Section 5 in The Merchant Shipping (Tonnage Measurement Of Ships) Rules, 1960
5. Propelling Power Allowance.
(1)The allowance for engine-room space in ships propelled by steam or other power requiring engine-room shall be ascertained in accordance with method IV specified in Schedule 1. The deductions on account of propelling power machinery shall be regulated as follows, namely :--(a)where the tonnage of the space occupied by and necessary for the proper working of the boilers and machinery is 13 per cent or above and under 20 percent of the gross tonnage, the deduction shall be 32 per cent of the gross tonnage;(b)where such space is below 13 per cent of the gross tonnage, the deduction shall be 32 per cent of the gross tonnage reduced proportionately;(c)where such space is 20 per cent and above of the gross tonnage, the deduction shall consist of the tonnage of the space occupied by or required to be enclosed for the proper working of the boilers and machinery with the addition of three-fourth of the tonnage of that space;(d)in cases falling under clauses (b) and (c), the space occupied by the shaft tunnel shall also be added to the engine-room space.(2)Such portion of the space above the crown of the engine-room and above the upper deck as is framed in for the machinery or for the admission of light and air shall not be included in the measurement of the spaces occupied by the propelling power machinery, unless the owner of the ship has applied in writing to the Central Government in that behalf:Provided that-------(a)the portion is first included in the measurement of the gross tonnage;(b)a surveyor certifies that the portion so framed in is reasonable in extent and is so constructed as to be safe and seaworthy, and that it cannot be used for any purpose other than the machinery or for the admission of light and air to the machinery or boilers of the ship.(3)The allowance made under this head shall not in any case exceed fifty-five per cent of that portion of the tonnage of the ship which remains after deducting from the gross tonnage the allowance on account of the space used for the accommodation of the master and the crew provided that this shall not apply to ships constructed for the purpose of towing vessels so long as they are employed as tugs but not employed for the carriage of passengers, cargo or stores or when using dry docks, floating docks or places provided for repairing of vessels.
