de Indias, the nave was destined to the south as the headquarters of the Casa. However, on June 5, the headquarters of the Casa to the Alcázar would be moved. In 1587 the customs of the city was located on naves 13, 14 and 15, south of the building. Throughout the 16th century one nave was rented as an oil warehouse and another as a wool warehouse. The warden would be in charge of the surveillance of the site and the collection of all rentals . Another nave was destined for a mercury store, which was brought in bags of lamb skins from Almadén mines and then used to help extract silver in the American mines. In addition to the need for warehouses, there were other reasons for the cessation of its use as shipyards. In the first place, after the end of the wars with England and the battles for the Strait of Gibraltar, the kingdom of Castile stopped needing fleets of war so frequently. Second, the architectural design of the Shipyards made them capable of building only galleys, and this type of vessel was losing combat capacity against novel designs of sailing ships such as the carrack and the nao, which were faster and stronger and had much greater range thanks to its less numerous crews. For the Crown it was also more economically advantageous to rent private sailships to its owners than to build and maintain permanent fleets of galleys. Finally, the ascent to the throne in 1475 of Isabella I and her husband Ferdinand II of Aragon (called the Catholic Monarchs years later) supposed that the sovereigns of Castile became available to the shipyards of galleys of the Crown of Aragon, which possibly were cheaper than the one in Seville. Although the workload of the Shipyards was decreasing, the number of artisans officially linked to them was scarcely reduced. This provoked frequent protests by the Council of Seville about the injustice represented by the tax exemptions of these "francs" as well as other protected occupations. Among other tasks, until 1549 the fourth nave of the Shipyards was destined to the manufacture of pumps to reduce water in the boats, for what was known as "the fireman's nave". In 1570 a large galley would be built in Barcelona that would be taken to Seville to be decorated with Renaissance allegorical motifs. This was the Capitana galley that