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Brits Attack at Arras

Erik Sass is covering the events of the war exactly 100 years after they happened. This is the 273rd installment in the series.

April 9, 1917: Brits Attack at Arras 

The German withdrawal to the Hindenburg Line in March 1917 didn’t derail Allied plans for a massive offensive in mid-April, as drawn up by the new French commander-in-chief, Robert Nivelle, an ambitious artillery officer who had been promoted to the top spot because of his successes at Verdun, including recapturing Fort Douaumont and Fort Vaux (the previous French commander-in-chief, Joseph Joffre, was kicked upstairs with an honorary position of Marshal of France, while General Petain, the architect of the original defense of Verdun, was sidelined for the moment).

Disregarding growing concern among French and British officers and civilians about the advisability of the strategy, Nivelle planned a multi-phased operation by four armies, depending on heavy artillery preparation and particularly a “creeping barrage” by French artillery, creating a curtain of destruction in front of the advancing infantry. Similar tactics had met with success at Verdun, prompting Nivelle to exclaim, “We have the formula!” But on the much larger scale of the Western Front, it proved a formula for disaster. 

The British were to play an important role in the “Nivelle Offensive” at the Battle of Arras (actually the second battle of that name), a major attack by the British First, Third, and Fifth Armies on the defensive lines of the German Sixth Army under Ludwig von Falkenhausen in the Pas de Calais region of northern France. The British attack was scheduled for April 9, 1917, a week ahead of the French attack, in hopes of pinning down German troops to prevent them from sending reinforcements. It included the famous advance by the Canadian Corps on Vimy Ridge from April 9-12, 1917, a stunning but costly victory; Vimy Ridge would come to be remembered as a key moment in the formation of Canadian national identity in some ways comparable to the impact of Gallipoli on veterans and civilians in Australia and New Zealand (whose ANZAC troops also fought at Arras).

The initial infantry assault was preceded by an unprecedented 19-day-long bombardment of German positions along 20 miles of front, ultimately expending around 2.7 million shells, including one million from April 2-9 alone. Philip Gibbs, a British war correspondent, described the bombardment on the final night before the battle: 

It was a beautiful and devilish thing… All our batteries, too many to count, were firing, and thousands of gun-flashes were winking and blinking from the hollows and hiding-places, and all their shells were rushing through sky as though flocks of great birds were in flight, and all were bursting over German positions, with long flames which rent the darkness and waved sword-blades of quivering light along the ridges. The earth opened, and pools of red fire gushed out. Star-shells burst magnificently, pouring down golden rain. Mines exploded east and west of Arras, and in a wide sweep from Vimy Ridge to Blangy southwards, and voluminous clouds, all bright with a glory of infernal fire, rolled up to the sky.

Gibbs also described the huge logistics effort and concentration of troops massing in the darkness for the offensive near Arras: 

… and then onwards there was the traffic of marching men going up to the fighting-lines, and of their transport columns, and of many ambulances. In darkness there were hundreds of little red lights, the glow of cigarette ends. Every now and then one of the men would strike a match, holding it in the hollow of his hands and bending his head to it, so that his face was illumined – one of our English faces, clear-cut and strong. The wind blew sparks from cigarette ends like fireflies. 

The first infantry assault was timed for 5:30 a.m. on Easter Monday, April 9, 1917. Minutes before the men went over the top, the British, French and Canadian engineers unleashed one final surprise, as the German trenches were rocked by 13 mines exploding under Vimy Ridge. R. Derby Holmes, an American serving as a volunteer with the Canadians, remembered the detonations: 

Then came a deep rumble that shook the ground, and a dull boom. A spurt of blood-red flame squirted up from the near side of the hill, and a rolling column of gray smoke. Then another rumble, and another, and then the whole side of the ridge seemed to open up and move slowly skyward with a world-wrecking, soul-paralyzing crash. A murky red glare lit up the smoke screen, and against it a mass of tossed-up debris, and for an instant I caught the black silhouette of a whole human body spread-eagled and spinning like a pin-wheel. Most of our party, even at the distance, were knocked down by the gigantic impact of the explosion. A shower of earth and rock chunks, some as big as a barrel, fell around us.

Now along miles of front, under the faint, growing light of early morning the Canadian and British troops advanced into the blazing chaos behind the creeping barrage of artillery fire (below, a map showing the timing of the barrage). The infantry attacks had been carefully rehearsed at the battalion level using full-size dioramas, while officers had trained with a large-scale model of the entire battlefield, and the preparation paid off – as did the decision to arm the attackers with mobile Lewis machine guns, a move towards “storm troop” tactics.

Click to enlarge Wikimedia Commons 

To the north, the four divisions of the Canadian Corps in General Henry Horne’s First Army surged forward and forced back the German defenders on Vimy Ridge again and again, occupying their first main objectives within an hour and had occupied the crest of the ridge by mid-morning – a remarkable success which left their commanders scrambling to maintain the momentum. 

The capture of Vimy Ridge gave the Allies possession of the strategic heights looking out over the plain of Douai to the east – a key advantage in the chess-like game of artillery and counter-artillery fire. The Canadians would ultimately advance almost four kilometers in places from April 9-12, but later attacks in the Battle of Arras would pit them against dug-in defenders; by the end of the battle the Canadians had lost 10,500 killed (a large figure in proportion to the dominion’s total population of around 7.9 million). 

As storm after storm descended dumped rain, sleet and snow on the battlefield, mud was inescapable, according to Gibbs:

In addition to the ordeal of battle they are enduring now a weather so abominable, when it is in the fields of battle, that men fight for days wet to the skin, lie out at night frozen stiff, and struggle after the enemy up to the knees in mud… Our men came back from this fighting like figures of clay, and so stiff at the joints that they can hardly walk, and with voices gone so that they speak in whispers. All over this lower slope of the Vimy Ridge is a litter of enormous destruction caused by our gun-fire. German guns and limbers, machine-guns and trench-mortars lie in fragments and in heaps in infernal chao of earth, which is the graveyard of many German dead. 

Meanwhile the British Third Army, attacking in the center, also scored a surprising victory from April 9-14, advancing up to three miles along a 15-mile front stretching on both banks of the River Scarpe – along with the Canadian advance, the single biggest advance in years of trench warfare on the Western Front. But the Brits soon ran into fierce renewed German resistance around the village of Monchy, as the defenders of the Bavarian 3rd Division dug in while German engineers worked feverishly on new defensive lines in the rear. 

Billy Bishop, a British pilot in the Royal Flying Corps, described the view from the air (often obscured by thick fog and snow) as British artillery fired at Arras on April 9: 

The ground seemed to be one mass of bursting shells. Farther back, where the guns were firing, the hot flames flashing from thousands of muzzles gave the impression of a long ribbon of incandescent light. The air seemed shaken and literally full of shells on their missions of death and destruction. Over and over again one felt a sudden jerk under a wing-tip, and the machine would heave quickly. This meant a shell had passed within a few feet of you. 

The British bombardment succeeded in splitting open barbed wire defenses and blowing enemy strongholds out of existence, according to Bishop, who next witnessed a shockingly easy advance by British troops: 

The waves of attacking infantry as they came out of their trenches and trudged forward behind the curtain of shells laid down by the artillery were an amazing sight. The men seemed to wander across No Man’s Land, and into the enemy trenches, as if the battle was a great bore to them… That is the way with clockwork warfare. These troops had been drilled to move forward at a given pace.

To the south the picture was much grimmer, however, as the troops of the British Fifth Army got their first harsh taste of German defenses at the Hindenburg Line. The offensive around the village of Bullecourt from April 10-11 got off to a bad start when some British units, not hearing about a last-minute delay, attacked early – suffering a bloody repulse and giving away any element of surprise. This battle later saw the second major attempt to employ tanks in offensive warfare, after the Battle of the Somme, but this time the Germans were expecting them – including new armor-piercing shells – and once again the new weapon proved prone to technical failures. 

Major W.H.L. Watson described the mixed performance of one section of tanks employed in the first attack: 

The first tank was hit in the track before it was well under way. The tank was evacuated, and in the dawning light it was hit again before the track could be repaired. Money’s tank reached the German wire. His men must have “missed their gears.” For less than a minute the tank was motionless, then she burst into flames. A shell had exploded the petrol tanks… Bernstein’s tank was within reach of the German trenches when a shell hit the cab, decapitated the driver, and exploded in the body of the tank. 

Although they captured the village of Bullecourt itself, the British otherwise mostly failed to advance in the south, frustrated by the new German tactics of “defense in depth” along the Hindenburg Line. Meanwhile chief of the general staff Hindenburg and his collaborator, quartermaster general Erich Ludendorff, were frustrated by Falkenhausen’s failure to grasp the tenets of the new defensive doctrine, and replaced him on April 23. To the north the British and Canadian advances soon slowed as well, leaving them in possession of Vimy Ridge and the lower Scarpe but still far from Lens or Douai, and the utter failure of the French Nivelle Offensive soon removed any reason to continue the attack.

The advance at Arras was still tremendous by the standards of the First World War, and British engineers were working feverishly to repair roads across newly-conquered territory behind the lines – in many cases, what used to be No Man’s Land. Coningsby Dawson, an officer with a British engineering unit, later recalled in a letter home: 

We ran across what had been No Man’s Land end entered the Hun wire… His frontline trench was piled high with dead. The whole spectacle was unreal as something that had been staged; the corpses looked like wax-works. One didn’t have time to observe much, for flames seemed to be going off beneath one’s feet almost every second and it seemed marvellous that we contrived to live where there was so much death. As we went further back we began to find our own khaki-clad dead. I don’t think the Huns had got them; it was our own barrage, which they had followed too quickly in the eagerness of the attack. Then we came to where the liquid fire had descended, for the poor fellows had thrown themselves into the pools in the shell-holes and only the faces and arms were sticking out.

As another icy storm swept the battlefield, Dawson felt a moment of sympathy for recently captured German prisoners-of-war, whose condition summarized all too clearly the human cost of the war: 

You never saw such a mess – sleet driving in our faces, the ground hissing and boiling as shells descended, dead men everywhere, the wounded crawling desperately, dragging themselves to safety. I saw sights of pity and bravery that it is best not to mention, and all the time my brave chaps dug on, making the road for the guns. Soon through the smoke gray-clad figures came in tottering droves, scorched, battered, absolutely stunned. They looked more like beasts in their pathetic dumbness. One hardly recognised them as enemies.

See the previous installment or all entries.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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iStock
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Here's How to Change Your Name on Facebook
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iStock

Whether you want to change your legal name, adopt a new nickname, or simply reinvent your online persona, it's helpful to know the process of resetting your name on Facebook. The social media site isn't a fan of fake accounts, and as a result changing your name is a little more complicated than updating your profile picture or relationship status. Luckily, Daily Dot laid out the steps.

Start by going to the blue bar at the top of the page in desktop view and clicking the down arrow to the far right. From here, go to Settings. This should take you to the General Account Settings page. Find your name as it appears on your profile and click the Edit link to the right of it. Now, you can input your preferred first and last name, and if you’d like, your middle name.

The steps are similar in Facebook mobile. To find Settings, tap the More option in the bottom right corner. Go to Account Settings, then General, then hit your name to change it.

Whatever you type should adhere to Facebook's guidelines, which prohibit symbols, numbers, unusual capitalization, and honorifics like Mr., Ms., and Dr. Before landing on a name, make sure you’re ready to commit to it: Facebook won’t let you update it again for 60 days. If you aren’t happy with these restrictions, adding a secondary name or a name pronunciation might better suit your needs. You can do this by going to the Details About You heading under the About page of your profile.

[h/t Daily Dot]

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