595/ Anchor Handling and Towing Operations Procedure / 992
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p
erations
P
rocedure
BOS-
P
RD-2
6
.900
6
14
f) A minimum of field-specific requirements (such as simultaneous operations, buoyancy buoys,
mooring lines, pre-positioned equipment/arrangements, changes in anchor lines). The
“appendix” should show the anchor pattern with line lengths and operations manual for running
anchor issued by the supplier.
D) Recommendations to related vessels, works specifications shall define requirements to
vessels:
a) Bollard pull;
b) Wires: Towing and working wires(number, dimension);
c) Winch capacity (pull, drum cap diameter and number of drums);
d) Gypsies, number and dimension;
e) Chain lockers, number and capacity;
f) Secondary winches, number and capacity;
g) Guide pins/wire stopper (minimum 2 each);
h) Requirement related to wire termination;
i) Stern roller: single or double for special needs;
j) System for removal of clay;
k) Spooling gear;
l) Minimum freeboard requirement for safety on deck;
m) Requirements related to crane on aft deck for handling equipment if applicable;
n) Keep initial heel as close as possible to even;
o) Lower the centre of gravity, notably by filling double bottom tanks;
p) Avoid any free surface effect within all tanks (keep tanks either full or dry);
q) Ensure that all hatches, manholes and any other openings on the main deck are kept properly
closed;
r) Ensure that all vent heads located on main deck are in good working order.
4.2.1.3 During operation
A) During operations, below procedures shall be observed at all times:
a) In case there are changes in scope of job which may alter calculated loads on the vessel, new
procedures are to be made and shall be approved;
b) Chain / wire shall be maintained within towing pins;
c) All efforts shall be made to maintain the direction of chain / wire aft of the stern roller parallel to
the vessel's centre-line during all manoeuvres. Increasing angles from the centre-line may
increase angles of list;
d) If the vessel is listing so that there is a danger of getting water on the deck, tension shall be
reduced or the on-going operations shall be stopped. If reducing tension does not decrease the
list of the vessel, wire or chain shall be released by using the emergency release system;
e) Avoid any sudden course changing or other “rough” manoeuvring, unless required for safety
reasons;
f) Prohibit fluid transfer, including the shifting of ballast;
g) The force in chain / wire during vertical lift pull (without bollard pull) shall not exceed maximum
tension stated in the stability calculations;
h) Permanent monitoring of the winch (drum position) shall be maintained via vessel electronic
devise (Control Unit, Alarms...) as well as periodic “traditional” checks (i.e. painting marks or
rag attached to the tow wire) in order to identify in the best time any eventual wire pay-out;
i) Whenever pay-out is noted, the Chief Engineer shall be informed, the brake will be then re-
adjusted.
j) In the case of significant pay-out, the
Master
shall notify the MOU about the situation.
k) Necessary actions (i.e. reducing ship speed, cable tension...) should then be necessary.
l) Hydraulic system shall be routinely verified to seek eventual dysfunction or leak.
m) The Use of Dynamic positioning is prohibited when vessel is engaged in Anchor
handling operations.
Version
S
F(
BOS-
P
RD-0
7
01.000
5
-
ver
.
C
R
)
. O
rigina
l D
ate
:
3
1/12/201
5
.
Version
D
ate
: N/
A
.
Va
l
id
version
on
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y on QM
S
site
.
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Procedure prepared
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y
: BOS
Head
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perations
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Approved
b
y
: BOS
Head
of
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perations
.
Va
l
idated
b
y
: BOS
Qua
l
ity
R
epresentative
.
595