Section 4 Bottom Surveys – In Dry-Dock and In-Water - Hull and machinery requirements

4.1.1 At Bottom Surveys the Surveyor is to examine the ship and machinery, so far as necessary and practicable, in order to be satisfied as to the general condition.

4.2.1 Where a ship is in dry-dock or on a slipway it is to be placed on blocks of sufficient height, and proper staging is to be erected as may be necessary, for the examination of the shell including bottom and bow plating, keel, stern, sternframe and rudder.

4.2.2 The shell plating is to be examined for excessive corrosion, deterioration due to chafing or contact with the ground and for undue unfairness or buckling. Special attention is to be given to the connection between the bilge strakes and the bilge keels.

4.2.3 Visible parts of the rudder, rudder pintles, rudder stocks and couplings and stern frame are to be examined. The pintles are to be examined either by removal of the inspection plates, or if considered necessary by the Surveyor, the rudder is to be lifted to enable examination. The clearances in the rudder bearings are to be measured. Where applicable, pressure testing of the rudder may be required if deemed necessary by the Surveyor.

4.2.4 The sea chests, sea connections, scuppers and sanitary discharges, their attachments to the hull and the gratings at the sea inlets are to be examined.

4.2.5 Visible parts of the propeller(s) and sternbush(es) are to be examined. The clearance in the sternbush and the efficiency of the oil gland, if fitted, are to be ascertained and recorded. For controllable pitch propellers, the Surveyor is to be satisfied with the fastenings and tightness of hub and blade sealing.

4.2.6 Visible parts of side thrusters are to be examined. Other propulsion systems which also have manoeuvring characteristics (such as directional propellers, vertical axis propellers, water jet units) are to be examined externally with focus on the condition of gear housing, propeller blades, bolt locking and other fastening arrangements. Sealing arrangements of propeller blades, propeller shaft and steering column are to be verified.

4.2.7 When chain cables are ranged, the anchors and cables are to be examined by the Surveyor, see also Pt 1, Ch 3, 5.3 Examination and testing 5.3.15, Pt 1, Ch 3, 5.3 Examination and testing 5.3.16, Pt 1, Ch 3, 5.3 Examination and testing 5.3.18 and Table 3.5.1 Survey preparation.

4.2.8 Where the anti-fouling system is changed completely, or partial repair is carried out affecting 25 per cent or more of the antifouling system, the coating specification and anti-fouling system is to be examined by the Surveyor in accordance with the AFS - International Convention on the Control of Harmful Anti-Fouling Systems on Ships, 2001 (AFS 2001) and Ch 15 Corrosion Prevention of the Rules for Materials.

4.2.9 To maintain an *IWS notation, at completion of each dry-docking the condition of the high resistance paint is to be confirmed and, as applicable, satisfactory access arrangements to take the sternbush clearance and rudder pintle/bearing clearances are to be verified.

4.3.1 The Committee will accept an In-Water Survey at alternate Bottom Surveys on ships other than those covered in Pt 1, Ch 2, 3.5 Existing ships – Periodical Surveys 3.5.3 and where an *IWS notation is assigned, see Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.11.

4.3.2 The Committee may accept an In-Water Survey at alternate Bottom Surveys on ships where suitable protection is applied to the underwater portion of the hull. If requested, an *IWS notation may be assigned on satisfactory completion of the Survey, provided that the applicable requirements of LR's Rules and Regulations are complied with, see also Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.11.

4.3.3 The In-Water Survey is to provide the information normally obtained from the Bottom Survey in dry-dock. However, for oil lubricated sternbush arrangements, the clearance in the sternbush is not required to be ascertained subject to the Surveyor confirming satisfactory operating history and condition data records (lubricating oil analysis, bearing temperature, lubricating oil consumption) and verifying satisfactory operation of the screwshaft.

4.3.4 When there is no access, special consideration shall be given to ascertaining rudder bearing clearances and sternbush clearances of water lubricated bearings based on a review of the operating history, on board testing and stern bearing condition data. These considerations are to be included in the proposals for In-Water Surveys which are to be submitted in advance of the survey being required, so that satisfactory arrangements can be agreed with LR.

4.3.5 The In-Water Survey is to be carried out at an agreed geographical location under the surveillance of a Surveyor to LR, with the ship at a suitable draught in sheltered waters and with weak tidal streams and currents. The in-water visibility and the cleanliness of the hull below the waterline is to be clear enough to permit a meaningful examination which allows the Surveyor and diver to determine the condition of the plating, appendages and the welding. The Surveyor is to be satisfied with the methods of orientation of the divers on the plating, which should make use where necessary of permanent markings on the plating at selected points.

4.3.6 Prior to commencing the In-Water Survey, the equipment and procedures for both observing and reporting the survey are to be agreed between the Owners, the Surveyor and the diving firm.

4.3.7 The In-Water Survey is to be carried out by a qualified diver employed by a firm approved by LR. In addition, for certain aspects of the In-Water Survey, consideration may be given to the use of a Remotely Operated Vehicle (ROV) operated by the LR approved firm.

4.3.8 The Surveyor is to be satisfied that the method of pictorial presentation is satisfactory. There is to be good two-way communication between the Surveyor and the diver.

4.3.9 If the In-Water Survey reveals damage or deterioration that requires early attention, the Surveyor may require that the ship be dry-docked in order that a fuller survey can be undertaken and the necessary work carried out.