Section 11 Screwshafts, tube shafts, propellers and water jet units

The means for protection against corrosion are to be installed/applied according to LR approved procedures.

11.1.2 Fresh Water sample test. At the Screwshaft Survey, a sample of the fresh water in a closed loop fresh water lubricated shaft is to be taken in the presence of a Surveyor. Fresh Water sample tests are to be carried out at regular intervals not exceeding six months. The samples are be taken under service conditions and are to be representative of the water circulating within the sterntube. The Fresh Water sample test shall include measurement of chloride and sodium content, pH value and the presence of particles from both metallic and synthetic materials. Analysis results are to be retained on board.

11.1.3 Lubricating oil analysis. Lubricating oil analysis is to be carried out at regular intervals not exceeding six months. The documentation on lubricating oil analysis is to be available on board. Oil samples, to be submitted for the analysis, should be taken under service conditions.

11.1.4 Oil sample examination. An oil sample examination is a visual examination of the sterntube lubricating oil taken in the presence of a Surveyor, with a focus on water contamination.

11.1.8 Tube shaft is a shaft placed between the intermediate shaft and propeller shaft, normally arranged within a sterntube or running in open water. It may also be called a Sterntube Shaft.

11.2.1 Oil lubricated shafts fitted with approved oil glands and closed loop system fresh water lubricated shafts fitted with approved adequate means of protection against corrosion or fabricated from corrosion-resistant material are to be surveyed in accordance with Pt 1, Ch 3, 11.2 Closed Systems – Oil lubricated shafts or closed loop system fresh water lubricated shafts: Frequency of surveys 11.2.3 to Pt 1, Ch 3, 11.2 Closed Systems – Oil lubricated shafts or closed loop system fresh water lubricated shafts: Frequency of surveys 11.2.5.

11.2.2 Shafts with a keyless propeller connection or a flanged propeller connection (including controllable pitch propellers for main propulsion purposes) are to be surveyed at intervals of five years in accordance with TS Method 1, 2 or 3.

11.2.3 Shafts with a keyed propeller connection with a keyway that complies fully with the present Rules are to be surveyed at intervals of five years in accordance with TS Method 1 or 2; TS Method 3 is not permitted.

11.2.4 For oil lubricated keyless shafts, the maximum interval between two surveys carried out according to TS Method 1 or TS Method 2 shall not exceed 15 years, except in the case when one extension for no more than three months is agreed.

11.2.5 For closed loop system fresh water lubricated shafts, the maximum interval between two surveys carried out according to TS Method 1 shall not exceed 15 years, except in the case when one extension for no more than three months is agreed.

11.2.6 Shaft configurations other than those listed in Pt 1, Ch 3, 11.2 Closed Systems – Oil lubricated shafts or closed loop system fresh water lubricated shafts: Frequency of surveys 11.2.1 to Pt 1, Ch 3, 11.2 Closed Systems – Oil lubricated shafts or closed loop system fresh water lubricated shafts: Frequency of surveys 11.2.5 above are to be surveyed at intervals of three years in accordance with TS Method 1.

11.2.7 TS Method 2 and TS Method 3 are only permitted where the prerequisite service records and data specified for those methods are to be provided. If at the time of survey the attending Surveyor is not satisfied with the service records and data presented, then the shaft may be required to be withdrawn. The service records and data are to be retained on board and audited by LR at the Annual Survey.

11.2.8 When the descriptive note ShipRightSCM is assigned to a closed loop system fresh water lubricated shaft, whenever a survey is to be carried out in accordance with TS Method 1, as required by Pt 1, Ch 3, 11.2 Closed Systems – Oil lubricated shafts or closed loop system fresh water lubricated shafts: Frequency of surveys 11.2.5 above, it may be replaced by a survey in accordance with TS Method 2.

11.2.9 For oil lubricated arrangements, the descriptive note ShipRight SCM is not a prerequisite in order to hold TS Method 2 and TS Method 3.

11.2.10 In order to assign and maintain the descriptive note ShipRight SCM, the requirements of Pt 11, Ch 2, 5.2 Screwshaft Condition Monitoring (SCM) and ShipRight Procedure Machinery Planned Maintenance and Condition Monitoring, Section 6 are to be complied with, including the requirements therein for onboard maintenance of records and review of them by the attending Surveyor at Annual Survey.

11.2.11 For surveys completed within three months before the shaft survey due date, the next period will start from the shaft survey due date.

11.2.12 See Summary of Survey Intervals and Extensions for closed systems in Table 3.11.1 Summary of survey intervals and extensions – Closed systems

11.3.2 Single shaft configurations other than listed above are to be surveyed every three years in accordance with TS Method 4.

11.3.3 For shafts subject to five-yearly surveys with keyless connections, at the Surveyor’s discretion removal of the propeller and NDE of the shaft taper, as required by TS Method 4, need only be carried out every 15 years, subject to a satisfactory visual inspection of all accessible parts of the shafting system at the intervening surveys.

11.3.4 For surveys completed within three months before the shaft survey due date, the next survey period will start from the shaft survey due date.

11.3.5 For shafts with a keyless propeller connection or a flanged propeller connection (including controllable pitch propellers for main propulsion purposes), and when the descriptive note ShipRightSCM is assigned to an open loop water lubricated shaft, a TS Method 4 survey may be replaced by a TS Method 2 or TS Method 3 survey. Notwithstanding this, the maximum interval between two surveys carried out according to TS Method 2 or TS Method 4 shall not exceed 15 years, except in the case when one extension for no more than three months is agreed.

11.3.6 For shafts with a keyed propeller connection, and when the descriptive note ShipRightSCM is assigned to an open loop water lubricated shaft, a TS Method 4 survey may be replaced by a TS Method 2 survey.

11.3.7 At the discretion of the Classification Committee, consideration may be given to accept special arrangements to monitor the condition of the screwshaft, bearings, sealing devices and the sterntube lubricant system so as to allow an extension to the interval between withdrawals of the Screwshaft required by TS Method 4. This is subject to the shaft being provided with approved adequate means of protection against corrosion or being fabricated from corrosion-resistant material.

11.3.8 See Summary of Survey Intervals and Extensions for open systems in Table 3.11.2 Summary of survey intervals and extensions – Open systems.

11.4.2 If the extension survey is carried out within one month of the shaft survey due date then the extension will take effect from the shaft survey due date.

11.4.3 If the extension survey is carried out more than one month prior to the shaft survey due date, then the period of extension will take effect from the date on which the extension survey was completed.

11.5.1 For the survey methods see Table 3.11.3 Shaft survey methods below.

11.6.1 Directional propeller and podded propulsion units for main propulsion purposes, inclusive of the propellers, shafts, gearing, control gear and the primary electrical components including any control and protection devices, are to be surveyed at intervals not exceeding five years. They are to be dismantled if considered necessary and generally examined as far as practicable. Non-destructive examination is to be carried out as considered necessary by the Surveyor on blade/fin roots. Consideration may be given to condition monitoring schemes for determining the condition of the unit.

11.6.2 Dynamic positioning and/or thruster-assisted mooring and athwartship thrust propellers and shaftings are to be surveyed at intervals not exceeding five years. They are to be generally examined so far as possible in dry dock and tested under working conditions afloat for satisfactory operation. All accessible parts, including sealing, locking and bearing faces, and any other moving parts are to be examined. Non-destructive examination is to be carried out as considered necessary by the Surveyor on blade/fin roots. Consideration may be given to condition monitoring schemes for determining the condition of the unit.

11.6.3 Water jet units for main propulsion purposes, including the impeller, casing, shaft, shaft seal, shaft bearing, inlet and outlet channels, steering nozzle, reversing arrangements, and control gear are to be surveyed at intervals not exceeding five years, provided the impeller shafts are made of approved corrosion-resistant material or have approved equivalent arrangements. They are to be generally examined so far as practicable.

11.6.4 Stationary supporting structure and any erosion protection inserts or doublers are to be examined in way of any propulsion devices.

11.7.1 The Classification Committee will be prepared to give consideration to the circumstances of any special case upon application by the Owner, where the level of safety achieved is equivalent to that obtained by the survey methods described in this Section.