an independent company. Furthermore, the Royal Netherlands Navy ordered an additional two Walrus-class submarines earlier than planned to assist RDM financially. However, at this time the Walrus-class submarines were facing many problems. New problems arose on 14 August 1986, when the command center of Walrus caught fire, while it was still on a scaffold in the shipyard. The fire lasted about five hours, and resulted in immense damage to the submarine; the command center was completely burned out. While some equipment could be rescued, most had to be replaced. This delayed the construction of the submarines once again. The costs of the resulting damage was 225 million guilders, which was fully covered by insurance. The exact location, origin and cause of the fire was never established. Presumably, the fire was caused in the vicinity of the corporals and men's washroom by a defect in the electrical work lighting. Repairs were reported as complete in 1987, but had so delayed construction of Walrus that the second submarine (with construction number 349) was put into service as the first of the class, with the name HNLMS Zeeleeuw (sea lion). HNLMS Walrus was put into service two years later. The two other boats were put into service as and (porpoise). The delays meant that , and of the Dolfijn-class had to remain in service longer than planned. All the problems, delays and rising costs were eventually dubbed by the Dutch national parliament as the "Walrus-affair". Nonetheless, at the time of their commissioning, the Walrus-class submarines were considered to be one of the most modern and advanced conventional submarines in operation. Design The Walrus-class submarines are unusual in that instead of a cross-shaped assembly of stern diving planes and rudders, they mount four combined rudders and diving planes in an "X" configuration. This tail configuration was first tested in 1960 on the United States Navy's , and has since been used by the Walrus class, all Swedish Navy submarines since the , the Royal Australian Navy's , the German Navy Type 212A and the Japan Maritime Self-Defense Force's . The X configuration is a complex system and therefore not implemented by many other navies around the world. The submarines of the Walrus-class, when submerged, are silent and therefore difficult to detect by ships, planes and other submarines once they go into hiding. This makes the boats very suitable for combating surface vessels and submarines,