RN:
Formidable-class pre-dreadnought battleship HMS Irresistible listing and sinking in the Dardanelles, 18 March 1915. Photograph taken from the battleship HMS Lord Nelson
The attack was launched on 18 March, and
Irresistible was again part of 2nd Division, which formed the second wave of the attack.
Irresistible joined the fray at 14:39, shortly after the French battleship
Bouvet was mined and sunk in the straits; she and several other battleships attempted to suppress Ottoman guns that were firing on boats that were picking up survivors from
Bouvet.
Irresistible engaged the "Namazieh" Battery, which at that time was not actively firing. She quickly came under heavy fire from the "Hamidieh I" battery, which targeted the ship with four-shell salvos
At 15:14,
Irresistible was rocked by an explosion, and by 15:32, had begun to take on a
list, prompting de Robeck to order her to withdraw to avoid further damage. At 16:15,
Irresistible, having idled her engines, struck a mine that caused extensive damage to the ship. The mine detonated under her starboard engine room, flooding it and killing all but three of the men on duty there. The bulkhead that divided the starboard from the port engine room collapsed under the sudden weight of water, disabling that engine as well. Unable to maneuver, with a list of 7 degrees to starboard, and down by the stern,
Irresistible became an attractive target for the Ottoman gunners. She drifted helplessly into range of Turkish guns, which laid down a heavy fire on her. Her main gun turrets began to malfunction, and she was obscured by smoke and spray. De Robeck ordered the battleship
Ocean to take her under tow and pull her out of range of the Ottoman guns, and the
destroyer Wear came alongside and rescued most of the crew—28 officers and 582 men—despite the punishing Ottoman shelling. A group of ten men remained aboard to try to secure a line from
Ocean. By the time
Ocean had arrived it had become clear that
Irresistible could not be saved. Her list had increased and the fire from the Ottoman guns had become very heavy, so the remaining men were evacuated and
Ocean began to withdraw.
With the heavy losses that day—
Bouvet,
Irresistible, and
Ocean, which had been mined and disabled after withdrawing from her attempt to rescue
Irresistible—de Robeck issued the order to break off the attack. That evening, the destroyer
Jed entered the Dardanelles to torpedo and sink the two abandoned battleships to prevent their capture in case they had remained afloat, but could find no sign of them. The Ottomans later reported that the derelict
Irresistible had drifted closer to shore and suffered further severe damage from their shore batteries before sinking at about 19:30.
Irresistible's crew suffered about 150 casualties during her sinking
