No ship was larger when she was launched; since then only a handful have ever superseded her. She had the speed of a cruiser, and the armament and armour of a battleship. She was tougher than a battlecruiser, and she sank in her only engagement on the high seas. She was the HMS Hood, pride of the Royal Navy, who blew up and died battling the Bismarck in one of the last battleship vs. battleship battles ever fought.
Hood was the first of four planned Admiral-class battlecruisers commissioned by the Royal Navy during World War 1, designed to counter the Mackensen-class German battlecruisers being launched in Germany. However, only Hood was completed; the other ships of her class were broken up, as the Mackensen-class was never completed. Despite this, Hood quickly became the jewel of the Royal Navy.
Named for Admiral Samuel Hood, HMS Hood was the largest ship in the world when she was launched, and held that record until her future nemesis Bismarck was launched. She remains the longest ship to ever serve in the Royal Navy; her length and her low, sleek superstructure gave her a graceful, fast look. Her prime armament was eight 15" guns capable of a broadside weight of 15,360 lbs with a preferred armament of armour-piercing shells, and she had around four dozen supporting batteries in secondary, and tertiary mounts.
Hood had thick armour for a battlecruiser; many battlecruisers bore an armour belt of around 8" - proof against a cruiser's guns, but not a battleship's. However, Hood had 12" of protection in her prime belt, giving her additional resilience. The armour was one of the first arranged after the individual ship disasters that occurred at Jutland; the vertical and horizontal belts didn't necessarily work together and provide adequate protection from all angles, and future developments (additional torpedo rooms that were later removed, new magazines) weren't intended, but occurred. Eventually, this poorly-designed armour would lead to Hood's fate.
Despite her status as a battlecruiser, given her increased armament and her thicker armour, she was more of a fast battleship. Hood's engines were incredibly powerful, and she could develop 31 knots on two turbines totalling 113 megawatts of work (approximately three times the potential work of a Saturn V rocket's first stage). This speed, the heavy (for the time) armament, and the general beauty of the vessel led to her being known as the "pride of the Royal Navy".
In this role, Hood took on a greater job in the public relations department. She would visit various ports-of-call and host tours, or moor for festivals. Such a job kept her working almost constantly - in the end, she barely had time for refits, even in the leadup to World War II.
Hood was kept in service following the outbreak of hostilities in 1939. She saw her first action when attacking the French fleet at Oran, developing heavy fire against the French ships there, to deny them from falling into German hands. Italians ran a bombing mission against her, and she shot down one of their bombers. But overall, Hood had a quiet first two years of war. She returned to Scapa Flow and moored with the Prince of Wales as part of the Home Fleet.
When Bismarck and Prinz Eugen made their famous sorteé, Hood and Prince of Wales were immediately dispatched to intercept. Prince of Wales was the newest ship in the Royal Navy, and the Hood was generally considered the best ship. They intercepted the Bismarck on the 24th of May in the Denmark Strait.
The battle was quick and fierce. Hood engaged for eight minutes, but due to the way Hood and Prince of Wales approached, neither ship could bring all of their gun batteries to bear on the German ships, while both Prinz Eugen and Bismarck had free reign. In addition, the Hood (with her suspect armour) was in the van, and she became the natural target for both German vessels.
While attempting to turn to engage the Germans with all guns, Hood was straddled by a volley from Bismarck. There was a gout of flame and the Hood exploded, breaking in two. At the time, it was assumed the Germans snuck a shell into one of the stores of cordite, but later examination of the wreck suggests a 4-inch battery blew up, igniting the main fuel line that caused a fuel tank to blow. Regardless, the Hood sank in three minutes - with only three survivors.
It was a shocking blow to the Royal Navy, as one of her finest and most famous ships was suddenly, completely gone; Prince of Wales was badly damaged. The entire Royal Navy set off in pursuit of the Bismarck, and she was sank some days later. But the loss of the Hood left a stain on the Royal Navy's record that would not be expunged.