Answer
Ans:
① Hull to be inspected for indentaƟon, buckling, Corrosion, Cracks, point adherence.
② Hull is cleaned of marine growth, painted with anƟ-corrosive, anti- fouling Paints & Sacrificial anodes around the hull renewed. (Anodes must be replaced every drydock)
③ Hull is inspected & damages are repaired.
④ GraƟngs on the sides of the ship are cleaned and repaired. All overboard & sea sucƟon values Overhauled.
⑤ Tanks specially below water level consisƟng of water ballast tank, fuel tnk, F.w. tank etc are inspected & cleaned internally after getting G as free & Man entry permit. (Additional not work permit & R.A. required for any repairs to be done)
⑥ Clearances of rudder & Locking devices are examined for rudder drop reading: -
a.) pintle bush clearance
b) Jumping bar clearance.
c) Rudder not breached (Integrity of Rudder) i. e. Water found on removal of bottom
d) External examination of rudder to check for Corrosion, condition of welded seams, cracks etc.
e.) Hydro test & Internal coat by Soak method.
Rudder Checks in drydock
① General condition of Rudder & Straightness of trailing edge.
② External examination of rudder to check for Corrosion, condition of welded seams , cracks etc.
③ Report on Rudder integrity by checking any water found on removal of bottom plug.
④ Pintle clearances
⑤ Inspection of pintle securing nuts & knocking Flange , palm nut, trunking& Rudder horn.
Propeller Checks in drydock
① Trueness of blade & blade Ɵps.
② Any signs of cracks / erosion & Crack detecƟon of boss.
A)Stern tube Aft seal:-
① conidiaƟon of seals ② Removal of rope guard ③ InspecƟon of seal ④ Measurement of Propeller drop between seal 1 & 2 ( seal No. from Aft to Forward )
B) Anodes: - Condition of anodes at all places during inspection ( hull / Ballast tank/ Rudder)
C )Ship Side opening : - Cracks around sea chest, scuppers, overboard discharge values, condition inside sea chest , anode , Blow through pipes & fitting.
D) Additional fittings:- Condition of Doppler, Eco sounder, speed log fitting and opening to be checked.
E) Bilge keel:- Condition of the bilge Keel attachment , damage & cracks specially at the ends.
F) Vertical sides of ships:- check for Indentation & pitting.
G) Flat Bottom.'- The trueness, signs of damage due to grounding, corrosion or Cracks , Condition of drain plugs threads.
H) Anchor checks → Trueness of flukes , freeness of the swivel , conidiaƟon of the pin & Shackle & Measurement of clearance,12 percent max wear, rigging table
I) Anchor chain checks: - Condition of the chain in general, calibration & Condition of stud links.
J) Bulbous bow: - Signs of indentation, pittings, damage to plates , erosions of welds.
K) Bow Thruster:- cracks at periphery of the duct, cracks at attachment of brackets, damage to blade.
L) Top sides → General conidiaƟon, indentaƟon, cracks , condition of Bulwarks.
Following things must be checked by a responsible engineer and Deck officers before water is filled up in the dock: --All Departments in charge to confirm that repairs assigned under their departments are completed successful with tests and surveys are carried out
--Check rudder plug and vent and also check if anode are fitted back on rudder
--Check hull for proper coating of paint; make sure no TBT based paint is used.
--Check Impressed Current Cathodic Protection system (ICCP) anodes are fitted in position and cover removed --Check Anodes are fitted properly on hull and cover removed (if ICCP is not installed)
--Check all double bottom tank plugs are secured
--Check all sea inlets and sea chests gratings are fitted
--Check echo sounder and logs are fitted and covers removed
--Check of Propeller and rudder are clear from any obstruction
--Check if anchor and anchor chain is secured on board
--Check all external connection (shore water supply, shore power cables) are removed
--Check inside the ship all repaired overboard valve are in place
--Secure any moving item inside the ship
--Check sounding of all tank and match them with the value obtain prior entering the Dry doc
--Check stability and trim of the ship. Positive GM should be maintained at all time
--If there is any load shift or change in stability, inform the dock master
--Go through the checklist ag ain and satisfactory checklist to be signed by Master
--Master to sign authority for Flood Certificate
--When flooding reaches overboard valve level, stop it and check all valves and strn tube for leaks --Instruction to every crew member to be vigilant while un-docking.
---Elelctrical bonding wire should be there
SAFETY CHECKS DURING DD DOCKING & UNDOCKING: -
1) Transducer cover removed.
2) Zinc anodes to be uncovered & free of paint.
3) Hull openings blanks & plugs which were put need to be removed.
4) Sea valves & water pipes are properly installed & is in closed position.
5) All under water body work completed.
6) Dock I's free of all debris & blasting material.
7) All Temporary services disconnection.
8) Verify Ship load condition (tank, draft, displacement)
9) Perform tank sounding within 12 hours of undocking.
10) Hull paint curing time has been met as per manufacturer on 24hrs have expired since the final coat of paint, whichever is greater .Final paint thickness to be recorded.
11) Verify draft marks are painted.
12) All sea chest strainer plates are bolted back in place & lock wired. Inlet plugs removed.
13) All Propeller protective covering removed.
14) All DB plugs in place & tight. (vacuum test is carried out & if integrity is Okay then cement is put back ) 15) Propeller shaft seals & rudder packing in place.
16) Rudder bottom plug in place.
17) Propeller free of paint or Contamination.
18) Grounding wires removed
19) Master permission to undock.