The two wing turrets were both moved to the centerline, one superfiring over the forward-most turret, and the other amidships between the funnels. The armor layout was also revised slightly to improve protection of the bow and stern. To offset the weight increase of these changes, a pair of secondary guns and the stern torpedo tube were to be removed. "K" considered the adoption of anti-roll tanks to help stabilize the ships, as the recently completed Nassau-class battleships initially suffered from severe rolling, though Tirpitz eventually decided against them. By December 1910, the decision was made to retain all fourteen of the 15 cm guns and instead remove two of the guns. Although initially intended to use diesel engines on their center shafts, delays in the completion of the prototype for Prinzregent Luitpold forced the Navy to return to the traditional all-turbine arrangement for the first member of the class. Partial oil-firing was introduced, which provided greater power for the turbines. The first three ships—, , and —were ordered for the 1911 program. Several shipyards, including AG Vulcan, AG Weser, and Schichau-Werke, submitted tenders to the (Imperial Naval Office) to build the vessels by 19 July 1911. Vulcan and Weser received contracts on 11 August, though the finalized orders were not issued until 12 October; final tinkering with the design continued, however, and Tirpitz's decision to abandon the anti-roll tanks came as late as 22 January 1912. The contract for the third ship—actually the first member of the class, König—went to the (Imperial Shipyard), while Schichau received the contract for the battlecruiser as compensation. It was still hoped that the diesels could still be installed aboard Grosser Kurfürst and Markgraf, but it was still not ready by the time work began on the vessels. A fourth ship was authorized under the 1912 program, and the naval command again considered increasing the caliber, this time to . The increase in weight from the larger guns would be offset by reducing the secondary battery from 15 cm to guns. The proposal was ultimately rejected in favor of building another vessel identical to the 1911 ships to create a homogeneous four-ship division to simplify tactical command. The naval command again hoped that the diesel engine would be ready in time for this vessel, so her propulsion system was redesigned with larger, more powerful turbines than her sisters received. But before work began, it