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Dy

na

m

ic

P

ositionin

g

O

p

erations

BOS-

P

RD-2

6

.900

6

0

6

4.6.5.1 DP Capability Plots

x

Vesse

l’

s

Master

shall

ensure

that

D

P

Capab

ili

ty p

l

ots

are ava

il

ab

l

e on

board

.

x

Capab

ili

ty

p

l

ots

shall

be pr

i

nted

and

arch

i

ved

i

n

appropr

i

ate

b

i

nder

as

per

BOS S

M

S

Vesse

l Fili

n

g

S

ystem

.

T

he p

l

ots

shall

i

nc

l

ude at

l

east

the

fo

ll

ow

i

n

g

scenar

i

o at

current

speeds

of

0,

1

and

2 k

nots

:

x

F

u

ll

y

i

ntact

power

g

enerat

i

on and

thrusters

(

for

any approved

conf

i

g

urat

i

on

documented

i

n

the

D

P

F

MEA

);

x

L

oss

of most effect

i

ve

thruster

(

s

);

x

F

o

ll

ow

i

n

g

the

W

orst Case

F

a

il

ure

D

es

i

g

n

I

ntent

(W

C

FDI).

O

p

erations Mana

g

ers

shall

ma

k

e

sure

that

D

P

capab

ili

ty p

l

ots

are

reca

l

cu

l

ated

, i

f

re

q

u

i

red

,

to

:

x

T

a

k

e

i

nto account

chan

g

es

i

n

vesse

l

thrust

,

w

i

nd or

dra

g

coeff

i

c

i

ents

;

x

Ensure

the

p

l

ots

are

su

i

tab

l

e

for

the env

i

ronmenta

l

cond

i

t

i

ons where

the

D

P

operat

i

ons

are

to

ta

k

e

p

l

ace

;

x

R

ef

l

ect

the

re

q

u

i

rements

of

the

contracted wor

k

scope

(

e.g.

e

x

terna

l l

oads

affect

i

n

g

the

vesse

l);

x

T

o address

operat

i

ona

l

constra

i

nts

i

mposed by

the act

i

v

i

ty

(

reference

i

s

be

i

n

g

made

to CAM

, T

AM

and A

SOG).

x

T

he p

l

ots

should

be

ca

l

cu

l

ated at

1

00%

thrust

i

n

order

to have

p

l

ots

to

compare

the

vesse

l

s

’

stat

i

on

k

eep

i

n

g

performance

to

the

performance of

other

vesse

l

s

compet

i

n

g

for

bus

i

ness

and

at

80%

thrust

i

n order

to

have

p

l

ots w

i

th a more

rea

li

st

i

c

20%

mar

g

i

n

l

eft for

compensat

i

on of

dynam

i

c

var

i

at

i

ons

for

use on board

(

“

Amer

i

can

P

etro

l

eum

I

nst

i

tute

R

ecommended

P

ract

i

ce

2SK”). W

here

20% i

s

found

to be

too

conservat

i

ve

,

the

capab

ili

ty ana

l

ys

i

s

should

be

comp

l

emented w

i

th

a

dynam

i

c

capab

ili

ty

ana

l

ys

i

s

.

T

he most

su

i

tab

l

e

type

of

p

l

ot

shall

be used

to

descr

i

be

the

li

m

i

ts

of

operat

i

ons

of

the

vesse

l

:

x

T

hrust ut

ili

z

at

i

on enve

l

opes

;

x

T

hrust

rosettes

;

x

D

P

capab

ili

ty p

l

ots

.

Masters

shall

use

D

P

capab

ili

ty

stud

i

es

(

hard

copy

D

P

capab

ili

ty p

l

ots

or

on

-li

ne

D

P

capab

ili

ty

ana

l

ys

i

s

)

for

p

l

ann

i

n

g

D

P

operat

i

ons

:

the

stud

i

es

shall

be used

to

determ

i

ne

the weather

operat

i

ona

l

w

i

ndow

the

vesse

l

should

be ab

l

e

to ma

i

nta

i

n

i

ts

pos

i

t

i

on and head

i

n

g

,

typ

i

ca

ll

y a

l

so after

a

s

i

n

g

l

e

fa

il

ure

for CAM

conf

i

g

urat

i

ons

and CAM

R

C

conf

i

g

urat

i

ons

4.6.5.2 DP footprint plots

x

D

P

O

shall

use

BOS D

P

footpr

i

nt

p

l

ots

form

to perform

these

tr

i

a

l

s

every

4

wee

k

s ma

xi

mum

.

x

D

P

O

shall

test

the

fo

ll

ow

i

n

g

s

i

tuat

i

on

:

x

S

teady pos

i

t

i

on w

i

th

a

ll

thrusters

se

l

ected

and

a

ll

sensors

se

l

ected

.

x

36

0

rounds w

i

th

a

ll

thrusters

se

l

ected and

a

ll

sensors

se

l

ected

.

x

S

teady pos

i

t

i

on

i

n

w

orst-case

f

ail

u

re

s

i

tuat

i

on

.

x

D

r

i

ft

test

.

x

BOS

foot pr

i

nt

p

l

ots

b

l

an

k

forms

are

ava

il

ab

l

e

i

n

BOS Vessel Filing System

and

appropr

i

ate

b

i

nder

referr

i

n

g

to

113

A

- D

P

Manua

l. I

n

add

i

t

i

on

, BOS

foot pr

i

nt p

l

ots

shall

be

ava

il

ab

l

e

i

n

T

as

k

Ass

i

stant

.

Vers

i

on

SF (BOS-

P

RD-0

7

0

1

.000

6

-

ver

.

C

R).O

r

i

g

i

na

l D

ate

:

31

/

1

2/20

15

.

Vers

i

on

D

ate

:

N/

A

.

Va

li

d

vers

i

on on

l

y

on

Q

M

S

s

i

te

.

Uncontro

ll

ed

document when

pr

i

nted

.

P

a

g

e

3

2

of

44

P

rocedure prepared by

:

BOS

Head

of

O

perat

i

ons

.

Approved

by

:

BOS

Head

of

O

perat

i

ons

.

Va

li

dated by

:

BOS

Q

ua

li

ty

R

epresentat

i

ve

.

478