Iron armour over a wooden frame suggested a compromise in the matter of construction with which the Admiralty did not at all agree. It, therefore, decided on building an iron ship in reply to the _Gloire_, and the _Warrior_ was the first seagoing ironclad. In her external appearance there was nothing to distinguish her from the average wooden steam frigate of the time, except her extraordinary length. She was a three-masted square-rigged ship, with a graceful overhanging cutwater, her dimensions being as follows: length, 380 feet, and 420 feet over all; draught, 25½ feet; depth from spar deck to keel, 41 feet 6 inches. Her engines of 1,250 h.p. nominal gave her a speed of nearly 14½ knots. She carried twenty-eight 7-inch muzzle-loading rifle guns, two other rifle guns, and two 20-pounder breech-loading rifle guns. She was built at what is now the Thames Ironworks, then the no less celebrated yard of Messrs. Ditchburn and Mare. In describing the vessel, the builders say: “It may be of interest to note here that the _Warrior’s_ armour plates were all fitted at edges and butts with tongues and grooves, the tongues being formed solid out of the plate 1¼ inch wide and ½ inch deep, the grooves being formed slightly larger to facilitate entering. This plan, which was very costly, and was suggested by the curving out of the plates tested at Shoeburyness after being struck by the shot, was not repeated in later vessels, in view of the great difficulty in replacing damaged plates. It is not generally known that the _Warrior_, though a sea-going warship, had a ram bow, the greatest projection being at about the water-line, the head knee or cutwater being brought on independently after the ram was completed, to maintain the then usual appearance of the frigates of the English navy.”[36] Besides the side armour, the fore and after ends of the main deck carrying the battery were protected by armoured bulkheads. The great length of the vessel rendered it impossible to armour her entirely, as had she been armoured from end to end the protection afforded to the vital parts of the ship would have been insufficient to withstand the heaviest artillery of the time. Therefore, some 85 feet at either end were left unprotected, and the weight of armour thus saved was added to that covering the central portions of the ship, so that she would be enabled to withstand the worst fire an enemy could bring to bear upon her. It was contended that were her unarmoured ends to be shot away or riddled and rendered useless, her armoured portion would remain afloat, an invulnerable citadel. The belt of armour on the broadside was 22 feet deep, and was backed by 18 inches of teak.