the salvage operation is carried out as a duty to normally perform a towage contract or other service contract with the exception however of providing special services beyond the performance of the above said duty
救助作业是作为正常履行拖航合同或者其他服务合同的义务进行的，但提供超出履行上述义务的特殊服务除外
以上为机器翻译结果，长、整句建议使用 人工翻译 。