When the user of a vessel intends to use her for a special service in a way in which she is not properly operated in relation to her licensed sailing area, the user of the ship should follow safety measures corresponding to such special service. The "Toya Maru" in question was not provided with a facility to prevent the entry of waves through the large opening on her stern and the closing devices of various openings on the train deck adjoining the large opening were not only large in number but also had low coamings, they weve not weathertight, and they were susceptible to damage from the circumstances of her operation, making it difficult to maintain themin good condition. In addition, they were extremely difficult to close in rough weather when the vessel was loaded with trains, and even if they had been closed as a preparatory measure against heavy weather, they were so structured that it was impossible to prevent the ingress of seawater. Even so, this service route is an important one connecting Hokkaido and Honshu and, because of strong demand for transportation using this route, the service was performed according to a certain schedule and, as a result, even in heavy weather which threatens the voyage, train ferries have been forced to continue their service as long as the voyage is possible, without the option of taking refuge early like other general vessels. Since, in the past, train ferries on this trade route had experienced encounters with weather and sea conditions under which sea waves had rushed into a train deck similar in structure to that of the vessel in question, there is no denying that her structure was not suitable for this service route. For this reason, the inability to prevent the ingress of water through various openings in the train deck constituted part of the factors leading to the vessel's capsizing and foundering and, hence, her improper hull structure is considered to have partly contributed to the occurrence of this casualty.
Furthermore, since the operation management section in charge of the ferries was aware of the fact that the service route was under a special arrangement of transport, employing vessels with a special structure, crewed under a unique shift system, they should have grasped an accurate picture of their operation and taken measures necessary for their safe operation to accommodate the special circumstances. However,because of the view that the management section, thinking that the safe operation of ferries would be achieved only by entrusting the matter to masters, should not intervene in this matter, they were not able to recognize that the vessel structure as it was, incapable of preventing the ingress of water to the train deck, was not suitable for operation on this service route. As a result, they were unable to appreciate the necessity for measures to achieve safe operation in abnormal situations where the occurrence of an accident was anticipated. The Company, therefore, did not have in the organization any arrangementof staff and authority to give due consideration and take necessary measures in respect to safe operation, nor install any specific provisions for work arrangements or for job authority in abnormal situations. Although such management system and policy for the rail ferries had continued over such a long time span, ever since the state took charge of the management of this ferry service route until the occurrence of this accident, it must be said that the operation management of the ferries had been improper in view of the actual circumstances of the operation of this route. When this case emerged, the persons in vital posts for the operation management of the rail ferries, including the Chief of the Seikan Railways Distruct Control Bureau, a designated person in the marine accident, the General Manager of the Marine Department of the Bureau and the Manager of the Marine Section of the Department did not mobilize their subordinates for emergency work nor go to their work place to take command themselves although they were aware of the situation in which all of the rail ferries had cancelled their departures on the schedule in Aomori and Hakodate since a warning of the onset of Typhoon No. 15 had been issued, threatening the safety of the ferry operation.
