for a towing attempt, a wire rope is used as the towline, sometimes in conjunction with a nylon spring and/or a chafing chain. Modern salvage tugs are equipped with powerful towing winches and may carry tow wires of up to 2000 m in length and 76 mm in diameter. The salvage vessel builds up power thrust slowly, and at the same time must monitor towline tension carefully.
Regulation v/15-1 of international convention for the safety of life at sea, 1974, as amended sets forth requirements for towing arrangements on tankers, It states that all tankers of not less than 20000 tonnes deadweight shall be fitted with a towing arrangement at the first scheduled dry-docking but not later than 1 January 1999.