as they were intended to be the most powerful ships on station in the area. The cruisers measured long overall and at the waterline with a beam of and a mean draught of . The cruisers had a standard displacement of and were at full load. As designed, the cruisers were to have machinery consisting of a three-shaft system of Germania geared turbines powered by steam created from eight oil-fired Schulz-Thornycroft boilers. This would give the vessels the designed power of allowing them to reach their design speed of . However, during construction a fire destroyed the machinery of Sumatra and the Germania turbines were replaced by Zoelly-pattern turbines which later proved troublesome. The vessels carried of oil giving the Java class a range of at . The Java class had a main armament of ten Bofors Mk 6 /50 calibre guns placed in single mounts, each with a forward facing gun shield. Two mounts were placed fore and aft along the centreline with guns "No.2" and "No.9" superfiring. The other six mounts were placed abeam, three to each side of the superstructure. A broadside from the cruisers would consist of seven guns. The 150 mm guns had a range of when firing at an angle of 29 degrees. For secondary armament, the cruisers mounted four /55 cal. (13-pounder) guns. As built, the cruisers had armour in a waterline belt that extended that covered the machinery and magazine spaces. This reduced to for aft to protect the steering gear. The vessels had deck armour that increased to 5 cm on the sloped sides where they meet the upper edge of the side belt. The funnel uptakes had 5 cm, the conning tower and the gun shields armour. Within the ship, the bulkheads had armour. Celebes, the third ship of the class, was to be constructed to a modified design. Displacing and a length overall of , the design was intended for the ship to act as the squadron's flagship and be able to accommodate a flag officer and their staff. Criticism of design Since the design was completed in 1916, the armament layout reflected the ideas of the time. The placement of the guns in single mounts was based on the ironclad-age belief that if a direct hit to a gun would only disable the one gun, instead of multiple if the guns were placed in turrets. Furthermore, the guns