RN:
Battlecruiser HMS Queen Mary leaving the River Tyne on sea trials, 1913
On 31 May 1916, Queen Mary put to sea with the rest of the Battlecruiser Fleet to intercept a sortie by the High Seas Fleet into the North Sea. The British were able to decode the German radio messages and left their bases before the Germans put to sea.
Queen Mary opened fire about 15:50 on SMS Seydlitz, using only her forward turrets. By 15:54, the range was down to 12,900 yards (11,800 m), and Beatty ordered a course change two points to starboard to open up the range at 15:57. During this period, Queen Mary made two hits on Seydlitz, at 15:55 and 15:57, one of which caused a propellant fire that burnt out her aft superfiring turret.
The range had grown too far for accurate shooting, so Beatty altered course four points to port to close the range again between 16:12 and 16:15. This manoeuvre exposed Lion to the fire of the German battlecruisers, and she was hit several times. The smoke and fumes from these hits caused SMS Derfflinger to lose sight of Lion – which had sheered out of line to starboard – and to switch her fire to Queen Mary, now visible to Derfflinger's gunnery officer as the second ship in the British line and therefore assumed to be Princess Royal, at 16:16. Queen Mary hit Seydlitz again at 16:17 and knocked out one gun of her secondary armament. In return, Queen Mary had been hit twice by Seydlitz before 16:21 with unknown effects, but the German battlecruiser hit the turret face of 'Q' turret at that time and knocked out the right-hand gun in the turret. By 16:25, the range was down to 14,400 yards (13,200 m), and Beatty turned two points to starboard to open the range again. This move came too late for Queen Mary, however, as Derfflinger's fire began to take effect, hitting her twice before 16:26. One shell hit forward and detonated one or both of the forward magazines, which broke the ship in two near the foremast. Stationed inside 'Q' turret, Midshipman Jocelyn Storey survived and reported that there had been a large explosion forward which rocked the turret, breaking the left gun in half, the gun breech falling into the working chamber and the right gun coming off its trunnions. Cordite in the working chamber caught fire and produced poisonous fumes that asphyxiated some of the turret's crew. It is doubtful that an explosion forward could have done this, so 'Q' turret may have been struck by the second shell. A further explosion, possibly from shells breaking loose, shook the aft end of the ship as it began to roll over and sink. Tiger, the battlecruiser behind her, was showered with debris from the explosion and forced to steer to port to avoid her remains.
1,266 crewmen were lost; just eighteen survivors were picked up by the destroyers Laurel, Petard, and Tipperary, and two by the Germans.
Surveys of this site conducted by nautical archaeologist
Innes McCartney in 2001–03 have shown the wreck is in three sections, with the two forward sections being heavily damaged and in pieces. Her aft end is upside down and relatively complete except for her propellers, which have been salvaged. Examination of the damage to the ship has suggested that the initial explosion was not in the magazine of 'A' or 'B' forward main turrets, but instead in the magazine of the forward 4-inch battery. An explosion of the quantity of cordite in the main magazine would have been sufficient to also ignite 'Q' magazine, destroying much more of the ship. The explosion in the smaller magazine would have been sufficient to break the ship in two, the blast then spreading to the forward magazine and ripping apart the forward section