Main bearing C 18-1/7. Remark): Both types of stud bolt and jack bolt have been adopted on the ship, which delivered before on March 2002.

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Main bearing 1132 1.1 Structure Jack bolt type Remark): Both types of stud bolt and jack bolt have been adopted on the ship, which delivered before on March 2002. 8 ~ 12Cyl Stud bolt Jack bolt No.

3mm 11 Jack bolt Check upper &lower face for damage 12 Column center piece 13 Vent valve Loosen center screw for air vent. Air vent must be completed.

1 Main bearing Structure Jack bolt type Remark): Both types of stud bolt and jack bolt have been adopted on the ship, which delivered before on March ~ 12Cyl Stud bolt Jack bolt No. Name of article Check item 7 Bearing cover Check unbalanced tightening P-S side. a1-a2 =max 0.3mm 11 Jack bolt Check upper &lower face for damage 12 Column center piece 13 Vent valve Loosen center screw for air vent. Air vent must be completed. 14 Locking wire 15 Set screw 16 Cylinder Before dismantling, give mating mark to cylinder & nut 17 Nut Keep jointing face clean between cylinder and nut. 18 Spot face 19 Piston seal ring 20 Locking wire D Pressure space R Round bar T Rope W Eye bolt Main parts weight table (Kg) Type Bearing cover Bearing shell Jack bolt RTA96C 850 ~ ~ C 18-1/7

Main bearing 1132 1-2. Structure Stud bolt type All stud bolts type has been adopted on the ship, which delivered after March 2002. No.

2 Main bearing Structure Stud bolt type All stud bolts type has been adopted on the ship, which delivered after March No. Name of article Check item 1 Pin 2 Air vent bolt 3 Cylinder 4 Piston Pre-tensioning jacks Seal ring 6 Nut Check unbalanced tightening P-S 7 Bearing side. a1-a2 =max 0.3mm 8 Stud bolt 9 Bearing shell K Slot R Round bar Main parts weight table (Kg) Type Bearing cover Bearing shell Jack bolt RTA96C 927 ~ 1, ~ Tools (For stud bolt / jack bolt) 2 Pre-tensioning jacks Feeler gauge / Depth gauge Connection piece 94934a 3 HP hose Hydraulic unit Connection piece Open end spanner AF95 Tools ( Main bearing shell) 1 Lifting tool Roller support Each 1 Turning-out device 94118b ~ c 1 Lifting yoke Eyelet 94120a 1 set Lifting rope with shackle 94120b ~ r 1 Support Working platforms set Port power / HP hoses / Hydraulic jack Dial gauge with magnet base 96C 18-2/7

3 2. Check item 2-1. Overhaul Normally, every 5 years (30,000 ~ 40,000 Hrs.) It will be enough by the Classification Society's requirement, unless there are damage of white metal, overheat of main bearing, unusual deflection of crankshaft (See the section on crankshaft of 16-3/3 page) were observed. a1 Height of bearing cover a2 Check items at the time of main bearing overhaul 1) Measure the difference in height (between S and P side) of bearing cover. Adjusted value : Admissible difference a1-a2 Max. 0.3mm 2) Check the loosening pressure for jack bolt. When loosening, press with 102 MPa. Adjusted value : The tightening pressure can sometimes go down to around 10 MPa at the first overhaul, which is not abnormal. Tighten it again by regular value (RTA96C=100MPa). 3) Check the upper and lower spherical surfaces of Jack bolts. If anything unusual is found about the following items, contact the engine maker after taking pictures and record of locations and sizes. Peeled segments of white metal should be kept to investigate the cause later. 4) Damage, discoloring and separation of white metal of bearing. Temporary measures : Remove white metal likely to come off and scrape around the removed boundaries slightly. 5) Worsened roughness and damage of journal surface. Temporary measures : Finish it smoothly with an oilstone and hand pad (nylon scrubbing brush). 6) Damage of shell metal back surface (fretting) Temporary measures : Remove the convex with emery cloth. By placing the shell metal on a flat face, check it for absence of twist and deformation. 96C 18-3/7

4 2-2. Points to be noted in measuring clearance of main bearing upper parts 2-3. Periodic checks Every 1,000 Hrs. 3. Overhaul / reassembly 3-1. Basic construction 3-2. History of white metal thickness and number of pin for lower metal 1) Measure the clearance of main bearing upper part with the depth gauge or feeler gauge after ensuring that the crankshaft is contacting surely on the lower bearing. (Refer to Standard inspection dimension in item 3-4 of page 18-4/5) 2) When measuring the clearance of main bearing upper part with the depth gauge, subtract a value equal to the metal thickness stamped nearby the measuring hole of shell metal. 1) Check inside of crankcase whether falling of white metal fragment is observed. 2) Check damaged place that can be presumed by the shape of fragment. (Crank / cross metal: curved surface, guide shoe: flat shape) 3) Check main bearing damage at F&A edge by using with L-shape wire bent at its end. Type Upper metal Lower metal RTA96C White metal into casting cover Shell metal RTA96C Thickness of white metal (mm) Positioning of upper & lower shell metal Upper metal Lower metal Until delivered on Nov.' ~ ~ pins After delivered on March ' ~ 3.2 Ditto Parallel key 4 pins (Parallel pin) Positioning key (Parallel key) Main bearing 96C 18-4/7

5 3-3. Cautions 1) Make sure to tighten the jack bolt after tightening the tie rod. (Loosen the tie rod after loosening the jack bolt) 2) When detaching the lower metal, never supply the hydraulic pressure of more than 102MPa (1020 bar), and/or put 2 jacks on one end. (An excessive force may bend the hydraulic jack support and the runoff the jack may damage the components inside the crankcase.) The permissible pushing up height of the crankshaft is 0.1 to 0.15mm in the main bearing unit where it disassembles. 3) Admissible difference of bearing cover is to be within 0.3mm. 4) After the work is finished, provide various locking devices, and take care not to leave rag and tools behind. (Secondary accident may occur with the rotating portions. The left rag acts as one of the major causes for bearing seizure.) 3-4. Standard inspection dimension Main bearing jack bolt tightening force (RTA96C): Tightening hydraulic pressure; 100MPa(1000bar) : Loosening hydraulic pressure; 102MPa(1020bar) (Unit: mm) Type Main bearing clearance (b1) Jack bolt Normal clearance Max. clearance Admissible difference a1-a2 RTA96C Until delivered on Nov.' ~0.68 Max. 0.9 Max. 0.3 After delivered on March '02 0.5~0.8 Ditto Ditto 96C 18-5/7

6 4. Failure sample 4-1. Metal damage sample 1) Hard contact, damage or peel off of white metal around the mating face of the lower shell metal and bearing cover. Measures: Improve the formation of lube oil film by means of an improved oil groove and a modified bearing clearance. 2) Damage and peel off of specific metal in a short time due to poor alignment of engine. 3) Poor centering of cover. One-sided contact and damage in the F-A direction due to unbalanced tightening Features of damaged metal 1) Features of white metal fragments found in the crankcase. White metal fragments with curved faces: Source: Refer the table of Thickness of white metal in page 18-4/6 for upper and lower metal Cause: Poor bonding, hydrogen blister, fatigue destruction due to overload. Foil-shaped white metal fragments: Cause: White metal foil runs out from the bearing clearance (Seizure) White metal fragment is struck and extended in the clearance between shaft and bearing. (Exfoliation) 4-3. Other damage sample 1) Fretting of the back of lower bearing shell 5. Technical information Service information DUQ1-038E Main parts where white metal is used 96C 18-6/7

7 6. Addition 1. Main ingredients of the white metal material 2. The bearings are cast in white metal by using mold. Mark % Sn Remainder Sb Cu Cd Ni Ag Co C 18-7/7

Main bearing T 18-1/5. No. Name of article Check item 1 Jack bolt Check upper &lower face for damage 2 Column center piece

Main bearing T 18-1/5. No. Name of article Check item 1 Jack bolt Check upper &lower face for damage 2 Column center piece Main bearing 1132 1. Structure Pin for fall prevention Fit plug after work is over No. Name of article Check item 1 Jack bolt Check upper &lower face for damage 2 Column center piece 3 Bearing cover Check