Tonnage and poundage Tonnage and poundage Tonnage and Poundage were certain duties and taxes first levied in Edward II's reign on every tun (cask) of imported wine, which came mostly from Spain and Portugal, and on every pound weight of merchandise exported or imported. Traditionally tonnage and poundage was granted by Parliament to the king for life until the reign of Charles I. Tonnage and poundage were swept away by the Customs Consolidation Act of 1787. Charles I's first Parliament, known as the Useless Parliament, broke with tradition and granted the king tonnage and poundage for a year rather than life out of
Net tonnage ship's net tonnage is constrained to be no less than 30% of her gross tonnage. The net tonnage calculation is based on a number of factors, one of which is the moulded draft "d". The choice of the value to use for "d" can be complicated. For ships subject to the International Convention on Load Lines, the Summer Load Line draft is used, with the exception of cases where that is a timber load line. For passenger ships, the draft used is the deepest subdivision load line assigned in accordance with the International Convention for the Safety of Life at