Customs duty split for ships-for-breaking triggers excise levy on ship-breaking scrap unless prior higher duty was paid. Customs duty on ships-for-breaking is divided into a basic customs duty per Light Displacement Tonnage and a separate additional duty, with auxiliary duty nil. Excise duty is imposed on ship-breaking scrap derived from ships that have paid the restructured customs duties, while scrap made from ships that paid the earlier higher basic duty is exempted to prevent double taxation; such scrap is also specified as an input qualifying downstream products for excise exemption.