Prediction of power of ships

SKIBS

-

0G HAVTEKNIK

Department of Ocean Engin eeri ng

PREDICTION

OF.

POWER OF SE IPS::

by

Sv. Aa. Harvald

DANMARKS TEKNISKE HØJSKOLE

The Technical University of Denmark

LYNGBY Danmark

CONTENTS O. Suxmnary Page i 1. Introduction 1 2. Necessary Power 2

3. Type Ship Methods and Statistical Methods 18

4. Essential Parametérs for Prediction of Power 19

5. Diagrams for Prediction of Power 23

6. Piecewise Methods for Prediction of Powér 26

7. Ship Model Experiments 43

8. Control of Power Estimates 44

9. Conclusions 45

10. Symbols and Units 46

SUMMARY.

Different methods for predicting the required power for the propulsion of

mer-chant ships are desctibed. Diagrams give the relation between the expected power

necesSary for transporting a desired

vo-lume of cargo at a given velocity. Such a

prediction is very rough. Therefore,

dia-grams giving the power as a function of block coefficient, displacement,

length-displacement ratio and. velocity have also been constructed. Finally, the method

normally used at the Department of Ocean

Engineering, The Technical University of Denmark is outlined.

1 INTRODUCTION1

When making preliminary proposals for new ships or

transportation studies the vitalj question facing the

ship-owner, naval architect, politician, economist or student is

often how much power is necessary. The answer can be found in different ways. Just as in preliminary ship design there are three groups of methods to choose between:

Type Ship Methods Statistical Methods Piecewise Methods

When the first-mentioned method is used, a type ship has

to be chosen. The type ship must be of the same type as the

type in the proposal. Further, the main dimensions of the type ship and the velocity must be nearly the saine as

expected for the proposal. An Admiralty. Coefficient for the

type ship is calculated

2, A A'3 y3 C P where A = displacement V = speed P = power

This Admiralty Coefficient is then used for the proposal when predicting the necessary power for propulsion.

Results from model tests and from ship trials can form basis for type ship methods but they can also form basis for

statistical methods. Possibly a regression analysis can be carried out on the results to find optimum solutions.

Results from model tests, from theoretical considerations and from ship trials are the foundation of the piecewise me-thods. With such a method the special features of the pro-posai can be taken into consideration in a better and more

logical way than with other two groups of methods. In addition the piecewise method can be used within a very

broad area. The different methods are still being developed.

2. NECESSARY POWERS

To get an impression of the power necessary for trans-porting a given volume of cargo at a given velocity the diagrams Figs. 1, 2, 3, 4, 5 and 6 have been constructed.

For ships built during the periods:

the shaft power is given as a function of the deadweight

and the velocity of the ship. All data have been taken from

t:

_1877-

₁₉₂₉

II: 1930 - 1939

III: 1940 - 1949

IV: 1950 - 1959

V: 1960 - 1969 VI: 1970 - 1977

the Registers of the Classification _Societies.

The following signatures have been _{used in the diagrams:}

4

_{for the veìocity - intervals: 3,1- 3,5 and}

For fixed values of the velocities _{a set of average curves}

have been drawn. _{As time has passed the deadweight and the} velocity of the ships have _{increased and with this also} the power necessary for propulsion. _{it is worth noting that.}

the system of average curves fits the points on the diagrams

from the different periods very well. Thus,. the technological

developments have not resulted in much better ship forms or

propellers than earlier, _{and as time has passed. it has only}

been practically possible to increase the dimensions _{of the} Ships and the amount _{of power available for propulsion.}

Fig. 7 also gives an impression of the development. _The

same average curves as in Figs. ito _{6 have been inserted,}

and in this net the data for _{three ships all named "Selandia"}

have been plotted. _{The first. "Selandia" was a twin-screw}

cargo and passenger ship built in 1912 by Burmeister & Wain

and the world's first _{ocean-going motor vessel. The second}

"Selandia" was a single-screw _{cargo and passenger ship built} in 1938 by Nalcskov Shipyard; and the third, built in 1972 is

a triple-screw container ship with _{one of the most powerful} diesel engine installations _{ever used in a merchant vessel.}

10,3-10,7 rn/s

£

" " " 3,6- 4,0 _10,8-11,2 n 4,1- 4,5 11,3-11,7

O

n U el 4,6- 5,0 " 11,8-12,2

D

" " n " 5,1- 5,5 'I 12,3-12,7 u it n 5,7- 6,0 _12,9-13,3 + n u 6,2- 6,6 " 13,4-13,8

V

lt n n tI 6,7- 7,1 n 13,9-14,3 n

V

1 " 7,2- 7,6 " 14,4-14,8

ó

_{for the velocity - interval: 7,7- 8,1}

d!'

eT Ii _n

8,2-8,6

el u ii II 8,7- 9,1 x u n n ,e si n U 't

9,39,

9,8-10,2

o

a.

¿ï.

o

p)

o

N - 4 . N

u.-- k.

.1IUUiIiUJUUU

uuutiiuuu

uuUU"

L:

iIUUIhhuIIuiUI

uiiiiiiiuiiuuu

IuliUli

IUIIII!!IIIIINIIIIIHIuIHHIII M 1111111 ii 1110 II

n uiuuuuu lu Hin U liii

. .0 MkUIItIWIuUUIU iuuuuiutuupuuum. UPU, III

Ill

I%ii1iiliIilifliÍ

IIIIIlflHulIIliI

111111

tiiuiiii

iu..uu fluu,U. S "U I

..__

_l'U,lI.iI.- u.Iu.N I.li uUuulUU i.... 111111.

..___

&iuIiiii.

iul.i

ilU

i....iiiiil.I.

:===&b1I' '

' r1I.:!m I

ui: IiI RxIi::uI::g

.

9l1

I!.Ii

_&1

'uhi:inhii.iuuuiiiiiDiuuiiiiuu

!I1IUlUI U

u..uiir IIaI.uuUUUIHiUhUUUUU

ill

lIIlL

.

I.IiNHhIIIIIUIIIII1IIIIIUhIHNhII

II

L!

II

'

imm:IiIIpIuumaIIiIuIuuIiuuuIiHuu

I! Ii!ii

i

_{I!II!IIHHI!!!llhI!!!'!!'IIIIIO!IIHII!!}

a

u

IuIihII

.

sI& 1$.

liii

III

IllS

Ii Iiiii u.0

!!!!!!!II

₍

_{II1IIHfl!I!AI!IIIIII 1111 I!}

!

I'

'

iq

I .

!!h:

"II

U '

',' '

.I

ii

.

II'!

III I

l

III I flUII

II L k.

h .

k'nu

ii

u i ini

a

Ui imiI#iE

I iL

jjjjjjliImjiIìihihI ï1IuIiMIk

t1EUUIllhIIJ ¡IiIHuÏi

iig1iIr

.:..:.ii. II

I. k h- i

..___i

I ii....iiuiuiiumuu

um.ii,u.U.i. uiu

sAaiuiUiiiiIiiuUuiiUUUIiII 1IUI !.

'II 'UUili

i.r' uuuiu.iiiiUhuiuiUUUflhuUUUIIU

kiUk'1

V!ti'IIiI

uiu.. Jaiuuuuiunrnuuuuua

uuuur

iuuuniiiinuuuuuuuuumiuiiuiiiiinuuuuivi 'II9!Ir

upIu.r:ulIuIIwnhIuIIuupu.IalIIuIIpIJuIiuiPi

i'iI .ii:h.

- UNU

_lila

IIJPPUIIItIUuIIIPUUU uiiUIIl,IiIIuIu.SUU

JIIilI1IIIHIUU1IIU uIIulIilIflhIlihlllL 'lklII

iíur'I II!uIMhIIIIIuI!II!!9I

:u:..iiuuiiii,insuu.i.h:irnI 8hIuIhIuIiI t

-

a

_.

UkIr

_{Zk1 ..1}

-IP.. I...U.U.UIIIIUU.UlU..

iiUUII kill hI e '

._ ...UIuII...lUU

..

- . ,uuu.iuu,.i... uuu.ii,uu...u... uIUUII Iq4.NU '

U

'I!!:! i!

;:IiiîiiIIuIIIIIoIIIiiiImIiìn II

i

ii

u u

iii.

i i iiuuuuiiiiiuuuuuuiu

N-f N

N _p,

o

f 4 N

N

o

N 4

' ,, ri

b

r,

..._

.._. .

.uI..:%jIIIHuIIIlnINIuIuu__uuhIulIIIuuIluIuuUHIliuIIIflhIIIIUIU

_,O

IliU%ihII9IHIIIIIIIUlUU1lIIIIIIIWIIIIIIUR1ilhhIIIUtIIIllhIIIhhhhI

_{uuuusuiitiuuu.I,u.S uuuuiuuiUuuuulUU}

.ÍIlUI%Ih11IilUtÌilhIÍI

IlIIlUhIIIHilhIllI

IIøIflhIllhIIIIIIU

_...ul

.____ .-

IL..uII,s. iu.

..___

..__

l.I_, l.'

IUUU-. IUUU-.__

iÍIlIIIIIU ..IIUUIIIlU1UU

== . , .'

iq i

IIU ii

-..__

iIIUtiÌl i. '

.. I.IuI

..

r' uaUUUu

-_uÍsÍ. S , i.ÌUSuIuItUUS

..___

tU'iiIiI !!U* 111 Í IU I

U II

.._____,

Il .11

I uI.ium-

UI .I,IlflURSUU

.I"'.' ,

'uiusi'

IUUU i

-....

uu...,ui...U..IIUIIuiflhIUIUU

I...

4IiiUiUUUUUIIIIIIIIIHIII

_uhU.

11111

liii IIIU

IHUIIIIIIIIII

liii

11111111

.

p.u..

uíia

uu.iwis'u

IlII-IuIuHu

_iiUffihIlU

_{111111 U}upu

iuuiuiu

_iuuiuui

EîI!..____ I k U. .

I

h I ,i iu. I I...

UI...

ianui

I

E!

P!!

. ihm

iiilii

ti -IIIIuI U .

uil

iII 1.lUSI1I(IIUUU .__ i II . _JI I I II IUSUuuuIUUU

LUI..n .iUUU

i...UIuulR

uU

ilhIIpIIIII

1H11

UhU liii IhN uluII VI 111111U1911111U

III,

giuiq l!IU 'IIII

--

s-

-

u... SII.., -- '

IL u.. _.uIl.Ii

,.u.u.urnIu..N.

uur;Itt.

II.IIIuIuIUlISU

_,,._,___ _.j1r___ -

I_ SI

-. ;

.-u...uUSuuUUU.0 .____uI

.l.I

i....IuIuIiU..0 .ISS III IHISk U& i al5IuaIuuIuumU

miIu","'m

I.lSUIIIIUISIUNUU .lu:Ul II UUS - -

uIIIIIuIUSSU-I uIIIIIuIUSSU-IuIIIIIuIUSSU-I.

!IIJIIIIIIHIIi

ii

iiiuiiii

iiuItLi;" II III

luÍ.

.uu.0

ipuiuilpi uuurluu

*ut1ri hr 'IuIUU

r-

u

iii uu

uI!Ir';

u

II

I

II

III

u i. .uuuulIUIuI.UNL

.I%.).ilIIUl' I'

I

1UNSI I UU u uL'

ei. r

IIIi!I lUi lu. I..iuuuuihli1h'

a

- EU .JJAiiE

I hiIllflU!UEIll!!Ull!!ld

I - -

-!

_ ._

...

----'

.

i:iu.

l_'_ O

-

I. -_--.,- --.u:F. -

-. -

u.u

u-ii i.,....

u

iilliirn:iiiiiii

111 11111 1g,

O 9

N 4

I t N

e

I, N f-4 I

Il

III I 1 f-4

O

In

_o

':

I!

M.

Ti -

:--n.

itIiiiII

¡

RI

i .0

u

.UI!i ii

I---!!IIil nil

i

iI

-

I J

-s .5

f

-n

's i

U URU

i

I

-

iliili L.i

%Í1Îìï

-

iii.

I

IIkIkII

U L J 't -r !1 u' II

r--

u

!iIIiIIIUIIII

-c

- =

t-. -t E

--i-

T k -i 1.1 u -1

\

.

I- U

g=_,--A_-1--- --4a

tt ,.- 1

i r .4 s In W

-o

In .4 e, ei 4 e, ei C')

o

u, 'f e, ei (.4

o

In In -z P, _In-z e ci _(I) u 'f ci u,

e

o

o

o

J

o

,n .z m ei

o

u, p,

o

In

o O

0

: .?

a

,)

_O

_O

.

m fi p, ei I ( - u,CD

:::r. ...1iIiIHiiiUhIUlIIIIIIIIII1llhIIIIIIlIIIIlIIIIIIIUIIIIilI

.u...1IIIuuIII nuiuUuuIuIUluIIIIIIuIIIIIlUU

IIUII iinii.uu....

IIlUUI1iLt!9IIII : IIII1IIIUIUIIIIIIIIIHUIIIIIUI

1111111 IIIIIIIIIUUIUU

O

IIUU%tliIIIIIilHIIuIIIlUUIIUIHhIllhIUhIIIIRIIIUIIIUhIU 1111111

U.U. iiiin,utiuuiuiuuUUIU muuuuuuIIiuIppiuuus u,IøIIII

liii

.

Ulm

I%IiuIIIuIIIilhIuuIU I1IiIIIIIIlHlihIIIUU IIIIIIIIIH liii -

',i.uilI.-.I

_{SI'I' III -}

li Ii.1i

.

n .

e.

.I._ iiiiiii

jj

ii

-

-:;::E5

---:Eh!h!!

h!!!!!

-IUL uIL'N UL 1_{IVIIIU ISI ....I.IIIUS...}

..___

A

.lI..iISlIluIU

u,.u.0 im

_{-. u.u...}

_{uinuu ininuuu}

u....i nuii

UIIlIIfl uiuilIII

Ir'"

I

II I%I iIIIkuIIkir5UuI.lI 'iII$IHUIUU.UUIIIflIHIIIIIIHIUU

I

! 'P

h

_{ulki ILÔI u iiUiiiUuuuuuiiønuuiii.iu}

_{UPIUIßflhuIUUU}

liii.

-I

IIIIUIIIIOIUIIIIR

U!

_{UH.III.I. .}

1IIUuuI'IUIuS e.

wu....IIIn.'U.

-

....

--L k UI1)iuIIU1P SS uIUUiuIIfIUPUU

I'm''hh1

_..uu.ii.ikr. - 1 II tuiuI1I uÍU.IuIIIII.

-:

4uuuuI3...m.

...,uu.u,...

C

.I.I.SIILUU.UuIUIIIl11I1UU

..iuluUuuIIUULIJi

1..( .tu.IuIrn.uI...-uuuuUuuuuuuuuIUM

'.'IuIII'hh'h"f''

:

- U Ifli1ThilUIUIuluIIl1IIIUUSU

I-4

UI.

IuuuuIuuIilhuILI

- .I'miIiuI....uuInuimuuuhuuu

o

uuuuaiiiuuuuiuiiniuiui

lIuuUIIUIuuiUUUI - IIuUIuIlIflhIUPUUI

!!l___..._!!1!1!!!!!ft11!UI

_'U-d

IIull!II!fl!l!I!I!U

uuu..iuin..S .N -- t

Il..uIu.nIu..u.

u iq

t- lPv

Ib I I

-I.l..,.,i*JuR..UU ulUSIhtlIIL UP I k

-.

.

)

..1111.IIIuUS..UUU

IuUIIl uIIubL

_{.uuiiIi i}

...IUflhI..uu,'IkI.I

!U 4iIuIIuiUhlu..0

U

uuuiiuIiuui,': J fU1IUJIiUiIIUU

---__II,IuuiiuiuIIUkUif. rì

ii.uiiiuunuuu.m

uS1uIIflhIllIHhIuUIUUIUIIiIuIIlitIUflU'PtII 1k:.41;!!'lIIIPuUUUU

iIlUL14JIluuIIIIIIIuIUIIUUUUI1IIILIIIIUIIlII?UF 1'JLIPI9IIUUIU

ilhIII!iIIIIIIIIIIIIIIIIIIIIlIlIIIIIIIIIUIIIIIil 'U'L9F1UIIIIIIlU

- e. ;i

u;;

--.----

__:

!:_'

iu.imuuiuii...ia:rndi jki -;

.t41r

_il

il

'-.ø IW

e.

O

_{- ,Iid}

O

;

uuuuiiiiuuiuuuuuuu

uiiuu

iuu

II I e. e.

- - -

p IIuI."ilg h k . e. e. C.'

O

O

V)

o O'

-

o

o

o

.4 - .4 .4 V) U N

_i m

1 rn

_{u i uuu}

Ii llhIIIIIIlIIIIIIUU ui.i INUU

I

V)

o

.4

L.':

!IUIflI

--

t. L.

k II

IW 1

I I

I'

.1 ____ ' .1 UI&

:, 'i%IIRtIU

&

k%&U 11111 .,

tILU iUUII

-.

-

--.irii IUIIT "

--

-- *

k

-j..

..

.:--- J

i

U

_{._r}

Sflk1i: 'i:.:

i i:

"..4.T

iiii Uk

--UIIlk'

-

_-

-

I -.L

IILLUlI H

i mi: - -

-

---

_{al_!ma}

'..;L

rnTlI=

-UhU

_l

I _{I IU}

Iii 2iIII 14I

L

-

.UhI

.. -. .

o

uiò.ru & ui

i .n1

..ui.

m i '

]FTk''IV

I IIIi

--uI

iurnui* r

'.i

riuu.iu. -

_{uiiuuua iiiuin}

n.rnu

)!u

;;;fl uIs

UL!JNIlIIluIIIR iiuuio

miumu

u:u: i:aiiuii

riiHII1I1I I11lliI

"r -

--:c:u -

J!iiii

_{_:}-

£Ik&

--

'L

-Ø - -. .R

.uIu.

- -

--.a

___I.l

---

O

-

--_-- mI__,__

L! *

-_.

uuuu uin

i

.. iii

I

iiiiiiiiiiii

I 'IIIHiIUI...

_{i Iuuri.... aiiu}

p u, u, 4 (4 u, .4 44 .4 r

o

o

c.1 u,

o

-4 8

..N.I!il

lu

I

fll I w a' r1

'

o

1 IH

w

_I 11

I

iii

o' - p ipa

III..

T

I

u

i

-'-4 'Q

iuii ..iui.0

..ui.iu...ui.i..uiu_U

uu

..

iii ullIllIuul

uuiiuuug,

hmiw uuuiuuuuu

urniuiuiniu..

I

.1I

ii

iu N III

n

1u

rnu

iiiu

-

n:

. uuw riu

I

iIilu.Ihi

.

--uuIl.._

'Ir"IN

iII:l'IIIb.lull!- .-- IIupIIpuppuu

I.

C iiiutuirnuuusa

HIIU!II

_..

_.

_{iiM l-:}

_-

1.21 I

h.

_-i.

_....lq

_;

-

....

ipu. E uI.sII.'I.u.

.

IIUUUH- t1IU .

%kUUIIuII1I

._

ì.uiuiuI %1IIuuIIIII

-u.

ui.u.iuuuiih iu,jLv¼'LIukU.IIII.ÑUU

'

....u,i.i u

u..uuuu'uÌ,1.UU u..u,uui u

I iii i

tu

I

_!!!!!II

I

I

III I III !

lulL k ,dÍ!q

I'I.iIl, IIk1

1.::-u L::

I:uhulflIrnIlihuIl.Il

-

u.u..IiII.uulu.

i

114 ii i&

iiullJUPt1lÍli 111111

IId sIueu.IuuuItuuu...

U!

IllUlliliA. ...i

,l

I

1 ..iu.u.uu

.:uJu

_{uuI i}

.i I

_'i

u1I luuIu,,iuUuIll..

i.i.í

uIuulIliuIsullau

- u..i.I. ii.uIIi.u.

1iiuI.uI,wuuu.u..

.&I

_{4.I.'SklUI'UlIiiiiIIIIIUU}

...au.uu.uhIuuuuu..u.I4r,u.r

uuui.iulIlIIIllrnulluuuuuIululluIIIIUhuIflP'r 1'L

II1II ill

IIIllbI 1111111

iiiÍI.

huIr'

I Hill

1UUllllhItIUlIIllI1UiI

P

ldIIIIrMpIuuu.

I Uil.

I 0111 IuIilhIlItUhá1111mI

I

lull

du... u.u... .

u uuuu

uuu..IIilfliuu.

...__!.. .!!!!!____!!!!!!!!!t.1uu!!!

'

-

liIIIPI!iIIII

_{. .. ..:::}

i

.flu.flauuuifl.l

__...Iuhh taus. 1._n

flfl

___:::..:::,ilIhiuu...s.uuiuiiunii.iil ¡i..u.a.iiiu.uruutunii

1

1.hhh.11h11hh1MII

ii

II Hl uHU

lluIIIuIII.U.IiUUu11I111UUU.

u..

uu

II..

iiuuuiniuiuuiuu

Il UI

g.

iiii

u.0

urna'....

iUU I UI

III

liii IIIRhllUIIUIUBlIIIIIIIIHIIllIIU

U

i u....si.,uuu...uuuI.IIuiI1IuuUuUmm1u1UUUu1Uhht

U13:k .iiulUIIuIilhuIuIUiIIlUuIiiUIIIIIlH

iiuui,iuiUiIlI.U.

UIULÀ&1I'UIIIII1IIIUIIIIIIUU iIuuuIiIIgulluUUUU IulllIIIIUilllUUU

uIUUUIuIIUIIIIIflhIIIIuIU I.IIulIIIIIflhuIlIUlU..IaiiIIuIIIINhillUUIU

Il III

H IIUIUl ,

IuuIhIkuiI!IIINhIIIIIuIIIUlIIIII1I

iql?uti$uupuuu. 1111111

III

i'liuIlIIlliuII

IflhlliliH 11111 11111 III

:.

_{.i.S..IU1I51u11115111U}

H1I

_{11...uuuitluu..U.}

i

-alu....--

uuauuuuJluuuU u....Iuuu.a...

.31 NIIuI.

IIUI.IIiiuUIUU11huhhhh111

_{IIlIRIU.)UU U. IZICIU IU2} N

=

l::up:.rUI i

. .::::!. rn!:::

:

-!!EE 111111 151111 iIumuuh1uII!EuiEE

''

"_!.JI1Il IIhIl IIIM!UIh1IlIgilhIIIIII 9

o

N '-I 4-' r-4 1-4 04

o

, o Il-i

i

.1-1 '0 t,) Il 0 g4 . 'D bs .1-I rxg g.)

o

w

N _'1

o

in -a ri N

o

N _r-4

o

di r, N di di N in e, N

o

r-1

o

._____ _._..n_,n. .nr

ae

. --- -

--- -- .

-in

. C,,

o O'

o

o

o

.7 ri rl

f

ri rl U, 4 ri ei - U,

.0

II

IIUhá

IIllhIlIHNIIHII.__Nh1ihlhhhhIM

_{uiuiuIiiII1iuuIuuiR}

¡Hill

uu.iiwiiruituh1IIflhIIIII.IIIIIIHIHIIIIHhIuIaIlilhInIrnInhuIu. O

s

.iiiiiiiiiivuiiiuiui.ui II,

4.) _.1-I :..

.::

-.

uu..ui.urn...

ri 1! i r1 - w

ulUli

rnu.u:uuI.iuiiIIIlIllIIßI11iul

_II...

hhhhhhh'IH'hbfh"0'h"hhh1.

'n'."o"uuuu.. :

!!I!MP

_{UIII!1IIII!!!!gIIIIIIIIIHIIIII!}

IÌ!i..!!!

_{Ill,,.. I}

_{. L1',:-}

_{.r,,sw.. ø}

-u..

I I . flI.* I '1Pk _.___ '.7

- u:iliiIiiiU

!!::::"

W

tun uuuiiuuuiiuuiiuuuuu

w I

hhhir"h"mn'hh,""h''

iiiniuuiiuuii øHhIIlIIl

U,

liii

!IuIIl

ilhiflillhl

115

liii IIIflIhuu usuiiiuiuuuuu

.7

- Il

liii IIIflhIÌll

L k 111111 11111111 r, O

1ui1fl1aULRUiUuiU IUuIIUUU

1u.U.uiuussi... IUI Nit tI L ULi

n...

IIuNNIÌIÍuuÍuu iSi.tlIVil t%SIIU S

ii...uii iii...

...

sull iiuuuu ui li.Il.1US

w1....iii uii...

IH1I1I

III 1UU10111111

iIPhh1."h'hhhhI

11UUU1L'i LS&ULI lUlL IlIIlIiIilUUUUi

i

u...

u

uu.uuui i

iuuuui

IIIuuU

-- i p .

"

HNIIII

1Ii

i

- .ì '11h

:iiI II 1H11

muii

I

I liii '

! Lb!!1

r,

!

.1 II!!!'I

l.Jki .1

I .1 _... I...

iQ I..i,.a.

IL ,I.p.. liii U.u__lis SUUUN UI NIIU.1lLUNs ('.1

s

s

II

lhUíìINL

_O

o

o

li lu

IiU

_{iilUIiul III}

'III

lull I

IIhuIIhIIflfl IIIIIHIIU!!!I

uuuuiinnuuu....IIIHhIIIHI1IIIIIll

uuuiiiuI iuuuiiuuiniuuuuuiuuuiiuuvmouuuuuia _Ui ri Ui4 4.1 ei UI.S ri ri r.1 U.,

o

lo

i

N

This ship, too, was built by Burmeister & WaLn. it will be

observed that, in spite of the big differences between the

three ships, the data fit very well in the system of curves. For shipowners with ships all of almost the saine type,

diagrams giving shaft power as a function of deadweight and speed.can give a very safe predetermination of the power

required for propulsion. Such diagrams for tankers, bulk carriers and shelter deck vessels are given in Figs.. 8, 9 and 10, respectively. For other types of ships, it is more convenient to use the displacement instead of the deadweight as a parameter, e.g. as shown for train ferries, tugs and

icebreakers, in Figs. li, 12 and 13, respectively.

In the diagram for the train ferries lines corresponding

2/

= k L

'

have been inserted.

With regard to the diagram for the tugs it will be ob-served that there is a relatively large scatter on the points, due to the fact that the propeller and the machinery of the tug are primarily designed to give big thrust at low velocity.

In discussing the problem "Necessary Power", the question

of extra power haS to be mentioned.

Extra power means here the power in excess of the power necessary.for giving the ship the desired speed on trial.

The extra power is also called service allowance and, provides

for extra resistance of wind, sea, fouling of the hull etc. Some shipowners want very little extra power while others

require a löt.

A little extra power means only that, in bad weather,the

ship has to work at 'a low speed, normally without risk to the ship and 'the crew for that reason.

Further, there is a te.ndency to give big ships relatively less extra power than small ships. The desired extra power can vary from 10% to about 40% of the power necessary in

trial cond.itïons. .

In special cases, the extra power can be about 20.0%, as

It) :

',

() N

o Q

_.z

_i

_f4

o

_d).

_i

o

_EI.: 11 P

o

-a

uiu II

..i...iii

__fl.fluI,u

"T fl"

11g

i.u..i

lull. UIIUIIUU uuIuIIIInl

II. 1WI. liii 1111

11111 11111

iiiuui

IIIIIIlIINIUhIUU

flu

ri liN

liii

11111

NIlilill

IIIIIIIIIIIIIIIIIIUU ,O

IIIIh Ii!1IIIIIIlIIllhUUIIUUIIIIIIIIIIlIIlIIIIIIlIlIIIIIUIIflhIIIIU1II

:::::I:1I:1llllIH:I:::::I:IIILnmIII:II::I:::uhuIiIiiHI:::;II::

-:::k1h:

aUIIIIII

..___

. . IiIir .u.mSIIIiI1uI. S-- IuuNmuiIuu....

...__

'il' .

dlU...____aUUPIIUWlSUShhihU1M

...__

IIIb__JI II

!-1

:

.tduh

...:-:::===

- :2 = .

::::

!!5I I Ih:1IIIuIiEJI!!E!

'u

__IiIi IUSS

ii...IiuuI.I.0

O

..__

iirn,r .1 .iIui..

IuU.uIIsuiiuU.NIIUSUIIIIUUUNU

_{UIUUUIIIIflIIUU}

u...iuunuiL Iu,i..IIu.uuulIIIIIuIU

III

III I

I!!"°I

II

UIIIIIHIIHIIIIIIUIU.IUIIIIuIIIIIIIilhIUuI

-

u..

u.... ii iu'u uiuvh

uuuumurnupuu uuuuiiuuuiuPuUiUU

-mi uni ii ii.rnuuunn.us ,uuuiiIiuululuIiN

!IU!!1IIIH i II

u

uu.

_Eui

IIIlIflI NOPI1III!iIIII!II!!'!!!E

i I

-.uIUuU I

liii Nil i NUN

:

1,1j :j

- ::

_{iup. In. .}

--n..Pi uijnuuuu

- Um

u...

*1..iU uIIuIIUaUUIk

_uuu

_I1A'

II !uuIIH..Il..uUlIIIIIuÌ

i .I..u...I.uuIiIuIuuUUuU

_IIIUIUIIIU

I iuuiuiiuiuui..iu.

IIIH"

IIIlIIIiiIIiIIL'l 11

i1iflIui?iuIUUUiUuIiiiIIIuIIIli

III

liii IIINIIIHIII% '

IiIihQ

hh"Fh'"hmf'hh"fu'hI''h'hh'hh"

UN

Ii

mIIIIIIHIIUUUIUU1111111 IflhlOUhP

_.

_{_uu...__.}

_I

lL1Í.III1liÌL'iliU_U ,n,I1IJUNU

_-

IUUPIIIIIIIIIIIIU

lilIlIllillillil

IU.N1h,

uuU.UuIiIViu..uu..I...UuU I1U4I iiI'...'u.'uUuS.- i.UU.luII DU.ii...IIIrnU.Uu..

u..

- __u

_{.-__}

_{__u.u.}

i.

IIB

..SIUiiI&I u

_{,u 'mu}

i 1....lIIIU.U...._{....uII._.uu} m

u

i..u.itii.uu._{uuu.iiiinu.u..}

uu....uu.uiuuiuuui...Suuuu.IiilUUuu.UJUmIuuU1111U1u11UU

...,n.uIInunuuUu.NRUHIIIII!HBIUIUUSUIuIIUIIIIUUIIUUN

...uun.inirniuu...iiiifluIIIIguiflhIlIlUIIIIIIIflUflflflhI

g 1 .l- in -, r ni g) .1 in ni

O

O

cg U) U)

-l'i'

_{:h.IIIIOIIllIIflh1I!II!iIIIIIPIIIlP1hh1NlIIJ11I00fu!! -z}

---:u:umb:IIIIIIIUII i

i

- _{- -}

N1

_{;::: krnu::}

_IflIILIHh

_--

jjjj1

--

I...,. - U

UiIIiaUUUIUUtIIIIJU

N u i1...iIIuI..U.U.._{.u.u.ISIIM.uuu.0}

-II'UiI!IIIIIIIIIIIIIIru'wu'1"'fh''hhhh»hhhhhhh'

luIIhhii Ii

IIIUIUI1I1IUUilIIOII1IIIIUU

U,

o

U) U F4 uIIIU

_1ii.

uI 1111 II

I IUU

Ill_fl

_l,

I VU

1111

IiI

iiauiaii i iui

iiu_______ - :- g::

::

,.-I.1

----e pr'

ni u_

__ .I__

:

uII_ u

:

-;= :: :

-:.

:'

c- -. -

---

I

-- --

u U S

__._

U I 1 I

.

il_i

u_i.

I l_I

i i u

ui iauu

i la i.____

- :g ::i

ìun :

- ..

- I ...__________ I

u_ .

--

E___

_-

_S

I

_______

______t.

._ -

--I

u

ir

.-,

---

-- i

--a

a

u

I

________

--

:=-.

----

___.

- L

-.

--

p t& uu &

-

_._I.iI k______

s41.4 4) 't,

o

l!

E

__I..

_{__,..}

_.

__i.I_.

__Iuu_.

--1=

--uun.

--uiaiui

IuIiHUl_I

u i i iu -

11UH1UU1

uiaiiaui

--u-.-.

--S-I-.

--uI-.

U) W

o

's r) I t r)

= -

_{arnnu_--}

.. aI

--

I -

-- --

-'U

FI = =______

---

-

-:

III

-'--

-

uu

- _{$: - -- -- - -}

-1l

__I.._S U_

--UI rl u,

O

o

FI UI .4 rl C...

o

______u.aï

U)

o Q

U) i..ui.uuu... .4

o

F4 IA J P F4

iuiiIUlIIUUR i.i

1111u11uH1R I

ii

...i,u.imiiuuu.uulIuuI

1U111U1111111111111II

!IIIrnumIIIuii.uI

:;iHlliflrni

_{ii nus}

_)uu

IUIU

'-in-i

] t .

i

_I u & I-

-

I

l.IIIL

I

._

I .4

o

UI .4 r) F4 U) .4 r) rU

o

o

io

4

kW

2 iO L 3 2 93 s 4- 3 ₁₀₂ s A

Fig. 10.

Power diagram for shelter deck vessels.

iO SPB 4

kW

2

i0

s 4 2 4 3 102

__..I

U.UuulIIUuIIIluUUla..SII.IIIUIIIUuIlISlUIIUuIIINIUU1111U11111111IUI

USIiIHIiUNIIIIUISI..UUUIIIUWiIIUIIIIUUUIflhIUIIIIIIIUflNUIIIIlUIIIIIIIIIlU11 UlIIlIIIIHflhIIlIuII1llIUhIliIWlIIIIlIIIUIIlUhIIflIllhIIIIIIlUIIUIIIIIIflhIliuIIIIUUII111

lIIIIIflIllIIIllhIHNIIIIIIVlIHhIIIIIUUIIIIIIIIJ1UWIIIVUNIIIIIflIHIIUIIIIIUUIII

..uuir-i- wirurvr .;riva

UIIUIIHIUIIIUN IIlUuIIIIHhIIUfl

uuii'ìii._

J

.t'!i

IIIIHIIUIIIIUM IIuIlIIUlIlII,uII

a

__

-___ -- _ . ___. ....a,u,uIsu.PP ___ - . .ul uIuIu.uI

---p : ....rui,I.au..

..

--uuIIHII

.. .au.vuui..ui..u.ullII4

.UU.UutIPuIIUU11

.

:::E ..!!E ___. .R..rnl

.

U I Ialfl

u...SJ,III...lIa

___. ...uu,ii ..u.I ' " 1

ua.ii,iii..u,I..

___.. .uuIuIIII u .u.uujuuI....l . . a.. uuiiuiiiiuuuII

LLLL1 IUiiiiUitiilliIURSI

mui

IUUI

___ . .fl.nuIII_flfl__

----mnnI.ttaaa.. a...U.IIU.U1S ___ u .u..wi., ___. u

_. dUIIIIIUI

.u..II.III....I

___. MlUNU5IIUUU

___..

.UII1iiIUIU

iii1.

- _.. u ....IIIIil..uuI

___.

.r;g.uarns*I. ....iuu,iia.UuU

--_.

-- --- . .

___. ....rn.ii ...,. ..u.IuIUU..RI U. - _. ...$iIN$..Ua

..vIIui.0

iiuiI..UaU..

-- _.

___..

__._. ..u.ni..1

__- .. u ..IattI,uuIuIl UflIIDUUI UUIHIItIIU1II

iinuiiiiuiiivauiii

IlUIIIIIHUBhIIflhIUUhiPd!!iiIIIIfthIUUUIIIIIlflIHhIIJHhIlIIIUuIPIllHhlIIIIlUUUIII

--fl_i e 1flS

flfl

flaSSSStUII SSUSUn SUflSUIIS.SSlfl

t1IUUfla. W44.U.IIIIIISUSflaaUflUI1ISUUUU

2

!!!!!!!!

2 .. ....I.II,I.eUI - - . ...UuIII.UUl -- -- . ....s.ui,I....0

. ...S..n

...aurnuiuuuIIl.U. ....nu,i....i...UuuJIulI..l..I11111IIUIU1

_{_.u.uiuunuiii.uuuUa_S.IuUflI.It,IU.III__U.I.IUlH11,t'IU'1_U1"fm.'hh1__u ....uiuunnuiuuuui---...u.u'Inuu'uuIII.u.lIuu'uu"uuPlU__m1111"H11Iu1u,'_..}

.UIiuI,uIIuiIiiiiuI.USUIIuIIlUIIIIIIuuIIUuuIUIfl111t1111ISU11IUhhlU1U

.UlIlIIlUHIIIIUIIIIRIl.IIIIIlHhUflliuII1NUUIIIIIIHIHIlIIUIU

iIIIIHfthIfluIiUUIUiUPI

IIUUHuIIlihIIIIIIfthIlIIUIUIIIWIIIIIIIIU1UUUUuuIHUIIIIIIIIIHU UUuuIIIUuIHhIuIIIIIIUUIuI

102 345

102 345

102

10

2'45

t II

'l'i'

'J J I J

I'''I''

'''J

III il

10± 2 2 3 2

iO5 t Dw

B5

10 C'I

a

_-

-

_,, 1

o

-

o

., 4.,

o

II ItlIllIll

_{U. _1uI.uuIilhIuI..IIIIU}

-

.1.,...1.i.IumuHnamhuIIuIahIIIIIHIHIIIh. .-

IIIIIUUUI

i

igii ii...

IIIuI..IuIUluu,IIIIilhIIIHhIIIIIIIII1IIIHOIIHhIIIHIOlIO11!!Ih1111U

IIUIRUIIIIIIIHIINllHIUhUuUuIIIIIIllHlIIIIIIIIuIUIflIilIh'HIIIIUIU

.. ..i

__

-..._iÏÎLWIHIh.uuuu.

Ii::uhIIIlu,luuI..mIIIulthHIIuI...

_i.u...

II.

iu....

-EEEEEt

.4 .

-u,

a.__

ilt.SIIIfl.IUI.S

qin..u..:

Í auIIIltUI .

o

a a ___ upu..iiIOhIIIIUIIHIIlIINI1U1H10111111.11.1111111U1101flIr

iiIiifliflhii

iIUUUUIuIulIlIIiilulUlISIuUIiIlHIiUhi

IIIIIUIIIIUIIII

U

IUl$IIiiiuIIIIIIliuIIUU

II.iiiIIIUIHiilIUUUMIaIilhIIIIliuiiuI

111

UUUUIIIUuIIIilIIIIIilU x

UUhiIiHhhIiiIiHIIIU.IlIIIIIIlihlIIIUuIIiIIIllII

UUI,IUIIIIIIHhlIlIlilhIiIlIIIlIIIIIlllhIHhIIIIUIIIIlIIIIIIUhlIIIIIII

I

-

IIUlU uuu.

-

_{____________}

...UIIIIIIIIIHIII....I.IiuU

____

!!!E:

.:r

_{,qP1. r.} - _{I aa a}

ìiiuun -

..'

--

o

juiuIti

.._____-um...sI_uiIIuIUhiIIiIuUE

ir'uiiiiiu.i.uiu.aiuiiuiuiuiifiiiIillhlI

1III1IlIIHII1IllhIIIIIII1uuuIIIdII,uuuIuuu,IIII'unhuIuIIa

_-'tuI9IIPPhI

.---

.;..;...-

_{1._l} uil,... . .

a..u.uuuuur.uau.

..._i

IIIIUUIIIIIIItIIIt'!!!

--

_IU ....a II _{,L\ .- u....}

. -

--u.iiu

iiuimu.iuuivai.iii;:::

..:'::::I ,..._

'iuIiIIIflIU

mu. uiIirnu.uu

HIuum*IIUEI'I

uUUuP...uIIUHIIIIuIIIURilhIU

uiuuiu....

Ia...i.uIIII IIIIIIIIIIIuIIHIIIIHII'Th'u1hh'"'

IUIIUx I1II1U1L.

uIlIU.lflhIIllIflUhUIUIUU.UIHhUHflflIUhIuIIlS!I19

IIIIflhIHIIIIUUuIIIu

11I!I'

..un.g... - -

--

:

!îIiu1lii9II

U

!

_{_uuii!IIIIi1l!P!.UU}

j

I5!l1!:il

e---

-:

, ,

U uIUU

I'ir

U rUr uilU

i $ 1111111

i

«' "II1! u u.

0

p II p.I I,

J

Ib 111

lii'

uiuuiuiiinuui Ilul Jill r, e.. r' fU C,,

o

-rl rl C'I I I i

I'

_k'1'

1 U, u, 't , .7 '7 . U,

o

-

.

o

o

_-

e

r

I.r

ri

ei,,

ri

o

ri ri

o

III

luau__s_Il

-_._ --

u....iuiEE..u.US

..______Í.

tri..

:===xfl--rT

:

::::

:::=====.i*.rndm-.

....

-____ __eI

J.... ._ --

.--..__

uIasUÌIItiIUUU

...__

u..u_s_IlluuuH,uullulL.11.liIInIur1suus_lIlIlIIIIHIluIulau

liiiia uIIIuII,IIahIunhU

. I ....iuu11.aU

.I..lUuiiii4lIUlUS'

__ _____

n,LaflaafltVflJuhuIflflU

..___

1-_

ii.,ici.u.I'.

.

___ uauliiflflis.L

IIU

I.ua.tIuI..

_S

_{uui..iuiinui.. U. - BlU .iiiiHlS.l W iulU.1IISJI'U U}

.0__________u.s...nln...aIUU

UUUU U

..iiU..i,IiUl.U.U1111UlI1i

U UiUUtUIiI ... SU - - hUIS ,iftl.11S S S - - ' I UJU IIIUIIUUUU 5

U -- - uiu..uiiiiiuuu S i1U u IIfll4UUll U - h iu IIII1IUUU UU

l..u...11lIIIIIIrnluulIIlIlIIIIlJIlIIUl .I..uIL.IIIlolllIuuuuu

lIUUIUIIIIUIIIIUIIIIIUIUU s_llllUflhIUllU Iuusk1uuuIIrnluluI1U

uuui..iiiuiuiiiniiiiiiii.,iiiIulIIIiUhIIIIIlIU.IaIIIWHINhIIIIIIU

iiiiiUiiiiiiiiiiiifluIUIIIUIIIIIItIIHhIIIIlIUlRRUIIIIIhIHIUIDhU

UUl.U,

lSl..UIUIIIIWIUUUSS

U.R.UUUUSthhuUUUUUUUUISllUIlIIlhIUU s,...i,unu'uuu

i Ì:.u.UUIÌh;IlllUlUSUhUUUUIIhI

.I..

hIlUUiuIhh1l...

!

1EIhi:

...U. lfl.1111

U hIUIhIIiJhh*

UI jI..uuii..lUUUIUUIIIhUUl15

ItUUSIhihhhÍhUU SU

...l,.u,l...111UU1II1111U11SS

hhUUlIUhllhlUU SU&

llU.U.uIIllUhlHlUIUllUIuIuIIIlIIIUUlUaM11U1111IH1UIh

uu....lululuhIuuhuluauaIuIllIIurnllIluUuaMlIuIUUilhIlluUlIURu

lUUUIUllUIIIII1flllflUIUUIllllIIIIIUhlilhlIUSUlIIUhIIIlIllIU IIU

uiiIN.ii,Uu.,iiInhiuIIU..I.liuIIIIlrnuhIuIII.IIUIuIHIIliuIIIuIIuI

UI UI .4 ri: ri Q. lAO

bwQ4

w

w o

'i 4 'I ri

'C

O

Uil

o

U) ! 41 11W

011

.4

(

øi 4,

krl

ri

rI

Cd P4U UI .4 ri

o

UI

16.

a

o

_i41

_ri ri ri

u,

C

u,

C

d) .1 r

o

-t

o

't I.' C,,

o

o

14 It, 4 t, t1 '.4

o

...--.iuuui,iirnu.uu...---.-Iu.uIulIiluu...--.-IuI..I,uI,u.I...--...uuiuuIiiiiim.I..U.UIUhIIIIAIIIIUaUIIIIUIIIIAhIIuU

i....uiHhIIIIInuhIIu.m.s.IIIIIuIuNhIUIBI..IuIIIlIilIrnIIUflIu

IiiUU.iiItIiItfluI1iIiilhIUUUIIflhIIIlflWIUUIUIIIIIIIIHIHIIIUhIU

iIiiiUIuiiiiilllluhiIIlIIl.UIIIIIIIIIHIUHIIUIUUIÌIIIIIIIHIHIIIIIIIIU

:::::::::IIunm::n:::iiiImtIImIu:II::::IIIillIH011UIHfl

:::::::::ulu

:::::

' .::I.!!!jf!:

::::

-

_{.____}

!...z!r..huEh!:

..___

hIaliiIIi4IUN

.

.IU..UUuIlEI.UU...IUUUUIISIUUUUSUUItUU1IUlU

__i...NuuI.rnl.uue.__

...Uli..,iiIIUi..U...IIU.II1UMI.IUUIUUIliIflhUUUUU

UUU.UUIIIIllllIIU....SlIIUIIUHIIIIUUlUUIIUIflINUIlUUUS

uusu..iuuip-: jifl.UU..lIliUflhlIIIIIlIUUIIIUlIIIIHIIIIlUUU

IuIIIIIIIII!;!IIIIIIilIUIIIIIIIIIUNhIIIlIUUIUIIIIUIIUhIUIIflhIURI

p...:III,Iu.uHIrn,uupuu.. -

iIuhuIIiIuhuuul uuuuuwiwupiuls.

-i...

riuituiniiiiiius

iuuuuiiutuhiiiui

iiiuuirniuuuiui.

:;;=- :R:IuImIt;EIB:::====uIIIIIwuIIIul...=I:IIIußrnI:u::==

..____ !uI u., liii . .

UIUu.IuII.IS

..____ -

I.. UI$.uHn

IIUmlIIU

..iu."ii

-_ -_-_-_-_-_-_ ,v,

.P UUUU

..

._.___ muii..i

'I

u..i..'lui.

u.

Ie_ I

U

I I.ItI

I ..;..;.

==

UUUiiUUP

u.0 I fli.Um

.____

. I i1.. U....uI.I.l..

.__

_{'U UIÌU,1...iIIÍUiUuiSI.UU}

i i i.iuU.

...IIIrnUU...u.IIIUiIiIIIuIIUiUUUuiUIMUI

...u.urnluiIliu.I.N.IuU'UiIiIL'ulU1UWIUUliIiUUlUU

u.0 uIIiuuItItrnIIuIuuuuIlnuIUIIL'IhILuIuIUIUIUHIIflUIIIUIIR

uIIIuuIIIIIIIIIrnIuuIuIuUUuIuIHuIIuIL1hIIuIUUhIIflhIIIlIIIIIlihIU

uuu ippp.uuuIIu..upu. iuuuuiiiiuuuui'mi' iuiiuiiuuiiiuuiuim

uNU :IlIuIIIlIIlIuuIuIU

tilhlIIHHIIuIi

uuÍlIIiUftIÌÌIuIa

-:;;;

;11iiilIli9IiIIft.

u

ia.j

iuiiuuiu.'

u..m...S

!t!

'I!uuItI!IHIllhulIi

ihIEI IIUIIllI=ii:E!::::::::u:::

fluuuqSIUSUalauuIUtSuÌu * iuu.a ulnuuuSa

-

p-q IuUUIlIuuUU U IIUII....

--..

UluUUIIIflHUliUIUUIIuUUIIiiHuIUIUUUhUIIIuIHIUU

..u..nuiuiui.rn.u...s.uuiuuiiiiu.uui...uuuuumunuuiu

uiUuuiuuIuiiuhiuuIuiUIUIuiIuluiInhiiiuiiUUUIIHIIHIAIIIIuU

iuuuiiuuiuiiiiuuuuiiiuivinuuiuiiniunuuiuuiiuuiuuiiiwiuuuuuuuu

It' 't t, CIt C,)

o

'I t, "4 .1

o

-r t,, (It -t

C

18

propellers at each end, working in fairways filled with

pack-ice. On the other hand, in some cases, the speed stated

can,. for various reasons, only be obtained when the ship is working in following wind and sea. In other words, the

extra power has been a negative amount. This also means

that the scattering of the points must be very large in dia-grams where the power installed is given only as a function

of deadweight and speed.

TYPE SHIP METHODS AND STATISTICAL METHQDSI Using a type ship method, first an Admiralty Coefficient

Ac for the type. ship is calculated and then the power for the proposal:

L«3 y3

_p

p A C where .

and VP

are the displacement and the desired

speed for the proposed ship, respectively. A great deal of

information about _Ac is availáhie and a preliminary design

formula for _A can be given by

= 3,7 (/r: +

L iS the length of the ship in metres and V is the speed

in metres per second. The power P will be in kilowatts if in the formula is the mass in tons of 1000 kilogrammes. Thus the type ship method and a statistical method are

com-bined.

Another formula of thistype for prediction of power

has been proposed by Watson [11]. In metric units and slight-ly modified, the formula is.:

= 510 v3(40 - Q,017 L + 400(K-1)2 -12 )

where

P = power in kw

4 = displacement mass in t V = speed in rn/s

L = length of ship in m

K = the constant in the Alexander formula

â = K - 0,5 -y- (kn/ft½) _{i.e. K l,Ô6} 't

6 = block coefficient

n= revolutions per second

This formula is built up in a rclatively logical way of all

the most essential parameters for the power required.

Neglecting the influence of the block coefficient, the

formula becomes

-2,

5,0 A V3 (33 - 0,01714

15000-llOn't

Application of the formulae given above must be done with

care.. The formulae norival.lyfit special types and sizes

of ships, and applied outside this area, the results can be

wrong. it is not often mentioned within which area th

formulae can be applied. In that respect diagrams showing the relàtions between the different parameters give a. better survey of the field of application.

ESSENTIAL PARAMETERS FOR PREDICTION. OF POWER,

When

constructing

a diagram for the prediction of. power

for the propulsion of ships the choice of parameters is of

the greatest importance. There are many conceivable

para-meters, and if simple diagrams are wanted, a selection must

take place.

To a great extent, parameters of importance for the ship resistance must also be of importance for the power

neces-sary fòr the propulsion f the ship at a given velocity or

20

Froude number. Thus, the principal dimensions and parameters describing the form of the ship will determine both the ship

resistance and the power for propulsion. At previous occa-sions (see "Ship Resistance" [4]) the author has used the

following parameters for describing the form:

Length-displacement ratio L/

Longitudinal prismatic coefficient

Breadth-draught ratio B/T

Longitudinal position of

centre of buoyancy LCB/L

If the ship has sections which are distinctly U-shaped

or V-shaped and if the ship has bulbous bow or special appen-dages, allowance must be made for this. in addition the con-dition of the hull surface influences the ship resistance.

The above-mentioned parameters are also among the para-meters determining the thrust deduction and the waké and

thereby the

hull,

efficiency. Furthermore, the. propeller(s),

the positión of the propeller(s) and the form and position

of the rudder(s) influence the hull efficiency.

In addition, the efficiency of the propeller and the total propulsive efficiency depend upon the dimensions and

form of the propeller(s). Fig. 14,gives an impression of the influence of the size of propeller upon the power

neces-sary for propulsion. Ship "U" is a bulk çarrier of about

50000 t. deadweight equipped with different propellers [6]. Using a large, slowly running propeller instead of a small, fast running propeller on the ship "U" at a speed of 8,5 rn/s

(16,5 knots), the necessary power for propulsion of ship "U" can be reduced by about 50 per cent.

Thus, at least 12 parameters are essential 'for the pre-diction of the power for propulsion of the ship. A diagram'

for predicting the power cannot be constructed in such a way

that all parameters are taken into account in the right way.

A standardization of some of the parameters has to take place. If it is assumed that diagrams predicting the power for pro-pulsion may only involve four parameters, the following

25000

20000

kW

15000

io 000

5000

O o

SH

v=

'Pu

8,5

,4

(m)

₆

Fig. 14. Necessary power for ship "U" equipped with

different propellers.

n

3,0

22

parameters are suggested:

= displacement.. Hereby the size of the ship is

fixed.

V = speed of ship. The power f or propulsïon will at least depend on the third power of the speed.

= _{- block coefficient, which to some extent}

describes the form of the ship.

i

= length-displacement ratio, which iS a form coefficient that has almost no correlation to

the block coefficient.

This means that all other parämeters have to be stan-dardized, which can be done in the following manner:

Hull form. The sections of the "standard"-form are

neither distinctly U-shaped nor distinctly V-shaped. Further, it is assumed that the "standard"-form is a form with well designed lines and with an

ortho-dox non-bulbous bow.

B/T = breadth-draught ratio. For most of the ships this

ratio is in the neìghbourhood of 2,5. For large

Ships, i.e. ships with a displacement in excess of

200000 t, the. ratio is about 3,0. Therefore,

these two ratios may be chosen as a standard.

LCB = longitudinal position of centre of buoyancy. The

position of LCB.is assumed to be optimum. As

mentioned in "Ship Resistance" ((4] p. 3), the

op-timum LCB is

unfortunately

a quantity that is in

some doubt.

Appendages. The "standard" form has no special

appen-dages. The rudder is a double plated rudder and,

in relation to the propeller,placed in accordance with the rules of the classifidation societies.

Number of propellers. It is assumed that the number of

própellers has very little influence on the power necessary for propulsion of the ship at a given

speed. The standard ship may be a single-screw

ship.

D Propeller diameter. It is assumed that the diameter

of the propeller (four bladed) is optimum (if possible) and less than two-thirds of the draught

of the ship fully loaded.

n Rate of revolution. It is supposed that standard ships are equipped with, a diesel engine running at

a rate of revolution corresponding to maximum con

tinuous rating.

V = Speed of ship on trial. Further, this means that the

surface of the ship is smooth in the standard con-dition.

Service Allowance. The diagrams will be valid only for

shïps in trial conditions. For service conditions allowances have to be made, depend', ing on the

sail-ing route. The values of these allowances can be given as percentages of the power necessary under

trial conditions.

DIAGRAMS FOR PREDICTION OF POWERI

As mentioned in chapter 4, the parameters in diagrams for prediction of power can be

i

L/V V

Therefore, first the effective power

E has been

ship forms: : loo t 200 t - 300 t - 500 t 833 t - 1000 t - 1667 t - 3333 t 5000 t - 7100 t - 14300 t - 21500 t 28500 t 37700 t 50000 t - 100000 t 142900 t - 200000 t - 300000 t 500000 t - 1000000 t I L/V : 4,0 - 5,0 - 6,0 - 7,0

(only some few 7,0-forms have been calculated)

: 0,55 - 0,60 - 0,65 - 0,70 0,80 - 0,85

V : From 3 rn/s to 13,4 rn/s

For the small ships the power has only been calculated at small velocities and for the

big ships only at big velocities.

In the calculation of the total ship resistance coeffi-cient CT the incremental resistance coefficoeffi-cient CA has been varied in such a way that

for disp1acement i = 1000 t _{0A =} 0,6

bObO t

0,4 . io

100000 t O

1000000 t - 0,6 ' 10

All forms have been standardized as mentioned.in the

preceding chapter.

Further, with regard to the rate of revolütion, the

24

following standardization is used:

For ships wïth displacement

up to 1000 t: n = 8,33 revs/sec (500 revs/mm) from 1000 to 2000 t: n = 6,67 revs/sec (400 revs/mm) from 2000 to 3000 t: n = 5,00 revs/sec (300 revs/mm) from 3000 to 5000 t: n = 3,33 revs/sec (200 revs/mm)

from 5000 to 7500 t: n = 2.50 revs/sec (150 revs/mm) from 7500 to 12500 t: n = 2,08 revs/sec (125 revs/mm) from 12500 to 25000 t: n = 1,92 revs/seò (115 revs/mm) from 25000 to 50000 t: n = 1,83 revs/sec (110 revs/mm)

from 50000 and up: n = 1,67 revs/sec

(100 revs/mm)

After the effective power has been calculated the shaft power is determined as follows: By use of the

.ISH-Logarith-mic Propeller Diagrams, which are based on the results from the Wageningen screw serieS B (Fig. 23), the optimum

propel-ler diameter for the standardized ship form is determined. if the diämeter is less than two-thirds of the draught, the

propeller efficiency Ti0, the advance coefficient J and

the pitch ratio are read directly from the propeller diagram. If the diameter is bigger than two-thirds, a diameter of two-thirds of the draught is used in the cálculations.

The hull efficiency

H = is calculated using the waké coefficient w and the thrust deduction coefficient t

estimated from the diagrams in "Wake of Merchant Ships"

([5] Figs. 52 and 104), taking into account that it is the trial trip condItion that is to be designed for (Wtriai "

0,7 wmei).

The diagrams giving w and t for models of

single-screw ships are reproduced in Fig. 25 in a slightly modified

version..

The shaft power is then calculated by

BflHflBTIS

where = propeller efficiency in the "behind" condition =

T1OTiR n0.

R

relative rotative efficiency)

26

All the results are plotted in diagrams (see Figs. 15-21), each diagram corresponding to a fixed value of the block

coefficient 6 (0,55, 0,60, 0,65, 0,70, 0,75, 0,80 and 0,85).

In these diagrams the abscissa is the displacement of the

ship in t (of 1000 kg) and the ordinate is the powár in kW

for propulsion òf the ship. Curves of constant speed for

three length-displacement ratios are inserted. By using re-latively large steps in the speed variation in the diagrams,

the curves for different length-displacement ratios at a constant speed become placed in groups, which facilitates

the later use of the diagrams. All curves in the diagrams are faired partly by hand, partly by use of a Hewlett-Packard

9830 A calculator.

The diagrams, Figs. 15-21, can be used in the preliminary prediction of the power necessary for propulsion at a given speed, but it has to be borne in mind that it is the power for the standard ship in the standard condition that is

estimated. In every case, service allowance has to be added

in accordance with the wishes of the coming owners.

The designer of the ship often has his own standard forni for the hull. It is then advantageous for him to make power curves for this standard form using the same parameters as

in the diagrams mentioned above. The use of such diagrams results in a very reliable prediction of the power.

PIECEWISE METHODS FOR PREDICTiON OF POWER.

In the previous chapter the prediction method normally used at the Department of Ocean Engineering, The Technical

University of Denmark, has been partly described. In the

following, a more detailed description will take place.

A. Dimensions of ship. It i assumed that the principal

dimensions for the proposed ship are already fixed or that the power has tobe estimated for a series of proposals with given dimensions to find optimum

o

4 4I Cd

IJ%

'kt

u.u.&.ius'

_{IINII....k\uIUUUuIuIIIuIIUUUIU11IIHulUIUN}

.ivu'u.

r:t'r.;'

\' uuP .IuuHruu. ,uuu.IuulIuuIuu.

-.

ui,1iiHIuirI

::I:i:iz:::& a:::::

flUhlIlIHIlIlI

:;:::::

.__ 1SIS

.i....I.UUUm.IIIUIU

'ucl% IIO%'IUUC'

.u...uIUUUtlIIWIU

...iva i'..&%ui' uII.u.I

u.ui.iii" iu.u..UU...uuuIIIIl.U

:!1 "k

I

::::

- _{SUuIIr lu} -un _{IIll %}

.

S

i.u.IU...III1fl1US

..__ _I

I.'S I 'IS

...__

ia

XuMiiUU uSIIIUUIfllUIU

...__

'...SHIIUIIIIIUIII

.____

-- . .L.I _{lull. ca%3 UuUIIIUI}u....muaIr u...

il..UIIIuI.'.

U.U..UIUIIflhIIIIUI.U.SIUUlIIIIIIIIIUIIlUtIIIit1u1IUU&

S...IIuUuIUIUhIUI.IU.UIlIIUuIilUUIUIUUMUUIIIlIIIIIIIIiI.0

iUUIUIIIIIIIIIIllhIIIlUUU.lIIIlIUIINIUUUUIIUIIIIIIIIIUhIIUIiIlI

4C

o

4 CI

o

In dl u,, Lfl

o

u....

...uuuuIIIIIIIuIuIUU

dl

0

II:I:tIÑuIn3s

'iII

I'-

Lhhi

..U= .,,..2J. ulI%%

i) IIIUIIIliUUIUI U

_!!!!!!!!hl

_su. -f 4J

..___

uIr'IeI

_UWL%IIUU

_I

..____._I..

i....iiuinuIu.U.. n

!!!!:

!E: E!E "-4 .. u.

--"

Cn

lIlUM IuIlL UMl

WlUIUi iuuIUIUUV

.__ JuSumulUiIIS IU%SPI'U

'

.._

uiu.ii. iiuilu.&

NM.lIi&i SIUÌ

o

S1I!dlI*UI '

ui..iiiinui..

_o

U..U.uIUURIIIIJuIUUI

- -

ill .. .._U...IIlSitltluÌ

It%III

_utti.

s____ i.U..ilIl..Ut IL 1111lit.. Ut _{'lUSZI liiIJUttt}IIiUttIllulUttUi

...l...UIIuhIIU.u.u ..I.II. lIULU

_{sIs_&}

IltLtl.IilIICl

_uukI.flhuu.L

..uuIUuuuuuIIIuIU ..iIuiUIilIUflhl4&aEUW51uIUÌtIUuUUIN

'r,

o

w

u...I1riIIlIIu,IIuIuIuII

Lfl dl I-4

::

_i

_{I lI..t1111: i.UU...i....iIuiStUUUUSltU ttiii,..i.t'}

-f

f, "-4

r14

I J

dU....Uu1UUUiIiiU11

PU.UJiIIIUUSU_HI

.

uiUti.Ul _4UltUlliIt ...Il.UUI1, ilit.lt

iIlibUtUU

.I...iu.IIIUUUSIItUUiiiiSlIIt

t iIIUIiIk

o

Cd

'r) IC, 4 r, Cd

Ig

..

,

g,, .

eO..

o

o

o

u 4

,

e In .2 r . r r'

.... '

-,

--I ___ . ' ' "s;

v'

"

';

i,uuiiirninuIu.UluIUUlIIUHhuuIU

1

1Rt»lIIIIItIIIIIlIUU

III III 1111111

-

1r'r;.\

IIui

p III IN PU

t;IdI

u.

lIhI'qIHIgl1

orn ni

iii

'III U% % UUUU su...IlIuUIUUU.

'5'

!"1' !f!!

t!!!

uuhI.

- :::

_..

'\ U \UUIIÌIU .' U\ usu,IIu '.

.

...IiiiI.m.S.

&' I III I t

IWI\IL'ISFtIIU I

' 1 '

.

I

iiUU-I U U I

nui. u

uiu;iiï;

9:Iill:IuuuIIIIUHhIHIUHI

UIIURITh IIIUiN I

IiIlIVlluiIURIIIlIIIIIlIilRI

IIIuripI

-

nu: &uu

:qA

-...lI$UdlIL .I. 'u'U*.

lIIk$'uIIUUU

.IuIUI\tIU

::i

_-

_i

IlI!L

'1

--

E!!!.

i

--

UJS1'

IIIII2UUU

U

IIU UlliltIL1U

_{i u i. .\i}

UI U(uuUt'U_,ruIuJIiU..Ik'S ksUuIUUIIulIUl_{'ii..iiilI.IU.U.N.}

kV'U IIUilNUULV uuUiIIIIUiiUi

O

..___

Uk'.

'IuUIuIuIUuu

i..

--

;I; ¡Iii!!!!!!

.IurauuIurIr.U2

urUIa.S r.i.I..'

_{1i.i k%} t%''u...uuIr.U.

U IUIIIIUIIllMIIIuIIIR '!!!'

.!!

!!

!!"!'!!!!__ N

IUI II il.

I!

d!

!!

Ei jEEEE

. i r

ii IIU

niII...i

...uul.iuIiImU..u. i

L

'

I.,u.IIUUU.%

O

..UuUU.IuII1UIU ..dI .iuiu..UI ..

UtIlI.uuIuiIilu

UIiiiitIIIIIUIU

uuUIIuuIIIIIIIIlII ii

1

"UI' iIi.Ik1

111119 9IIlII.

...r.,9IiuIt,IilIIlIIUI

I h

IIVI ti

'III hLIIuuII

ni uhInhiu,:Ju.

!I1 'I

ii Liiuiiiii

-

III

- -

'-Ì1P1E9!

_-

II

U IiiI!

'I!IIIIICi1flI

:

II

' .1 III iuJI. . I I II

lii ÍIl.

' IIlL111111111

I

::=

_¡ii

:i: ;

nui

I

ii '

u

ii

-

iiuiu;uu: nu u.

-

ia

__

-

I -

-EÎ -

_---:

Uil 5 -áIU d'

L:

i u i :.

-aizuiI.r..i,l.SU U i.u....'.

ulu.

- VP ---

1-tII'

-

IìI

b

b

q.I - ..u..___

up IA 28 I N N

o

û

o

4 , C' 4 I1 Cl C,,

o

Cl c'1

o

\

II

II

'

I

I 11111 I I

-

11

- .a..fl.uuIUfl.U....

5

_{'ivi 'y t'}

_\1uIUIUII,

"iiufl i

--%

111U1 unuiiuu.. r

niiiiurnuiuuuuiunuiirnuiuu

I I

!1

w

e

___L;'

-I-

-ii

' I

. ilUIIURlIIII IINIlIiIIiU

u,f"."huuuh'hh' 'u.u..---

I_1I

I- 4111J

IiiÌ11II I

O

!Irni

LIuIUIlIIIIIIIII 11111111$

1111111

iÌ!III?lIuIIIIrnlIIrnlIIIIIuI

II

L

I!!011hI11111111111!

- ::::: h

_{uillilhhlli!!!}

:::aw;:niu,1

_iøi1 ju::: ....

n.---..---I---Iu.

_I

I..uu,,unuua . -

--iii'

'IIiuPII1II!H!!IIIIII!II

-

iii __ii.i

IHÌÎÏ

.y&L__1I .I,IIIUU.U.B.

;;u

e

'II"'u"

.uii'iiiiiuuiiiiiuuu

91IOjIIll'iiÏÏj

.O!Iuji1I11j

Ilallilhl . _ku.

_{1flUIaUk\iIIII}

uIlL1U

...a,n....

_\UU

!I!I!Uu

1hhIIltP

-

-uII

_iiI..ui

_{_I__.*...}

ul:qiluIuuiIulu

_O

iIiIiIIiIiHIllhiIllhlii I!IIuiiuuoI:fl:h

.IIwL1I:m:NIlIoEtII

itiuiiuiIIIIIIII!llIiHiIIii!1HhIi!iOIb!I

IIUIILJIllhhIO!!I .!I!?IlIlIIUIltHIHhIhIi

-.uuuu'IIIup3

U

¡iHui!llhiliHHin

11111 rI!hhhl

IÎIiilihiilhI!ilUhI

uiuuî'nunriuii..

¡iIiJIIIU

i

aa

_{.___ _uuuu}

,..I..

i. . !uIiiuuiluIuIuuuIIFIIIIIJIUUIUI..0

_{:: älj:}

IIJ...II:u9Ll1IpI\

-uii.inmiiÍÌIIIIIII1l

llhinhIIluiIliIIIIiI!uhiiuI

U, 4 rn Cl Cl U) .4 II Z U)

o

o

o

In up -,

o

Q, -3 c:'

o

o

n ri 4

'

n Û C.. J .7 ¿., e (n (D

'

. 'I

o

u '

ki ' %lI...WIflhUU..UU___IuuuuuIUW1UuI1II_U

"

'

"

. \

"

uuuiu..uIUIiflhIAhUuUIU.

I

I

Kill II

III

HI

t\

_lI

u!"11r

.1!'L....

:

w-'

..

.'

Il

'U I lUI U

-iI

. Ihi

!IHIilI1UIIIIlIIIuIIIIIIIflhIlIIU

1.

'A:.I;tru;:;R

- -

-' - iii I uiiUkU1'I I, 11%! . . -

;_. . !!I!I9N!I!1_I!u!

!IIINIIIUU!U c. (.. _A1

j

L _

!

!!!!_..!!!!!!!!!!

-

..I

.U''

_uSUIBUUUU - N

--.

'r .iii.li .i. t'-

.

mj.'.s.IiI

_ I . . -i:,, I I

II

III ' 1'

...iiulnu.ul.

. O

-.-

ñiu..' i

--

flL' I fl & U UHhIl1U

.'LI IIIk

_{u.. lu iii.}

_{iqs'i inui'uii}

uI11uP

ii

1.ii.11

_iuuin

_'o

uuiui

iiii

IIIuuIhiInh'

i

iiiiuuuu' ri PIUPIIIIPUPIRU

IPI ruI'II9 I

IIUIIIIHUIIUID

..

ii.IUt L I..

I1Ui'I.Dh!VU.I

s.

q,a1INUÍI. ii

í..iqrui..ui, mIu.mi,iII.uu...

.'IS.USUuIII i L'i

.U.III% UII

iIIIUuI .i....iiliuIU...U.

_{_ 5IIIIIIIIINJIIIIIUUU ri}

EE

'

--

."

m.dUlluIIfli.1l i.iI

uU1Iu1ur

.__'___.Iu..-...---U...

_{uiuUIIuI:;;flhl1lI' UI1IIIIfflI'IkIIfl\IU L%}

.IuuuuI..!Uku1Uii.u1uuilu1IIflhIh1I

II

IUEt

IkkI E

i

Ii

I I U .r.0 Iluuunni . 151=._I

-

I SUU,ST..Se_u _._ - - ____ -

EET1Í'! 9!

1!!E

___. u s

I

i u. s. . s

Iii.

i

.

i i

sii gi..

11 Ql

______uI.iiii,I.

...,ulU.iIiuIluiuUU ..uuuu..IiiiiIII.0 ui

iuuii IIIIUI,IA

i

u u uui1UUkIJ

iuuIuI%'uuuufllu

IIIIIrIIIi1iLiI!1II1IIIIU!IIII!IIflI ;:'i

il

'ì'iIIIhI

-

I!!

-

!1i IFaI!I!!!!'1III!'uO!

_I!hhu

L11

L

I

I i

ill

II vìJiL * 1h11h11 I I ' -

I

1

ii

::5 g: ii I2uuIu.IIr.=::u:I::I:::::

L

sui.. iI.II ni 'IIEIII!l!118111.11.

. i i. i

....iuiii...ul

' urriii.íi'ui..

. f!i.

!1r!'-uL1

_{l -*Cfl flUO lu.. I a,.,aS1's}u,nOliu1Ì.t*SE was. - a nuis. _{IiiiuB U....lI} . - ---_*1

s'uI1IIIL ...ia sLitsIl'L iuuU.'L'U5J.

..

i iuu..Uc'uifl uuI..

.r%i.lu.

.

.iii.NIi.!l

I...

is

luII

uiU'i !!!!!!!!IIIIIIIU

'I'll

v.

IkòiiiiiiiSe

:11

_lI9IuIiUU

i:iiiiiiiiiuiii

U....

-- - - r

-. _{- u.: I}

3zl:v::::=='

-

..

IIUUUIItII u..5IiuiuS

E!EEE3i i!hIiiiiii

r iiiiiiiiiihiiiii -

I iUUU iBUiUuu

iuu..uiI s u....u.u..IiuiiiuuUu

C1

_uI . i

II

IllIllIllhlIlli...

ii

I

II 11111

I

I'

U, 30 U) -S ri t ri (5) II) 't f) fi U)

o

o

_

o

o

U) 'i

9a

In _co

'\

1

: :

o

' . . \ . . k ' . ' ' ' . \ I

UIUIIHIIIIIIIIIIUIIIOII

<

îiuuiuiiiiiiiiiuiiisiuuuu

F'.r.'q-_..

.'II'\II

'U

'

uui'i lIli

IIl

u i II u u

u

.

Sk

PuIH 'iI1I

uIiOiIIibiIiOuiIi

iiIk

II.

I11Ii

kuuui i:iuiiuiuiiuiiiva

iriui'

I3!!

. I b

III

. u1. P I%

liii

Il I

.'ì'

'1'!

kW IuI''IflPP

HIII

'I:oImih?1IIIIlI

I

'iuuiiiuiiiiu

I Ih!iiiiti

11 IIIJIUUhh '

Iii

IIfIUIlfl

r ₁

.._

.M II n i,, U.S IS ' . ,emU k'.IluIIh IV

TJ i.i lì...

I

I I&S.S%I

.

!!!UII!I! Ih!H

_{I1!IIÍ [I}

_III

1uII'IUIIIII!!IIWIIHIII1U

i '

_{j 'I}

I _\V II

¡I

lI! _{f! Ii i'u.iiçu.'i}

I1

_i

_{IkI1IIlgOIHh1I}

I

g

£iII)iIIIIII IuiiHHhII

u.

---

- I '

Iwiui

liii

I

IllI'I

IflhIuIIU

u i

'dli

_:

-- IUUUUIIUIIUI 111111110 pII kIuII% 'IIOIIIRUU

III I ffUflhhllWIW

ftlIfllPiUiiIfl

i

kIIliIhIIllIIIIII

..._u..uuR..11l!!5i

IIIIíiIroi ni

'

.iuiu

uiiiiiu..

1111111.

...

_'

'I:'

-:e!!a!-- l!!III!!

! -- - -

-HIII1IIUIllII! 1111111111

!lu

1HII

I

I

ìii

iiuiuiiniui liii IIIUU

oh :11 1111111

o iIuu

IIIIIM!lIIHhIIIII1II IIUlIHIHIIIHIHhIIUIUtIHUIIIOhIIHII

:

- uuuu .dIupuIIII,zI,pau upIuIIIiI0uufl.pU 1U111fl111 Il uUL'II

lflhIIIIiJI&Ih.IR

IflhIIIIIIIIIIIIIIIIa..IlIuI

i' IllIIIOIlIIlIII1I

_{llHilJiiIHhIUiliiIiiPIIIJ}

_IIU

!!!!Ç

r;...

Cd

!!!!!!!

-u.i...uuu,uiitrii!iu.n...i,,.uiuiuuuu,.i.u,...'i!!flhI 11111111

-t

_o

'Ifl'.

11 Cd c'

o

c4

o

- Ill 't CI Cd dl 't CI Cd UI 'i Cd UI

o

o

o.

dl I u-) N

o

g)

o G

o

o

o

g . - U

i

in (D

' t t .. t I.

O

r IE% %'i& I1CI 1IMM

iuiii.11

-k.IiiiiUWIIIUINIUHhIIilhIHIIUlIUIU

'iiilIlIIIï,iIlIIIlIIIIflhIllhIllhIUII

:L ki%

hIII1llllI

"

p! uui:i; c

I

flft

- '

\

I ''Uhu!

"h!!

h!. !!!

'-L-' II!!! !L

il

-!IMkI II

i\

UIi 111111111''

IUI

'b

J

jutiuii

!IUIHlIll LWIhlEII1 L MflhiIUIUIIhII

IIhllhILlIIMItilhIUU .1

:f

11111011

i.,

llhp!lIIIpdIri

"iIhllIflhI

IIH!IIF

IIIH

!N!O

!!II!!!

ii,uii..

...___uI ihU'iIU INJ

uiiuiuui..

fr

.i....UIIIIhIIIIHHHhlU1l

I

uDUUUIluUUIIUflhuIU11

UII UIIUBUUL'

---- in

-- -- -- ¡ ¡ I' U NI

!iIllhIll1HHIflIIIINUllhIflI

-. .

II

I

! IB B

r ii

¡ _{I Il} !

I

WII A ' fl"hhI1

!uIÏ

I ! iii

i j.ui 9 t; HEIu.MIiI

1LÇIUU u - I - I

!h !h!'!14

r

-

.

.

._i

._

1 a ...

i.

----

_{: IIE EEEIhEI}

¡I

tIIilE==,uiii::u:::'

l'i

' ..

' '

I', u

i

,

I.

I I UUUU.IIuuuIIHIIIIUUU

uIr.1IIIIIIIIILlIIIul I....aIIIIrnIIIIIEJIUiu1IUI1IIIIIIUIIIIUUM

ir ;

'I

1 ¡19111 !

111iì!IIbIhIiiI1Ïì1III

II''huII P

IlUiripi 4i11ik

.. E:ht,1

I

I!

II.ifIU liii

-j..áJ

,,...,..Jii..i...IIi uilIllulhhhl I

,..,II.Ru,uIuu.r

o

...

Iuuuuui iu,.,.I._{rul uIIIIUU}

I...i

U

-UUU..UIIIUIIIHIIIIUIIUUUIUIIIIIH iui.UUI.U111111111111 uuUUUiUi

I I

I I

II ii I

nuunuInrnIuhI.UaIJ

II I 1I - u' g) u' .. un . r rl in z r' r. u' u, 32

g)

o

C-

a-fI

o

o

.4 I., .

'.

. . . i I'

_t

UU,\iI.UL

U.11.UUliuIDhIU

IUL'

9

p,unInnI

IIki

\

UbIWIilJl

III1IIUIH

uIuI .

I

IIIIIIP1I

.%l

Iu.ri'N

"

S

UUUUIIIIIJPUUUS

.Iv ti

iiiu

t

s.s..

IuSIuIIIIUUU

kÌJL .IIhuIIi'i.I:.

AUUIlIL

..a..

.u.I"u..iS

EEE!

'!!!

_'9!!!!I!!!!I!!!!

-

-!!!U!ll!IUII1Ifl!!

iau

- .ri.i1I.1

muu

IIPlMlfiII

____ __pI._v. iifl.u.

U

rI%uJ. 'iu...II

.UUUUIU.

_.__

__.... ,u.i.ua....ru.I

ini uuu,fliI...uS

.._

uplr.. wn. .msuii

i.II.i..'iAU..U'U. IIS.UluII!UuIU

._

.. o1

haul aSLi

I

u....

I.luUUllIUIUIUr.Rft1IIuIIWuIIIUU

IuIU..IUuuIulIIIIHul!ItIUa.UrII1IIIIIfltUIuILmIII1"1IU'lIIUIII

IIIIUIIIIIIIIIHhIIIiîIhFlUNI1Il IIIllhIIIMIUI%i'II1IIW1IIIIIIUIII

._____

.----

__...u...u. a..ui,I.gUlaI %1UUIJI

._.__

WiUI iuuiiiiiiiIti

_I....

Eihjj ,ni

;_!:..».::!;::

...iI.IU.U...N ..U.uIpÌ.IUkUU.I UUUPIPPUI1 .

..U..,.ul.l1.s.I a _i. .l,IIu'I% ..

.II...11IIIIIUIU i

_{...u.n.itnauu..l}

...uuIluI

I.N

%LUL iIIUii I

...II..UuIIIIIIuIUU uulIIIIIPJIUaLflI ...u.UiuIII'._

..USuuuuIIIIIIIIIIU

uiUNI11IIIuI!IIIUIuuuUI

ifl..L4iIiilhifliHIlIIJUUIIIIIIIIIflUhIIIIUIUIUlIIIIIIIIflhIlIIllIU

IUUIILJIlIIIIII1!!I!!UllUI1IIIlItOIUhIIIIIIlIRUIIIII!IIINIIIIIIU

- p

*ddpppulpIp(JIqpY upiuuiiniuuuuiu uiiiuu u.uiiuipuuruii

III

I ..1IIflhIII;aL.øI.l

IlihllIllhIllIllIl

uviiiruuuirniiiiuiii'

::a.dI1I!IlII,flflh1!f5.!El9IIXIcuuIuIIU

UIIdB p

- ::J.

_.1..UuIII

.u...,.n_.U..UIUI..

_.

.

tI

I

...MiiIi.IIIIUhIIlU.U..SIIliuIIUUIIIIUUUUUUIIUIIIIAUIIIUWW.I

lI...I.IflUIIIIIlIuIIIII.U.IUUhIIIuIINlihuuII.UuIuIIIUIAIIIUI1UiU

Iuu...IIIIIIuIIIIIHIIIUUIU.IUlIuIIIIIIflhIIIuullUNIuIIIIHuIHIII!2UIi

o

o.

U) .4 U) 1 ri

o

o

i.) i.. U) '1 rU U) '7 i., U c.4

e

U) U) .2 ri rU rU 'f) 'n

_o

g)

o

34

For the prediction of the power, the following principal

dimensions have to be known:

Leñgth of waterline L

Breadth B

Draught T

Further, it is assumed that the displacement volume V at

the draught T of the proposai is known.

B. Form data for ship. From the displacement volume and the

principal dimensions the block coefficient t5 = is

fixed. The midship section coefficient is fixed in

accordance with the type of ship. Hereby, the prismatic

coefficient p is also fixed. The longitudinal position

of the centre of buoyancy (LCB) is determined on the basis of trim calculations and of cónsiderations regarding the

best possible positión. The form of the hull might then possibly be one of thé forms from the series in

"Form-data" (2]. Ali hydrostatic data are hereby easily

deter-mined. Also the wetted suif ace S can be calculated in a simple manner by use of "Formdata" or by use of "Wettéd Surface of Merchant Ship Forms" [3]. A good result with

regard to S may further be oltained by use of a formula

given by E.R. Muxnford (1]. The formula is

S = . B + 1,7 T)

where LP is the length between the perpendiculars, B

the moulded beam, T the moulded draft and the

-block coefficient based on

C. Resistance. By use of "Ship Resistance" (4] the resi-stance R and the effective power _E for a "standard" ship form -can be calculated.

R

= cT½PVS

(N)

-= RV (kW)