→
The
Stability Information Plans and general particulars of the vessel.
→
The
‘General Arrangement Plan’.
→
The
Dry Docking Plan.
→
A
Tank Arrangement Plan.
→
The
‘Shell Expansion Plan’.
→
The
‘Plug Plan’ if not incorporated into the ‘Dry Dock Plan’.
→
The
Rigging Plan.
→
The
Ships Fire Fighting arrangement.
→
The
Chief Officers ‘Repair List’.
→
Cargo
plan (if appropriate).
→
Relevant
certificates for respective survey work.
Preparation
and precautions for entry :
→
All
hatches and beams stowed (to give continuity of strength)
→
Derrick
and cranes down & secured (to counteract roll)
→
Eliminate
free surface
→
Adequate
stability check (adequate GM to counteract the rise in ‘G’ due to
‘P’ force)
→
Consult
dock authorities on draft and trim required.
→
Sound
round all tanks and note all soundings in sounding book.
→
Security
lock-up spaces
→
Lock-up
toilets
→
Rig
fenders.
When
dry docking with cargo aboard :
→
Inform
dock authorities where to position extra shores or blocks to take
account of additional stresses caused by the weight of cargo aboard.
→
Give
cargo areas a lock-up stow whenever possible.
When
in dock :
→
Obtain
telephone/electricity/water, pressure fire line, garbage and
sanitation facilities as soon as possible.
→
Have
documentation ready, inclusive of repair list, for dock personnel.
→
Should
tank plugs need to be removed, sight their removal and retain the
plugs for safe-keeping. Ensure that plugs are labelled after removal.
Checking after completion of docking :
Before
flooding:
o
Sound
round all tanks. The soundings to be same as the initial soundings
when the ship landed overall.
o
Calculate
the stability. The stability must match with the initial stability
condition when the ship landed overall.
o
All
the plugs are in place and pressure tested.
o
Grease
removed from the transducer points.
o
Anodes.
o
Ship
side markings
o
Anchors
heaved up.
o
Paint
dried up.
o
Scaffoldings
removed.
o
Propeller
and rudder are clear of any obstruction and cover.
While
Re-floating :
o
Inform
E/R when flooding dock.
o
Check
for water tightness.
o
Sound
all tanks.
o
Following
times to be logged down:
Flooding
commenced
Vessel
floated
Dock
gate opened
Vessel
left dock.
After
refloating :
o
Check
operation of all equipments.
o
General
cleaning and washing
o
Normal
sailing checklist.
o
Check
water tight integrity of the vessel.
Maintenance
for Anchor in Dry Dock :
o
Arrange
in the dock.
o
Water
blasted.
o
Check
for thickness of the links (if 10% reduction from the original, then
change the whole shackle).
o
Cracks
on the links (hammer tested).
o
Correct
marking.
o
Overhauling
of the bitter end.
Critical
Instant :
o
It
is the instant just before the vessel takes blocks overall.
o
The
upthrust ‘P’ of bilge block acts on the stern frame.
o
The
upthrust ‘P’ will increase in direct proportion to loss of
buoyancy as the water level falls.
o
As
the upthrust ‘P’ increases due to the falling water level, it has
an increasing trimming effect on the vessel.
Trimming
moment = P x LCF
Change of
Trim (COT) = Trimming moment / MCTC
Therefore,
P x LCF
COT =
------------------
MCTC
COT x
MCTC
P =
-------------------
LCF
o
The
upthrust ‘P’ is maximum at the critical instant.
o
It
is called critical instant because maximum loss of GM occurs at this
instant.
If
negative GM occurs in the Dry dock :
o
The
vessel will lose positive stability.
o
She
may capsize.
o
She
may slip off from the blocks.
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