Pilates

After the outbreak of World War I, Joseph Hubertus Pilates, a German physical trainer and inventor, was interned as an enemy alien on the Isle of Man. During his three-plus years at the internment camp, Pilates developed a regimen of muscle strengthening through slow and precise stretching and physical movements, using minimal equipment. 

To allow those who were confined to their beds to exercise, Pilates used springs and straps from the beds as resistance training, greatly aiding their rehabilitation. He later opened a fitness studio in New York City in 1925, offering the exercise system he developed during the war to the general public. He went on to patent 26 exercise apparatuses, and his eponymous Pilates regime gained worldwide popularity. 

Trench Coats

Today, trench coats are associated with an array of colorful fictional characters such as Dick Tracy, Columbo, Silent Bob, and Hellboy. But these waterproof, heavy-duty, and typically double-breasted coats were initially developed for British army officers. 

Similar coats existed before World War I, but manufacturers — most notably Burberry and Aquascutum (both of which claim to have invented the trench coat) — modernized and modified the design to keep officers warm and dry in the trenches (hence the name). Shoulder straps were included for the attachment of epaulettes or other rank insignia; D-rings were added for attaching map cases, swords, or other equipment to the belt; and the addition of a gun flap buttoned at the chest offered extra protection in combat. And so the modern trench coat was born — a practical piece of attire that remains in fashion today. 

Plastic Surgery

Modern plastic surgery originated in Britain, a nation that saw some 735,487 troops discharged following major injuries in World War I. Many of these were facial injuries, which were initially covered using masks and patches. Then came Harold Gillies, a young ENT surgeon from New Zealand, who developed techniques to rebuild faces using plastic surgery. In 1916, he was tasked with setting up Britain’s first plastic surgery unit, where he began treating disfigurements using tissue from elsewhere on the patient’s body. 

The pioneering work of Gillies and his team laid the foundations of modern plastic surgery, which today continues as a life-altering medical treatment and a sought-after cosmetic product. 

Zippers

Ever since the mid-19th century, various inventors had been working on combinations of hooks, clasps, and eyes to find a smooth, convenient fastening device. None of their attempts quite worked, due to design flaws and other issues, until Swedish American engineer Gideon Sundback invented the “hookless fastener” during World War I. 

Improving upon previous designs, the inventor came up with a product very similar to the modern zipper. His hookless fasteners were soon put on money belts, which became an instant success among U.S. sailors, whose uniforms didn’t have pockets. Then, in 1918, the U.S. Navy ordered fasteners for 10,000 flying suits. The zippers caught on, quickly becoming a standard part of all kinds of bags and apparel. 

Kotex

In 1914, researchers at the consumer goods company Kimberly-Clark were touring pulp and paper plants in Europe when they came across a material that was five times more absorbent than cotton and cost half as much to produce. The company took the material back to the U.S. and trademarked it as cellucotton. 

When America entered World War I in 1917, Kimberly-Clark used the material to produce wadding for surgical dressing. Red Cross nurses soon discovered that the new material made an excellent sanitary pad — superior to the flannels and other products they were previously using. When the war ended and demand for surgical dressing dried up, Kimberly-Clark heard about the Red Cross nurses and repurposed its product for commercial use. In 1920, Kotex hit shelves, forever changing the market. 

Kleenex

Surgical dressing wasn’t the only use of cellucotton during World War I. By flattening out the material, Kimberly-Clark developed a thin, highly absorbent crepe paper used as a filter in gas masks — a vital piece of equipment in trench warfare. When the war ended, the company once again found itself looking to repurpose a product. It cleverly remarketed its cellucotton sheets as makeup and cold cream removers, and launched the sheets in 1924 with the name Kleenex. 

It wasn’t long before people began recommending the product as an ideal tissue for blowing noses during colds. So, in another astute marketing move, Kimberly-Clark started promoting Kleenex as “the handkerchiefs you can throw away” — creating the brand that’s now synonymous with disposable tissues. 

The Tide Turned With the Battle of Amiens

The Allied surge began with a surprise attack at Amiens on the morning of August 8, 1918. Following a barrage of gunfire at 4:20 a.m., the combined French, British, Canadian, and Australian forces overwhelmed the outnumbered German defenses along the river Somme. Upon losing some 26,000 of his troops on that day alone, Ludendorff referred to the disaster as "the black day of the German army."

When their advance slowed by the third day of fighting, the Allies continued hitting the Germans along various points of the front. As part of what is sometimes called the Second Battle of the Somme, the combined British and Australian forces drove the Germans out of Albert, France, on August 22, and a New Zealand corps helped wrest control of the town of Bapaume a week later.

Having only recently entered the war, the U.S. First Army was given the task of eliminating the St. Mihiel salient (a protuberance of German territory along the line) in mid-September. It was an easy victory for the newcomers, as by that point the Germans had largely retreated to the Hindenburg Line, a nearly 100-mile-long series of heavily defended trenches, tunnels, and fortifications across northeastern France.

The Allies Broke Through the Hindenburg Line 

In late September 1918, the Allies pressed their advantage with the launch of a four-pronged attack. On September 26, a combined American and French force invaded the Meuse Valley to commence the Battles of the Meuse-Argonne, also known as the Meuse-Argonne Offensive. On September 27, the Canadian Corps led the charge across the Canal du Nord in the Battle of Cambrai. The following day, a Belgian force joined the British in an attack on the battle-scarred terrain outside Ypres in Flanders.

The main target of this offensive was the St. Quentin Canal, which formed part of the Hindenburg Line. Following a massive fusillade of shells from more than 1,600 guns, the Allies launched their ground assault on the morning of September 29. 

On one end, the American and Australian corps struggled to pass the German defenses at Bellicourt Tunnel. However, the British were well prepared to cross the canal to the south with their rafts and life preservers. Aided by the dense fog, they overtook enemy positions on the steep eastern bank and thwarted the detonation of the Riqueval Bridge. By the start of October, the St. Quentin Canal was effectively in Allied hands.

Germany Began Seeking Peace by October 1918

Even with the once-impenetrable Hindenburg Line breached, the Germans largely held their ground in the fighting that continued across the Western Front. Nevertheless, the string of Allied victories, combined with deteriorating conditions at home, prompted the German high command to reach out to U.S. President Woodrow Wilson for a peaceful resolution in early October. The following month, Germany agreed to the strict terms that enabled the armistice to take hold at 11 a.m. on November 11, 1918.

All told, the celebrated Hundred Days Offensive lasted about 95 days. Yet it’s no exaggeration to say that its successful strategy and execution were crucial in bringing the First World War to a long-awaited end.

Defense Against Rifle Fire and Machine Guns

Rifles were by far the most commonly used weapon of World War I. These were sophisticated weapons, with a firing rate much greater than that of their 19th-century predecessors. The standard British rifle, the Short Magazine Lee Enfield (SMLE) Rifle Mk III, had a maximum range of 2,493 yards (with an effective killing range of 600 yards), and a well-trained infantryman could fire 15 aimed rounds a minute. This alone made advancing across No Man's Land — the area between the two opposing front lines of trenches — incredibly perilous, and anyone sticking their head above a trench was an instant target. 

Then there were machine guns, which made traditional infantry attacks a near-impossible undertaking. The modern machine gun, invented in 1884 by Hiram Maxim, was used in battle in the late 19th century, in conflicts such as the Boer War and the Spanish American War. The weapon revolutionized battlefield dynamics, as a single machine gun could fire hundreds of rounds per minute, effectively defending against hundreds of attacking troops. Trenches provided essential cover from both rifle fire and the sustained attacks of machine guns, allowing soldiers to move and fight while staying below the enemy’s line of sight. 

A Deep Defensive Strategy

As World War I progressed, trenches became far more than just ditches for duck-and-cover protection. They quickly formed part of a sophisticated defensive strategy (much like the layered battlements of a large medieval castle). On the Western Front, the line of trenches stretched from the North Sea all the way down to Switzerland — a distance of about 475 miles. 

The classic British trench was about 6 feet deep and 3.5 feet wide, although deeper and more elaborate trenches were built. They were typically constructed in a zigzagging pattern, so that any enemies who managed to infiltrate the trench could not fire along its entire length, and blasts from exploding grenades and artillery shells couldn’t travel far along a single trench. 

Behind the front line there could be three or four more lines of trenches, all connected by a system of communications trenches. If attackers captured the front line, they were then faced with additional entrenched positions that could be quickly reinforced. Support trenches housed reserves, supplies, and command posts, creating a defensive depth that meant any major enemy offensive required massive resources, and usually resulted in heavy casualties for minimal gains. These support trenches also allowed soldiers to be rotated in and out of the front line. A soldier might spend four to six days in the frontline trench before being sent to the support or reserve trenches further back for some much-needed rest and recuperation. 

The End of Trench Warfare

The trench systems of World War I represented both the pinnacle and the end of static defensive warfare. While trenches were used in later conflicts, they never again dominated warfare as they did from 1914 to 1918. 

The stalemate of trench warfare came to an end with the Battle of Amiens and the beginning of what came to be known as the Hundred Days Offensive, a string of Allied offensive successes on the Western Front that led to the collapse of the German army and the end of the war. At Amiens, the Allied forces launched the largest combined arms offensive of the entire war, with thousands of heavy and super-heavy field guns, more than 600 tanks, and 2,000 aircraft. They advanced some 8 miles in three days, along a 15-mile-wide front, a massive achievement in a war characterized by minute gains. The deadlock was broken, and the German trenches were ultimately overrun. In time the trenches dug during the war were reclaimed by nature, or filled in and returned to agricultural land, though unexploded ordnance remained a problem for many years. Others were preserved or turned into monuments, such as the trenches at Vimy near the Vimy Ridge Memorial in France, and Sanctuary Wood in Ypres, Belgium.

The expanded, torpedo-equipped U-boat fleet wreaked havoc. Between March and December 1917, 925 British ships were sunk by U-boats — a rate of approximately 23 per week. England needed countermeasures, but anti-submarine weapons were limited at the time. Depth charges (underwater bombs) were in use by 1916, but they were primitive; their effectiveness was also limited by the inability to accurately locate a submerged U-boat. The hydrophone could detect the presence of a submarine in the water, but it couldn’t indicate distance — sonar was still years away. England needed a way to protect its ships.

The U-boats’ targeting strategy was to locate ships by the smoke emitted from their smokestacks against the horizon. The submarine would then close in to a distance of approximately 1,000 to 2,000 feet from the target, in order to be in torpedo range. Achieving a hit with the torpedo depended on accurately determining the speed and heading of the target; at the distance the submarines kept, even a slight miscalculation would result in a miss. It was Royal Navy lieutenant and painter-designer Norman Wilkinson who realized that the narrow margin between torpedo success and failure provided a defense opportunity. 

U-boats viewed their targets through a periscope for only a very short time, so as to avoid the periscope being spotted and giving away the location of the submarine. “I suddenly got the idea,” Wilkinson later recalled, “that since it was impossible to paint a ship so that she could not be seen by a submarine, the extreme opposite was the answer — in other words, to paint her, not for low visibility, but in such a way as to break up her form and thus confuse a submarine officer as to the course on which she was heading.” The idea was to disorient and dazzle during the short amount of time a U-boat commander had to view the ship.

After the strategy was successfully pitched to the British Admiralty, 50 ships were ordered to be dazzle painted, and Wilkinson was tapped to lead a Dazzle Section to prepare the paint schemes, which Wilkinson described as being designed for “maximum distortion” — in other words, to create a distorted view of the ship when viewed through a submarine periscope. 

No two ships had the same design, and each ship was painted differently on its port and starboard sides. When the Royal Navy asked observers for their impressions on whether or not the dazzle camouflage was effective, they made comments such as, “[It was] almost impossible to say how she was steering,” and “[It] sometimes appears to be going in the opposite direction.” Satisfied by that result, the Admiralty ordered all merchant ships to be painted in dazzle camouflage in October 1917. By June 1918, more than 2,300 ships were dazzle painted.

The concept made its way to the United States as well. When U.S. Navy Admiral William S. Sims visited England, he was so impressed with dazzle painting that he convinced the U.S. government to request that Wilkinson be brought to the United States in order to help establish a dazzle painting operation stateside. Wilkinson traveled to Washington, D.C., in March 1918 and met with Franklin D. Roosevelt (who was then the assistant secretary of the Navy). FDR expressed his enthusiasm for dazzle painting, while also noting, “We have no department of camouflage here.”

Wilkinson spent the next month establishing the American Camouflage Section, which consisted of two subdivisions: a research division at Eastman Kodak, composed of scientists, and a design division in Washington, D.C., composed of artists.

In both the U.K. and U.S., the dazzle designs were strikingly angular and futuristic. A 1918 issue of Popular Science suggested that the “crazy splashes of paint and freakish stripes” might be seen as “the whimsical color schemes of half-demented cubists and futurists.” Other critics called the camouflaged ships “a futurist’s bad dream,” a “flock of sea-going Easter Eggs,” and “a cross between a boiler explosion and a railroad accident.”

But was the dazzle painting effective? A definitive answer is elusive — additional defensive measures such as convoy escorts were put into practice around the same time, making it impossible to isolate the impact of dazzle painting. But the reduction in ships sunk by U-boats by the summer of 1918 does correlate with the widespread introduction of dazzle camouflage. And Wilkinson pointed out in a March 1920 issue of Journal of the Royal Society of Arts that the German navy also adopted dazzle camouflage, suggesting the enemy found value in the tactic. What’s more, according to a 1918 issue of Popular Science, the United States War Risk Insurance Board ordered that any ship that was not dazzle painted would be subject to higher premiums for maritime insurance — in a world where money talks, that may be the most telling of all.