in the event of accident, danger, damage or disaster before or after the commencement of the voyage resulting from any cause whatsoever due to negligence or not, for which, or for the consequences of which, the carrier is not responsibie by statute, contract or otherwise, the goods and the merchant jointly and severally shall contribute with the carrier in general average to the payment of any sacrifices, losses or expenses of a general average nature that may be made or incurred end shall pay salvage and special charges incurred in respect of the goods. if a salving ship is owned or operated by the carrier. salvage shall be paid for as fully as if the salving ship belonged to strangers.