Section 5(1) in The Merchant Shipping (Tonnage Measurement Of Ships) Rules, 1960
(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.
