Section 7 Special Survey of tankers with cargo tanks independent from the ship’s structure – Hull requirements

7.1.1 The requirements of Pt 1, Ch 3, 4 Special Survey – Hull requirements and Pt 1, Ch 3, 5 Special Survey of ships over 15 years old – Hull requirements and of Pt 1, Ch 3, 6.1 General 6.1.2, Pt 1, Ch 3, 6.2 Preparation and inspection of tanks 6.2.2 and Pt 1, Ch 3, 6.2 Preparation and inspection of tanks 6.2.3 are to be complied with so far as applicable.

7.2.1 Special attention should be paid to the ship’s structure underneath the cargo tanks and the supports, chocking and securing arrangements, etc. of these tanks.

7.3.1 All cargo tanks are to be tested by filling the tanks with water to the top of the hatch coaming or equivalent method. Cofferdams and cargo tanks of tankers of Type G, C and N, see Pt 4, Ch 4 General Requirements For Tankers Carrying Dangerous Liquids in Bulk, Pt 4, Ch 5 Tankers of Type G and Pt 4, Ch 6 Tankers of Types C and N, are to be pressure tested with water to the top of the hatch coaming at odd-numbered Special Surveys (first, third, fifth and so forth). At even-numbered Special Surveys (second, fourth, sixth and so forth) the tanks are to be pressure tested in accordance with the requirements of Table 1.7.2 Testing requirements in Pt 3, Ch 1, 7.3 Acceptance testing on completion.

7.4.1 The requirements of Pt 1, Ch 3, 4.3 Thickness measurements are to be complied with for the hull structure at each Special Survey. Cargo tanks independent from the ship’s structure are to be gauged, by ultrasonic thickness measurement or other approved means, to determine the amount of general diminution in thickness. The gauging is to be done in at least one place on each tank (in two places on each tank over 20 m in length) in each strake of bottom, forward and aft side and top plating. The remainder of the plating is to be gauged as deemed necessary by the Surveyor, taking into account the results of gauging already carried out.