Diploma_Thesis_Presentation

On
the
EEDI
and
Minimum

Propulsion
Power

A
case
study
of
Interim
Guidelines
for

determining
minimum
propulsion
power
to

maintain
the
manoeuvrability
of
ships
in

adverse
condi:ons

Diploma
Thesis
Final
Presenta9on

Supervising
professor:
Dr.
Apostolos
Papanikolaou

Na9onal
Technical
University
of
Athens

Georgios
N.
Antonopoulos

R.N:
08107044

The
Energy
Eﬃciency
Design

Index
(EEDI)

What
is
the
Energy
Eﬃciency
Design

Index
(EEDI)?

•  EEDI
is
a
performance
based
indicator
that
expresses
ship’s

carbon
dioxide
emissions
(in
grams)
per
ship’s
transporta9on

work,
given
as
capacity-‐mile

•  EEDI
takes
into
account
the
involuntary
loss
of
speed
due
to

adverse
weather
condi9ons
(considered
BF6),
which
is

expressed
by
the
fw
correc9on
coeﬃcient
and
may
be

referred
to
as
EEDIweather.

What
is
the
required
EEDI?

•  Ships
bigger
than
400
GT,
with
building

contracts
as
from
1st
of
January
2013

and
the
delivery
of
which
is
on
or
a]er

1
July
2015,
will
have
to
meet
an
EEDI

marginal
value
criterion
(or
not

surpass
the
relevant
EEDI
reference

line),
which
depends
on
ship
type
and

size.

•  Following
the
two-‐year
phase
zero
period,
the

reference
level
will
be
9ghtened
incrementally

every
five
years,
in
2015,
2020
and
2025
(via

10%
EEDI
value
reduc9on
each
9me)
to
keep

pace
with
technological
developments
related

to
new
efficiency
and
powering
reduc9on

measures.

•  This
required
price
(Required
EEDI)

comes
from
a
baseline
created
from

different
exis9ng
ships
build
from
1998

to
2007
(Reference
Line)
with
data

form
IHS-‐Fairplay
data
base.

•  Concerns
about
the
validity
of
the

exis9ng
database
are
expressed

Agained
EEDI
and
compliance

measures

•  Ships
whose
agained

EEDI
is
greater
than
the

required,
need
to
take

measures
in
order
to

comply

•  There
are
various

op9ons
regarding
the

way
one
will
choose
to

decrease
a
ship’s

agained
EEDI
value

Op9ons
regarding
EEDI
compliance

•  Slow-‐steaming,

meaning
the
voluntary

reduc5on
of
a
ships

MCR
and
consequently

its
fuel
consump9on,

speed
and
its
carbon

dioxide
emissions

•  Shi]ing
the
powering

curve
to
the
right,
by

means
of

hydrodynamic

op5miza5on

•  Making
realis5c

predic5ons
for
the

power
requirements
of

a
vessel,
based
on
its

intended
trading
routes

and
expected
weather

condi9ons

•  Use
of
alterna5ve
fuels

•  Installa9on
of

innova5ve
eﬃciency

technologies

Slow-‐steaming

+ A
method
already
widespread
in
the
shipping
industry
since

2007,
when
a
drama9c
increase
in
the
price
of
crude
oil

occurred

+ Enabled
the
shipping
industry
to
both
reduce
opera9onal

costs
and
comply
with
the
new
regula9ons

-  Opera9ng
ships
at
a
lower
speed,
than
originally
planned,
is

not
op9mal
in
many
respects

-  With
the
introduc9on
of
slow
steaming
and
of

underpowered
ships,
ships'
manoeuvrability
will
be

aﬀected,
especially
when
ships
operate
in
extreme
weather

phenomena

IMO
Standards
for
Ship
Manoeuvrability
in

2002,
Res.
MSC.137(76)

Currently
Manoeuvrability
is
evaluated
with
specific
trial
manoeuvres

in
calm
water,
in
full
load
condi5on
and
in
deep
water,
addressing
the

following
ship
abili9es:

•  turning
using
hard-‐over
rudder

•  ini9al
turning
(course-‐changing)

But
Manoeuvrability
is
also

influenced
by:

•  Adverse
weather
condi9ons
(dri]
forces
due
to
waves
and
wind)

•  Loading
Condi9ons
that
maximize
the
lateral
windage
area
and/or

lead
to
rudder
surfacing

•  Low
speed

•  Shallow
waters
(squakng
effect)

•  yaw-‐checking

•  course-‐keeping

•  emergency
stopping

Minimum
Propulsion
Power

The
IACS
study
on
Minimum
Power
suggested
that
the
ship
should
be
able
to:

1.
keep
speed
through
water
of
at
least
4.0
knots
in
waves
and
wind
from

any
direc9on

–  ship
must
be
able
to
leave
coastal
area
in
suﬃciently
short
5me,
before

the
weather
condi9ons
become
even
more
severe
that
the
ship
will
not
be

able
to
sail
in
the
open
sea
–
includes
margin
for
currents

2.
Keep
course
in
waves
and
wind
from
any
direc9on

–  Course-‐keeping
is
used
as
a
conserva5ve
criterion
to
ensure

maneuverability

•  To
address
this
issue,
IMO
developed
(on
the
basis
this
study)
the
Interim

Guidelines
for
determining
minimum
propulsion
power
to
maintain
the

maneuverability
of
ships
in
adverse
condi:ons

•  These

Interim
Guidelines
include
a
three-‐level
assessment
(the
third
level

has
been
removed
for
now)
aimed
to
determine
if
a
ship
has
the
available

propulsion
power
to
maintain
her
maneuverability
in
adverse
weather

condi5ons

•  If
a
vessel
complies
with
any
one
of
the
assessment
levels,
it
means
that
its

installed
propulsion
power
is
deemed
suﬃcient

Interim
Guidelines
for
determining
minimum
propulsion

power
to
maintain
the
maneuverability
of
ships
in

adverse
condi:ons

Assessment
level
1:
Minimum

power
lines

•  Installed
power
must
be

greater
than
Minimum

installed
power=
ax(DWT)-‐b

[kW]

•  a,
b
deﬁned
per
ship
type

Assessment
level
1:
Simpliﬁed

Assessment

•  Consists
of
Excel-‐level

arithme9c
calcula9ons

•  Requires
the
calcula9on
of

added
resistance
in
waves
in

respec9ve
environmental

condi9ons

•  RAW
Needs
to
be
determined

through
tank-‐tests
or
computer

codes

Greek
Document
in
MSC
23.91.5:
Safety
evalua:on
of
the
interim

guidelines
for
determining
minimum
propulsion
power
to
maintain

the
manoeuvrability
of
ships
under
adverse
weather
condi:ons

•  Proposed
an
increase
in
the
lower
values
of
Minimum

Power
Lines
by
10-‐15%
in
an
agempt
to
correct

revealed
conﬂicts
between
the
two
assessment
levels

•  Proposed
that
a
more
suitable
adverse
weather

criterion
for
safe
maneuverability
is
minimum
speed

•  Proposed
the
use
of
10Bf
weather
criteria
as
a
result
of

serious
concerns
expressed
regarding
the
adequacy
of

the
current
weather
criteria
(which
were
considered

not
suﬃciently
severe)

Scope
of
this
Thesis

•  inves9gate
the
viability
of
these
sample
ships
in
regard
to

compliance
with
both
the
EEDI
and
the
Interim
Guidelines

•  further
inves9ga9on
on
some
of
the
proposals
made
in
MSC

23.91.5

And,
also
for
one
of
the
ships:

•  the
coeﬃcient
fw
is
determined
and
the
EEDIweather
value
is

calculated

• 
the
rela9on
between
added
resistance
in
waves
to
total

resistance
is
explored

A
case
study
on
4
ships
of
incrementally
bigger
size
and
installed

power
aimed
to:

Approach
of
Added
Resistance
in

Waves

NewDriT
v.7

•  3D
frequency
domain
panel
code

based
on
near-‐field
poten5al

method

•  used
to
solve
the
basic
sea-‐
keeping
problem
and
to
calculate

the
first
order
poten9al
and
the

linear
ship
responses

•  computes
the
added
wave

resistance
as
the
steady
second

order
force
obtained
by
direct

integra5on
of
the
hydrodynamic,

steady
second
order
pressure

ac9ng
on
the
hull’s
weged

surface,
which
can
be
calculated

exactly
from
first
order
poten9al

func9ons
and
their
deriva9ves

LIU

•  3D
9me
domain
panel
code

based
on
far-‐field
poten5al

method

•  is
based
on
considera9ons
of

the
diffracted
and
radiated

wave
energy
and

momentum
flux
at
infinity,

leading
to
the
steady
added

wave
resistance
force
by
the

total
rate
of
momentum

change

Construc9on
of
panelized
surface
for

“TEST_SHIP”

•  for
the
applica5on
of
the
computer
codes

used
for
our
calcula9ons,
a
panelized

surface
of
suﬃcient
accuracy
of
the
hull

needed
to
be
produced
(1080
panels)

•  the
surface
was
described
by
quadrilateral

elements
(panels),
which
are
formed
based

on
four
points

•  Based
on
the
geometric
complexity,
the

hull
was
divided
into
groups
of
diﬀerent

density

Approach
of
added
resistance
in
short

waves

•  Short
waves:
waves
which
are
less
than
0.5
of
the
ship’s
length

•  High
prac9cal
interest:
most
encountered
waves
are
of
short
wave
size

•  Zaraphoni9s
and
Papanikolaou
method:

•  Inputs:
nodes
from
known
waterline
and
assigned
flare
angles,
Cb,
Fn

•  Liu
and
Papanikolaou
simplified
formula:

( )
1
cos 1 4
2 2
sin
1 0.87
sin 1 5
2
n
L
Fn
n a d
B
F F d
L
F g Fn
C
α
θ
ρ ζ α θ
λ
+
=
⎛ ⎞⎛ ⎞
= +⎜ ⎟⎜ ⎟⎜ ⎟
⎝ ⎠⎝ ⎠
∫
r
l
r
•  The
integral
can
be
approximated
by
the

curve
shown
in
the
following
figure,

according
to
the
vessel’s
Cb:

Calcula9on
of
EEDI
for
all
vessels

and
EEDIweather
for
“TEST_SHIP”

EEDI
calcula9on-‐important
factors

•  EEDI
calcula9ons
correspond
to
the

loading
condi9on
that
maximizes

draught,
namely
Load
Line
or
Scantling

•  PME:
The
vessel’s
main
power
is
defined

as
a
75%
of
the
installed
MCR

•  SFCME:
Specific
fuel
oil
consump9on
at

75%
of
MCR

•  PAE:
the
auxiliary
engine
power
is

calculated
as
a
share
of
the
installed

power

•  SFCAE:
Specific
fuel
oil
consump9on
of

the
auxiliary
engines

•  CFME/AE:
conversion
factor
fuel
oil
to
CO2,

dependent
of
the
fuel
type

•  Capacity:
for
most
ship
types
is

considered
equal
to
the
DWT

•  Vref:
reference
speed,
in
EEDI
condi9ons

In
order
to
determine
Vref,
in
absence
of

tank
tests
in
EEDI
condi9on,
the
following

graphical
method
proposed
by
IACS
was

employed:

Calcula9on
of
Vref

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

11
12
13
14
15
16

P
(kW)

Speed
(knots)

SHIP_1

holtrop@se
atrial

hotrop@EE
DI

sea
trial

75%MCR

0

2000

4000

6000

8000

10000

12000

11
12
13
14
15
16

Power,
P(kW)

Velocity
V(knots)

SHIP_2

measured

sea
trial

corrected
@EEDIco
ndi9ons

75%MCR

0

2000

4000

6000

8000

10000

12000

14000

16000

11
12
13
14
15
16

P
(kW)

V
(knots)

SHIP_3

measured

sea
trial

holtrop@
seatrial

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

9
10
11
12
13
14
15
16

P
(kW)

V
(knots)

TEST_SHIP
Powering
curves

Full
Load

Departure

HOLTROP
@EEDI

75%MCR

Agained
EEDI
of
studied
ships

0

2

4

6

8

10

12

14

16

18

20

0
50000
100000
150000
200000
250000
300000
350000
400000
450000

EEDI

DWT
(tons)

EEDI
phases
0-‐3
for
studied
ships

EEDI(phase
0)

EEDI(phase
1)

EEDI(phase
2)

EEDI(phase
3)

TEST_SHIP

SHIP_1

SHIP_2

SHIP_3

•  All
studied
ships
complied
with

EEDI
phase
0
required
value

•  Smaller
ships
marginally

complied
with
phase
0
values

•  Larger
ships
more
easily

sa9sﬁed
future
phases
required

values

Calcula9on
of
EEDIweather
for

“TEST_SHIP”

•  The
correc9on
factor
fw
is
expressed
as
the
ra9o
of
speed
in
adverse
condi9ons

(BF
6)

to
the
ship’s
speed
in
calm
water

•  In
order
to
determine
the
ship’s
speed
in
adverse
condi9ons,
the
added

resistance
in
waves
had
to
be
calculated
in
the
speed
range
0.6Vref-‐Vref

•  A
peak
wave
period
of
Ts=6.7s
corresponds
to
a
wave
length
of
λ=70.1
m,
for
the

studied
vessel,
which
accounts
for
less
than
half
of
her
length
(short
wave
domain)

•  The
new
method
from
Zaraphoni9s
and
Papanikolaou
was
used
to
determine
the

added
resistance
in
waves

•  In
order
to
calculate
the
added
resistance
from
wind,
a
formula
proposed
by
IACS

was
used:

0.00

5000.00

10000.00

15000.00

20000.00

25000.00

30000.00

4.00
6.00
8.00
10.00
12.00
14.00

Added
wave
Resistance
Raw(κP)

V
(knots)

Ts=6.7s,
χ=180

ARISW_FAL

ARISW_new

ARISW_JAP

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0
0.5
1
1.5

Added
wave
Resistance
Raw
(kP)

λ/L

Fn=0.163,
χ=180,
ζw=1.5
m

LIU

ARISW_new

ARISW_FAL

ARISW_JAP

NEWDRIFT

λ=70.1
m

•  A
new
powering
curve
was

constructed,
which
takes
into

account
the
added
resistance
in

waves
and
wind:

Calcula9on
of
EEDIweather
for

“TEST_SHIP”

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

7
9
11
13
15

P
(kW)

V
(knots)

TEST_SHIP
Powering
curves

Full
Load

Departure

HOLTROP@EEDI

75%MCR

ΔRwave+ΔRair

Rela9on
of
Added
Resistance
in
Waves

to
Total
Resistance

0.00

20000.00

40000.00

60000.00

80000.00

100000.00

120000.00

6
7
8
9
10
11
12
13
14

Resistance
(kp)
Velocity
(knots)

Components
of
total
Resistance

Rt(kP)

Ra

Rtr

Rw

Rapp

(1+k1)Rf

Rwave

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

6
8
10
12
14

V
(knots)

Raw/Rtotal

Raw

•  In
increasingly
larger
Froude

numbers
RAW
increases,
but
with

a
decreasingly
gradient
rate:

•  Signiﬁcant
in
rela9vely
low
speeds,
as
it

accounts
for
almost
a
20%
of
the

vessel’s
RT

•  In
greater
speeds,
fric9on
resistance

proves
to
be
the
main
component
of
RT

Applica9on
of
the
Interim

Guidelines
for
determining

minimum
propulsion
power
to

maintain
the
maneuverability
of

ships
in
adverse
condi:ons

Applica9on
of
Minimum
Power
Lines

•  “SHIP_1”
and
“TEST_SHIP”
(the
two
smaller
vessels)
manage
to
successfully
pass

the
assessment,
with
the
second
doing
so
marginally

•  “SHIP_2”
and
“SHIP_3”
fail
to
pass
the
assessment,
and
according
to
the
method

are
found
seriously
underpowered

•  The
Greek
Proposal
stated
that
MPR
lower
values
should
be
increased
–
but
this

may
lead
to
a
large
number
of
vessels
being
considered
underpowered

Applica9on
of
Simpliﬁed
Method

•  Reference
Environment
for

“TEST_SHIP”
and
RAW
results:

0

20000

40000

60000

80000

100000

120000

140000

160000

0
0.5
1
1.5
2
2.5
3

Added
wave
Resistance
Raw
(kP)

λ/L

Fn=0.115,
χ=180,
ζw=2.00m

LIU

ARISW_new

ARISW_FAL

ARISW_JAP

NEWDRIFT

0

50000

100000

150000

200000

250000

300000

0
0.5
1
1.5
2
2.5
3

Added
wave
Resistance
Raw
(kP)

λ/L

Fn=0.115,
χ=180,
ζw=2.75m

LIU

ARISW_new

ARISW_FAL

ARISW_JAP

NEWDRIFT

0

100000

200000

300000

400000

500000

600000

700000

0
0.5
1
1.5
2
2.5
3

Added
wave
Resistance
Raw
(kP)

λ/L

Fn=0.115,
χ=180,
ζw=4.00m

LIU

ARISW_new

ARISW_FAL

ARISW_JAP

NEWDRIFT

Applica9on
of
Simpliﬁed
Method

•  Reference
Environment
(opera9on
in

Mediterranean)

for
“SHIP_1”,

“SHIP_2”

and
“SHIP_3”
and
RAW

results:

0

5000

10000

15000

20000

25000

30000

0.00
0.10
0.20
0.30
0.40
0.50

Added
wave
resistance
Raw
(kP)

λ/L

Raw
(kP),
χ=180,
Tp=7.0s,

ζw=4.0m

SHIP_1

SHIP_2

SHIP_3

0

1000

2000

3000

4000

5000

6000

7000

8000

0.00
0.10
0.20
0.30
0.40
0.50

Added
wave
resistance
Raw
(kP)

λ/L

Raw
(kP),
χ=180,
Tp=7.0s

SHIP_1

SHIP_2

SHIP_3

Results
from
applica9on
of
Simpliﬁed

Method

•  For
all
ships
a
required

advance
speed,
namely

course-‐keeping
speed,
was

calculated

•  The
needed
thrust
to

maintain
this
speed
was

determined
from
the

Resistance
components

•  For
each
case,
the
ΚT(J)=C·∙J2

curve
was
produced
which

was
then
matched
with
the

propeller
open
water

characteris9cs

0.00%

200.00%

400.00%

600.00%

800.00%

1000.00%

1200.00%

ORIGINAL
IG
IG
peak
values
ISC2008

Comments
on
the
results

•  The
formula
proposed
in
Interim
Guidelines
for
calcula9ng
the
Lateral
Submerged

Area
yielded
results
as
much
as
40%
greater
than
the
actual
value
between
all

ships
inves9gated
–
for
“TEST_SHIP”
the
devia9on
was
about
8.0%

•  For
the
same
ship,
it
is
observed
that
even
for
the
reference
environment
assigned

by
Simplified
Assessment
the
power
needs
are
almost
190%
of
the
installed
power

–
this
may
be
agributed
to
the
computed
rela9vely
large
course-‐keeping
speed

which
is
affected
by
the
hull
form,
the
freeboard
and
rudder
area

•  The
ship
”TEST_SHIP”
successfully
passed
the
MPR
assessment
but
failed
to
pass

the
Simplified
Assessment
(any
of
the
three
cases
explored);
this
result
is

contradictory
-‐
higher
levels
on
a
mul5-‐level
assessment
should
be
stricter
than

lower
ones

•  When
tested
against
the
ISC
2008
criteria
(Greek
Proposal),
she
fails
to
comply

with
a
far
greater
margin

•  harmonizing
the
proposed
condi9ons
with
that
described
in
the
Greek
Proposal
is

an
excessive
measure
–
it
would
lead
to
installa9on
of
much
bigger
engines
and

compliance
with
both
EEDI
and
Interim
Guidelines
would
be
impossible

Comments
on
the
results

•  adop9on
of
the
Greek
Proposal
means
that
shipyards
have
to
consider
the
design

changes
such
as
not
only
main
engine
but
also
propeller
sha],
steering
capacity,
main

spec.
and
hull
structure

•  all
three
vessels
that
were
tested
for
intended
opera5on
in
the
Mediterranean

(Tp=7.0s),
successfully,
and
by
a
great
margin,
meet
the
requirements
for
available

propulsion
power

•  for
the
case
of
wind
and
waves
characteris9cs
according
to
the
Greek
Proposal(which

are
highly
unlikely
to
come
across
in
Mediterranean
shipping
routes
)
regula9on,

“SHIP_2”
fails
to
meet
the
requirements,
“SHIP_1”
complies
marginally,
and

“SHIP_3”
complies
with
a
sufficient
margin

•  it’s
unclear
if
the
same
ships
would
successfully
pass
the
assessment
if
the
proposed

by
Simplified
Method
range
of
peak
wave
periods
to
be
tested
in
were
inves9gated

(applies
to
both
cases
considered)

•  SHIP_2
and
SHIP_3
were
not
successful
in
level
1
assessment,
they
were
found
to

have
sufficient
installed
power
to
retain
their
maneuverability
from
level
2

assessment;
this
kind
of
results
show
how
this
mul5-‐level
method
is
supposed
to

func5on
–
although
conserva9veness
is
advised
for
these
results
due
to
the

limita5ons
of
the
opera5onal
scenario
considered

Theore9cal
approach
to
op9mize
the

performance
characteris9cs
for
“SHIP_1”

The
objec9ve
was
to
reduce
the
value
of
the
anained
EEDI
while

retaining
a
posi5ve
assessment
from
the
Interim
Guidelines

Finding
a
suitable
trim
that

minimizes
the
wave
making

resistance
(and
hence
RT)

•  HOLTROP
method
was
used

for
different
trims

•  The
change
of
trim
had

effec5vely
no
impact
on

the
vessel’s
powering
needs

•  Partly
due
to
the

insensi9vity
of
HOLTROP’s

method
in
this
respect

Installa9on
if
a
Wake

Equalizing
Duct
(W.E.D)
in

order
to
enhance
propeller

performance

•  a
reduc9on
of
almost
five
9mes
greater
is

needed
to
achieve
the
required
EEDI
value

for
phase
1

Conclusions

•  Vessels
that
were
designed
prior
to
the
introduc9on
of
the
EEDI
will
struggle

to
comply
with
the
required
EEDI
values
of
future
phases
without
a

significant
decrease
in
speed

•  The
introduc9on
of

Interim
Guidelines
for
determining
minimum
propulsion

power
to
maintain
the
maneuverability
of
ships
in
adverse
condi:ons
is
a

posi5ve
first
step
towards
the
guarantee
of
safety
for
ships
sailing
in
lower

than
indented
speeds

•  Ageing
and
fouling
of
the
vessels’
hulls
should
be
accounted
for
in
the

method

•  This
case
study
showed
that
the
Greek
Proposal
for
stricter
limits
regarding

the
Minimum
Power
Lines
assessment

as
well
as
the
proposed
weather

criteria
used
in
Simplified
Method
has
some
basis
but
needs
to
be
further

inves5gated

Conclusions

•  The
proper
defini5on
of
the
severeness
of
the
weather
condi9ons
(wave

height
and
wind
speed)
is
crucial
for
the
ra9onale
of
the
guidelines;
this

should
be
based
on
accident
analysis
and
related
weather
sta5s5cs

•  The
applica9on
of
different
environmental
criteria
should
be
based
on

indented
opera5ng
routes
of
individual
vessels,
if
not
become
uniform
for

all

•  Correctly
norming
maneuverability
standards
in
adverse
condi5ons
is

very
important,
as
ships
with
required
minimum
propulsion
power
that

are
badly
designed
can
turn
out
to
be
adverse
weather
inadequate
–

different
hull
forms
experience
different
forces

•  Its
important
for
the
shipping
industry
to
find
a
balance
between
safe
and

environmentally
friendly

Ευχαριστώ
για
τη
προσοχή
σας

Τhank
you
for
your
agen9on

Diploma_Thesis_Presentation

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