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Repair of Crankshaft of MAN B&W Engine Model no. 5L 16/24 | Grinding of MAN B&W Engine Crankshaft


RA Power Solutions was informed about the repeated failure of crankpin bearings of MAN B&W 5L 16/24 by one of our client base in Dubai. 

We deputed our technicians to Duqm port in Oman to undertake the inspection of the crankshaft and repair. The crankpin diameter and other details are mentioned below. 

S. No

Crankshaft Details

 

1

Engine Make

MAN B&W

2

Engine Model

5L 16/24

3

Crank pin Diameter Standard

130 mm

4

Crankpin Bearing Width

56 mm

5

Place of execution of crankshaft repair

Duqm Port, Oman

 

Inspection undertaken by RA Power Solutions of Crankshaft of MAN B&W Engine Model no.5L 16/24 

 i) The connecting rods of all the five crankpins were removed. 

 ii) On visual inspection the crankpin bearings were observed damaged with line marks.

 iii) All crankpins were checked dimensionally for taper & ovality and to our surprise the ovality ranging from 0.13 mm to 0.20 mm was observed. Considering the standard size of crankpin as 130 mm minus 0.03 mm, It is very much on the higher side. Copy of Inspection report of crankpin is pasted below. 

WHENEVER IN DOUBT, ASK, DO NOT SCALE

 

 

 

 

 

 

 

REPORT NO.:-

 

 

 

 

 

 

 

 

 

 

 

DATE OF INSPECTION:-

 

24/1/2022

 

 

 

 

Engine No.

1

 

 

 

 

 

 

 

 

Site:-

Daqm 

Drydock 

OMAN

 

 

Type:

In Line

 

Bearing Length:

 

56MM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Standard Dimension:-

 

130.00MM

 

 

 

 

 

 

 

 

STANDARD/SPECIFIED NO.

 

 

 

 

 

 

SIZES IN MM

 

SIZE OF CR Pins

 

A

Aa

C

Cc

B

Bb

Min

STD

Ovality

CR-1

129.95

129.84

129.85

129.84

129.86

129.92

129.84

130

0.16mm

CR-2

129.95

129.91

129.89

129.8

129.9

129.87

129.8

130

0.20mm

CR-3

129.96

129.86

129.92

129.89

129.88

129.85

129.85

130

0.15mm

CR-4

129.94

129.9

129.9

129.87

129.89

129.88

129.87

130

0.13mm

CR-5

129.92

129.93

129.88

129.87

129.88

129.84

129.84

130

0.16mm

     

SIZE OF CR PINS BEFORE GRINDING

   

 iv) All the crankpins were subject to checking of hardness by portable hardness tester and it was observed within limits.

 v) As a protocol the crankpins were also subject to crack detection test by MPI. No cracks or abnormality was observed.

 vi) Bearing line marks and rough surface was observed on all crank pins journal. 

Inspection of Crankpin of MAN B&W Engine Model no. 5L 16/24

    Rough surface of crankpin of MAN B&W Engine Model no. 5L 16/24

Inspection of Crankpin of MAN B&W Engine Model no. 5L 16/24

 

 Rough surface of crankpin of MAN B&W Engine Model no. 5L 16/24

 

Action taken by RA Power Solutions for successful repair of Crankshaft of MAN B&W Engine Model no. 5L 16/24


 i) The five number crankpins were ground to the first step size of 0.5 mm maintaining the tolerances as per the manufacturer specifications. 

 ii) The final diameter was maintained between 129.47 mm and 129.50 mm. 

 iii) The radius and lubricating oil profile was maintained as per the original. 

 iv) Final readings of crankpins after grinding are pasted below. 

WHENEVER IN DOUBT, ASK, DO NOT SCALE

 

 

 

 

 

 

 

REPORT NO.:-

 

 

 

 

 

 

 

 

 

 

 

DATE OF INSPECTION:-

 

27/1/2022

 

 

 

 

Engine No.

1

 

 

 

 

 

 

 

 

Site:- Daqm 

Drydock 

OMAN

 

 

Type:

In Line

 

Bearing Length:

 

56MM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Standard Dimension:-

 

130.00MM

 

 

 

 

 

 

 

 

STANDARD/SPECIFIED NO.

 

 

 

 

 

 

SIZES IN MM

 

SIZE OF CR Pins

 

A

Aa

C

Cc

B

Bb

Min

Max

Ovality

CR-1

129.49

129.5

129.48

129.49

129.49

129.48

129.48

129.5

0.02mm

CR-2

129.5

129.49

129.49

129.49

129.49

129.48

129.48

129.5

0.02mm

CR-3

129.48

129.48

129.49

129.49

129.5

129.49

129.48

129.5

0.02mm

CR-4

129.49

129.49

129.48

129.48

129.48

129.47

129.47

129.49

0.02mm

CR-5

129.5

129.5

129.48

129.49

129.49

129.48

129.48

129.5

0.02mm

       

SIZE OF CR PINS AFTER GRINDING

   

 

Supply of undersize Bearing of MAN B&W Engine Model no. 5L 16/24

 RA Power Solutions supplied 0.5 mm undersize bearings to the client. 

 The engine was commissioned in the presence of our technicians and performance was observed to be satisfactory.

Crack detection of crankpin

Damaged Crank Pin of MAN B&W Engine

Model no. 5L 16/24

Crack detection of crankpin

Damaged Crank Pin of MAN B&W Engine

Model no. 5L 16/24

We have been regularly executing the repairs in Madagascar, Oman, Qatar, Philippines, Bahrain, Srilanka, Bangladesh, Myanmar, Turkey, Nigeria, Greece, Saudi Arabia, UK, Dubai, Malta, Cyprus, Singapore, Malaysia, Colombia, Indonesia, Hong Kong, Spain, Netherlands, Dubai, Portugal, Estonia, Morocco, Belgium, Vietnam, Canada, Jordan, Libya, Kuwait, Egypt, Morocco, Yemen, Bahrain, Tunisia, Sudan, Oman, Algeria, Saudi Arabia, Iraq, UAE  etc.

This blog is written by Mr. Raj Shahani (Managing Director of RA Power Solutions India Pvt. Ltd.).

Mr. Shahani is a highly experienced business leader with rich experience of more than 40 years in the field of Power, Heavy and Shipping industry. He is Technical Adviser to many shipping and heavy industries across the globe.

Mr. Shahani is one of the most enthusiastic professional and he has all the brilliance of an exemplary leader. Mr. Shahani is an extremely effective coach and mentor of teams and is adept at providing leadership in a global, cross-cultural environment.

please email us at rajshahani@rapowersolutions.cominfo@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.Visit our website:  https://crankshaftgrindingrepair.com/ 

Crankpin after successful repair

Crankpin after grinding & polishing

Crankpin after successful repair

Crankpin after grinding & polishing

 

 

WHENEVER IN DOUBT, ASK, DO NOT SCALE

 

 

 

 

 

 

 

REPORT NO.:-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DATE OF INSPECTION:-

 

24/1/2022

 

 

 

 

Engine No.

1

 

 

 

 

 

 

 

 

 

 

Site:- Daqm Drydock OMAN

 

 

 

 

Type:

In Line

 

Bearing Length:

 

56MM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Standard Dimension:-

 

130.00MM

 

 

 

 

 

 

 

 

 

 

STANDARD/SPECIFIED NO.

 

 

 

 

 

 

SIZES IN MM

 

 

 

Do not Scale the drawing Remove all burrs and sharp corners all dimensions are in mm

SIZE OF CR Pins

 

 

A

Aa

C

Cc

B

Bb

Min

STD

Ovality

 

CR-1

129.95

129.84

129.85

129.84

129.86

129.92

129.84

130

0.16mm

 

CR-2

129.95

129.91

129.89

129.8

129.9

129.87

129.8

130

0.20mm

 

CR-3

129.96

129.86

129.92

129.89

129.88

129.85

129.85

130

0.15mm

 

CR-4

129.94

129.9

129.9

129.87

129.89

129.88

129.87

130

0.13mm

 

CR-5

129.92

129.93

129.88

129.87

129.88

129.84

129.84

130

0.16mm

 

CR-6

 

 

 

 

 

 

 

 

 

 

CR-7

 

 

 

 

 

 

 

 

 

 

CR-8

 

 

 

 

 

 

 

 

 

 

CR-9

 

 

 

 

 

 

 

 

 

 

CR-10

 

 

 

 

 

 

 

 

 

 

Remarks:

 
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Outside Micrometer

 

 

 

 

 

 

 

 

Make:

Mitutoyo

 

 

 

 

 

 

 

 

 

Date of Calibration

 

10/7/2021

 

 

 

 

 

 

 

 

Calibration Valid upto

 

9/7/2022

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The drawing is the sole proprietor of RA Powersolutions Pvt. Ltd. Unauthorised use of this drawing or making product as per our drawing without our permission or any other misuse is not permitted

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIZE OF CR PINS BEFORE GRINDING

 

DATE

SIGN

 

 

PREPARED BY

24/1/2022

 

 

 

CHECKED BY

24/1/2022

 

 

 

CLIENT:

 

 

ENGINE: MAN B&W 6L 16/24

 

 

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