This is the talk I gave at Earth Sciences back in May. It’s long and picture heavy and much of it will be be familiar to regular readers, but some people expressed some interest in it so here it is. I’ve lightly edited it, mainly to correct typos in my written copy. I’ve put in links to the Boswell drawings because they’re under copyright, and I’ve replaced one photo because I realised it was of British Army Aeroplane No. 1b, not British Army Aeroplane No. 1a! How embarrassing.

Facing Armageddon: Britain and the Bomber, 1908-1941

Today I’m going to give you an overview of my PhD thesis topic. My broad area is the history of military aviation in the early twentieth century, so first I’ll give you a little background on that.

The first heavier-than-air manned flight was made by the Wright brothers in 1903, as you can see here. Within a few years, countries around the world started thinking about how they could use this new technology for warfare.

This is the British Army’s first aeroplane, which wasn’t very succesful but did at least make the first ever flight in Britain. In 1914, the First World War broke out and this pushed aviation along very quickly. At first, aeroplanes were mostly used to find and report on the movements of enemy troops, but soon they were used to drop bombs on them too.

And when aircraft became powerful enough, they started to bomb targets far behind enemy lines. This is the German Gotha G.IV, which was used to bomb London in 1917 and 1918. Of course, each country also developed fast fighter aircraft to try to shoot down their opponents’ slow bomber and reconnaissance aircraft.

Here’s one of the most famous fighters of the First World War, the British Sopwith Camel, as flown by both Biggles and Snoopy. It was fast, agile, and armed with twin machine guns.

After the war ended in 1918, aviation technology continued to progress, though not quite as quickly. By the 1930s, air forces were starting to be equipped with sleek biplanes such as this Hawker Hart, which was the fastest aeroplane in the Royal Air Force — which is a bit startling since it was actually a bomber and not a fighter!

The late 1930s witnessed the birth of a new generation of aircraft, powerful monoplanes with maximum speeds well in excess of 200 or even 300 miles per hour. They were also better armed than earlier aircraft: these Hawker Hurricane fighters had 8 machine guns.

This is one of the bombers that the Hurricane would be defending Britain against, the Ju 88, Germany’s most effective bomber. It could carry up to 2.5 tons of bombs. Germany built over 14000 of these bombers by the end of 1945.

Finally, this is one of the most powerful bombers of the war, the British Avro Lancaster. It was capable of carrying up to 10 tons worth of high explosive or incendiary bombs to Berlin and beyond.

But that’s all just by way of introduction. My research isn’t actually about aeroplanes as such or how they were used. What I’m looking at is the fear of bombing in Britain in the early twentieth century, from the early days of flight before the First World War, up until the end of the Blitz on British cities in 1941. More specifically, I’m interested in how the threat of aerial bombardment of cities was debated in the public sphere, as distinct from what was being discussed behind closed doors by the government and the armed forces. A number of historians have written excellent studies of British air strategy and air policy. Many of them mention the pervasive fear of bombing on the part of the British public, especially in the 1930s, but nearly always, they just take this fear as a given, and don’t spend much time trying to understand it or its origins. This annoyed me, because the little that they did tell me about the popular fear of bombing was fascinating, and I wanted to know more: why was the public scared of bombing, and what were they afraid would happen? Hence the thesis!

However, it’s very difficult to measure public opinion itself, especially before the introduction of opinion polls (which means virtually all of the period I’m studying). You can get the occasional odd glimpse into what the average person really thought about the dangers of bombers coming over and blowing them up, but perhaps not enough to do a whole thesis on. So instead I’m focusing on some of the most important influences on public opinion: primarily books, journals and newspapers which discussed the air menace and what should be done about it. And to a lesser extent, I also use things like cinema newsreels, films and radio broadcasts. Concerned citizens — often professionals such as military experts, doctors, or scientists — used all of these forums to present predictions of what would happen to cities and civilians under air attack, along with their proposals about how to solve the problem. Novelists took the serious speculations of the experts and turned them into nightmarish visions of what future wars held in store for the inhabitants of great cities. These fictional scenarios in turn coloured much of the debate about bombing. In fact, fictional and non-fictional discussions about bombing were often remarkably similar to each other.

So, what was the threat? Most people today have probably heard of, for example, Guernica, the Blitz or Dresden, which are all still potent symbols of the horrors of total war. This is Guernica, a small town of about 5000 people in the Basque country in northern Spain. In April 1937, during the Spanish Civil War it was devastated by a German air raid.

London was bombed by the Luftwaffe on 57 consecutive nights from 7 September 1940, forcing more than 200,000 people to take shelter in the underground railway stations every night. Here are just some of them in Elephant and Castle.

And this photo was taken from a British aeroplane during the Allied air raids on the German city of Dresden in the middle of February 1945. The little points of light are incendiary bombs, which started a massive firestorm. About 30,000 people — men, women and children — were killed in these raids.

But as terrible as these events were — and there are many more I could have mentioned — they were nothing compared with the predictions made before the war. Essentially, the widespread belief in the 1920s and 1930s was that at the beginning of the next war, a huge fleet of enemy bombers would suddenly strike at London and other cities and destroy them with high explosive bombs, incendiaries, and poison gas, causing hundreds of thousands of civilian casualties within a matter of hours or days, shattering essential infrastructure and leading to mass panic. Under such circumstances, it was widely assumed that Britain’s government would be forced to surrender within days or weeks of the outbreak of war. This is what was sometimes called the ‘knock-out blow’, that is, the sudden blow which would knock Britain out of the war.

This graph shows the effects of the German air raids on Britain in the First World War. ‘Casualties’ means the number of people killed or seriously wounded, in this case in each month. Green shows the casualties caused by airships, and red the casualties caused by aeroplanes. Note that it peaks at about 600 casualties in any one month.

And this is the equivalent graph for the Second World War. The peak casualties per month has shot up to more than 16000. That’s September 1940, when the Blitz began. In all, there were more than 146000 civilian casualties in Britain during the war, around a third of whom were killed.

Now, here’s a comparison between what actually happened in 1939-1945 and what British government officials in 1938 predicted might happen if a war started in 1939 — that’s the knock-out blow: over a million casualties per month, half of them fatalities, over only two months. Nearly two orders of magnitude more destructive than what actually happened. These estimates were not plucked out of thin air, but they weren’t much more than naive extrapolations from the First World War experience: divde the number of casualties between 1914 and 1918 by the tonnage of bombs dropped, and then multiply by the number of bombers the enemy had and the amount of bombs they could carry. This turned out to be a huge exaggeration, but you can see why everyone was so worried!

In extreme versions of the knock-out blow, civilisation itself would collapse, as the complex webs of commerce, transport and social control which bind society together break apart, leaving people to fend for themselves as best they could. From the perspective of a later generation, this sounds a lot like the effects of nuclear war.

And in fact in 1966 Harold Macmillan, a former Conservative Prime Minister who had been a backbench MP in the 1930s, wrote that ‘We thought of air warfare in 1938 rather as people think of nuclear warfare today’. It could in fact mean the end of life as we know it.

I’ll now give you some typical examples of how this fear of the bomber was manifested in literature and the arts. The following quotes are from a knock-out blow novel published in 1934 called Invasion from the Air. Firstly, the enemy air force attacks suddenly, with little or no warning, just after or even before the declaration of war:

At five minutes to twelve on that fateful night Germany struck from the clouds. The blow was totally unexpected, for the declaration of war by Britain against Germany and Italy had no more than been conveyed to the departing Ambassadors [...] London’s bewildered eight millions were precipitated into actual war conditions before the majority of them knew there was a war.

Secondly, the attack is massive in scale:

Squadron after squadron assailed the cities and towns in waves, each wave having its separate duty and aims. Upwards of two hundred enemy aircraft — fighters, bombers and [poison gas] sprayers — were brought down that morning as against only fifty British machines, but eight hundred broke though all attempts to stop them.

And thirdly, it is devastatingly destructive:

Thousands of people were killed or burnt to death or died subsequently insane at the memory of that battle, while, as always after the raids, vast numbers developed later the agonies of poisoned
lungs and throats, eyes and nasal passages [...] When the battle had passed Regent’s Park was scarred with great pits where explosive bombs had fallen [...] the bodies of old and young, broken and mutilated, lay everywhere.

So the knock-out blow would bring the horrors of the trenches of the Great War into everyone’s homes.

The Fall of London: Waterloo, by James Boswell (1933)

Next, here are some drawings which were actually commissioned for the novel I’ve just quoted from, but in the end weren’t actually used. They show the aftermath of the attacks, as the terrified mob revolts and rampages through London. Wrecked trains at Waterloo Station.

The Fall of London: Corner House, by James Boswell (1933)

A patrolling soldier in gas gear tramping past the body of a woman.

The Fall of London: The Colosseum, by James Boswell (1933)

The rioting crowds, clashing with troops. An upper and middle-class fear of the unruly mob goes back at least to the time of the French revolution; more recently, since 1918 there had been an increase in working-class assertiveness and the example of the Russian Revolution to worry about. So the fear of the knock-out blow was not only about the possibility of war but also reflected other anxieties about British society.

Now, I’ll show you a clip from the 1936 film Things To Come, which was adapted from a novel by HG Wells. This was a history of the future in three parts, and was a big-budget spectacular for its day. The first part of Things To Come features a graphic depiction of a gas attack on a city called Everytown, which bears a suspicious similarity to London. It was Wells’ argument that the destruction of modern society by total warfare was a necessary prelude to its recreation into a technocratic, utopian world state.

So much for the threat of the knock-out blow. What could be done about it? Surprisingly, the obvious answer, the one that actually did work in the Battle of Britain — air defence by fighter aircraft and anti-aircraft guns, harnessed to a sophisticated command and control system — was given little credit. It was widely believed that bombers were too fast and too well-armed to be shot down, at least in sufficient numbers to stop an attack.

I’ll show you a graph which helps explain this pessimism. First here’s a map showing Britain in relation to Europe, and some of the directions from which enemy bombers might attack. Ideally, the defending fighters would intercept the bombers before they reached London, the biggest and most important city. But there weren’t nearly enough fighters to keep up a standing patrol, so they’d have to wait until an air raid was detected, and then take off to intercept it. However incoming aircraft could usually only be detected once they’d crossed the coast. And it’s only about 50 miles, give or take, from the coast to London. The problem was that as technology improved and bombers got faster, there was less and less time for the fighters to react.

This graph shows in blue the time in minutes it would take for a bomber to cross the 50 miles from the coast to London. In the First World War, this could take around half an hour. By the Second World War, this time was down to only 10 minutes or so. The points in red show the time taken for the defending fighters to take off and climb to the height of the attacking bombers. As you can see this time is generally less than the crossing time, so in theory the fighters would have time to find the bombers and hopefully shoot them down. But lots of things could go wrong — the bombers might be detected late, the detection might not be reported soon enough, the bombers might have changed course or be hiding in cloud and so on. So the greater the margin of safety the better. In the 1930s, this margin was only 5 to 10 minutes which was not reassuring at all. Air defence exercises in the early 1930s seemed to confirm the difficulty of intercepting bombers before they could reach their target.

As the former and future prime minister Stanley Baldwin pessimistically told Parliament in 1932,

I think it is well also for the man in the street to realise that there is no power on earth that can protect him from being bombed, whatever people may tell him. The bomber will always get through

A widely-quoted remark at the time and for years afterwards. He went on to offer the standard alternative: essentially to bomb the enemy harder than they bombed Britain.

The only defence is in offence, which means that you have got to kill more women and children more quickly than the enemy if you want to save yourselves. I mention that so that people may realise what is waiting for them when the next war comes.

One solution, then, was a bigger air force so that Britain could kill more women and children more quickly than any enemy.

This was a solution generally favoured by those on the political right, such as the Hands Off Britain Air Defence League. This is a leaflet they distributed in 1933 or 1934. As you can see, they ask ‘Why wait for a bomber to leave Berlin at 4 o’clock and wipe out London at 8?’

Their demand is for the creation of ‘a new winged army of long-range British bombers to smash the foreign hornets in their nests’. This was in fact the official Royal Air Force strategy at the time, pretty much, though due to years of disarmament and budget cuts, it did not have nearly enough aircraft to carry it out. The British governments of the 1930s did begin to rearm, but were reluctant to do so too quickly for fear of harming the economic recovery or offending the Germans.

There were also those, generally on the political left, who rejected the logic of two nations trading massive blows with each other, for it seemed likely that even the victor in such a war would be devastated. What alternatives were there? One was to mitigate the effects of bombing, by preparing Air Raid Precautions, or ARP as it was known. This could mean everything from training civilians in how to survive poison gas attacks, to the construction of deep shelters able to accommodate thousands of people during air raids. Although this sounds unobjectionable, some pacifists could and did argue that ARP was a mere palliative, and might actually invite war by making Britain feel over-confident about its ability to withstand a knock-out blow. So they favoured more radical solutions such as complete disarmament, or at least the abolition of military aircraft. But this in turn encountered problems. During the 1920s and early 1930s, the idea developed among aviation specialists that large civilian aircraft such as airliners could be easily turned into bombers, more or less by strapping bombs under the wings. This possibility undermined disarmament efforts because it was feared that once all nations had disbanded their air forces, an aggressor could arm its airliners and hold the rest of the civilised world to ransom. So, one proposed solution to this dilemma was to place the civil aviation industries of all countries under international control.

From there it was a logical step for many supporters of collective security to propose the formation of an international air force, a very popular position in the early 1930s for parts of the left and one which was under serious consideration at the World Disarmament Conference in Geneva in 1932. An international air force would harness the devastating power of the bomber to uphold collective security, because if one country attacked another it would immediately be bombed itself by the combined air forces of the world. It was also attractive to some people as a possible foundation of a world state, which would end war forever by ending nations themselves.

So, I’ve explained what people thought bombing would do, and what they thought could be done about it. I would lastly like to talk about the discourse itself, how these problems and solutions were propagated from specialists to the public. In the ordinary course of things, most people don’t pay much attention to even existential threats such as terrorism, nuclear warfare, asteroid impacts, or indeed the knock-out blow. They may well be aware of them, and even anxious about them to some degree, but such information as they may pick up from the media, books or conversations with acquaintances will be random, fragmentary and possibly unpersuasive. It often takes some crisis, real or perceived, to concentrate people’s minds on the supposed threat to society, and here the mass media plays a key role in creating the perception that there is a threat, and in suggesting solutions to the threat. So I suggest that this process is very much like the concept of a moral panic, as proposed by the sociologist Stanley Cohen in 1972. Usually this is a media-driven panic about the danger posed to society by some group within it — like criminals, drug users, religious cults. But it seems to me that something closely analogous can happen in relation to external threats to society. To distinguish these incidents from moral panics, though, I call them defence panics. Defence panics seem almost endemic in Britain in the late 19th century and early 20th century. Initially these expressed fears about the loss of British naval supremacy and the possibility of invasion by a foreign power such as France or later Germany. The most famous expression of this was the great dreadnought panic of 1909, when an intense press campaign called for the laying down of 8 new battleships to pre-empt a supposed acceleration in the German naval construction programme. But only a couple of months later, there was a similar panic, this time time over German airships, and this panic was itself repeated on a larger scale in 1913. From then until the Second World War, the threat of air attack was unparalleled in its ability to create defence panics. Examples include scares over the size of European air forces in 1922 and 1935, claims about German preparations for biological warfare in 1934, the bombing of Spanish and Chinese cities in 1938 which were part of the background to the Munich crisis, itself a major defence panic, and finally the shocks of the Gotha air raids on London in 1917 and the Blitz in 1940.

In the end, the knock-out blow never took place, because the power of the bomber was greatly exaggerated. But the belief that it could happen itself shaped how the British prepared to fight the war that did come. The internationalist solutions such as disarmament or the international air force never worked, because few nations could even contemplate giving up their sovereignty like this. Britain did invest in trying to avoid the worst effects of a knock-out blow, with air raid shelters and plans to evacuate the cities. But their ARP schemes were never very comprehensive, and individuals did little to prepare for bombing on their own behalf until war came. Far more was spent on the armed forces, and most important here was air defence. Even though in the early 1930s nearly everyone was pessimistic about the fighter’s chances against the bomber, effort was still put into improving them, resulting in fighters like the Hurricane which I showed earlier. These played a essential part in blunting the bomber offensive in 1940, at least in daylight. But another crucial technological component of the solution to the the problem of the bomber came, bizarrely, from almost pseudoscientific attempts to find an electromagnetic death ray. Death rays didn’t help shoot down bombers, but radar did help find them.

A top-secret chain of radar stations around the coast was set up in 1939, just in time for the Second World War. This had an effective range of 120 miles. So instead of only being seen when they crossed the coast, bombers could now be detected far out to sea.

Returning to our graph showing how long it took for bombers to cross the 50 miles from the coast to London. With radar, this distance effectively increased to 170 miles.

I’ve factored that into this graph, and as you can see, from 1939 the defenders had a much greater warning time, 30 to 40 minutes. Radar tilted the balance greatly towards the defenders. No longer was it a certainty that the bomber would always get through.

So part of the answer to the problem of the bomber came from an unexpected quarter. But it didn’t just arrive by accident, it only came because people were worried about the problem and were looking hard for a solution. Sometimes, muddling through and hoping for the best just isn’t good enough, not when the survival of civilisation is at stake.

Image sources: Wikimedia Commons (Wright Flyer, Avro Lancaster); RAF (here and here); Gotha GIV; RAFA Costa Blanca; World-War-2-Planes.com; Guernica, specchio del Novecento; Caring on the Home Front; Wikipedia; Airminded (here, here and here); YouTube; Norman Macmillan, The Chosen Instrument (London: John Lane The Bodley Head, 1938), 21; eBay; David Davies, Suicide or Sanity? An Examination of the Proposals before the Geneva Disarmament Conference (London: Williams and Norgate, 1932); An International Air Force: Its Functions and Organisation (London: The New Commonwealth, 1934). I can’t find where the photo of the Hurricanes came from; but it’s almost certainly under Crown Copyright.

Some more plots from the talk I gave the other way. I was trying to think of a way to illustrate in concrete terms the problem of speed for the air defence of Britain. I came up with the following:

Simply put, it shows the length of time it would have taken for an attacking bomber to fly from the coast to London (in blue) — call it the crossing time — and the time it would take taken for a defending fighter to climb high enough to intercept (in red) — call it the intercept time. And how these changed over time, obviously. As can be seen, the fighters generally had enough time to climb high enough to intercept the bombers before they got to London, but the margin decreased over time, from 15 or so minutes during the First World War, to less than 5 in the Second.

But all this is not straightforward so I’ll explain further. To begin with, the data is slightly dodgy. It’s mostly drawn from the same source as this, which is fine as far as it goes. But that means that I’m showing how long it would have taken British bombers to penetrate from the coast to London, which was not really a great worry. Having said that, it’s probably reasonable to assume that the performance of British bombers was roughly in line with those used by Continental air forces. (And the RAF’s own air defence exercises had to make this assumption, too, because borrowing somebody else’s air force for a day wasn’t feasible.) One day I’ll create a dataset for European aircraft …

How are the numbers derived? First, the bombers (blue). This is just the distance from the coast to London divided by each bomber’s maximum speed (which is not necessarily realistic). Why the coast? Because it was only when the incoming raiders crossed the coast that they could be detected by ground observers, and fighters dispatched to intercept them.¹ What is the distance from the coast to London? Well, obviously it varies, depending on which direction the enemy came from (and some writers expressed fears that they would fly up the Thames Estuary and avoid detection). Looking at a map, 50 miles seems like a reasonable approximation.

Next, the fighters (red). The time it takes for a fighter to climb meet the bombers is the height of the raid divided by the climb rate of each fighter. This climb rate is a bit of a problem. I don’t a good source for this number and had to plunder Wikipedia. That’s bad enough in itself, but it’s worse because the data is inconsistent. Sometimes — when it’s not missing — it’s expressed in feet per minute, and sometimes in the number of minutes to reach a given height. Obviously one can be turned into the other, but actually both are only approximations, and I’ve had to extrapolate and interpolate from these to get a usable number.² What height would the bombers be at? Well, that varied — it was higher on average during the Second World War than in the First because aircraft were more capable, and also because bombers tried to climb higher to escape the fighters. I’ve assumed that this height was 10000 ft in the 1910s, 15000 ft in the 1920s, 20000 ft in the 1930s, and 25000 ft in the 1940s.³ I just plucked these numbers out of the air, more or less, but they seem to work well in terms of keeping the red and blue trends in touch with each other. If anything they are probably underestimates.

Some other points. Firstly, the fighters would generally have to move horizontally to intercept the bombers, as well as vertically. This plot says nothing about that. But given the edge fighters had in speed and the location of their aerodromes, they should be able to cover that distance while climbing. Secondly, the data points are for the year each aircraft entered into RAF service. But since they remained in service for several year, at least, the data points should really be horizontal lines.⁴

Thirdly, I’m assuming a perfect command, control, communications and intelligence system. Fighter Command (and its predecessors) was good, but it still took a finite but non-zero amount of time for sightings to be reported, sifted, collated and reported, and then for squadrons to be allocated, given orders, and take off. Also there was a chance that raids might not be observed, that squadrons could be given the wrong vector, that the enemy could be missed in cloud — so the greater the gap between the red data points and the blue ones the better. The more inefficient Fighter Command, the narrower the margin for error.⁵

Now we can show what difference radar made. The Chain Home system came into operation in 1939 and had an effective range of 120 miles. What this means here is that instead of only having to cross 50 miles from the coast to London after being detected by the observers on the coast, the bombers now had to cross 170 miles after being detected. As the above plot shows, this pushed up the crossing time dramatically: from 1939, the defenders could generally expect to have around 40 minutes’ warning of any raids. The margin for error increased dramatically, from only 5 minutes or less, to more than half an hour, which is far better. In theory, the defending fighter squadrons would now have plenty of time to get in position before the enemy arrived. Of course, that’s not the whole battle, but it’s a good start!

Lastly, here’s a counterfactual which I’ve long wondered about. Between 1933 and 1935, the Air Ministry put a fair amount of effort into researching the feasibility of using acoustic mirrors as a comprehensive early warning system. The acoustic mirrors were, mostly, concrete hemispheric dishes for focusing sound, which had been used as early as 1916. The biggest ones, at Dungeness in Kent and Maghtab in Malta, were 200 feet long curved walls. Land was actually purchased along the Thames Estuary for the beginnings of a national acoustic mirror system, but work never started because radar came along. But if it hadn’t, then in 1940 Fighter Command might have relied upon a network of these acoustic mirrors all along the coast.⁶ How useful would they have been?

The experimental mirrors had a maximum detection range of 22 miles (on very windy days it was a lot less). I’ll be generous and call it 25 miles, which is then added to the 50 miles from the coast to London for a total distance of 75 miles. The Thames Estuary acoustic mirrors probably would have come online in 1936, and so again I’ll be generous, and assume that London at least would have a working early warning system from that year.

Taking all this into account, the results can be seen above. And sadly the acoustic mirrors wouldn’t have made much difference — a margin of only about 10 minutes, not much improved on the 5 minutes with no warning system. Of course, even a few minutes’ extra warning was worth having, but the Air Ministry was right to terminate development of the acoustic mirror network in order to concentrate on the far more promising radar.

John Ferris has argued against the idea that ‘Air defence in Britain began during 1934 and only because radar was developed’, and that the importance of the C³I system — ultimately a legacy of the First World War — has been underestimated by historians: it was ‘ideally preadapted to radar’.⁷ And he’s right. Even without effective early warning, as long as the enemy bombers could be intercepted and shot down on their way back home, air defence could still work by inflicting prohibitive casualties. Except, that is, when the casualties from bombing were predicted to be massive, and then a failure to stop the bomber getting through would have devastating consequences. Radar was part of the antidote to the fear of the knock-out blow. Or rather it could have been, if it hadn’t remained secret until 1941 …

(Just to repeat: the data and assumptions underlying these plots are on the dubious side, and are not fit for any purpose, probably including this one!)

1. I’m neglecting radar, obviously, but see below. I’m also neglecting the fact that sound detectors, of the type that had been developed during the First World War, had a range of about 5 miles. But see even further below. Distant patrol aircraft were also used as a kind of picket line.
2. What I really need are curves showing climbing time vs. height because the higher an aeroplane flies, the harder it is to climb in the thin air. I assume these are available somewhere, but digging them up is too much work for a quick and dirty plot like this!
3. Fighters got a lot better at climbing very rapidly by the late 1940s, but as that happens I’m shifting the goalposts ever higher, as it were, and so the above graph is understating the rate of climb of fighters.
4. E.g., the two red triangles in the late 1930s are the Hurricane and Spitfire, which between them were the RAF’s primary interceptors throughout the war. This plot makes it look like there wasn’t anything able to catch raiders in 1940, which was not the case!
5. I could model this inefficiency by adding a fixed number of minutes to the climb time of the fighters — call it the response time — but I don’t know what a reasonable number is and it might vary a fair bit. For instance, in 1918 LADA (London Air Defence Area) had a response time of 2.5 to 5 minutes, according to John Ferris, “Fighter defence before Fighter Command: the rise of strategic air defence in Great Britain, 1917-1934”, Journal of Military History 63 (1999), 853 (JSTOR). But it presumably rose after LADA was dismantled after the war. David Zimmerman, Britain’s Shield: Radar and the Defeat of the Luftwaffe (Stroud: Sutton, 2001), 25, seems to suggest that 5 minutes was the time it took in 1933 just to transmit observations to ADGB (Air Defence of Great Britain) HQ, but that’s for the big acoustic mirrors which probably required more computation than normal acoustic detectors. So, pending more comprehensive figures, I’ll just leave the response time out of it.
6. See ibid., chapter 2, for more on the acoustic mirror research of the 1930s.
7. Ferris, ibid., 845, 884.

The talk at Earth Sciences went well, I think. It was a good-sized audience and they seemed interested in what I had to say, judging by the questions afterwards. I also found out that one of the honorary fellows had actually lived in London during the war, and though only a child could remember watching out for V1s passing overhead and even the ‘electric’ atmosphere of the day that war was declared.

I was all set to record the talk, but forgot to fire up the audio app. At some point, I may try recording it again at home or just putting the text up. Until then, here are a couple of the graphs I used, along with some different ways of presenting the same numbers. (Except where indicated, the data is courtesy of Dan Todman, who compiled it from Home Office files. Thanks Dan!)

Firstly, this shows the civilian casualties (killed and seriously wounded) each month in Britain due to enemy action between 1939-1945. Most — all? — of these will have the result of bombing, so I’ve labeled it accordingly. (This is the counterpart of a histogram I did for 1914-1918, except that combined civilian and military casualties, and separated different forms of attack.) It’s easy to pick out the Luftwaffe’s major offensives: the biggest peak is September 1940, when the Blitz started; it ended in May 1941, after which casualties were never so high again. There’s a relative lull in January and February 1941, due largely to bad weather conditions. In April-June 1942, there’s the Baedeker Blitz and from January 1944, the Baby Blitz. Then there’s the V-1 offensive in June-September 1944 and the V-2 offensive in September 1944-March 1945.

I thought it might be instructive to compare what actually happened with what was predicted would happen: if the knock-out blow had attempted and if pre-war estimates of German airpower had been correct. I derived this from figures provided by Richard M. Titmuss, Problems of Social Policy (London: H.M.S.O., 1950), 9 and 12-3, which were estimates made circa 1938 by government bodies for a war starting in 1939. These lead to the following assumptions:

1. the Luftwaffe could deliver 3500 tons of bombs on London in the first 24 hours of an attack, and an average of 700 tons per day for some weeks thereafter (Committee of Imperial Defence)
2. the casualties caused per ton of bombs dropped would be 48 (24 killed, 24 seriously wounded) (ARP Department, Home Office)
3. the war would last for 60 days (CID)

It’s then simple to calculate that a German knock-out blow launched on 3 September 1939 would have led to a bit over 1.1 million casualties in September and a bit over a million in October, 168000 on the first day of war. More than a million fatalities in just two months.

It’s easy to quibble with these assumptions — for example, I’m using the most pessimistic multiplier for casualties, but that’s partly because it’s easy to relate it to the definition of casualties I’m already using. And my assumption that the 700 tons per day could be kept up for 60 days may well be too high, but I can’t find anything better. The CID did estimate in 1937 that an aerial war of this length would kill 600,000 and wound 1.2 million, so that shows that I’m in the right range and also that officials did make these sorts of calculations at the time.

Anyway, the point of the histogram is to show that the actual bombing, as bad as it was, was nothing like as terrible as ‘the expected holocaust’ (as Tom Harrison termed it), and I think it succeeds — you can just make out the Blitz and the V-1 attacks, but they’re just tiny blips. However, precisely because of the huge disparity in scale, it’s hard to make a meaningful comparison.

In his graphs of all British casualties, Dan opted for running cumulative figures rather than monthly ones, and that is indeed better for showing the overall picture — whereas monthly is better at showing intensity, I think. So, here’s my actual vs. predicted plot redone in cumulative fashion. Even by the end of five and a half years of total war, the scale of the knock-out blow isn’t even approached. (In fact, I think that even when military casualties are taken into account, the knock-out blow still wins handily.)

Here’s a different way to present the monthly data. This time I’ve plotted the casualties on a log scale. This is good for showing changes in the order of magnitude, and it’s immediately apparent that the knock-out blow was around two orders of magnitude (i.e., about 100 times) more intense than the worst month of the Blitz.

Finally, the cumulative casualty figures on a log scale. So, overall, the civilian experience of bombing over the whole of the Second World War (mainly meaning the Blitz) was about one order of magnitude (i.e. about 10 times) less devastating than the knock-out blow predicted shortly before the war.

The knock-out blow would have been 100 times more intense and 10 times more devastating than the Blitz was — I’ll have to remember that!

[Cross-posted at Revise and Dissent.]

It’s time again for my six-monthly look at that portion of the blogosphere devoted to military history, as defined by the ‘Wars and Warriors’ section of Cliopatria’s blogroll. So, let’s begin.

Not a lot has changed since September, actually, and this plot shows why: the number of military history blogs has grown by only 13%, whereas between March and September 2007, it grew by more than 50%. Does this mean that fewer military history blogs are being started than before, or that instead Cliopatria is missing a significant portion of them? I’d be tempted to say the latter — the Cliopatricians are only human, after all, and can only add those blogs which come to their attention — but I can’t think of any they’ve missed. Also, the rate of growth of the blogosphere may be slowing — it’s hard to say, as Technorati seem to have stopped publishing their quarterly state of the blogosphere reports.

Here’s one change: the Australian share of the military historioblogosphere has doubled from, from 7% to 14%. This is almost entirely due to the Australian War Memorial’s new group blog, which draws on a wide range of its staff. (I’m not sure if this means the AWM will abandon the practice of separate blogs for each of its exhibitions — at the moment, the forthcoming Over the Front exhibition is the main focus.)

This growth has been at the expense of the Americans. Even taking into account the bloggers of unknown nationality — who are mostly going to be Americans too, given their predominant interest in the American Civil War — they’re now closer to three-fifths of the military historioblogosphere than three-quarters, as before.

The number of women blogging about military history continues to slowly edge upwards. Much of the growth, and most of the bloggers, are in group blogs, mostly attached to an institution or research project, rather than individually.

Nothing to see here …

… move along …

… move along.

Finally, we come to the only bit that anybody ever looks at, the top 5 military history blogs by Technorati rank. And here there has in fact been quite a bit of movement. Two of the top 5 are new to the list, and there is also a new number 1. That’s Civil War Memory, which has been threatening to become the most popular military history blog ever since I started doing these posts. Second is one of the new entrants, Kings of War. Though it’s an excellent blog, and has impeccable academic credentials, it’s only very rarely about military history: reflecting the interests of its maintainers, it’s mostly about contemporary wars. But as it is in fact in Cliopatria’s blogroll, and it has become very popular very quickly, Kings of War has earned its place at number 2. At number three is the former number one, and still the doyen of military history blogs, Blog Them Out of the Stone Age. Fourth is the other newcomer, Rantings of a Civil War Historian. And bringing up the rear is Airminded (phew).

None of this proves anything, other than the fact that I enjoy plotting numbers in a half-arsed fashion (and really, who doesn’t?) But what will happen next time? Will Australians take over the military historioblogosphere? Will Kevin Levin still have bragging rights over Mark Grimsley? Only time will tell …

Well, not just corpses …

The data for the above plot are drawn from the War Office, Statistics of the Military Effort of the British Empire During the Great War, 1914-1920 (London: His Majesty’s Stationery Office, 1922), 674-7.¹ It shows the total (i.e. civilian and military)² casualties (i.e. killed and wounded) from all forms of bombardment (i.e. by airship, by aeroplane, and by warship) in Britain for each month of the war.

There are three distinct, colour-coded stories here. The first is that of naval bombardment (blue). I knew of the German navy’s raid on Scarborough, Hartlepool and Whitby in December 1914, but not that there were so many casualties (137 dead, 592 wounded). That one raid caused more casualties than any of the later air raids — more than were caused by air raids in any one calendar month, in fact — and on that basis the post-war Admiralty ought to have been arguing that the battlecruiser will always get through! Of course, it was a highly singular event: no other shore bombardment came anywhere close to doing as much damage. And most places in Britain were not as exposed to attack from the sea as seaside towns in Norfolk.

The second story is that of the airship menace (green). During 1915 and 1916 Zeppelin raiders were fairly successful, often causing about 200 casualties a month — in those months that they did attack. They mostly came during the spring and autumn; I suppose the summer nights were too short and the winter nights too foul. But after 1916, they inflicted much less damage. That’s partly because they came less often, and that’s partly because in the autumn of 1916, seven airships were shot down by British air defences, including that commanded by the legendary Kapitänleutnant Heinrich Mathy. The RNAS and RFC had largely gotten the measure of the Zeppelin raiders by then.

Aeroplane raiders are the final story (red). Though these are largely forgotten today — at least in comparison to the Zeppelins — from the summer of 1917 they caused even more fear than did the Zeppelins, and the graph shows why: they did significantly more damage, and did so over a more sustained period of time. (They kept up the offensive on London over the winter of 1917-8, for example, which the Zeppelins did not.) The two great daylight raids on London on 13 June and 7 July 1917 were particularly shocking. Though the activities of the Gothas and Giants led to the formation of the Royal Air Force and the London Air Defence Area, ultimately the end of major aeroplane raids owed more to the needs of the German army in France than anything else: first the March 1918 offensive, and then the Hundred Days.

This is a slightly different way of representing the same data, I think less successfully. The casualties are shown per day instead of per month, which means you can see just how frequent raids were (aeroplanes ahead, not by much though; and there are a number of raids of all types which caused no casualties and so don’t show up). But the bars are very thin and indistinct, and I can’t make them bigger without some of them overlapping each other. Still, it has some useful information lacking in the first plot, which is why I include here.

1. Which was kindly scanned by Mike Yared of the WWI-L mailing list, and made available online. Be aware, it’s over 80 Mb in size.
2. Interestingly, Statistics distinguishes between the two categories (with civilians nearly always predominating). I suppose the point of that was that the lives of soldiers and sailors were expected to be at risk in wartime, whereas those of civilians shouldn’t be.

[Cross-posted at Revise and Dissent.]

Six months ago, I used Cliopatria’s list of history blogs to assess the state of the military portion of the historioblogosphere. My original plan was to do this every year, but because things move fast online I’ll update it every six months instead. I won’t waffle on too much about my methodology (if it can be called that!); for that, please refer to the original post, as well as for the plots from March 2006.

First, let’s look at the number of blogs in the military historioblogosphere. This increased by just over 50% in six months, i.e. an annualised rate of more than 100%, which is considerably faster growth than in the year to March 2007. This is now only slightly slower than the rate of growth of the blogosphere as a whole, which as of April 2007 was doubling every 320 days (as measured by Technorati. Of course that rate may have changed by now). Some 13% of the blogs in the March 2007 list don’t appear in the current version, which, sustained over a year, would be a touch higher than the churn rate last time.

The nationality of bloggers in the military historioblogosphere. The American dominance, though still a majority, has receded somewhat (although as before, most of the 20% of unknowns are US Civil War bloggers and so are likely to be Americans). British bloggers now represent about a sixth, instead of an eighth, of the total number of bloggers. And Australian bloggers are up from 2% (i.e., me) to 7%! The reason for this is largely the emergence of institutional blogs, such as Osprey and UKNIWM in the UK, and the AWM’s blogs in Australia (which I’ve counted as one blog, as that’s the way it’s listed at Cliopatria). These are all group blogs, which means they count for much when adding up numbers of individual bloggers.

The gender of bloggers in the military historioblogosphere. The number of female bloggers is still only 10%, but at least is nearly double the proportion of six months earlier. Again, this is largely because of the rise of institutional blogs: the majority of women who blog on military history now do so as part of a group blog (7) and not on their own (3).

The periods covered by blogs in the military historioblogosphere. There’s not a lot of change here; mainly greater diversity. (Especially since “None” covers blogs which range all over time.)

The theatres covered by blogs in the military historioblogosphere. Again, the proportions have stayed pretty much the same — basically a bit less North America and a bit more non-specific None.

The wars covered by blogs in the military historioblogosphere. Here, the biggest change is that the proportion of blogs focusing on the World Wars has dropped from about a quarter to a fifth, while those not dealing with any specific war now represent 28% of the whole sample, up from 16%. The American Civil War is still the most popular war, but it has lost its absolute majority.

The top five most popular blogs in the military historioblogosphere, by Technorati rank. I wondered whether I should include this again. After paying closer attention to my own rank in the last few months, I’ve become aware of just how dodgy it is (for example, Technorati counted one link to my blog as coming from four separate blogs!) But as this was the chart which attracted most interest last time, leaving it out would minimise the boost that this post will give to my Technorati ranking :) So I’ll just remind you that these figures should be taken with a large grain of salt.

As in March, Blog Them Out of the Stone Age is the most popular blog in the military historioblogosphere. But only just! Civil War Memory is almost level (in fact, had one more blog linked to it they would be tied). Third is Airminded itself, which has risen about 50,000 places in the Technorati ranks — which is further evidence for the unreliability of this measure, as my stats program tells me that traffic to my site has actually held steady or perhaps even declined a little over the last six months. Next comes Investigations of a Dog, which has slipped a little in the rankings (in fact, most of the blogs in the sample have: with an expanding blogosphere, you have to keep running faster just to stand still). And in fifth position, About.com’s Military History blog has been displaced by Military History Podcast. This has been around for a couple of years, and it’s particularly noteworthy because its author is still only a teenager! It’s also a good example of the rise of generalist military history blogs, which aren’t tied to any particular historical time or place.

So, the military historioblogosphere is rapidly growing and somewhat more diverse than it was in March 2007; but still dominated by American bloggers writing about the American Civil War. The biggest change, however, has been the increase in institutional group blogs, usually attached to museums but sometimes also to publishers or archaeological projects. No doubt there’ll be a few more of these by March 2008 …

[Cross-posted at Revise and Dissent.]

With the inaugural Military History Carnival coming up, it seems like a good time to ask: what does the military historioblogosphere look like? The obvious answer to that is another question: what on Earth is a military historioblogosphere anyway? Well, ‘historioblogosphere’ is just a silly word I invented to describe the history blogosphere, and so the military historioblogosphere is the part of that to do with wars and suchlike. (And actually, of course, it’s the Anglophone military historioblogosphere …) In practice, I will take the ‘Wars and Warriors’ section of Cliopatria’s History Blogroll as the closest thing we have to a census of the military historioblogosphere. Which is not to say that it is complete, nor that I think everything on that list should be there, but it’s a whole lot more comprehensive than any list I’m willing to maintain! It obviously excludes blogs which may discuss military history, but are not primarily focused on it — but it’s a good place to start.

So I’ve gone through the blogs listed there and compiled some basic statistics with them, and made some basic plots with them. (I used Keynote because it’s soooo much easier and prettier than Excel, or Powerpoint for that matter; and because my otherwise go-to app for plotting, Plot, doesn’t do pie charts.) I actually intended to do something along these lines ages ago, but never got around to it; fortunately I kept the data on my hard drive; and as it happens it was almost exactly a year ago that I compiled it, so it’s perfect for a year-on-year comparison! So let’s begin.

The number of blogs in the military historioblogosphere. The red portion represents the increase in the past year. The blue part (blogs active in March 2006) actually decreased. This is because some blogs have moved out of the military historioblogosphere since then, according to Cliopatria — mainly because they’ve ceased activity, but not always. The percentage of blogs in the list in March 2006 which did not make the cut the following year — call it the churn rate — is 23%.

The total percentage increase is 65%. This sounds impressive, but actually it’s well below the growth rate of the blogosphere as a whole (which would predict a 151% increase in a year). Of course, the Cliopatria blogroll is human-generated, not machine-indexed, so it might be expected that it would fall short of the actual increase. And of course there may well be selection biases affecting what is considered blogroll-worthy by Cliopatria.

The nationality of bloggers in the military historioblogosphere. This I tried to determine by visiting each blog and looking for information as to where the blogger(s) — members of group blogs are counted individually — live or originated from. I did not read every entry (!), and for some blogs I couldn’t get any positive indication as to origin. These are labeled ‘Unknown’ — but as it happens, every single one of these unknowns blogs about the American Civil War, so it’s a pretty safe bet that they are all from the US. So the blue and red sectors combined represent the American part of the military historioblogosphere.

Now, it’s not unexpected that Americans would dominate the sample. Based on population, the share from each nation is probably about right. But as somebody from (in fact, who IS) the smallest wedge in the pie chart, I would have liked to have seen the non-US proportion at least stay constant. Instead, it has fallen from 23% to 18%. It’s an increasingly American ’sphere. Having said that, I noticed that two of the ACW blogs have announced they going on hiatus (or worse), and there are a couple of British blogs not yet on the list, so in a month the picture might be different. But that’s the sort of thing that happens with a snapshot like this.

The gender of bloggers in the military historioblogosphere. Again, there was a (much smaller) number of bloggers whose gender could not be positively determined. As one might expect in this area, there’s a very small number of females, certainly much lower than in the historioblogosphere as a whole. But at least it’s improving: in absolute terms, from 1 in 2006 to at least 3 now; in percentage terms, from 4% to at least 6% now.

The periods covered by blogs in the military historioblogosphere. Here, ‘None’ means that the blog in question did not confine itself to one period, not that I could see anyway. Leaving these ones aside, the biggest sectors are the 19th century by a big margin, followed by the 20th century. Again, there has been a significant change since March 2006: blogs covering the 19th century now make about half of all military history blogs, up from just under two-fifths a year ago. The 20th century’s share has remained about the same, at a bit over 25%.

The theatres covered by blogs in the military historioblogosphere. This is the most subjective of my classifications, and it doesn’t help that ‘theatres’ (as in, of war) doesn’t quite cover what I mean, which is not necessarily the part of the world where the wars under discussion were fought, but sometimes it was more the nation the blog was about, if that seemed more appropriate. Maybe ‘perspectives’? Well, that’s not great either. Because of the vagueness, I went broad with the bins and made them continents.

So, there’s a pattern developing here. North America was the biggest sector in 2006, and it’s only getting bigger: a whopping 58% of the military historioblogosphere, up from 42%. The next biggest is Europe, which maintained about the same share over the year, just over a quarter. It’s the generalist blogs which have declined relatively (though not much in absolute terms, it’s true).

The wars covered by blogs in the military historioblogosphere. And here the reason underlying the aforementioned trends becomes clear: blogs about the American Civil War numbered just 10 in March 2006. Now there are 22 on Cliopatria’s blogroll! So just over half of the military historioblogosphere is now devoted to the Civil War, up from under two-fifths a year ago. Just over a quarter are about the World Wars, a figure which has remained about the same; again, it’s generalist blogs which have fallen behind in relative terms.

There’s clearly a strong correlation between the nationality of a blogger and the period/theatre/war they blog about: at the risk of over-generalising — it’s probably true about 75% of the time — if they’re American, they blog about the Civil War; if they’re not, they blog about the World Wars. Well, it’s not exactly news that Americans have far more interest in the Civil War than non-Americans, nor is it in any way surprising. But where are all the American blogs about the Second World War? You know, the Greatest Generation, Saving Private Ryan, Call of Duty 2 and all that? Conversely, to all the non-Americans out there, aren’t there any other wars worth blogging about than the two big ones?

The top five most popular blogs in the military historioblogosphere, by Technorati rank. Here, lower numbers (shorter bars) are better, meaning higher popularity. I didn’t think to check this last year, so unfortunately there are no comparative data. It’s still interesting, though. As expected, War Historian (AKA Blog Them Out of the Stone Age) is the most popular blog in the military historioblogosphere; it just breaks into the top 50,000 of all blogs. Civil War Memory comes in a very creditable second; also no surprise. Most remarkable is Investigations of a Dog, which as I have remarked previously has very quickly become entrenched as a must-read blog — and hosting the Military History Carnival is only going to increase its popularity and Technorati ranking! Then follows, a long way back and close together, *modest cough* Airminded and Military History.

I must admit that I’m surprised to see Airminded in the top five; I had thought that the cluster effect of so many Civil War blogs linking to each other would mean that they would dominate the Technorati rankings. That’s not the case; there’s only Civil War Memory (and I don’t consider War Historian to be one, as it always had very substantial non-Civil War content even before Civil Warriors was founded). However, it must be noted that Technorati rankings (which are based upon the number of inbound links a blog receives from other blogs) are a bit dodgy; for example, it sometimes claims a blog has no incoming links, when the search results clearly show several. Also, the URL which Cliopatria has listed for Victor Hanson isn’t recognised as a blog by Technorati; instead this one is, which would be ranked at 4 if it were included here — but it’s not :)

So there it is. There are other metrics I could have compiled, such as blogging platform (WordPress is quickly coming up on Blogger’s position) or a clustering diagram (as has been done for the historioblogosphere as a whole), but I think that the ones I have done tell us something useful about the current state of the military historioblogosphere, even if it’s not perhaps very surprising.

Edit: fixed a minor error in the period plot.

[Cross-posted at Revise and Dissent.]

The minute hand of the famous Doomsday Clock of the Bulletin of the Atomic Scientists has just moved closer to apocalypse: it is now set at five minutes to midnight. This is the most dangerous level it has been since 1988. The dangers currenty facing humanity are summarised thus:

The world stands at the brink of a second nuclear age. The United States and Russia remain ready to stage a nuclear attack within minutes, North Korea conducts a nuclear test, and many in the international community worry that Iran plans to acquire the Bomb. Climate change also presents a dire challenge to humanity. Damage to ecosystems is already taking place; flooding, destructive storms, increased drought, and polar ice melt are causing loss of life and property.

Obviously, the precise position is fairly arbitrary — the relative movement back and forth is more significant, i.e. whether the world is getting more dangerous or not — but it’s interesting to reflect on the past movements of the minute hand:

So there are roughly four periods. The 1950s and most of the 1980s were periods of great danger; the 1960s/1970s and the 1990s periods of relative safety. We’re now entering a fifth period, a dangerous one, according to the Bulletin.

Mostly this makes sense. The US lost its nuclear weapon monopoly in 1949 (and its thermonuclear one in 1955), and so in the 1950s, the possibility of a nuclear war had to be confronted. Fall-out shelters, duck-and-cover and Them! all pointed to a burgeoning fear of nuclear war. The 1980s was the era of Reagan and the oldest Soviet leader who was still alive on any given day. SS-20s, MX Peacekeepers, Cruise, Threads, The Day After. ‘A strange game. The only winning move is not to play’. On the more hopeful side, there was détente in the 1970s — SALT I, SALT II, the ABM treaty, the Helsinki Accords. The 1990s was the first post-Cold War decade, when a peace dividend seemed plausible. Significant cuts were made to the stockpiles of American and Russian nuclear weapons.

But what about the 1960s? Judging by the Clock, this was the sanest period before the early 1990s. Can that be right? The decade of Tsar Bomba, the Cuban Missile Crisis, the Berlin Wall, General Jack D. Ripper and that episode of The Twilight Zone where all the suburbanites are fighting over the only fallout shelter in the neighbourhood? It’s true that there were signs of hope. The hotline between Washington and Moscow suggested that dialogue was possible between the two superpowers. And the Partial Test Ban Treaty in 1963 was the first step back from the brink; the Nuclear Non-Proliferation Treaty in 1968 was another. But actually, a serious two-way nuclear war only became possible during this time. During the 1950s, when the Doomsday Clock was set at two or three minutes to midnight, the USSR had derisory numbers of strategic nuclear warheads, only a couple of hundred or so (and given the illusory nature of the missile gap, would have had to brave US air defences to deliver them), whereas the US had already accumulated thousands, as the orange line in the following figures show:

So, in the 1960s, Soviet stockpiles of strategic nuclear weapons increased dramatically (over a thousand by 1966, twice that by 1969), and for the first time a strategic nuclear exchange worthy of the name was possible. So while, as I said at the start, the position of the hand is somewhat arbitrary, it does seem to me that it was running slow for most of the 1960s (or at least was running fast in the 1950s). Of course, the full scale of the nuclear armaments on both sides was not publicly known at the time, so perhaps all this says is that ignorance really can be (relative) bliss after all.

One final question …

… anyone else feel like playing Missile Command all of a sudden?

Image sources: all Wikimedia Commons: here, here, here, here and here (but first seen at The War Room), respectively.

As promised, here’s a revamped version of the speed plot I did the other day, this time distinguishing between biplanes (and triplanes), monoplanes and jets (just the one — the Meteor). It’s now a bit harder to read, though — it’s still red for fighters and blue for bombers, but now biplanes are represented by crosses (of the appropriate colour), monoplanes by open triangles, and jets by filled triangles. Also I noticed that my criteria for inclusion in the dataset had changed part-way through, so I’ve added a few aircraft to make that consistent (mainly torpedo-bombers) — I’ll update the original post shortly.

This shows very clearly the big jump that came with the move to monoplanes in the mid-1930s. And not just in fighters — bomber speeds increased by around 100 mph. In fact, the last British biplane fighters, introduced in 1937, could barely keep up with their own bombers. Again, cubic spline fits to the various combinations illustrate this. (Referring to the left-hand endpoint of each fit, they correspond to biplane fighters, biplane bombers, monoplane fighters and monoplane bombers.)

Looking at the data again, there is another feature worth remarking upon. Based solely on the number of models entering production (ie, and not on the actual numbers of aircraft that were built), the period up to about 1925 is dominated by fighters, while the period from then up to the start of the Second World War is dominated by bombers. For the 1914-8 period, I think this is explained by the constant battle for air superiority over the Western Front, which saw new fighters rushed into service every few months to counter new German types. But I’m somewhat surprised that there were so many fighter types introduced in the early-to-mid 1920s, given that the bomber orthodoxy was supposedly being established at this time (though some of the fighters were for export or were otherwise speculative ventures, not designed to Air Ministry specifications). For the bombers, the reason would probably be the desire for a heavy bomber as a deterrent, but more so the increasing need for specialised aircraft adapted for different roles, as opposed to the “general purpose” aircraft common in the 1920s.

Last year I was playing with a plotting program for Mac OS X, which was pretty good, but not quite satisfactory. I’ve found a better one, Plot, which is free (as in beer), fairly easy to use, and very customisable. It has its own idiosyncrasies, but I like it a lot. Here’s an example plot, showing how the top speed of British combat increased up to the end of the Second World War.

The data are drawn from John W. R. Taylor, Combat Aircraft of the World From 1909 to the Present (New York: Paragon, 1979). This excludes aircraft which never saw service as well as those not intended for combat (though not all actually saw combat). The year is that in which it entered service (usually with the RAF), or if this wasn’t given, the year when the prototype first flew. (Some aircraft unfortunately had neither, and so were omitted.) The maximum speeds, in miles per hour, are not necessarily comparable, because they were often obtained at different heights; also, they may not have been sustainable under normal conditions. But they should be broadly indicative of real-world maximums. I’ve classified each aircraft as either fighters (red) or bombers (blue), based upon their actual use. However, that’s fairly arbitrary for the period up to 1915, which is when aircraft adapted for specialised roles began to appear. I haven’t included seaplanes but I have included carrier-borne aircraft. Generally, I have only included data for the most representative version (eg not for each of the innumerable marks of Spitfire). Because of these caveats and inconsistencies, the plot should not be taken too seriously — it’s just for illustrative purposes.

Three things stand out:

1. The post-war gap from 1919 to 1923. This was due to the huge surplus of aircraft left over from the war, and the RAF’s rapid shrinkage. It ended in 1923, when the Home Defence Air Force was set in train after scaremongering by Trenchard in Whitehall, and Groves in Fleet Stree, over the French air menace.
2. The 1920s saw little improvement in maximum speeds — in fact, the performance of the fastest aircraft in 1918 was not bettered until the end of the decade. It should be remembered, however, that there were many other improvements being made during the 1920s, for example in moving to sturdier airframes, improvements which laid the foundation for the rapid improvements of the 1930s.
3. Fighters did not have a marked superiority over bombers in speed until the mid to late 1930s (and sometimes none at all — the Hawker Hart was faster than any British fighter when introduced in 1930). This was one reason for the widespread (though by no means universal) scepticism of the possibility of air defence.

Just for fun, here are 4th-order (cubic) spline fits to the bomber and fighter data, only to illustrate the general trend (I certainly wouldn’t argue they correspond to some underlying law).

There are other performance data in Taylor, which I’ll put up in due course. It would also be interesting to do international comparison (say, between British fighters and French+German bombers), but that will involve a lot more data entry!

Update: I’ve added a few aircraft that I missed initially, and also deleted a bogus datapoint that was dragging down the fit for the bombers. Browser caches may need to be reloaded.