbatiello, 2005). They used electrostatic transducers, which were later superseded by magnetostrictive and piezoelectric options (Abbatiello, 2005). Their work, though, did have a strong influence on the future of sonar and the designs that were used. It was the first use of sound to find submarines underwater, and very important not only to the troops in WWI, but also to what would take place in WWII (Abbatiello, 2005).

Both France and Britain had active prototype systems at work by 1918 (Price, 2004). The British system was tested in 1920 and production of it was begun in 1922 (Howard, 2007). By 1923-1924, many vessels were equipped with the version of sonar that was available at that time (Howard, 2007). It was not yet actually called sonar, but it was the ancestor of the current system. More important than what it was called, however, was what it did. Using sonar, Naval vessels were able to "ping" the waters around them and bounce sound waves off of objects in those waters (Price, 2004). This would provide them with information on things like the ocean bottom (depending on the depth), reefs, and sand bars (Price, 2004). That knowledge could help keep them from running aground or hitting anything. However, sonar did much more than that. It also provided these vessels with information regarding the location of other vessels -- including submarines (Price, 2004). That knowledge allowed vessels to change location, prepare to defend themselves, or simply report the location of other vessels to their commanders so choices regarding them could be made (Price, 2004).

It is important to note that, during WWI, it was the French and the British that had this technology. The United States had not yet developed sonar, and had not worked with other countries to create it or a version of it for their own use. While not necessarily a bad thing, per se, it did put them behind the times when it came to what they were capable of offering as an ally. They did not have the ability to find submarines in the ocean, because they had not yet mastered how to use sound waves to do that properly (Abbatiello, 2005). That would come, but not until the British provided what they knew to the United States -- and that did not occur until WWII, when sonar improved significantly in a number of ways. In WWI, there were still many problems with the sonar that was created, and one of them was a frequent loss of contact between the vessel using the sonar and the vessel it located (Abbatiello, 2005).

The depth-charge was the weapon used against submarines. A vessel would pass over the submarine, on top of the water, and drop charges over the stern (Price, 2004). The goal, of course, was for the charges to strike the submarine and disable or destroy it (Abbatiello, 2005). However, there was a problem executing this maneuver because of the way early sonar worked. In the few short moments leading up to the attack, the proximity and location of the two vessels would cause them to lose sonar contact (Howard, 2007). The vessel that was dropping the depth-charges was, in essence, firing blind because it could no longer see the submarine's position on sonar. During the few minutes that was taking place, the submarine crew could take evasive action and actually move out of the way (Howard, 2007). That rendered the depth-charges ineffective, and was a tremendous waste of effort, manpower, and ammunition. Problems of that nature were eventually remedied using multiple ships, but that did not develop until WWII (Abbatiello, 2005).

Even though WWI did not have good sonar, it did have rudimentary options that led to the development of much better choices for WWII and up to the present day. That is worth considering, because it had to start somewhere and would have been far less successful in WWII if the groundwork for it had not been laid in WWI by the French and British. Between WWI and WWII, developments continued to occur, but at a slower pace. Without a war taking place, there was no sense of urgency to the development of technology. As it became clear that WWII was inevitable, however, countries began working on sonar and other devices in earnest once again, in order to be prepared.

Case Two: World War II

World War II was far different from WWI in the sonar abilities that were available, how they were used, and what they provided to the countries who were involved in the war (Adamthwaite, 1992). For example, the problem of the vessel needing to fire blindly where depth-charges were concerned was solved. There are two issues that allowed for this. One was the coordination of multiple ships so where the target submarine was could always be determined (Lightbody, 2004). The other was the development and use of weapons that could be launched at a target ahead of the vessel instead of only directly underneath it (Lightbody, 2004). These two options changed many things for the countries that developed and used them, but the continued development and improvement of sonar was still very vital to the war efforts. As WWII began, the British gave the United States free use of their sonar technology, which at that time was called ASDIC (Barber & Harrison, 2006). Both the UK and the U.S. started researching what else could be done with the technology and how it could be further developed in order to be more valuable.

Additionally, further sound detection options by the military were created, including mine detection options and sonobuoys (Lightbody, 2004). Many of those options laid the groundwork for ideas that would be further developed once WWII was over. During the war, though, sonar was a very important component of a number of battles. The Axis power, such as Germany, had also been working on developing sonar (Lightbody, 2004). One of the areas on which they focused was countermeasures. In other words, it was not just about creating sonar that could "ping" ships and other objects, but also about finding ways that detection with current sonar could be avoided (Barber & Harrison, 2006). Blocking technologies and other countermeasures were strongly explored by the Axis powers, in order to determine the best ways to evade detection and still determine where other ships were located, whether they were enemy or friendly vessels (Adamthwaite, 1992). How well sonar worked depended on many factors, but continual improvement was made.

Since there was continual improvement seen, that meant that continual improvement in avoidance and countermeasures was also needed (Adamthwaite, 1992). That was a significant issue for Germany and other Axis powers throughout the war, and was ultimately a part of their demise and the victory of the Allied countries (Lightbody, 2004). Sonar's quick development in wartime was valuable, but as it languished somewhat between WWI and WWII there was less value in it than would be expected. Still, it did change and provide options like more range and better accuracy (Adamthwaite, 1992). Some were very pleased with the value of sonar during WWII, and others were concerned that it has not experienced enough development and change between WWI and the start of the Second World War. One of the largest issues was not that sonar had not developed or improved by the time WWII arrived, but rather that the other countries -- most notably Germany -- had caught up to where the Allied powers were (Lightbody, 2004). Since that took place, the sonar that was used by the Allies was not as valuable to them, and did not work as well as it had in WWI.

Rapid changes had to be made in order to ensure that the Allies were able to stay ahead of the Axis powers (Lightbody, 2004). Since those changes had not been made after the end of WWI, WWII left some countries scrambling to do more. Still, the value of sonar in WWII is worthy of note as an intelligence-gathering device and also as a way of locating the enemy and ensuring that he did not get too close. Many submarines and other vessels were damaged or destroyed on both sides, largely because they could not avoid detection as easily (Lightbody, 2004). Once they were located, new and better weapons also made it more likely for them to be harmed, instead of having the opportunity to take evasive action before the damage could be done. While troublesome for those who were attempting to avoid damage, it was also a highly valuable turning point for the war and the Allied powers.