Tonnage and poundage to be one of the complaints of his Long Parliament. The refusal of and subsequent disputes about tonnage and poundage rights is seen as one of the many events bearing responsibility for the English Civil War. 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
Gross tonnage is constrained to be no less than 30% of her gross tonnage. The gross tonnage calculation is defined in Regulation 3 of Annex 1 of "The International Convention on Tonnage Measurement of Ships, 1969". It is based on two variables, and is ultimately an increasing one-to-one function of ship volume: The value of the multiplier "K" varies in accordance with a ship's total volume (in cubic metres) and is applied as an amplification factor in determining the gross tonnage value. For smaller ships, "K" is smaller, for larger ships, "K" is larger. "K" is calculated with a formula which uses