Ship Maintenance Management

Periodical Survey Regulations

1. Annual survey
1. Hull

· Side shell above the waterline

· Cargo ports

· Accesible part of rudder

· Decks

· Bulkwark and railing

· Ventilators

· Air, overflow and sounding pipes

· Clossing appliances of structures

· Engine casing, skylights, miscellaneous hatches.

· Ladders on weather decks.

· Anchoring and mooring equipment is

· Hatch covers and coamings

· Protection of other openings

2. Machinery

· machinery and electrical installations

· main source of electrical power is to be tested under load

· fire fighting equipment

2. Intermediate Survey
1. Hull

· Ballast Tank

· Cargo Holds

2. Machinery

· During the Intermediate Survey to the ship’s machinery, the requirements of the Annual Surveys are to be met.

3. Special Survey Hull I (Age of ship up to 5 years)
1. External examinations
2. Examination of tanks
3. Tightness tests
4. Holds and other spaces
5. Hatch covers and coamings
6. Thickness measurements
4. Special Survey Hull II (Age of ship 5-10 years)
1. Examination and testing of tanks
2. Thickness measurements
5. Special Survey Hull III (Age of ship 10-15 years)
1. Examination and testing of tanks
2. Thickness measurements
6. Special Survey Hull IV (Age of ship over 15 years) and Special Surveys there after
1. Examination and testing of tanks
2. Thickness measurements
7. Bottom Survey
1. Docking Survey
2. In-water Survey
8. Propeller Shaft Surveys
1. Complete Survey
2. Partial Survey
3. Modified Survey
4. Maximum and minimum clearances for propeller shafts

Recommended clearances for lignum-vitæ bearings

Recommended minimum bearing clearances for oil lubricated stern tubes

9. Special Survey Machinery
1. Survey of main and auxiliary engines
2. Survey of machinery other than main and auxiliary engines
3. Survey of electrical equipment
10. Periodical Surveys and testing of machinery Items
1. Steam boilers

· External inspection

· Internal inspection

2. Pressure vessels
3. Carbon dioxide low-pressure fire-extinguishing systems and Halon tanks

PART HULL

RUDDER

1. Twisted Rudder Stock
1. A < L/d : Stock acceptable
2. L/d < A < 5L/d : The Stock is to be stress relieved
3. A > 5L/d : Stock to be fully annealed or normalished
2. The Repair of rudder stocks by welding
1. Where Carbon ; Content < 0.25% or C equiv < 0.40 % (This May be considered weldable)
2. When Carbon ; Content > 0.25% or C equiv > 0.40 % (Seek advice from head office)
3. Weld Procedure

· Use low hydrogen electrodes

· Preheat at least surrounding area of weldment to 100^oC – 150^oC and maintains this temperature during welding process

· Welding should as far as is practicable be done downhand

· Welding may be manual or automatic as appropriate

· A weld procedure qualification test should be carried out in conjunction with the repair.

3. Use of “Second Hand” Forgings

Guidance :

· If its stamped by an IACS try to find the original certificate.

· If this is not possible – Test the material as per the rules.

· If the component is to be welded the the chemical analysis must be verified

o C content 0.25 % max.

o C equiv 0.40 % max. ( C + Mn/6)

PART MACHINERY

1. PROPELLER SHAFT

a. Propeller Shaft Cleareances – Measurement

b. Propeller Shaft Cleareances – Initial Maximum allowed

c. Crack Detection of propeller shaft

d. Repair the propeller shaft cone

e. Protection of propeller shaft against corrosion

f. Propeller shaft with bronze liners

2. BEARING CLEARANCES, CRANKSHAFT DEFLECTIONS, MISCELLANEOUS WEAR LIMITS OF ENGINES AND GEARING
• Clearances of Fiesel Engines

General Rule

· D < 150/ mm : Jo = D/1000

· D > 180/ mm : Jo = D/1200

For diameter between 150 mm – 180 mm : Jo = 0.15 mm

Bottom and top ends (connecting rods) of four strokes engines

· D < 150/ mm : Jo = D/1200

· D > 180/ mm : Jo = D/1600

For diameter between 150 mm – 180 mm : Jo = 0.125 mm

• Thin shell bearings ( medium speed engines) Reasons for rejection
• Connecting rod Bottom ends
• Crankshaft Deflections

3. BOILER SURVEY (Including oil heaters)
• Water-tube boilers
• Scotch Boiler Type
• Miscellanneous auxilllary boiler
• Hydraulic Testing
• Plugging of Boiler Tubes
• Thermal oil heaters

4. HEAT EXCHANGERS

As a general rule up to 10% of tubes may be accepted satisfactorily plugged

DAMAGE

1. Damage Identification

a. Damage Cause

· Building stage – structural detail, material, misalignment, welding defects, etc.

· In-service stage – maintenance, navigation, weather, loading/unloading opertaions, fire/explosion etc.

b. Damage and damage location

Structural deficiences are normally recognized as the following

· Material Wastage

· Fractures

· Deformations

I. Material Wastage

a. General corrosion (steel surface)

b. Grooving corrosion ( side frame)

c. Pitting Corrosion ( Ballast Tanks)

d. Crevice Corrosion (Pitting)

e. Erosion (occurs abrasive sand or muds held in the sea water impinges)

f. Bacterial corrosion (Pitting)

g. Stress Corrosion

II. Fractures

These could be due to :

· Discontinuity

· Cuts in highly stressed areas

· Abrupts changes in continuity

· Fabrications problem

· Poor welding

· Rough plate edges

· Misalignment structures

a. Fractures initiating at latents defects

b. Fatigue

Typical cyclic loading mechanism are :

· Hull girder bending

· Local pressure variation

· Cargo or ballast internal pressure variation

Typical Locations for high sensitivity to fatigue failure : deck, bottom and side shell connection of longitudinal stiffeners to transverse webs or bulkheads.

c. Lamellar tearing ( plating under deck crane)

d. Brittle fracture ( on the edge of the torn plate )

III. Deformation

Such deformation is often identified as :

· Local deformation ; deformation of a panel or stiffener

· Global deformation ; deformation of beam, frame, girder or floor, including associated plating.

a. Buckling (cause by in plane loading, found in web frames or floors)

b. Limit of hull deformation ( sagging/hogging = 1mm/m length for ships)

IV. Coating

Corrosion prevention system is normally considered as :

· A full hard coating

· A full hard coating supplements by anodes

Coating types :

· Hard coating

· Semi-hard coating

· Soft Coating

Coating failures

· Cracking

· Flaking

· Blistering

MAINTENANCE AND REPAIR OF CONSTRUCTION

1. FORCES ENCOUNTERD BY HULL GIRDER

The forces experienced can be divided into:

1. Static forces - buoyancy, weight and any local concentrated loads
2. Dynamic forces - caused by wind, waves and motion of the ship (roll, pitch, heave, surge, etc.)
3. Thermal forces, caused by differences in temperature (sea, air, cargo, etc.)
4. Other forces - docking, mooring and accidental loads (collisions, grounding, etc.)

Most forces on a ship are cyclic with many different frequencies (see Fatigue).

These forces cause:

a. Bending in the longitudinal plane i.e. hogging and sagging

b. Bending in the vertical plane

c. Racking, slamming and torsion strains

d. Local strains due to concentrated loads

2. IDENTIFICATION OF DIFFERENT COMPONENTS OF HULL STRUCTURES

In general, hull structures consist of:

1. Plating (bottom shell, side shell, decks, etc.)
2. Primary structure (bulkheads, girders, web frames, cantilever beams, stringers, etc.)
3. Secondary structure (ordinary stiffeners including: longitudinal, transverse frames, deck

beams, etc.)

Transversely and longitudinally stiffened ships

1. Stiffeners

a. Ordinary stiffeners ( flat bar, angle, bulb section.)

b. Primary supporting members (L-section or a T-section)

2. Span and support of stiffeners

a. Sniped ;

b. Bracketed ;

c. Welded ;

3. Bulkhead

a. Watertight Bulkhead (are grouped as ordinary and tank bulkheads : to tank boundary, to prvent flooding, to provide global transverse or longitudinal stiffening of the hull girder).

b. Non- watertight bulkheads (in accommodation areas or swash bulkheads used in tanks to reduce sloshing and provide extra strength.)

4. Pillars (to support the structure above especially where space is limited.)

5. Grillages (structures with stiffeners of similar or almost similar size, transversely and longitudinally, forming a flush structure)

3. IMPORTANCE OF SHAPE AND CONTINUITY
1. Shape

Stress area : effect from Effect of radii, Avoiding square corners, Hatch corners

· Openings

1. Stress concentrations and cutouts in structures

2. Cutouts in primary members for secondary stiffeners

· Opening orientation

· Compensation for openings

1. Doublers

2. Heavy insert plates in the plane of the plate

3. Flat bar rings welded around the periphery of the opening and normal to the plane of the plate.

· Pipe penetrations

· Openings in primary members (deck beams, girders, floors, and stringers)

b. Continuity

1. Importance of continuity of structure

Ensuring continuity can be made by the following:

Ø Avoid discontinuity (abrupt change of section) in the first place.

Ø If discontinuity is unavoidable, alleviate its effects

2. Hard Points

Hard points are caused when a load is transferred from one structural member to another through a limited (concentrated) area.

MAINTENANCE AND REPAIR OF MACHINERY

1. MAN B&W low speed engines

1. MC ENGINE DESIGN FEATURES

The key elements comprising :

1. Bedplate

2. Frame box
3. Cylinder frame

4. Crankshaft

5. Connecting rod

6. Cylinder liner

7. Cylinder cover

8. Piston

9. Piston rod

10. Camshaft
11. Exhaust valve

12. Fuel pump

13. Fuel oil system
14. Reversing mechanism
15. Shaft generator

2. L - GB TYPE ENGINES

The key elements comprising :

· Bedplate and main bearing

· Thrust bearing

· Frame section

· Cylinder frame, cylinder liner and stuffing box

· Cylinder cover

· Exhaust valve and valve gear

· Cover mounted valves

· Crankshaft

· Connecting rod

· Piston—piston rod—crosshead

· Fuel pump and fuel oil high pressure pipes

· Camshaft and cams

· Chain drive and reversing

· Moment compensator

· Governor

· Cylinder lubricators

· Manoeuvring system (without bridge control)

· Turning gear and turning wheel

· Gallery brackets

· Scavenging air system

· Exhaust turbocharger

· Exhaust gas system

· Auxiliary blower

· Starting air system

3. LOW SPEED ENGINE LICENCIES

a. MAN B&W LOW SPEED ENGINES

b. MITSUBISHI LOW SPEED ENGINES

c. SULZER LOW SPEED ENGINES

d. BURMEISTER & WAIN LOW SPEED ENGINES

e. DOXFORD LOW SPEED ENGINES DOXFORD LOW SPEED ENGINES

f. MAN LOW SPEED ENGINES

2. MEDIUM speed engines

1. Allen (Rolls-Royce)

2. Alpha Diesel (MAN B&W)

The key elements comprising :

· Frame

· Combustion

· Fuel valves and pumps

· Combustion chamber

· Cylinder head, valves and ducts

· Cylinder liner

· Piston

· Camshafts

· Bearings

· Turbocharger

3. Caterpillar

3600 series :

· Cylinder block

· Crankshaft

· Bearings

· Connecting rods

· Cylinder liners

· Pistons

· Valves

· High efficiency turbochargers

· Cooling system

· Lubricating system

· Fuel injection

· Exhaust and air intake systems

4. Deutz

5. MaK (Caterpillar Motoren)

6. MAN B&W Diesel

7. Rolls-Royce Bergen

8. Ruston (MAN B&W)

9. SEMT-Pielstick (MAN B&W)

10. Sulzer (Wärtsilä)

11. Wärtsilä

12. ABC

13. DAIHATSU

14. GMT

15. HYUNDAI (HIMSEN H21/32 AND H25/33)

16. MIRRLEES BLACKSTONE

17. MITSUI

18. NIIGATA

19. NOHAB

20. SKL

21. STORK-WERKSPOOR DIESEL

22. YANMAR

23. TWO-STROKE MEDIUM SPEED ENGINES

3. HIGH speed engines
1. CATERPILLAR
2. CUMMINS
3. DEUTZ
4. GMT
5. ISOTTA FRASCHINI
6. MAN B&W HOLEBY
7. MITSUBISHI
8. MTU

The key of elements :

· Crankcase

· Cylinder liner

· Cylinder head

· Valve actuation

· Crankshaft

· Bearings

· Connecting rods

· Piston

· Fuel injection

· Governor

· Lubricating oil system

· Cooling system:

· Turbocharging

9. Other Licences for High Speed Engine

· MTU/DDC designs

· NIIGATA

· PAXMAN (MAN B&W)

· SEMT-PIELSTICK

· WÄRTSILÄ

· ZVEZDA

· SCANIA

· VOLVO PENTA

4. Stroke of Engine
1. The four-stroke engine

2. The two-stroke engine

3. Comparison of two-stroke and four-stroke cycles

· The two-stroke cycle engine : with one working or power stroke every revolution, will, theoretically, develop twice the power of a four-stroke engine of the same swept volume.

· The Four-stroke cycle engine : can operate efficiently at high speeds which offsets its power disadvantage; it also consumes less lubricating oil. usually rotating at medium speed, between 250 and 750 rev/min

5. Auxiliary Boilers

Boiler Types :

1. Watertube boilers

Furnace wall construction :

· tangent tube

· monowall or membrane wall

2. Firetube boilers

· Package Boilers : This will include the oil burner, fuel pump, forced-draught fan, feed pumps and automatic controls for the system.

· Cochran boilers : has a fully spherical furnace and is known as the spheroid.

· Composite boilers :

3. Exhaust gas

· Exhaust gas heat exchangers

· Auxiliary steam plant system

· Exhaust gas boilers

4. Boiler mounting

· Safety valves

· Main steam stop valve

· Auxiliary steam stop valve

· Feed check or control valve

· Water level gauge

· Pressure gauge connection

· Air release cock

· Sampling connection

· Blow down valve

· Scum valve

· Whistle stop valve

Boiler mountings (water-tube boilers)

· Automatic feed water regulator

· Low level alarm

· Superheater circulating valves

· Sootblowers

Water level gauges

Safety valves

6. Pumps and pumping systems
1. Pumps
2. Pump types

· Displacement

· Axial-flow pump

· Centrifugal pump

3. Piping systems

· Pipes

· Valves

· Cock

· Globe valve

· Gate valve

· Relief valves

· Quick-closing valves

· Valve chests

· Other fittings

7. Auxiliaries
1. Air compressor
2. Heat exchangers

1. Coolers

· Shell and tube

· Plate type

· Maintenance

2. Heaters

3. Distillation systems

4. Oil/water separators

5. Sewage treatment

6. Incinerator

8. Shafting and propellers
1. Thrust block
2. Shaft bearings
3. Sterntube bearing
4. Sterntube seals
5. Shafting
6. Propeller
7. Propeller maintenance

MAINTENANCE AND REPAIR FOR DECK MACHINERY AND EQUIPMENT

I. Deck Machineries

1. Mooring equipment

2. Anchor handling equipment

3. Cargo handling equipment

4. Maintenance

II. Safety equipment

1. Lifeboat

2. Davit

III. Steering gear

1. Ram Type

2. Rotary vane type

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