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Dry Dock Preparation: Drydock prep

The main objective in carrying out dry docking is to ensure ships are operational and to maintain their class license. Structural machinery and various components are subjected to inspection and maintenance to ensure sea worthiness. Dry docking is also required if a ship has sustained damage to the underwater structure due to grounding, collision or any other damage which will affect the water integrity of the ship’s hull.

Preparation for Dry Docking

Planning:

1. To brief engine room staffs before docking and ensure they understand their respective duties.
2. Preparation of machinery survey in dry dock
3. Preparation of dry dock list.
4. Study previous dry dock reports and note clearance to be measured.
5. Ensure all tools and spares are ready for use.
6.  Prepare necessary spares and store, drawings, Manuals, Certificates, special tools and measuring equipment.
7. Safety meeting to be carried out.

As a second engineer

1. Make a repair and maintenance list, create or obtain a dry-dock handbook if required, and assign responsible ship staff to their duties on the list. Divide staff into groups to observe the work carried out by yard gangs.
2. All spare parts must be checked, and repair items kept ready for use.
3. Previous dry dock reports should be studied, and previous clearance measures noted.
4. Clean engine room tank top and bilges.
5. Prepare sewage treatment tanks, dirty oil tanks and bilge tanks.
6. Flushing of bilge lines is to be carried out prior to dry dock.
7. For tankers, all cargo tanks are cleaned and gas freed.
8. Minimum bunkers (Fuel Oil and Fresh water) and ballast carried
9. All tanks and cofferdams must be sounded and recorded.
10. The oil-water separator filter element should be renewed, and the system checked for satisfactory operation.
11. Fill up Settling and Service Tanks.
12.  Press up Air Bottles and Emergency Air Bottle and shut the valves tightly.
13.  ME crankshaft deflections to be taken and recorded.
14. All heavy weights secured prior to dry dock.
15. Firefighting plans and safety measures discussed before dry dock
16. Firefighting equipment on board should be checked and kept ready for use.
17. Emergency lighting and generator should be tested before entry.
18. Escape routes must be clearly marked.
19. All valves and sea chests to be overhauled must be clearly marked.
20. Shore connections for cooling water and fire line are to be readied.
21. Main engine, generators, and boiler are changed over to diesel oil.
22. CO2 total flooding systems are secured and locked before entry.
23. Vessel must approach dock with even keel.

Trouble/Damage if Dry Docking is Unprepared:

1. Dangerous confusion if no proper defects list is made and staff not briefed.
2. Explosion hazards when hot work is done on a tank not emptied of volatile substances.
3. Engine room bilges may become fire hazards if not cleaned.
4. If spares are not checked, arranged properly, work will be delayed due to time wasted finding or waiting orders.
5. Leakage due to draining must be pumped to the empty drain/bilge tanks if not empty prior to dry dock.
6. Extra unplanned work needed in shore reception required in dry dock costs time and money.
7. Wrong frequency and power supply information given to dry dock will cause machinery to overheat and eventually fail.

Procedures Adopted to Ensure Safety During Dry Dock:

1. Firefighting equipment ready at all times.
2. Fire detectors and fire alarm in good working condition.
3. Fire officer at site of work and extinguishers available.
4. Fire line is always ready with 2 hydrants open if no hull work is carried out.
5. CO2 total flooding system door is locked to prevent accidental actuation.
6. Acetylene and oxygen bottles are properly stored and secured.
7. Proper working permits obtained before carrying any work on board; e.g. hot work permit, enclosed space entry permit.
8. Safety gear worn while working- safety shoes, helmet, overalls, safety goggles, ear mufflers, and gloves.
9. All lifting gears checked to be in good working condition.
10. Safety lamps are used – never use a naked lamp.
11. Escape routes should be clearly marked.
12. Co-ordination of work, so no chemical cleaning and hot work around boiler area is done at the same time.
13. No transfer of oil carried out in dry dock.
14. No boiler blow downs; in emergency, necessary notice given.
15. No unauthorized personnel or chemicals allowed on board.
16. Ship properly grounded to shore earth.
17. Safety meetings should be carried out every morning before stating the work in dry dock.

During Docking:

1. Discuss with the superintendent and dockyard repair manager about repair jobs.
2. Assist Surveyor and record the survey items.
3. Witness all alignment works and clearance measurements.
4. Take and record propeller shaft wear down, rudder wear down and jumping clearance.
5. Check oil tightness of stern tube.
6. Check all completed underwater jobs, done by dockyard.
7.  Check all sea valves, shipside valves and cocks, after overhauling.
8. Check all repaired jobs done by ship staff, and used spares and store.
9. Make daily records.

Undocking:

1. Check all repair and underwater jobs in accordance with repair list.
2.  Check all measurement data are correct and completed. Make price negotiation.
3. When sea water level covers the sea chest, each sea valve should be opened and checked for any leakage.
4. Test run the ship generators, until satisfactory, and cut out shore supply, cut in ship generator, disconnect the shore connection, restart seawater pump, record the time and read watt meter.
5. Purge air from cooling seawater pumps, run the pumps and check pressure.
6. Prepare for ME.
7. All sea valves, shipside valves, repaired pipes, repaired jobs must be finally checked, before leaving the dock.  
8.  All DB tank soundings checked.  

After Leaving the Dock.

1. checked ME crankshaft deflection and compare with former record.
2. Prepare for Docking Report.

2/E should be instructed to perform the followings:  

a) Label all sea valves, all shipside valves and cocks. Mark the positions of items to be repaired, with tags or color code.

b) Keep Emergency Fire Pump, Emergency Generator, Air Compressors, Emergency Air Bottle, and portable Fire Extinguishers in good order.

C) Lock Fixed Fire Fighting Installation, as per shipyard rules.

d) Shut down Boiler, OWS, and Sewage Plant if dockyard does not allow.

e) Lock overboard discharge valve in closed position.

f) Fill up Settling and Service Tanks.

g) Press up Air Bottles and Emergency Air Bottle, and shut the valves tightly.

h) ME crankshaft deflections to be taken and recorded.

I) Hose down tank tops, and empty Bilge Holding Tank, Sludge Tank, Waste Oil Tank.

j) Prepare for receiving of Shore Power Supply, International Shore Connection, cooling arrangement for Air Conditioning and Provision Plants.

k) Provide fire watch in ER at all times, and follow Dockyard Fire and Safety Regulations.

l) Adjust required trim and draught, with deck officer.

m) Take soundings of DB tanks and cofferdam.