Section 32(2) in The Merchant Shipping (Cargo Ship Construction And Survey) Rules, 1974
(2)The survey to be carried under sub-rule (1) shall be as follows :(a)the hull and ship's side fastenings shall be examined in dry dock at intervals not exceeding two years and ship's side fittings shall be thoroughly examined at intervals not exceeding four years :Provided that where the principal officer is satisfied in the case of any ship that an extension of this period is justified, he may, on application of the owner, extend the period between the two surveys by such period as he may consider necessary but such period of extension shall not exceed 12 months.(b)all boilers including exhaust gas or steam heated steam generators, economisers and domestic boilers, other than domestic boilers having a heating surface of 4.65 sq. metres or less and a working pressure of 3.52 k. gms. per sq. centimetre or less, shall be examined internally and externally at intervals not exceeding two years until they are eight years old and thereafter annually :Provided that where the principal officer is satisfied in the case of any ship that the extension of this period is justified, he may on application of the owner, extend the period between two surveys by such period as he may consider necessary, but not exceeding six months.(c)screw shafts and tube shafts with continuous liners or running in oil shall be withdrawn and surveyed at intervals not exceeding three years and other screws and tube shafts shall be withdrawn and surveyed at intervals not exceeding two years :Provided that in the case of single screw ships where shafts have liners or approved oil glands or are made of approved corrosion resistant material, the interval between two surveys may be extended by a period not exceeding twelve months if the principal officer is satisfied that-(i)the shafts are withdrawn and examined at each survey by an efficient crack detection method; and(ii)the design of the keyway is such so as to justify the period of extension.
