World War I was shaped by the new vehicles developed during the four years of conflict. A century after the start of the war, we’re looking back at the most remarkable vehicles—the planes, cars, tanks, ships, and zeppelins—it helped bring about.

Aviation and the automobile were in their infancy when World War I started in 1914, but naval warfare had thousands of years of history behind it. It was, however, in a period of dramatic change, and the ships Britain poured its resources into building helped the country win the war—and eventually lose its empire.

At the time, the backbone of the British Royal Navy's Grand Fleet consisted of dozens of dreadnought battleships. The HMS Dreadnought, commissioned in 1906, was the latest in a line of warships that had carried the name since the 1500s. The name referred to a heavy overcoat worn in stormy weather, but the HMS Dreadnought was so revolutionary its name came to describe an entire class of battleships.

Though still a matter of some dispute amongst military historians, World War I largely ushered in the end of British dominance of the high seas and the beginning of the end of the British Empire. The Grand Fleet's enormous number of first-class battleships—some 35 ships, including a half-dozen from the US—played a key role in the war effort. They forced Germany to pour huge sums into its own navy, making it difficult to effectively finance its war effort. However, the massive cost of the ships, at a time when the British Empire was in severe financial distress, was ruinous in the long term. By the end of the war, the nation had nearly bankrupted itself building close to 30 dreadnoughts that faced significant threats from torpedo ships operated by even small navies.

"The lure of a convenient enemy, intent on fighting a battle that the Royal Navy relished, was too much," says Angus Ross, a professor at the US Naval War College in Rhode Island who has written about the topic. "So, Britain went into Dreadnoughts. In so doing, she bankrupted the Empire and lost her position as the world's premier navy forever."

Two of the HMS Dreadnought's 12-inch guns. Wikimedia

The Dreadnoughts were developed to do more with less while simultaneously addressing issues with previous battleships. For one thing, battleships of the era found it difficult to hit their targets. All ship guns were unguided, with gunners using splashes in the water to judge missed shots and adjust their aim. However, because both the target and the gun were constantly moving, by the time the gun was reloaded and ready to fire, any information gleaned about range and direction was nearly useless.

Pre-dreadnought ships included a variety of gun sizes, as smaller guns were quicker to reload and fire but did limited damage to capital ships at range. They were used to target and range the enemy, with larger guns used to do actual damage. The problem was that having guns of multiple sizes dramatically increased cost of ships and the cost of training crews, and complicated ammunition storage.

By the time the dreadnoughts began to appear, a decade before World War I began, a 12-inch gun with a faster rate of fire had been developed. It allowed gunners to zero in on enemy ships using the larger caliber gun. But the guidance and targeting problems hadn't disappeared, significantly limiting the practicality and usefulness of dreadnoughts. The development of the torpedo, which could severely damage even a huge battleship, made things worse. Navies were reluctant to put their ships within range of the underwater missiles, even though that was the only distance from which its own guns were at all effective. "The real limitation, which no navy was about to admit," says Ross, "was that these ships were designed to perpetuate a naval strategy that was already obsolete."

Dreadnoughts and hydroplane, British Grand Fleet, North Sea, 1914. Print Collector/Getty

With the development of underwater mines and torpedoes, defeating a battleship no longer required another battleship. That meant smaller, cheaper navies were suddenly much more dangerous. "This was something new and it completely altered the naval calculus," says Ross. So the huge battleships were generally held in reserve and used more as a psychological threat than a practical one. No dreadnoughts were lost to enemy guns during the war, though the HMS Audacious was sunk by a mine off the coast of Scotland, and the HMS Vanguard was destroyed by a magazine explosion.

Dreadnoughts "were good at inculcating fear and uncertainty in opponents," says Ross, "in the same way that a ballistic missile submarine does today." They're not often used, but enemies can't dismiss them either. In some ways, naval warfare in World War I was like a giant chess game: lots of skirmishes, but because the big pieces were too valuable to risk losing, they stayed behind in relative safety.

A few of the leftover dreadnoughts played a role in later conflicts, after being converted into early aircraft carriers. The USS Lexington and USS Saratoga eventually helped prove the concept of a floating airbase, leading to the Essex-class of carriers in World War II and eventually to the Nimitz- and Gerald R. Ford-class super-carriers of today.