Allowance for propelling machinery space. In the middle of the 19th century steam engines were replacing sails as the main means of propulsion.
AH range. A range of ports between Antwerp and Hamburg in Europe. If the owner agrees with this range of ports he accepts that Antwerp and Hamburg are warranted by the Charterer as being "safe" but he may have to dispute the "safety" of any other port nominated within the range. This description of a range of ports is sometimes abbreviated to "AH.R".
AA AA. Always afloat, always accessible.
Always afloat. In order to prevent a vessel from being ordered to proceed to a berth where she cannot load or discharge without touching the ground or which can only be reached safely after discharging part of the cargo into lighters or which can only be reached with spring tide, the so-called "always safely afloat clause" is inserted in the charterparty.
Block coefficient. The block coefficient of a vessel is obtained by dividing the underwater volume of displacement of a ship by the volume of a block of the same length and breadth, and of height equal to the draught of the ship. The block coefficient depends upon the “lines” of the ship. Passenger vessels with fine lines have a lower block coefficient than cargo ships with full lines. The abbreviation for Block Coefficient is generally given as Cb.
AWRI Additional War Risk Insurance. This is an extra amount paid to the owner of a time-chartered vessel if the ship is ordered to a port or an area in which war or hostilities are taking place and the shipowner's insurers require an additional insurance premium for the vessel to be considered to be covered against risks in that place.
Ballast bonus (BB). It may occur that charterers, in order to attract tonnage agree to pay a certain ballast bonus. The ballast bonus serves as a compensation and incentive for the ballast (empty) trip from the ship's last port of discharge to the port where the charter will commence, for example, the first place of loading under a voyage charter or the point of delivery under a time charter. It is more common under time charters, especially in a good market when charterers are unable to obtain ships easily or at a low rate of hire.
Additional premium.This may be payable by charterers or shippers to the cargo insurers because of the ship's age, class or flag. The charterparty can provide that this extra premium is deductible from freight or from hire. The owner should attempt to qualify a clause with such a provision by limiting the amount of deduction and also by requiring the charterer to provide proper documentation as proof of the extra insurance before the deduction.