Wednesday, June 22, 2022

Visualizing the Invasion of the Soviet Union with Luftwaffe Locations

On June 22 1941 (81 years ago) Nazi Germany invaded the Soviet Union with the largest military force assembled in history. Behind the ground troops the Luftwaffe (German Air Force) quickly setup forward bases to support the campaign. Using data from http://ww2.dk I put together an infographic visualizing the monthly movements of the Luftwaffe during this time (map borders are current not the ones that existed in 1941). 

One can see planes flying into Poland from the west (Denmark, Norway, France, Belgium, and The Netherlands were conquered the previous year) and Greece (conquered the previous month) right before the campaign. As the Germans advanced along the Northern, Central, and Southern fronts one can also see the indecisive plan of attack. First they locate more planes to the North to attack Leningrad and then shift focus to the attack on Moscow. 

Stopped outside of Moscow in the winter of 41/42 the invasion did not succeed in taking over the USSR. Instead the conflict lasted another three and a half years and ended in May 1945 when the USSR took over Berlin - about 1000 miles from Moscow.

Code can be found here https://github.com/samcarlos/luftwaffe_locations



If you like this plot and want to see the first two years of the war through plane movements check out this post I wrote up here

Monday, June 6, 2022

Nazis, Data, and Planes: A Data Science Tour of the Luftwaffe in WW2 Part I 1939-1942

"What now?"  Adolf Hitler - September 1939 upon learning UK will declare war on Germany


June 6, 1944. Imagine you’re Nazi Germany. The western allies just launched the largest amphibious operation in history and landed in Normandy France. What do you do?  


Send in the navy? Yea, that's a good idea against an amphibious landing. Better to sink the ships carrying the troops than fight the troops on land. Except you don't have much a navy at this point. Certainly not one that can travel to northern France and make a dent against the invading armada. 


What about the army? Yea, not a bad idea either. But the vast majority of your army is on the eastern front fighting the soviet union. What forces you do have can't travel too quickly due to incessant air attacks and the damage they've done to roads, bridges, and trains. It will take time to get large amount of tanks and artillery necessary for a counteroffensive to reach the area. Time you don't have. 


Perhaps you see the writing on the wall. With the Russian's coming from the East, western allies from the south through Italy, and now a force in France it ... doesn't look good. Maybe you suggest surrender? HA! After what you’ve done? No, you have no choice but to fight this one out till the end. 


So what does Nazi Germany do? They send in the force relied on time and again. Whether it's providing support during an offensive, hastily sending them in defense, or resupplying units encircled by the enemy. They send in the Luftwaffe.




Luftwaffe Sizes, Types, and location by Month



In one of the largest air movements of the war the Germans send hundreds of planes from Germany to France leaving the heartland temporarily exposed to allied bombers. With most of the specialized ground attack aircraft awaiting the upcoming summer offensive in the east the plan was to attach bomb racks to the fighter planes in order to provide ground attack support.


In preparation of the fight a Luftwaffe field Marshal sent his pilots the message:


"Men of Luftflotte 3! The enemy has launched the long-announced invasion. Long have we waited for this movement, long have we prepared ourselves, both inwardly and on the field of battle, by untiring, unending toil. Our task is now to defeat the enemy. I know that each one of you, true to his oath to the colors, will carry out his duties ... Great things will be asked of you, and you will show the bravest fighting valor. Salute the Fuhrer." [1,  p.280]

And the military effect of moving hundreds of planes, pilots, and material from Germany into France was ... bubkus.



The planes landed in airfields without ammunition or supplies. Closer to England, the western allies were able send short range fighters that were previously unable to fly to Germany and fight the Luftwaffe there. 

The idea that sending the air force into a region where allied fighters were in great strength, with little supplies, and lack of fighter-bomber training demonstrates the disconnect with reality that became common among Germans decisions towards the end of the war.

The result was something of a rout with the Germans losing hundreds of planes and pilots with essentially no effect on the allies ground invasion. It was part of the reason why June 1944 saw the largest number of fighter planes lost in a month up to that point. 






Not that the Luftwaffe pilots were well trained at this time. After months of attrition fighting over Germany the Luftwaffe increasingly sent barely trained pilots into combat. The US strategic campaign against oil was began to effect aviation fuel supplies at this point. And while production of fighter planes increased to keep up with the attrition the limited number of trained pilots and aviation fuel decreased the effectiveness of the Luftwaffe as a fighting force. 

It wasn't like this the previous year. Indeed for the first four years of war it maintained it's combat effectiveness and routinely displayed its adaptability to influence the battle field. By attaining and maintaining air supremacy the Luftwaffe was one of the key reasons the Nazi's were able to take over Europe (and beyond). It then became an important part of maintaining this empire as it was capable of moving large amount of forces (itself and supplies) across large distances on short notice. 

This is the story of how the most technologically advanced country at the time developed and used a new kind of warfare ultimately succumbing to warfare's crudest strategy: attrition. Due to the economic nature of attrition warfare I think it's best to start this story with the economics the Germany economy in the 1930s. But first a brief overview of the geolocation data I use for this post.

The dataset

The Germans kept records every 10 days on Luftwaffe strength. Online I found locations and monthly aggregates at ww2.dk. Below are some examples of the location and dates data along with the monthly aggregates of sizes and losses of these groups. 


The lowest form of a group was a staffel or squadron which consisted of about 16 planes.  Three staffel generally made a Gruppe and three Gruppe's generally made a geschwader. Each geschwader had a lead pilot and a few additional pilots, generally around four total, known as a Stab. In general we have good data on the Gruppe level and sometimes at the Staffel level. As the war progressed the Germans included additional Gruppes and Staffels to an individual geschwader.


The main type of groups analyzed here are single engine fighter groups, twin-engined fighter groups, night fighter groups, bomber groups, and ground attack aircraft groups. The groups were split into intended role of the aircraft in combat, not necessarily the plane itself. For instance a JU-88 was designed as a medium bombers and those that were used as such were attached to bomber groups. But they were also successful as night fighters and those were attached to night fighter groups.

Example Location Data http://ww2.dk/air/jagd/jg27.htm

Here we can see a particular gruppe location for the first few years of the war. It began the war in Germany, flew to France, back to Germany, on to Greece, and then to North Africa. These exists for fighters (day fighters, night fighters, and twin engined fighters), bombers and ground attack aircraft. Unfortunately not all location data - particularly transport planes information is lacking - but what exists constitutes the bulk of the Luftwaffe throughout the war.

Geolocating the data proved to be difficult and inexact. In part this is due to the nature of recording the dataset itself. Germans would land in fields and generally describe a village or hamlet and not generally care about the spelling. Moreover the location names also highlight how different cities were named over time by different peoples and underscores that different ethnicities coexisted throughout Europe for hundreds of years. Where possible I made guesstimates and tried to get within the generally area. If a particular location is not found I use the previous known location.

In addition the dates are sometimes available at the monthly level eg a particular squadron landed at a place sometime in May 1940 and not 15 May 1940. This has the effect that some groups appear in a location before or after they should be there. I trust the reader understands the limitations of using this data and can understand how this error will be displayed in the visualization. 

Example Size and Loss Data http://ww2.dk/oob/bestand/jagd/biijg27.html


While the location data exists for most units throughout the war the sizes and losses data exists mainly staring in early 1942 through 1944. If the size or loss is not available I impute the size based on the group being analyzed (gruppe, staffel, or stab size) and the losses based off of the loss rate available in the same region. Here I refer to losses as total losses including those planes lost not in combat. Due to the dangerous nature of flying non-combat losses were a sizable part of overall losses especially in severe weather conditions. 

I understand that potentially the incorrect dates, locations of individual squadrons, imputed sizes and losses, and lack of size data before 1942 and after 1944 limits the precision we can analyze this data. However, all together I think this constitutes a powerful dataset that can be used to recreate large sections of the WWII in the European Theater. 

Finally, one area that will be somewhat ignored is the Battle of the Atlantic. This was an important campaign that was a central focus of the allies in 1941-1943. Allied airpower was one of the reasons why the allies won agains the U-boats (German submarines). For instance, in 1943 78 U-boats were sunk by warships while a 147 were sunk by aircraft (see here). However, the Luftwaffe was increasingly tasked with supporting the army and its effect on battle of Atlantic was relatively small. 



Economic and Politics of 1930s Germany

Unemployment Data p.6 here

In the November election of 1932 - the last free one - the Nazis (the German abbreviation of NSDAP or Nationalist Socialist German Worker Party) won 33% of the vote, a plurality. Hitler becomes Chancellor of Germany January 30, 1933. Many countries in Europe during this time had a, not unfounded, fear of communism and voted for conservatives. The Nazis were radical not conservative. 


At its core the Nazi ideology was inherently racist and embraced the idea of eugenics. There was a racial hierarchy with Aryans (white and generally German) at the top. Given their racial superiority it was German people's destiny to expand into and colonize land needed for their own "living space" (Lebensraum).


But with unemployment reaching a maximum of over 40% (one, if not the worst of the Great Depression) and the country on the verge of civil war those in power thought his radicalism would temper with power and be useful.  


While initial Nazi ideology was initially a hodgepodge of incoherrent ideas there were some items that resonated with German society at the time. The Prussian aristocracy constituting the old military guard respected his ideas to increase the size of the military and Germany's previous glory. Big business liked the idea of large government spending and contracts that military buildup entailed. And spend they did.


Before Keynes wrote the General Theory of Unemployment, Interest, and Money and before FDR had his New Deal, Nazi Germany spurred growth through deficit backed spending. The vast amount government spending during this time was on the military. Indeed the aircraft industry was a central part of this with production increasing from effectively nothing to over 8000 planes by 1939. [2, location 173] 

The result was a dramatic decrease in unemployment and an economy back to running at full employment by 1939. In contrast to the USA which still had a large unemployment rate of over 25% and France and England around 10%.

Airplane technology was changing rapidly during this time going to monocoque aluminum production. The Nazis kept up by investing heavily in R&D and by the end of the decade were producing some of the best aircraft around. Germany effectively leapfrogged to the state of the art airplane technology during this time as shown by airplane speed records above (data here).



Data Found in [3, p.10, Table 1.3]

However, it's worth noting that Germany wasn't as productive or efficient as the UK or USA. Even with substantially more unemployment the USA still had a GDP per head ~20% greater than Germany. To a large extent this was because Germany was a much more agrarian society with 27% of employment as farmers in contrast to the USA of 17%. But it was also because many German factories did not apply state of the art techniques in manufacturing like moving assembly lines. 

Overall, the German economy appears to be somewhat bifurcated at the start of the war. On the one hand it had some of the best engineers and tech. But on the other it was less efficient and crude. 

One thing is clear is that the combined economies of France and England were much larger than Germany's in 1939. How then did Germany win a ware of attrition over France in WW2 when it couldn't in WW1? The answer is that they didn't need to fight a war of attrition. With new tactics and technology the Nazis were able to take over Europe quickly without resorting to attrition. 

The Ascent (1939 - 1942): An Air Force's Air Force

The Germans deploy a new kind of warfare known as 'blitzkrieg' (lightning war) to take over Europe. Using concentrated formations tanks, planes and mechanized forces the Germans would attack deep into enemy territory, bypass strong defenses, and encircle the enemy.  This warfare was only possible with newer technologies like tanks and planes. 

However, note that the mechanized forces represented a small percentage of the Germany military. The vast majority of the army relied on horses and and slow moving artillery. It was these forces that would come up after the tanks encircled the enemy to finish the job. In this regard the Germany military mirrored its economy: it had a very technologically advanced elite but the majority was still partially agrarian. 

And at the top of that technologically elite hierarchy was the Luftwaffe. While the tanks role was to encircle the enemy the Luftwaffe had a distinct role separate from the main battlefield. While it made a large contribution as a 'mobile artillery' to help the advance it would often leave the battle alone due to the threat of friendly fire. The Luftwaffe generally struck independently of other forces behind the front lines by attacking troop movements, logistics, communications, factories, and cities. [4]

This independence was clearly valued by the Luftwaffe and would be in other air forces too. In the 1920's and 1930's there were military theorists that debated the role of the airplane in the next war. Many airmen from different countries (USA, UK, Italy) came to similar conclusions: that a new form of strategic air warfare can be used against the economic machine of the enemy. 

This is keeping with the idea of a super-battlefield [6]. If one can bomb an economy enough cripple it one doesn't need to fight them (at least as much) on the battlefield. Propenents of this idea optimistically thought it would require few resources to complete destruction of enemy infrastructure and economic movements. For instance one study created by the US Army in the 1920s on a potential air campaign against New York City concluded that by attacking a mere 17 targets the city would be unable to function. (Fun fact, due to the restrictions placed on the war department at the time no offensive plans could be drawn up so it had to be defensive in nature. This was keeping in line with America's pacifism at the time.)[5]
 
But why stop only at the factories, railways, and infrastructure of the enemy? They could be rebuilt if the population wasn't harmed. The logical next step was viewing the civilian population of the enemy as an enemy combatant to target. The potential dueling air forces aimed against civilians lead some theorists to think war wouldn't happen because the destruction would be so complete (a precursor to nuclear MAD). 

These concepts of a long strategic air campaign only existed once during the period of 1939-1942 during the Battle of Britain. For the rest of the first six months the campaigns generally wouldn't last long at the start of WWII.

Nominally WWII started similarly to WWI; Germany fighting on two fronts immediately both east and west. In reality the first couple of years (give or take a few months) saw Germany take over the continant through a sequence of distinct and serial campaigns. Below are the movements of each



August 23 1939 Germany and the Soviet Union, lead by Stalin, reach a deal to partition Poland. September 1 1939 Germany declares war on Poland citing a (false flag) attack on it's border. Two days later France and England declare war on Germany. After declaring war the allies ... sat and waited (there was a strategically irrelvant offensive by the French). 

Germany's forces were divided at this point with most of its forces in the East fighting Poland. The UK and France could have invaded but they decided to wait it out and launch more small scale offenses while the Poles wore down the advancing Germans. 

The Polish army was the fourth largest in Europe and it was expected to hold out for some time. People were surprised at the speed, if not the outcome, that Poland fell. The USSR invaded from the East and on October 6 1939 Poland surrendered. Shortly after Germany positioned just about all its forces on the West. For the next eight months not much happens. This period from October 1939 to April 1940 is called the 'sitzskreig' or 'phoney war'. 

The USSR continued it's territorial expansion and attacked Finland in November 1939. Showing military ineptitude, the Russians eventually won a long campaign against a much smaller force. The poor performance of the Russian military was a lesson the Germans would not forget.  
Germany initially expected a long campaign against France. In order to assure the iron ore shipments from Sweden it preemptively invaded Norway (and en route needed Denmark) to protect the transportation of the raw material from English attack. 

The Germans had amphibious landings at several locations and the Luftwaffe proved instrumental in bombing the coastal defenses allowing the troops to land safely. Paratroopers landed and took key locations too and Norway's strategic situation was hopeless within the first day. The English and French did manage to land but had to evacuate as the situation in France grew worse. 

This operation was tactical success but something of a strategic failure for Germany. While minimal costs to in terms of troops the German navy lost a significant part its surface fleet reducing the chances of a channel invasion of England in the future. In addition it required the germans to places hundreds of thousands of troops to defend against potential invasion throughout the war. Finally, the loss of Norway caused Chamberlain, the English prime minister, to lose a vote of no confidence. In his place a man dedicated to the destruction of the Nazi's is made Prime Minister -  Winston Churchill. 

The Battle of France was the main event during the period of 1939 - mid 1941. If France held out then there would most likely have been a long campaign potentially lasting years. If that happened it's hard to see the dystopian reality of 1942-1945 unfolding as it did. Instead France, with a much larger and better equipped army than Poland, lasted about the same time in the battlefield and surrendered in about six weeks. 

France thought it was playing an updated WWI. With the horrors of trance warfare fresh in its mind, it invested heavily on a fortification system known as the Maginot line during the interwar years. It ran from Switzerland to Belgium and consisted of underground railroads, bunkers, and artillery with the goal of lasting a few weeks of defending a potential German invasion. The French strategy was to use this defense system in the south while placing its best troops in the north where the Germans were expected to attack (much like WWI). And while it had very good tanks France spread them out and attached them to units in support roles rather than use them as independent forces. 

Unfortunately for the French (and the world) the Germans were playing WW2. Unlike the French army the French Air Force was smaller with inferior planes compared with its adversary. The Luftwaffe established air supremacy in quickly after starting the invasion on May 10 1940.

Concentrated formation of tanks and mechanized infantry sliced through the Ardennes, a forest previously thought impenetrable to any army. These forces rushed across the Muese in part supported by dive bombers. French troops were particularly terrified from the siren fitted on Stuka dive bombers and further demoralized them. Scared refugees clogged the roads making French military maneuvers difficult and easy targets from the air. 

As the Germans marched on we can see above that the Luftwaffe landed planes across the Meuse in the middle of the campaignHistorian Williams Murray details it:

By the 17th, within 24 hours of the French evacuation, German fighters were establishing their operational base at Charleville, west of the Meuse. For several days, fuel, ammunition, parts, and ground personnel flew in by Ju 52's since the army's movement into the ever-deepening pocket had choked the Meuse bridges . The forward operating base was so short of fuel that ground personnel siphoned all but the minimum amount of gasoline from every noncombat aircraft landing at Charleville.This rapid deployment forward was due entirely to an air transport system of Ju 52's.58The system supported the army as well as the air force in its drive to the Channel. [1, p 38]


This is the first time we're seeing the Luftwaffe moving large forces of planes to continue an offensive campaign and is something of an under-appreciated hat-trick. We'll see the Luftwaffe do this kind of operation again and again over the years. 

As the English army retreated to the English Channel at the port city of Dunkirk the order was given to stop the German army's advance. The head of the Luftwaffe, Goring, claimed his force could destroy the English army being evacuated. Instead this was the Luftwaffe first defeat. The RAF was much closer to Dunkirk than the Luftwaffe, even with its forward bases in France. The RAF held off the Luftwaffe and England evacuated some 300,000 troops from continent thereby saving an already demoralized army. 

With Germany victorious in the north, Italy entered the war on June 10 and France surrendered on June 25 1940. Germany occupied the northern half of France and, with French collaborators, created the Vichy government in the South and North Africa. The English, understanding that the Germans could use undamaged ships of the French military, attacked and sunk a large part of the French Navy at Mers-el-Kebir killing almost 1300 sailors. This proved to the world that the English would fight on.

It's worth remembering that the English didn't have to fight at this point. Hitler respected the English and would have been happy to make peace. 

 



The Battle of Britain was more than just a meme or speech generator. This was the first air campaign fought almost exclusively in the air. All the theories of air power could now be put into place. Practice is another. The luftwaffe's first mission was to gain air supremacy. But how do you do so and what targets should you hit? Should you attack the airfields, the factories, maybe the radar stations? Or maybe just try to go against the civilian population?  

The Luftwaffe did each of these not quite committing to a particular strategy but often changing course when they weren't seeing results quickly enough.

The strategic air campaign highlighted the falsehood of the 1930s believe that "bomber would always get through". This idea proved wrong again and again. Bombers needed to be escorted by high performance fighters in order to defend against attack. 

A particular technical problem was the short range of single engine fighter planes, in particular the BF-109. One can see this in the graph above with the fighters at the closest point to England while bombers with longer range were in airfields further away. Longer range twin engine aircraft such as the BF-110 did not have the maneurverability dogfights against English Hurricane's and Spitires required. Interestingly the Germans did know of drop tanks but for some reason did not use them here. Drop tanks were a particular advancement that help the USSAF achieve air supremacy over Germany later. 

The plans for the invasion of England were never really serious and the germans called off the attacks in the fall of 1941. The effects on the English production of aircraft was slight 96, p 124]. Level bombing, especially from high altitudes, had very poor accuracy and the relatively low numbers of German bombers contributed to the ineffectiveness of strategic air campaign and the UK

Here we have a case of strategic air power missing the mark compared with what its proponents believed. Without heavy escort the bombers were shot down. Even when they were able to hit the targets level bombing was very inaccurate and the damaged done was relatively small. These are problems the USAAF will have in 1943-1944. 


The period between November 1940 and April 1941 saw a lull in German major combat operations where its armed forces rebuilt its strength. After the fall of France the Romanians and Hungarians allied themselves with the axis powers providing Germany. Italy campaigned against the English in the Mediterranean and attacked Greece in October 1940. Neither campaign went well and German sent planes to Sicily to help Italy in the Mediterranean and to Romania to protect its oil. 

In order to keep the English from creating a southern front and in order to protect Romanian oil from potential RAF attacks the Germans launched an offensive against Greece and Yugoslavia (which refused to ally itself with Germany) in the Fall of 1941. 

Once again we see German planes moving quickly into the area and providing support. These campaigns followed the speed and efficiency of the previous western invasions and within weeks Yugoslavia and Greece fell. 

One particularly interesting operation was the invasion of Crete which was completely done by paratroopers. While the paratroopers managed to take over the island it proved to be extremely costly and the Germans would did not launch a large scale paratrooper operation for the rest of the war.  









In the middle of June 1941 the Luftwaffe quickly assembled a major Luftwaffe force in Poland to attack another country (shown above). The campaign was expected to last between 6 and 12 weeks and ?? was to be similar in speed an outcome as the previous nine countries (by my count) it took the preceding two years. Instead it took near four years of continuous fighting that eventually lead to the defeat of the Nazi Germany. 

With three million Germans and 650,000 troops from Finland and Romania, with over half a million horses, and ~2,500 planes the Invasion of Russia in on June 22 1941 was the largest land invasion of all time. This underscored the strengths and weaknesses of the German war machine. 

The initial results underlined the tactical superiority of the Germans during this time. The Germans had about the same number of planes on the eve of invasion of USSR as the invasion of France except now its forces would be divided (fought 2/3 of its planes would be in the east).  Superior planes and pilots ensure that the Luftwaffe destroyed some 1800 aircraft on the first day and quickly gained air supremacy thereafter. Most of these planes were destroyed on the ground potentially saving Russian pilots from having to fly obsolete aircraft against a stronger opponent. It then continued to support the ground offensive by moving with the army throughout Russian territory.

The tanks and army had tremendous success using Blitzkrieg tactics. The USSR did not believe initially did not use tactical retreats and were encircled again and again. Millions of soviets were captured by the Germans in the first few months of the war. 

In the above graph you can see the three main routes of attack; in the North to Leningrad, center to Moscow, and the south through Ukraine. There was a degree of indecvienss of where to attack. You can also see the shift of focus from Leningrad to Moscow halfway through the campaign.

However, victory was predicated on the belief that Soviet resistance crumble and the government would collapse (as they did in WW1). The soviets held firm and it wore down the invaders. The Germans struggled with supplies, oil, and manpower towards the end of the campaign culminating in the largest battle of WW2 the Battle of Moscow in December 1941. 

Here the Luftwaffe was worn down and without many supplies it couldn't sustain it's attack. Many units would have to fly back to Germany to refit and rearm while the campaign was reaching a climax. This was generally true of the military itself and was underscored but the fact that they did not initially have winter clothes during the Battle of Moscow. 

Barbarossa was the first real failure of the German army in WW2. The initial campaigns against western countries proved to have few casualties compared with WW1 battles; Poland killed 17k and France killed 27k German troops. In contrast the invasion of Russia killed over 180k German Troops. 

The failure of quickly taking out the USSR assured that WW2 became a war of attrition where economies and production featured more prominently than quick tactical success. Hitler's position waging a war of attrition was not helped by Germany declaring war on the US. 

Why did Germany invade Russia? Part of it was economics. Hitler wanted Ukrainian agriculture land for food and Russian natural resources to continue the fight against the Anglo world. But it was also ideological. Hitler's main reason for going to war in the first place was to create an empire in the East defined by race. 

Moreover on December 11 1941 Hitler declare war on the US. Military this wasn't a great idea. Scholars debate why he did so. However, one thread between invasion of USSR and declaration of war on US was Hitler's (nonsensical) belief that they were both controlled by and part of a Jewish world conspiracy.

So in the Winter of 1941/1942 Germany found itself at war with the UK, USA, and the USSR. If you were in Germany's shoes what would you do? 


The Holocaust and Atrocities 

January 20, 1942 a group of high Nazi party and German officials met at a mansion (stolen by a Jewish businessman) outside Berlin. Among other documents they pass around a spreadsheet. The discussion turns on how using new technology the Germans can minimize the final tally of eleven million. 

So began a new phase in the Holocaust where Jews were rounded up, put on cattle trains, and sent to death factories. This was more of a tactical change than the start of campaign against the Jews. The holocaust arguably started with the invasion of Russia. Behind the German advances were special German troops called Einsatzgruppen meant to shoot Jews, communists, other undesirables. This "holocaust by bullets" was found to be inefficient and potentially damaging to troop morale. The Nazis therefore developed special gassing facilities to murder civilians in a more efficient manner.

The Death Factories really got going in the spring of 1942 going into overdrive in the summer. In the summer of 1942 about 1.5 million men, women, and children were murdered. It seems like an apt metaphor that in the middle of WW2 both in terms of time (summer 1942 is ~ halfway mark of the war) and location (Auschwitz, the largest death factory, is about mid point between London and Moscow). This idea of racial superiority and domination was a central reason Hitler went to war.

While the holocaust against the Jews was at the pinnacle of the atrocities committed in WW2 the Germans didn't stop there. Those millions of Soviet prisoners captured ? They starved in open air prisons. A commissar order given out before the invasion of the USSR declared that any communist could be shot. In practice this meant that in the east German soldiers could kill any civilian or soldier without repercussions. German atrocities against unarmed civilians happened throughout the its occupied terrorities.

There's a lot of good 'war porn' in WW2. Often it verges on idolization of the Nazi war machine. Even with the graphs above it's kind of fun to see movements throughout time of the military campaigns. But it's important to remember the devastation and attoricites that followed with each of those points expanding outward from Germany. It's important to remember that the German military, by and large, went along with the Holocaust and the concept of a "clean" Wehrmacht is more bullshit myth than fact. That the military campaigns shown above enabled the largest genocide in human history.

never forget




[1] Murray, W. (1983). Strategy for defeat: The Luftwaffe, 1933-1945. Air University Press.

[2] Daniel Uziel. Arming the Luftwaffe: The German Aviation Industry in World War II (Kindle Location 176). Kindle Edition. 

[3] Harrison, Mark. The Economics of World War II: Six Great Powers in International Comparison. Cambridge University Press, 2005. 

[4] Deane, J. R. (1947). The Strange Alliance; the story of our efforts at wartime cooperation with Russia. The Viking Press. 

[5] Crane, C. C. (2016). American airpower strategy in World War II: Bombs, cities, civilians, and oil.

[6] Phillips Payson O’Brien  (2105) How the War Was Won: Air-Sea Power and Al- lied Victory in World War II, 

Sunday, February 6, 2022

A High Altitude Overview of the European Theater 1939-1945


Intro:

In this post I outline the infographic I made on the European theater in World War Two using Luftwaffe plane locations found on ww2.dk. This dataset includes both information on the location and size of individual plane groups throughout the war. While clearly not encompassing everything about WW2 I think using this dataset could be an effective way of describing the war for a few reasons.


First, with the exception of the Battle of the Atlantic (which is missing from this infographic) and the last few months just about all battles of WW2 in the European theater had some nominal Luftwaffe presence. Being experts in tactical air power (the ability to fight and influence the battlefield directly) required the Luftwaffe required the planes to be located near the battlefield. Due to the range limitations of WW2 aircraft (particularly single engine fighters) the airfields needed to be very close to the front lines. Therefore, the airfields locations provide a fairly accurate representation of the front lines. Below is a plot of most airfields (I've excluded the airfields in the arctic in this plot due to size limitations) used in ww2 below.


Second, while the majority of the fighting casualties were on the eastern front the majority of military expenditures were not necessarily on the eastern front. More recent research has found that the belligerents of WW2 spent a large amount on producing aircraft. Germany, for instance, spent about 48% of its output on aircraft production in July 1944 compared with only 7.8% on tanks. Similar expenditures exist among American and Great British forces.


Finally, in I think in part because planes were so expensive there’s pretty good data on them. While there were certainly more men involved in large battles they’re aggregated at a fairly high level and no month-month data exists (to my knowledge) of strengths and locations. Ships on the other hand of very good data. I think you can geolocate a ships location by the day. But there were only a handful of large scale engagements. Airplanes have both good data and large number of observations making it a “sweet spot” for data analysis. 


And finally the atrocities. Most military histories treat the holocaust as a side show. Something that happened in the background, undercurrents of the main tidal waves. However, that reading kind of misses the point of what WW2 was about. It was a war of annihilation. Of racial hierarchies and where certain people were better and therefore had the moral authority to impose their will. The German atrocities are well documented. To name a few; starvation of millions of soviet prisoners, reprisal attacks against civilians, slave labor (to such an extent that it eventually amounted to 20% of its output in agriculture and industry), and human shields in combat, and dark ways to maintain law and order. All of Europe suffered. At the apex of this was the systematic murder of Jews - the holocaust.


I’ve included markers (in yellow) that determine the holocaust events. Shown are four types of events. The first is general deportations of Western Jews to ghettos, generally in Poland. The second coincides with the invasion of USSR and is knows as ‘holocaust by bullets’. This is where special german troops einstatsgruppen followed the invading army and shot Jews and other undesirables.Then there were deportations to death camps starting in early 1942 lasting until the camps were liberated in early 1945. Finally, as the Soviets were about to liberate the camps Nazis forced survivors to march to Germany. Perhaps I have bit off too much on this infographic but I think it would be remiss of me not to include it.


This history isn’t necessarily new (I follow the timeline of Strategy of Defeat by Murphy). But I have not seen this information in one infographic. Airpower was very important to the conflict. While it may not have been as decisive as its proponents expected it to be (it didn’t win the war single handedly) It’s hard to imagine WW2 unfolding the way it did without it. Could Germany have gone so far without it using it as effectively as they did? I don't think so. To a large extent the story of the European Theater between 1939-1945 is about planes and atrocities.



Description of charts:

Below shows a gif of two charts. The top one is the map that shows the allocation of Luftwaffe Forces by Fronts. There are bar plots for Bombers, Ground Attack, Fighters, Night Fighters, and Twin-Engined Fighters (abbreviations for each one). Arrows between maps show where large scale movements of planes are going to. 


The second chart shows similar information but 'flattened' out into one dimension so as we can see movements through time. I have included the large plot below that as well. 



Code and data in R can be found here 












Here are a couple of additional plots I made: 


Minard Plot:

Monday, December 21, 2020

Did the P-51 Mustang Defeat the Luftwaffe?

14 October 1943 -  291 US Army Air Force (USAAF) heavy bombers took off from England to attack a Ball Bearing factory in the heart of Germany. The goal was to destroy the Nazi war machine’s fighting ability and means of war production. As the bombers flew deeper into enemy territory their supporting escorts had to return to England due to the fighters’ shorter range. The unescorted bombers were vulnerable to enemy fighters and paid a heavy price. 60 did not return leading to a loss rate of over 20% thus cementing October 14, 1943 as ‘Black Thursday’. The ten crewmen on each of those planes had to survive 25 (later pushed to 30) missions to return home. They could not sustain losses like this indefinitely.


But they wouldn't have to for long. Within a year similar missions could be completed with far fewer casualties - often well below 5%. 





The above plot shows raids for the Eighth Air Force during two time periods; on the left the second half of 1943 and the right July - Mid August 1944. Each point represents a raid’s distance and percentage of planes that did not return back to base. This does not count bombers scrapped after landing due to heavy damage. Nor does it account for wounded, killed, or POWs in a mission (even if a plane came back not all of the crew did). 


In the chart on the left one can see a fairly strong if imperfect relationship between distance (I chose London as a starting point but airfields were scattered throughout southern England) and bomber losses. The second chart on the right shows this relationship is far less prevalent. The average loss rate of planes during the second half of 1943 was around 3.9% compared with 1% loss rate in the summer of 1944. Using these as proxies for survival probabilities and 30 as the number of missions required before a crew member finished a tour of duty the probability a member came home went from 30% to 74%. How did the loss ratio decrease by so much during this period?


The consensus story of those two plots goes something like this: after Black Thursday USAAF operations suspended long range attacks into Germany until a fighter was capable of escorting the bombers. Enter the P-51 Mustang. 

A P-51 with drop tanks. Notice the Swastikas underneath the canopy - the only acceptable place to display a swastika - each indicating an aerial victory. Having met the criteria of five aerial victories this pilot has earned the moniker of “ace”. 

An American aircraft (with an English designed engine) it was capable of flying to Berlin and back. Not only did it have the necessary range but also outclassed the German interceptors of the period. The P-51 was therefore able to ‘break the back’ of the Luftwaffe and gain air supremacy over europe. This allowed USAAF bombers to go into Germany and beyond without heavy losses.


But the claims of the P-51’s importance often goes farther than that. With air superiority the Allies launched the D-Day landings of Normandy unencumbered. And with Allies now fighting Germany in the west a Nazi Defeat was inevitable. A causal line of reasoning is therefore established between the P-51 and the ultimate destruction of Nazi Germany. Perhaps this is why - somewhat uniquely for a fighter plane - it’s achieved something of a totem status


But did the P-51 Mustang “break the back” of the Luftwaffe? This post will go over the consensus history of operations between the summers of 1943 and 1944. It will go over Mission Level data. An index is created of German Pilot Strength over time. 



This follows the history laid out by McFarland and Newton. But it seems most histories are similar to this and conclude that the Luftwaffe was defeated prior to D-Day. 



Strategic Bombing and Pointblank

Air power was still relatively new at the beginning of WW2. It wasn’t clear at the outset how best to use it in a military conflict. Broadly speaking there were two ways of thinking how the airplane could affect the course of the war. 


This first and most obvious use of airpower was as a tactical force. A precision armaments system that can provide ground support in real time to assist tank and infantry forces. The Germans seized on this use of airpower as a form of  ‘mobile artillery’ with devastating effectiveness. 


In contrast the English and American Armies focused more on Strategic Bombing. Instead of focusing and directly influencing a battle the bombers would fly deep into enemy territory destroying the means of waging war. The target wasn’t tanks and enemy defenses but enemy factories, oil refineries, transportation networks, and even civilian populations. However, an enemy has never been subdued by strategic bombing before. The USAAF got their chance to see whether they could destroy the enemy from the air with Operation Pointblank. 


To prepare for the D-Day Landings in summer of 1944 the Allied command issued the Pointblank Directive in June 1943. The objective was to destroy German Morale and ‘capacity for armed resistance’. It was to do this by imposing ‘heavy losses on Germany day fighter force’ and draw German fighters ‘away from Russian and Mediterranean theatres of war’. Once completing the objective the heavy bomber forces would be put to use in a supportive role of the D-Day in the Spring of 1944. 


For a brief overview of tactics in the European Air War see here


Attrition Warfare

Between the summer and through the fall of 1943 US bombers attacked German factories with high losses. After regrouping forces in late 1943 the allied offensive continued in early 1944. The new P-51 Mustangs were thrown into combat as soon as they could arrive during this period thus providing some cover to bombers at long distances. 


Despite the imminent need to destroy the enemy before the summer of 1944 they were often grounded due to poor weather. A break came through at the end of February with a forecasted week of clear weather. This was to be the start of Operation Argument (also known as “Big Week”) targeted specifically against the Luftwaffe in order to gain air supremacy. It’s objective was to minimise the ‘Production-wastage’ differential by attacking both the factories on the ground and Luftwaffe in the air. 


However, it became clear that the bombing offensive actually wasn't destroying industry at a rate where Germans could be kept up. Indeed during this period of increasing attacks German industry was put on a ‘war footing’ and increased fighter plane production despite the increase in bombing. In 1943 Germany Produced 25,500 planes. That number increased to 40,500 in 1944. 


But a realization occurred to US high command - even if the Germans could replace their fighters they could not replace their experienced pilots as easily. Instead of minimizing German ‘production’ they’d focus on maximizing the ‘wastage’ of german pilots in combat. They just needed to lure the enemy up to attack the bombers with the knowledge enough would be shot down by P-51s.


This was the logic behind attacking Berlin in early March 1944. The bombers would be used more as bait for the Luftwaffe than the bombing of industry. The USAAF did so with enormous costs. The largest one day loss of the eight air forces occurred on the first Berlin Raid of march 6 1944 with 69 heavy bombers lost and known as “Black Monday”. Due to the large number of aircraft dispatched this amounted to a 10% loss rate. 


These were losses the US could sustain. Luftwaffe pilot losses weren’t.  After the Battle of Berlin and heavy fighting the Luftwaffe changed tactics. They would only attack en masse and other times not confront the invading bombers at all. But ultimately they ceded air control to the USAAF.  The German Luftwaffe was defeated before D-Day. Or so the consensus history goes...


To look into this I gathered some data on Eight Air force missions and did some analysis. 



Eight Air Force Data

The original data set came from 8thafhsoregon.com/8th/. There is an excel spreadsheet that has missions broken out between the start of operations and August of 1944. This data includes (among many things) target location, number of planes dispatched and lost for both bombers and escorts. I used this as a template and then edited it as necessary, often looking at the WWII chronology on which it was based to fix any errors (also in that link). I’ve tried to be as accurate as possible but this was a manual process so there are probably errors. I appended Latitude and Longitude to the dataset using ggmap functionality in R. 


Some problems with the dataset are:

  • Some names of places have changed since the original. German names are now in modern day Poland for instance.

  • The location of dispatched planes are often ambiguous. Often there are several targets for a set of planes. I’ve no way to be sure which particular location each plane went to so I just chose one location for the lot. 

  • After July 1944 escort by plane type wasn't broken out so I am unable to show the relative distribution of fighter types per mission. 


Eight Air Force Analysis






As noted previously a key feature of bombing losses was the distance travelled to the target. The longer the distance the more likely there were


The above plot shows a scatterplot of Distance travelled by Date for a unique raid location between January 1943 and August 1944. It’s colored and numbers by percentage lossed (red is higher, blue is lower). I’ve also removed missions that exceeded 800 miles for readability as they were few in number. 


One can see that loss rates decrease in both the time and increase with distance. Heavy fighting before winter of 1943 for distances more than 400 miles were particularly costly for the USAAF. These raids included Hamburg and the first two Schweinfurt Raids. One can also see a decrease in activity at the end of 1943 as weather conditions were poor and USAAF regrouped after those costly raids. 


Starting in February and March the USAAF went deeper into enemy territory - a period that covered both Operation Argument and the Battle of Berlin. While these raids sustained high losses they are represented in the low teens of percentages because of the larger number of bombers attacking. 


As Operation Pointblank ended focus shifted to targets in France and therefore smaller distances. In April, May, and June they attacked transportation targets, airfields, and sometimes more direct tactical support. 


Overall one can clearly see that as time progressed it became less and less costly for USAAF forces to fly far into Germany as a percentage of aircraft dispatched. 


Below is a plot of statistics by month to better see the aggregate losses more clearly. 







The above are aggregate statistics by month for heavy bombers: total dispatched, total lost and the lost ratio. 


Heavy monthly loss ratio existed prior to 1944 with a maximum of over 7% in October of 1943 (Black Thursday was the culprit). In part this was due to the small number of planes dispatched. 


Starting in February the number of planes dispatched increased to a maximum in June 1944 and then slightly back down in July 1944. Total lost planes increased throughout this period as well reaching a high point in April of 1944. Even in May 1944 the USAAF lost 300 heavy bombers. In June it dropped to 200 heavy Bombers. Why was there such a drop in losses between May and June? 


Looking at the increase in P-51 usage there was a sizable  increase in escorts p-51 more than doubling from April (3151 to 6844) to May but only slightly from May to June. Moreover there doesn’t appear to be an obvious relationship between increased P-51 Escort usage and decrease in Heavy Bomber Losses (at least on the aggregate data - see below for further analysis). 





The history I’ve described above suggested that most of the fighting was done in February and March. After this period the Luftwaffe was supposedly defeated and air supremacy passed to the USAAF. Looking at the loss ratio statistics one can see they were much more acceptable range for USAAF forces - especially compared with 1943. In some sense the Luftwaffe may have been irrelevant at that point in that the USAAF could expect replacements at that point to replace any lost bombers. 


But the evidence suggests that the Luftwaffe was still inflicting heavy damage through May and didn’t cease after March as the original history suggested. What happened? I think we need to continue looking into data from the German perspective and its relative strength over time. 


Luftwaffe Data 

 

I couldn’t find similar mission-level data for the Luftwaffe during WW2. (Who knows, maybe some of that data was destroyed by the Eighth Air Force?) I did find there is a good amount of data on Luftwaffe Pilot aerial claims and planes they shot down. Pilots had strong incentives to report the planes they shot down and such claims are probably overstated. However it’s a dataset that should provide some indication of fighting strength and activity over time. 


This Dataset comprises two parts.The first are the aerial claims for a pilot that includes (among other information) date, aircraft destroyed, and fighter group. The second includes data on when a pilot was removed from the war either MIA, KIA, or POW. 


Ater joining these two datasets to get precise entrance (first claim in database) and exit dates there are 2,565 pilots with a total of 50,419 combined claimed victories. As the average pilot in the dataset as over 19 claims it clearly is biased towards the elite pilots and doesn’t include those pilots who had no claims. However, this could still be a useful dataset to show relative strength over time. 


As an EDA I first looked at first entrances and exits by front over time. If a person transferred between fronts it would not show up in these charts. Note that I removed two entrance points from the graph as they were so extreme; May 1940 on West had 273 and June 1941 had 251 entries of pilots in the dataset. These correspond to the Battle of Britain and Invasion of Russia so we can expect a lot of pilots had their first claims during those periods. 


Also Note that the West involves mediterainan, north african, and southern europe where the Eight Air Force did not generally operate. They also include night fighters targeting against English bombing raids that were somewhat distinct from the day fighters against the USAAF.


On the Eastern front one can see exits and entrance follow a seasonality pattern that corresponds to German offenses summer offenses: Invasion of Russia in 1941, road to Stalingrad in 1942, and Battle of Kursk in 1943. 


For both fronts the Germans had Entries higher than existed throughout most of 1943 and early 1944. Only after the summer of 1944 were losses consistently higher than entries  for both fronts.


On the Western form there was a lot of activity for the Battle of Britain - this was the Luftwaffe’s failed attempt at strategic bombing. Starting January 1944 there was a sustained increase in exits corresponding to the attrition warfare of the Eighth Air Force discussed above. While there was clear damage to the Luftwaffe during this time it reached a maximum loss of 66 pilots in July second only to losses in December 1944. If the Luftwaffe was defeated by the USAAF before D-Day then why were they losing so many pilots after that? 


Luftwaffe Defeated at Normandy?

As mentioned above the Luftwaffe was a tactical air force designed to support ground offenses. German command clearly intended to use it as such during the expected Allied invasion of France as they moved a large number of Fighters towards France after June 6, 1944. 


To better understand this dynamic I created an index of fighter strength by day for Reich Defense with the pilot entrance / exit and claimed data. For a particular date a pilot was included in the dataset he had claimed an aerial victory before that date and did not exit by that time. We can also see, from the most recent claim, which fighter group he was in. Using this we can tie a particular pilot to a location and therefore if he was actually under the Reich Defense.


Determining which Fighter Group and squadron were actually defending the Reich at a particular point in time was a manual process greatly helped by this website. It showed that most fighter groups defending Germany moved to France immediately after the allied invasion of Normany in June 1944. For example III Gruppe of JG 54 went from Illesheim, Germany to Villacoublay, France on June 7 1944. Moreover one can see (but not shown here) the claimed planes shot down after June 6 changed from US heavy bombers to short range english fighters (Spitfires and Typhoons) adding further evidence of the shift in priorities. 





Above is a plot of the number of Pilots defending the Reich compared to all other fronts combined between Summer 1943 to October 1944. I narrowed down the Dense of Reich to those that were likely to face the Eighth Air Force in Battle so did not include fighter groups in Italy or Nordic countries. One can see it remains relatively constant up through the spring of 1944 when it actually shows an increase in the relative number of pilots. By the early summer over half of the pilots in this sample were in Defense of the Reich. It then dropped dramatically when Day Fighter forces moved to France following the invasion of Normandy. 


But wait, an increase in pilots when there’s heavy attrition fighting in the first half of 1944? How is this possible? 


To check I created a stacked barchart by time. If the Pilots exited it counted a negative number and if they entered it counted as a positive number. One could either enter from another front or be a new pilot. They could exit to another front or exit the war entirely. (For an additional check see 2) below in the appendix. )





While there was an increase in pilots exiting throughout the first half of 1944 it appears that was offset by a combination of new pilots and reallocation of pilots from other fronts. There were few pilots exiting to other fronts until June of 1944. While it seems hard to imagine the fighting strength of the Luftwaffe increasing significantly during this time the evidence suggests that the USAAF did not destroy the Luftwaffe prior to D-Day.


Assessment of P-51


But that doesn’t mean the P-51 wasn’t instrumental in defending the bombers. I created a regression for the time period before June 5 1944 using data from the Eighth Air Force and combined it with Luftwaffe data. The response variable of interest is the number of bombers lost in combat for each unique raid. 


The data generally gave precise locations of where the bombers went; it did not give similar information of where Escorts went for all missions. For example, Mission Number 367 on May 24, 1944 USAAF sent 616 bombers to Berlin and 490 bombers to French Airfields. They were escorted by 144 P-38’s, 178 P-47’s and 280 P-51’s. While USAAF would probably have sent a majority of P-51’s to Berlin there’s no way to encode that. Instead I assume an weighted percentage of fighters going to each location proportional to the relative size of the bomber fleet. In this case I calculate a weighted_p51 score of 156 (616/(616+490)*280 ) escorting the Berlin Bombers.


Using the Luftwaffe Claims Data I am able to calculate the sum of all claimed kills for pilots defending the Reich on any particular day. This is something akin to the liberty ship ‘learning by doing’ literature. I’ve found this to be the strongest predictor for any single Luftwaffe pilot data. 


I include date as a continuous feature and also include dummy variables if there were no particular escorts. 


Below are the results. 



One can see that distance is a very important feature but that time isn’t statistically significant. This is promising as it shows there isn’t a trend that cannot be explained with features given. Also note that the total_kills variable - a proxy for strength of luftwaffe - is positively correlated and has a p-value of .06. While it’s not a strong variable in the regression it adds some credibility as a feature in general. 


Of particular interest is that the P-51 is negatively correlated with a p-value of .02. This indicates that the more P-51 escorts there were the fewer the bombers lost. Interestingly we also see a somewhat positive correlation with regard to P-47’s. This could be due to the fact that Pilot’s transitioned from P-47’s to P-51’s and the regression is picking up on that trend.



Conclusions


While evidence presented here is contrary to the general story of the Air War over Europe I believe it displays a more nuanced and realistic version of events. The Eighth Air Force did not defeat the Luftwaffe but it clearly made an impact and drew resources away from other fronts - a key objective of the Pointblank Directive. Moreover it made sure the Luftwaffe was tied down in Germany and not defending France while D-Day occured. It also seems clear that the P-51 was instrumental as it allowed the Eighth Air Force to launch attacks deep into Germany while maintaining acceptable losses. 


But it also seems clear that the Luftwaffe threw a large number of fighters from defending the Reich towards defending the western front and lost many pilots as a result. It wasn’t so much that the Eighth Air force defeated the Luftwaffe so D-Day could happen. Instead it seems like D-Day drew Luftwaffe resources away from Reich Defense so that the Eight Air Force could fly more freely over Germany after June 1944. 




Appendix 


  1. 1)



Thought I’d just add this chart that shows the types of targets the Eighth Air Force attacked during that period. Initially U-Boats and naval sites were a large target but after they became less and less of an issue they focused more on aircraft and industrial targets in Germany in early 1944. During that time they also attacked V-Weapon sites. I thought that was interesting since it wouldn’t be until the summer when they were operational. Towards the end of the sample period they started attacking oil and even some tactical support in France.


2) As an additional check to using this data I compared the monthly exit rates by a dataset at the end of To Command the Sky (curiously they didn’t make a similar plot in their book).  While the index I created using Tony Wood’s focuses on Pilots this dataset from TCTS looks at the number of planes shot down. They should be correlated and that is what we see below. However the scale of TCTS data is almost an order of magnitude higher suggesting that my index is missing a lot of data and is incomplete. I think it’s ok as a relative changes but probably not as levels 






Works Consulted


Big Week: BIggest Air Battle of World War II - James Holland 

To Command the Sky - Stephen L. McFarland, Wesley Phillips Newton 

Engineers of VictoryPaul Kennedy 

DOOLITTLE, BLACK MONDAY, AND INNOVATION - J David Rogers

How the Mustang trampled the Luftwaffe - Robert W. Courter

The P-51 Mustang: the Most Important Aircraft in History?  - Marshall L. Michel 

The Battle of Britain, in 1940 and “Big Week,” in 1944: A comparative Perspective - Arnold D. Harvey  Github