Artikel 74

In the case of any ship propelled by machinery for which space is required, an allowance shall be made for propelling-power in accordance with the provisions of Article 75, and the amount so allowed shall be deducted from the ship's gross tonnage.
The space occupied by and necessary for the proper working of the main propelling-machinery and the auxiliary machinery necessary for the proper working of the main machinery, as specified in Articles 78 and 79, with or without, as the case may be, light and air spaces referred to in Article 77, shall, within the meaning of the present Regulations, be regarded as propelling-machinery space.
Apart from the differences in method for obtaining the cubic capacity of the space below the tonnage deck and that of the propelling-machinery spaces, as provided for in Articles 41, 80 (1) and 82, no space shall be included in the cubic capacity of the propellingmachinery space when determining the propelling-power allowance, unless it has first been included in the ship's gross tonnage.1) See Figure 99, indicating the method of measurement of the height of a shaft-tunnel when the tonnage depths in way of same are measured to the top of the ceiling supposed to be situated directly on the top of the double bottom.
All propelling-machinery spaces shall be measured and their cubic capacity be ascertained in accordance with the provisions of Articles 80, 81 and 82.