was located between the midpoints of the fore and aft barbettes, and thinned to further towards the bow and stern, but did not reach either. It was continued to the bow by a small patch of armor. The upper armor belt had a maximum thickness of , but it thinned to from the forward barbette all the way to the bow. The casemate armor was also thick. The sides of the main gun turrets, barbettes, and main conning tower were protected by of armor, except for the turret and conning tower roofs which were thick. The thickness of the decks ranged from in two layers. The underwater protection system consisted of the extension of the double-bottom upwards to the lower edge of the waterline armor belt, with a thin plate acting as the outermost bulkhead. It was backed by a torpedo bulkhead that consisted of two plates. The total thickness of this system was only , which made it incapable of containing a torpedo warhead detonation or mine explosion without rupturing. In the spring of 1909, Montecuccoli sent an officer from the Naval Section of the War Ministry to Berlin in order to obtain input from Alfred von Tirpitz on the design of the Tegetthoff class. The Imperial German Navy had conducted gunnery and torpedo tests and concluded that, "The angle between [the] armored deck and belt armor should be as flat as possible", and that "The armored torpedo bulkhead should be angled inwards, the second longitudinal bulkhead outwards. The distance of the torpedo bulkhead from the outer plating should be raised from 2.5 to 4 meters." While Popper adopted several of Tirpitz's suggestions regarding the external layout of the belt armor for the Tegetthoff class, the internal modifications put forward by the Imperial German Navy were not implemented. Assessment Although smaller than the contemporary dreadnought and super-dreadnought battleships of the German Kaiserliche Marine and the British Royal Navy, the Tegetthoff class was the first of its type in the Mediterranean and Adriatic Seas. The Tegetthoffs were described by former Austro-Hungarian naval officer Anthony Sokol in his book The Imperial and Royal Austro-Hungarian Navy as "excellent ships", and were acknowledged as some of the most powerful of their type in the region. Their design signaled a change in Austro-Hungarian naval policy, as the ships were capable of far more than coastal defense or patrolling the Adriatic Sea. The Tegetthoffs were