These guns were too small to be useful against the torpedo boats before they got within torpedo range. They fired a shell that weighed and was fired at a maximum muzzle velocity of . This gave it a range of at an elevation of +20°. 250 rounds were carried for each gun. The ships also mounted three submerged 18-inch torpedo tubes. They carried a total of eighteen torpedoes in addition to the six torpedoes that could be used by the two steam pinnaces. Armour The Duke of Edinburgh-class ships had a waterline armour belt of Krupp cemented armour that covered of the hull amidships. It covered the side of the ship up to the upper deck, a height of above the waterline and reached below it. Between the central citadel and the bow, the belt armour was thick and it extended to the stern with a thickness of . Transverse bulkheads six inches thick protected the citadel from raking fire. The faces of the gun turrets were 7.5 inches thick with sides and a roof. The barbettes were protected by six inches of armour as were the ammunition hoists, although the armour for those thinned to three inches between the armour belt. Two-inch armour screens separated each of the six-inch guns. The thickness of the lower deck was only except for a patch of armour over the steering gear and another thick over the engine cylinders. The sides of the conning tower were thick. Modifications The funnels proved to be too short in service and they were raised about four years after completion to keep the superstructure free of smoke in a following wind. In March 1916, both ships had all their six-inch guns removed, the embrasures plated over, and six of the guns were remounted on the upper deck. In May 1917, two more were added to Duke of Edinburgh on the forecastle. The ship's foremast was converted to a tripod mast to support the weight of the fire-control director probably added in 1917. Ships Service history Duke of Edinburgh and Black Prince served in the Channel, Atlantic and Home Fleets before World War I. They were stationed in the Mediterranean when World War I began and participated in the pursuit of the Goeben and Breslau as part of the 1st Cruiser Squadron, but was ordered not to engage. After the German ships reached Ottoman waters, the ships were