Section 25(2)(c) in The Merchant Shipping (Cargo Ship Construction And Survey) Rules, 1974
(c)the auxiliary steering gear shall be capable of being brought rapidly into action and shall be of adequate strength and of sufficient power to enable the ship to be steered at navigable speed. In any ship where a rudder stock of over 35.56 centimetres diameter in way of the tiller is required to comply with the requirements of Cl. (a), the auxiliary steering gear shall be operated by power.