archief technische hogeschoo deift

r FEB. 1984 Lab. y. Scheepsbouwkunde

ARCHIEF Technische Hogeschoo

Deift

Sonderdruck au

Jahrbuch der Schiffbauiechnjschen Gesetischafi

l6Rand L982

Spnngcr-Ver!ag Berho Hc.!dberg Ne York Tokyo

Prtnted in Germany

V

Development of Large Cellular Containervessels

By E Vonack, C. T. Buys, S G Vrlead, NewbuilthngDepartment, Nediloyd RecSeñjdiensten, Rotterdam, and

A. logik, J. y. 4. Seek, N.S.M.H., Wageningen

(1) Propuhon - Fuel Coniumption

IfltTOdUCtiOfl

Modern trends in cargo liner ship operation call for changes in ship design in various aspects,almost all aiming towards improving their economy. Differently from ten years ago, changes are aim-ing mainly towards savings in propulsion fuel expenses. l'bis is because fuel costs in the late sixtiesbeing just 'part of total' costs, nowadays they are rather dominant.

Therefore the emphasis in changes at present is laid vety much onReducing the Fuel Consumption-Versus-Speed

Consequently, whilst adding improvement in other fields as well, we arrive at a number of changes indesign, as follows:

- Slow-turning large-diameter propeller(s);- Slow-turning long-stroke diesel engine (long. scav.) with a minimum number of cylinders;- Continuous optimalisation of hull form, especially at stern and at the bow;- Excellent surface preparation and painting;- "Self-eroding" underwater antifouling paint giving minimum frictional resistance;- Shaft generator;- Thrusters at bow and stern - for ease, safety, and rapidity of manoeuvríng around of (rela-

tively) long ships in confined port spaces;

- Qrginol bulbous bow.8ubous bow otte'C S Q

winy wi

20 Bose line

-.1

Fig. 1. Conversion of bulbous bow Nediloyd Dejima with onginal bulb, (right). Nediloyd Deift with shortened bulb,(left)

246 Development of Large CelluLax Containervessels

2x

- -- ==.- . _..-==.==Ir E I

.g

raI[?O pFig. 2. Thirdienertion cellular container vessels for Europe-Fszeast service in "Scandutch" consortium

N

s

T

Fig. 3. Main particulars of ships shown in Fig. 2

Development of Luge CeiJular Containervesseis 247

381 P3I T LIS

CLFTSS.ip ClIMA

¶972 1972 1972 1973 158Z

puns ¡oisL4tA e... 775,27 I 274,32 R 275,09 I 2r, I1.ib 6.P. 257,60 - 257,60 - 259,00 - 273,00

32,28 32,31 - 32,31 - 32,3'-sth, .1d.d 32.21' 32,23 32,20 - 32,2454ptA, .I4sd,

to Ipp.r4. 23,90 23,90 26,00 - 29.00'0.014 tO d a. 20,96 - 14,39 iDi. 17,70 20,46'0..i. z. 11,61 I 11,60 I 11,41 I 12,72 8

C A PA Cull IS35.000 t 34.730 5 34. t 49So '

22 000 24 623 23 827 t'o. !!!_ ocseDtap2.t 58.446 t 56.730 t 58.828 t 71 77 ... 71.977 t

Ct..a.,-'1.. a. (?R) 1,2 1. L60820'-x.. 964 950 840 1.252

364 356 374 434

LXV. Look (3-b)(?Z) 850 83820-Xx.. 850 874 810 932

416 430 386 466

Or t.t.2 (?)Of aA ..fsr. 110 110 100 110

(At..s/8.lee) ()'60) (54/60) (52'50) (44/70)

Pi0 PULS ICRL L.A DI-.' Dt.s.1 010.., ?tzbiis DcsrI.PS .A 33 Lo0.

- u_575. O.v._a850/1700s I è W- %84 U ..t7p. 8U P..t.r Wb.. S..zto10 071. 9 1. 9 1. Sts.l Zsv,.1/St. t.o..o-

c_t.,. 0.4t023.400/1,5 22.500/117 22.500/117 40.550/136 2S40/ll2

- IOk./t75. 0.V.-850/17003 S à W- 184D -t7p. '84U -12 2. 12 l. 12 1.- 26.204/115 30./119 30.J119 -

TotAl b.A.p. 75.000 75.000 75.000 81.100 50680L....il.b et &.800. 34,20 I 34,17 U (oet .5.rsbl.) 30,60 U

PRO PILL Li S1 z Vor. PItok, 5.-I1.A.. I z V.r.Pitok, 4-12. 1 z Vor.Pltok, 4-bl. (Re et.,. 1...)

c_ts .. ..it 6,25 1, 39,7 t 1.90 I, 40 t ... 38,6 t -Std.. 2 z fIxok p1t, 6 12M.. 2 z ttzM p., 6.'.b 2 i ft.p., 6-bl. 2 z ft p.,5

JQ 03? Li5,85 I, 19,6 i

I z i.2 Ip, V.z.patMPt.. 6,7 .2 s.MPr.... 136-140

5,85 U, 19,6 tI z l. Ip, V.PP2... 6,7 .2 ooMPp 136-140

... 19,3

I z 3.000 15. V.P.Pia. 6,7 ol -

150.155

1 DZi 6,30 U 4&2 z 1. Ip, V.P.Pt.. 7 .2 ..MPr0... 165-168

650-1

516 RI . IC ro s

i u_p s ¡ i-?7p. 3l-.pM. 54x. door'- 340f... .. Abt. 48 .2 abt. 48 .2 abt. 46 .2 Abt. 98 .2- 602*1AL1I.II.L2T PlV5

45 t4 z 1.300 [8(1742 Ip)

48t 96t5 z 1. [8(1350 Ip) 5 z 960 fl(1313 Ip)

120,3 z 1500 [I 3t 2

+2z 900L1 7e 500 40

Pr.s / S of L.b.p. 85-128 / 13,3 5 83-.127 / 13,3 5 88-128 / 11,2 S

Volt.j,/P,.qo.ay 440/220oo/60b. 440/220s./601. 440/220..,/601a 440/220../601.

248 Development of Large CelluLar Containervessels

lx

- ..1 -- r$1

2 x (.s. trb.)

s a .s-u-, u- -e

- - i . _I_ -- - i___ 1______,__ - - uin-_--= -:_.='---:= = .-I

m mt ,-..: T_- - -- -__b.____v_ -- :--- - - -

I) Jr

--b i. .-1.d. _. - - - - - -w- i--- ' --

?II?OP V111

ItI3Ud (i972)

-

!LI3UIO u8 (i972)

E E P 17 R S ¶9 )

Fig. 4. Thirdgeneration cellular container vessels for Europe-Fareast servi in "Trio" consortium

2x (tts.s1 .oai.) PIAWIFØIP w(i)

SB

CAPACITI ¡S

D.pl.otLpp z kid z D .14

.o t.a.r.BsS.. d..0 (?I.7)

2O'-z4O-z..

AX.. ds (?L)(4.-) j.1j20-X... 717 d:

40'-Xzs. 150

Ord tojal (?R7)

Of .tci r..f.r. 40TOIlAS B

Oros.l.tt

PRO POL! ICI

IMS/t7D.p.ri o,.i.r.

tOr ...5..h.p./ pDop.r.v.

3.!.?. tots.l

II kO

Cs.r4.o Myky

DveIopment of Large Ceflulax Containervessds 249

1972 19721.2.5. L.l 1.2.5. I.i

289,50 I 288,75 I274,32 274,22

Psc.z P...x.3.2,26 32,26 -24,60 24,60 -13,03 13,03 -

JOP.R 2041

288,75 I274,32

psa-ml.32,26

24,6013,03

48.542 t 49.600 t 49.74.2 t 42.470 t 51.5.402, 'lo2 21 23400 24 2'O

73.642 t 73.64.2 t 73.642 t 65.870 t 4l0217.800 .3 217.800 .3 217.800 .3 219.800 .3 209.500 .3

1.9 1.

.708 1.284 1.708 1.126 1.104418 332 418 432 418

1.020556 4 856 or 7.020150 428

2.967 2.804 2.800 3,010

2 z 40.560/13681.120

2 z 2.500 r.

2 z 1.250 15

S%. turb3.z./2 St. t.J62.z./2Pb.i.r-..i.r/L III P-5 / R III121, 145 T/b.r .t 718/13.8 ?/hx65,6 ste, 5.13 C 63,4 bar, 516 C2 z Stal..La...2./LP 40 2s Q2/i.L.

2 z 46.000/14088.000

3 z 1. n440V 60!.2. 90C

'973 1972 79871.2.5. Kiel 30.8 Ve.., Ia.61. R.LW., Kj.l

66 .JA. 66 ./d.66

2 z 6.750 2 z 6.750 2 z 6.1502 z 1.000 bp, Par.?. 2 z 7.000 HP/TP 2 z 1. HP/TP(2 z 71 ? (2 z 17 7) (2 z 'It 7)Pisa, Dzy-R.,/b Pia., D-)/& Pia., D-A

PLO PPLAJIftJT?Yo.jo 1pr..0

58.088 R.?.38.425

Stess tu.rbt.n./2 SI... tarRioe/2 Di...1/2P-. / III .a.i./ ¡952 90/1601115/138 ?/br64,5 t5, 515 C2z St.0_L.ajal/AP402 z 40.560/736 2 z 27.200 /122

81.120 54.400

3 z 1.& r.440V 6CR.2z 15

2 1.9% ¡JIS

440V 401eI z 1.650 n

5. Main partcuIars of ships shown in Fig. 4

287,70 IZ73.00 -

32,2632,19

25,00 -12,03 -

287,73 u

271,00

32,2024,00 -13,06

58.385 8.?.37.93.4

2 z 2.800 15450V 608.7 1 900 15

450V 601.2 z ,.ioo n

2 z 6.l5 2 z 6.100 , 6 bi.2 z 1. IP/VP 2 z 1. 15(3.300 V)/(2 z Il T) Pi P11.5.Pt.., h.P-misi... Pi..,

12 3 - 9,1

58.889 R.?. 57.887 RI'. 57.249 R.?.35.191 - 34.014 33.967

P-S / III/732 7/br

64,7 bar, 516 CO, kgi.1.i.

2 z 44./14O88.

PROPII.I.ZB SBO STR 605 ?5

3 ?4 B ILS Z 1k!

P7.41'?

trS-.nsr.%or.Bol t.s/Pr.qucy

Dj..

36aZt (r.t.F

r

250 Development of Large Cellular Containervessels

MOO RN

TAaLE BAY

BS

S V EN DRKA E SI

!.--..'- . . -

Fig. 6. Shorter/slower ntainer'esirIs for Southern Africa, Australia and Fareast services

J U X L?, 7&r

Development of Large Cellular Contamervessels 251

¶979 ¶979 1974 ¶979

4.0.1., 1$ 1.2, 0p ¡.1.1. ¿3.ot (oft) V.0.3.1. Ist.

Fig. 7. Main particulars of ships shown in Fig. 6

CA PAÇ ¡?5 ¡:5

(.t z. ¿zf t) 47.197 5 49.149 t 31.771 5 48.637 i

24 3 2: j.&q 270671.542 5 71 27 t 71.343 1

LPp z l(.) z 4ptl(.) 193.367 .3 '50.4)5 .3

Cozt&iz.x,

1.780 1.7801o. 6.08 (rL)

20-x. l.036 1.004 388 1.0)2

372 388 298 378

£v. 6.08 (rL)

20' -box.. 656 672 548 660

326 3)0 274 330

0r t.t.2 (TL)(..rvta.) 2.436 2.452 1.532 2.448

- ()(ox)2.696 2.770 2.000 2.708

st 08.108 1.st.rs 941 308 YL 151 43(IC 154 box4O')

(Abows/IsO.. 4k) 55/886 132/176 / 35/886

PIOPOLS ¡Ql[ii41qUt Di...1, 2 z Dt..., 2 i 01.s.1, 2 z Di.1, 2 z

aoo / IJ.,1 8 52.-90/160

Is..1_ 3.2sz,

9 0-9Q I

1 /

*2 0.-90

D. 308.14e! 3s11.r,

e DO-90 I

p11115 I 013(f08) 1.0.3.1., 5.16

LtA ... 258,501 267,00* 241,201 258.501

Lt b.,.tA, .Xtr.

248,20 - 250,00 24.2, 247,00 -

32,26 I 32,24 I 32,20 I 32,26 I

24,15 24,15 - ¶9,50 24,15

13,03 ¶3,03 - ¶1,70 13,03

s.. LI.P./I.P.1. 25.660 / 122 30.150 / 122 34.800 / 122 26. / 122

V.5.2 LIP. 51.360 60.300 69.600 53.600

710 PILL 113 2 z Pt 11508 2z LP. 21 PP., 6,50. 2zP.P.,6,35I6-bl08s. 5-6108.. 4-6108..

)0W?I,D5?II3 2 z l. IP I z 1.500 IP 1 z 1.400 IP (V.P.) 2 z 1.000 IP

75..

LLUI P D P ¡ I

1, Ops. io 41, I.M2s.o.

6 z 1.500 D

pt 1, I.erly C1c.08

1, $I-3...

2 z 1.360 D

,

1,Op..I-2..o.

2 z 1.360 D

1,

6 z 1,100 n2 z 1,000 D

V.1te./Pr.qscy 440 Y / 60 Ii oc 440 V / 60 Ii oc 450 T / 60 Ii ic

I5A PLL1 ITPLL IA.4 LILA IAL

252 Development of Large CeUular Containervessels

Four to five mooring winches fore and aft:Utmost simplicity in lay-out and in construction:Minimum number ol rewmembers:Sophisticated and reliable equipment for control and for communication:Reefer containers to be of integral type if their number is relatively low - about 250 units pervessel.

Vessel Types Under Consideration

Already soon after the outset of I.S.O-container trades rather big vessels have been introduced onthe trunkline routes. (For the purpose of this paper we have the Europe - Far East and vv. trade inmind) (Figs. 2-7).

As for propulsion and steering arrangements. various kinds and configurations were chosen oraccepted by the equally various owners.

\iain movers were either steam turbines or diesel engines. There were twin-screw and triple-screwu n its.

Nearly all had single-rudder steering, but skegs varied from wide-open to completely-closed typesand semihalance rudders as well as skeg-rudders were applied.

Fuel Consumption in Service

For marine engineers and naval architects it is an exceptional and rare opportunity if results fromreal practice are available for comparision (Figs. 8li).

Of some eleven ships in the same service recently such an opportunity arose where a number couldbe compared, viz.

Ship designation Propellers Main mover typesKorrigan" 2-screw steam turbines

Nedllo i Dejirna/Deift 2-screw steam turbinesNedllo d Houtman/Hoorn 2-screw dieselBP!BS 2-screw diesel--N". "T'. 'S 3-scre diesel

Results of compilations from a number of voyages showed that at 20.5 knots service speed.average consumptions per day were as follows:

Conclusion (A) - Steam v.à.v. Diesel

The difference between steam and diesel was about 90 tons per day in fuel consumption at thespeed of 20.5 knots.

This fact made it clear to a number of shipowners that it was necessary to convert their mainmovers from steam to diesel.

Note: Other owners may maintain their steam turbine plant, mainly with a view to possiblefuture downward trend in fuel oil quality. By example - we assume - Hapag Lloyd thusconverted their steam turbine ships from twin-screw into single screw with a propeller ofslow-turning and large diameter type in their endeavour to save on fuel oil expenditure andretain the reliability of the steam plant.

Conclusion (B) - Triple-screw v.à.v. Twin-screw

Twin-screw diesel is better than triple-screw diesel propulsion as to fuel consumption.Note: The centerline propeller of triple-screw ships, working in the zone between the race ofthe two side-propellers does not take advantage of the wake belt which normally on single-screw vessels increases the propulsion efficiency ("Hull Efficiency").

Main mover type Propellers Ships Average consumptionSteam turbine 2-scre Nedllovd D 196 202 tons, dayDie'el 2-screw Nedlloyd H 112 tons/dayDiesel 3-screw "S", 'SL". "T" 124-130 tons/da.Diesel i converted) 2-screv. Nediloyd D 112 tons/day

3CvCf

250

200

150

100

50

O

Development of Large Cellular Containervessels 253

15 15 17 18 19 20 21 22 23 24 25 kn 27

a Speed lServfte)

Ftg. 8 a and b. a) Fuel consumption of Diesel-vessels, b) Daily fuel consumption in t/d

Recent tests in Lyngby-Hydro showed the optimum twin-screw to be about 4-6 % betterthan the optimum triple-screw vessel (SSPA already mentioned this phenomenon earlier.)(Fig. 17).

S-.

.- N. Hoorti

in service-.5

:.- .- '

- Pilot-Pilot

IEI ¿

N.Rouen

o S«pShip

s Hoorn

N (3-screw)T 13-screw)

(2-screw)N. Bahrain

5peeJ5$

J

3 S

SL

I5E.

T N

flY'S! VPSS%DL

25-5TAM

OP KW005SSSu'

H

2SSLEF ES

aS5L(Cv.rt Íroa Stsaa)

$tLYI ',, I'Sa*W

23 173 15,) 165 202 251 261 303 160 165 185 149

22,5 161 169 172 18_ 239 247 286 149 174 175 141

22 151 159 160 176 227 235 273 137 164 165 132

21,5 149 147 149 165 216 223 263 129 154 156 125

21 14 139 138 155 205 212 248 120 145 147 118

2).5Y 124 130 128 146 196 202 237 112 134 139 '12

20 117 121 118 137 187 192 226 105 128 131,.. re_ ç.,. fl n*sA WOh/ ev

Conat. - 5._ I W110

St... a. AAL Afl13 Sei:

cono. Ta Te 2.5 To/thty DO ir, .crt: Di) DO80 Ta FOL8D prt ir, port:

7 1TTo DO

300

t /24 h

254 Development of Large Cellular Containervrsaels

Conclusion (C) - Sea Margin

From the practice figures we also learned that for the mmss Nediloyd Houtman/Hoorn class vessels- having a chlorinated rubber underwater painting system at the time, the sea-margin on the FarEast-Europe andv.v. route amounts to about 13 à 14% forS years lifetime (Fig. 8a).'

Moreover, improvement would still be possible by the application of modern anti-fouling paint ofself-eroding kind on the ship's (sun-lit) sides for the prevention of fouling by algae.

We expect that this will result in a sea-margin of some 10-12% only, in future.Nediloyd Dejima/Deift, after conversion to Diesel have exact the same fuel consumption in com-

parison to Nediloyd Hoorrt, Houtman at 20,5 knots.

Conclusion (D) in Fuel Consumption Difference on Similar Vessels

From separate information (figures not compilated by us) we learned that of very comparableships in size, main movers, propellers and rudder, but of different owners/operators, the fuel con-sumption levels differed appreciably. (Ships Nediloyd H v.à.v. ships "BS" and BP".)

350

t /24 h

300

250

200

150

50

Ship DM

Turbine

a 5 202224 kn

- 202

Differenceto t/24h

DMMotor---t---- fl2

16G

140

120

40

zo

O

I N. B.: Sea margin upon thais is 1.13 1 1.14. Margin upon Tank-S.H.P. is 1,18.

Fig. 9a and b. a) Actual fuel consumption figures Steam and Díieset. Vessels of mç.rabIe hull shapes but slightlydifferent lengths. b) Fuel oil consumption-to-speed ratio. H (t x 1.18) Nediloyd HoutrnanfHoorn, at 10.6 M draft,1.18 P,j Tank; H (t) Nediloyd Houtman/Hoorn (d Tank); D (sp) NL Dejima/Detft, Savice Pilot-Pilot ( PTank 1.13); D (sn) NL DejunalDelft, normal at sea ( P4 Tank 1.065); D (ta) NL Dejim.a/Delft, PdT3flk

inclusive appendages

H11118

Service, from Pilot to Pilot.

Normal at sea: 1.02.Triats.Tank. inCL. appendages.

N11- - - -

OIP Ad40,--..,,

OIP

us

K,

K,

b

b 14 16 18 20 22 24

Speed Ika)

Ship N

MUftí100

oQ-E

80C

ow

60

Development of Lage ceuuiar Conzainerveuels 255

Possible causes may be found in the following differences:- Quality of hull forni (i.e. slender pipe with brackets on Nediloyd H's propeller shaft may give

less resistance than the fat bossing of the vessels BS and BP);- propeller design;- hull roughness.Other causes may be the possible driving of the turbo-generator by the auxiliary boiler (instead of

by the exhaust gas boiler) during legs at reduced speed. In such cases the exhaust gas temperatureoften is too low for steam production by the exhaust gas boilers.

Propulsion Features on Poible Future Tonnage

In case any future units of appreciable size - say 3000 TEU or over - would be required, ourbasic assumptions for the design would be: an MCR of 85-90%, sea-maigin 12-14%, draft 12,5 M.

Propellers

- Twin-screw? In case 20.5 knots mean service speed is wanted, with peaks of 23 knots max. forkeeping up to schedule, then Nediloyd would propose a twin screw vessel.

- Single screw? In case 19.5 knots mean service speed is required only, with peaks of 22 knotsmax., then Nediloyd has the courage to go for single-screw. (Courage, because of greater risk ofpro-peller-induced vibrations and noise hindrance on a high-powered sLngle-screw vessel than on a twin-screw vessel.)

Service Speed

A reduction of service speed from 20.5 down to 19.7 knots will bring the fuel consumption downto an extent of some 12 tons/day.

vaar-t.d h,. ) si.. DO. e. f3. or .j. ;'ort

- kPlOUTM* . ' . '75N. 2.kw. '7

338ES

33573

56L

16163E)).26

633,.593,.

123,23,,4

2t286,7

M.MOO$ 3 '7 !2 L! 663.. 'si 336,494677 466.

KNOT5

21633 1761, 486,3 83,22311.

20,3 T/E3.

.rego

p 1.

2S..s'rrAjl '7: 324Y 1585 1)371 C 1376 192.k'w. '7 294) 14)2 13343 0 1363 233. k. '7 247 163 1736 2 !2 .

94317 4..3 43152 2 4725 63FNOI3 ',2G T20,3 '

-Je oc T

25-STeAM -NI..Df4JT '.k. ''.. 26.?). 1,3. 13735 16)- 152.4w,'). 3z114 147 1)999 13 1657 253.. '7. J4

9370<. 4..7 j..9 1,) 4333 51.

KMOrS2 5 3:/:::. 4 20 T0,

Ç000,,uzs

45.2 700T

VR

256 Development of Large Cellular Contamervessels

300

250

200

150

100

50

o

350

300

250

200_202

150 7

100

Ship DM

Ship J

f.

/Shp N

I

146

Ship K

237 -

./

r.

b

Ship Dl

J-

:.y..

15 20 22 25 15 20 22 25 15 20 22 25 kaa 21 23 21 23 21 23

15 20 22 25 15 20 22 25 15 20 22 25 15 20 22 25 knb 21 23 21 23 21 23 21 23Fig. IO a and b. Fuel consumption/24 hours. a) a twin screw steam turbine ships; b) triple screw motor ships

Shaft Horsepower Maximum

At 19.7 knots service speed the mean level of shaft horsepower lies at about 30,000 1-IP on onescrew. At this or lower level there normally would be only minor trouble as to vibration, noise,cavitation-erosion to the propeller and as to fracturing of ship's structure above the propeller.However, we strongly object against utilizing more horsepower continuously. This objection isbased on experience with the first generation containershs, especially those having their accomrno-dation right aft.

¡ I I

Ship SL

130

200

1/24 h

150

100

50

200t/2.h

150

9g

150

1.13'

200

t/ 2 4 hi

loo

50

o

u.u.....-........uuuiuualUUV4UluUlPNA.....u.auUU!U....zu...u.r ' ....u., uu..u, ' l.l.P Rcu.u.....uu.......u.....0uu......uuuuuuu

Fig. 11 a and b. Fuel nsumpton/24 hours twin sew motor ships

20212223 2 25kn 15

250

20212223 2425kn

250

15 2021 2223 2425kn

Shp H 5h llI/

200

150

135 t

zoo

150

Allll2t100

5G

/I'll

100

50

oOI'll

Ud L)

Od

118

50

o

-95

A4Yç U/. .._..._u....-lu......

uu.u.............I

Development of Large Cellula: Containervessels 257

Nedfloyd H Nediloyd Deift Nediloyd Deimo

1 year service 1/2 year service Z months serviceChtorin. rubber SPC antitouling SPC anti outing

b 15 20212223 25kn 15 20212223 2Skn 15 20212223 ZSkn

a 15

250

200

150

loo

50

O

258 Development of Large Cellular Containervessela

55000

SMP

50000

45000

40000

35000

30000

75000

20000

15000

10000

5000

50000

SMP

45000

40000

35000

¡

30300

25000

20000

15000

10000

5000

o17 18 ¶9 20 21 22 23 24 25 26 277 8

Speed )kn) -9 10 11 12 13 ¶4 ¶5

Draft rn)

Fig. 12. Nedlloyd Houtman+Hoorn, SHP-V-Draft (NSMB). Built as diese! vessels, 1977

125m12.0

¶1.5

11.0

10.5

10.0

9.5 m

o17 18 19 20 21 22 23 24 25 25 277 8

Speed )kri) - 9 10 11 12 13 14 15

Draft (mf -Fig. 13. Nediioyd Dejima + DeIft. SHP-V-Draft, NSMB tests Steam to Diesel. June 81

IIliAIU23

22/i

21 '/

r ,l9kn

__I!1'II/WAl

i

Ml

llffi':lR/IPF,(4Ull

24kn

23'/i.........

23

i

22 '/2

/2kn

35000BHP

30000

100 -

'i. 25000

75- 20000

5015000

10000

25-5000

O

Development of Large Cei1u1a Contamervessels 259

P 104S y.iau. anoraK PA I.045..YtI4I. C0ND,TIOK

(Itnon'\ fIAI C.0 °N .1.13 f ¶NIAL ca.DrT.0n al

IAn A'.) P0. I-18 ,*. 5RVl( IO ,an) P 113 ,- - SrqvuCt

Fig. 14. Specific fuel consumption in pr*cti Diese' and Stearnturbine

Hull Lines Aft Ship

The hull lines of single and twin-screw models are (to be), according to the latest developmentsand much attention has been (and has to be) paid in keeping the "12-o'clock" wake peak of thesingle-screw ship, as small as feasible (Figs. 16, 18, 19).

32450 hp

224 5

Fuelconsumpiion\in service1.09 higher

CaloricvQlue3/. Margin

j5/138148155162

Separation

122RPM5°°°1

"F

red

I IL

RIA70-87

84R

94-102egOh \

RND9O112

SpecifiedService

Oelft. HoornOejirno Houtman

WCDLOY P4OUIMAN* NtDL.L.OVD Dt IMA +2ca.cL

V TANK A T A i.l8 V TA.AN A A 2.4 III l.13. 10.6" .. IQ.fl - 14Ar ¿41VI 5 400 A 70 2.4 .3 I.3 -

I?i T9OO i8 '7 7'.2 8100 67

l 600 l S 77 8/;IS SIDO

20 400

A

67

24

31

i.u8 St

87

I5

ISj

21000

23300

162,

162

82 93

33

20 2500

23 300 .65

89

35

04,

ilS

20

no

24000

23700

161

160

33 IO

SSi Il5II 35800 64 ucD 120 Dl 17400 '38 104 II/!I 2,000 64 ¡lO 130 ZI 29300 37 I0 I 25

23 30400 63 113 40 ¿3 .31300 I2 II7 32

22,

23

32800

35300

l3

60

29

38

131

63

21,

23

33500

300

15$,

33

Its l'I134 ISt'

23f 38300 IZ 42 176 Sii 1*800 15$ 144 63

24 LI000 n 62 24 16ø l.I8 99 .24 .45100 n 15$ 24 157 IlS_77

Oiesel Steam turbine

mm

ss"N

ED

LLO

YD

HO

UT

MA

N+

HO

OR

N"

SLA

GE

N L

JJS

TJE

PR

OP

ULS

ION

PE

RF

OR

MA

NC

EfP

TA

NK

a 1.

045

TR

IAL

C0N

DIT

JCS

Dii

- gP

UD

- P

owis

-N

DLL

OY

D: D

°2o

.Jti*

D 1

0 t't

'3U

LZ&

Rl

NO

II II

to 1

5440

9H

P/ lit

SP

It

1o0J

102i

440

9112

/pt

OP

Li19

III S

Pn

0. s

ao_L

IP2

w1l

6.r,

t4.6

7I

P. 9

140

(041

1.10

15C

INS

AL

TyA

14K

wI.Q

6-

rrna

.b.C

ØN

DIT

ION

S,.

i.øa

Fig

. IS

. Pro

puls

ion

perf

orm

ance

mm

ss N

edllo

yil

Hou

iman

/l-(o

orn

(bui

lt as

Die

sels

) an

d N

edllo

yd "

D".

Iype

(afte

r co

nver

sion

Ste

am lo

Die

sel)

o'. Q

I. P

.1 ,

S P

L I

D,

I. Is

lOt.,

SO

P.

toi.i

,O

IÄfl

011*

1.5&

UP

I'lc*

.0/C

-'lo

ok ..

..

ri.00

olI,

dr.i.

5i;,

lao.

fT

On.

J¿4

hoU

,.4r

.er

P.

1911

sI

;.;t

0.'i

ION

tlID

Ie,

MR

PI, r

11.5 I

11.5 I

1,611 51.01

¶,.9

5.9

5.5

9.1

35

40

5.

'.5,

1.75

6.5

1.9

1.92

LIt

7.9I

5151e . 45

5.9

5.9

9.1

8.5

50

9.69

3.72

9.6

9.42

losJ . 55

10.8)

IO.?

10.55

0.19

11.85

PP.?

PI.'5

PP.35

45

12.82

15.94

P3.5

12.22

10

Ij.O4

P1.1

'3.5)

13.34

s,

Io

14.95

14,65

14,46

14.1)

5.5)

¡5.67

I'..44

15,15

NU. .

.I',

90

6.54

¡6.01

¡6.42

16.06

17.8.4

17.54

10.41

11.00

P5500 I5OO 1)705

6500

9'

18.04

11.8

¡1.56

11.14

95

b3.26

ISO)

'1.19

11.)

93

94

P9.45

P5.20

P1.9',

11.52

11.6)

15,41

15.16

1.15

95

5,61

P0.6?

8. js

¡7.92

18200

19200

l86.

¡9800

96

¡3.04

P8.80

10.54

8.01

9!

¡'2.25

P9.04

16.11

6.54

98

19.4)

19,/2

P5,95

0.42

99

I'j.65

¡9.42

l,.l)

8.60

P00

i.9

P9.6,

¡9.3.4

l6.&J

11*15 21X0 21900

23200

P6',

84.4

61.4

8.,. I

2.O

ISP

20.06

P9.3

¡9.5

¡8.95

22I

51I

P5.O

5jJl

Pb'.

81.2

81.2

8M.?

91.1

Pos

20.25

50.0

9.65

II. IO

.2I

S21I

S 1200

245 0

¡65

2.I.I

.J.O

').0

91.0

Po)

20.45

20.2

¡9.85

9.

151015

2iI

23900

I)XX1

64

91 7

'l.}

94.0

91.5

¡04

20.65

50.4

20.01

¡9,90

240535

215IO

2461M)

56120

64

94.5

94.5

96.0

P02.1

I0,

20.65

50.4

¿0.22

19.15

54100

24?

25)185

26&.0

11,4

91 .5

91.2

93.5

¡"'.5

106

fl.03

50.8

¿0.4P

19.82

55500

355002

26P

21&tO

IL I

99. 7

99 1

l0.o

It8.0

lIli

01.13

20.91

20.58

I9.8

/6100 252110

26903

28500

ILl

11.0

0.4

lu',.2

111.5

OD PP.45

21.?

/11.8

30,2

241510

/0911)

SIlO)

29500

ISI

04.9

S'i

I 4.2

11.5

1119

fl.OS

71.44

25.91

/0.5

/1600 lISO)

25503

5h51)

6)

Ißt)

¡06.8

111.3

II).?

¡PO

?I.

2P,80

21.15

20.52

284.11

.'BODO

29400

3111X5

Il

11.0

11bPS

It4,9

P21.6

PII

52.05

31.14

21.3

20.61

291(X)

295140

30500

1210.0

163

'1.6

114.1

114.4

¡75.2

PIS

22.51

21.94

21.4*

20.05

110X21

10200

31200

330.sI

162

ll,.I

11.5

P21.2

'8.2

II)

22.46

22,05

21.6',

51.0

306.40

1110G

¡22(21

341X2)

11.2

i'j.8

121.0

¡2' .2

132.2

110

22.67

27.1

21.81

21,15

1165X3

319(21

35h29)

)49.0l

P.2

55.1)

124.0

520.2

155.7

P5 22.30

22.49

22.01

21.31

)i25)

328,10

jj9(P.)

360.2'

P1.2

.5.4

P21.'.

P11.9

142.0

lIP.

23.1

72.57

77 19

21.5

1141X5

553.0

14911)

311.31

162

'9.8

III.'.

115.8

14.1.2

113

il.??

22.85

.2.14

21.65,

¡4)00

PIlO.

55/3)

1811'.t

6,2

III

11,11

1)9.6

ISti.'l

IlS

21.48

21.1.4

22.9

21,01

392110

5,51)

36810

39211)

10.1

11.0

11i.5

141,0

I'.)'. I

119 tiLl

21.22

22.Li

21.31

35.43

366503

311621

4080)

162

411,8

07.3

1.11.4

',1.8

P20

is.90

21.11

22.89

27.14

31200

1171X1

p09(1)

414111

162

1.1.1

¡41.6

151.2

161.0

I/I

24.03

21.55

25.04

17.20

1021X5

53111.01

411111

42011

P62

40.5

P50.0

156.0

165.8

¶22

20.22

23.3)

25.2v

22.41

5X311)

39',I2)

41100

451.111

11.2

',7.5

159.2

59.8

170.0

171

74.41

23.69

/3.36

22.91

411111)

411'»J

5210

04505

161

51.1

160.0

P65.0

115.4

1.4

'4.6

.11)10)

oDA1T.IO,SS M

DArT a udS Pj

5,14'

0%.. '1

Ks

SI-PP

?IJLL

IO

1311

6,.L

IL

I'

10.4

5700

ItO

s.i

'i

< nI

It

13

, 17.0

I 7.3

S pis

15341

l'i

'7.

I0

I5

4.p

199

Li

i

al 1 ai

Ib.4

i,8

i/O

i6jo

SIlO

7450

io 53

50

j

71.0

i

p, P4

'

I 7,1

iII

.a

14

F7.Z

9.

567

ÎJ.5

Ii7

IS

47,1;

¡lIb

ì.i.0

I& 91

i 7.4

11.000

l4

73.3

Ito

oa

iImo

''

?5i

Ils

e'

iI9

4lD

79.5

ii

Il

i 9.4

'4?°

'3

PIS

i,l

(0,110

145

sI Il

1

Il

I94

11.50

154

904

IL

II

i Lo

11,031

dc

Ui

it)

13

p9,6

blU

55

a,J

ils

II

182

1I.40

P44

Il.

I9

0 i

l&V

49.0

*1)90

53110

1W.

p

544

a

119

90

II

49.4

11.4

51.4)9

I,U40

44

43

914

,o

.900

los

=1

49.2

lillO

I1

32

19.1'

*4,010

'51

r,0

loO

34

3.5

*3.7

Li/e..

1441e

lib

t'.?

loi

9.1

94

I Isp

34.939

13.510

i0,

65

13.0

z 114

033

36

19.3

loi

5*.;.,

il .a.

. W.4

qj.I

1e

bO

93 54

35

ip

l410

ii

0

ssp

101,4

ios.0

L '7

''°

37

20,4

151.0

51

losS

303

57

i., I

51140

III

loI,,9

PIJ

n9e

2o3

sjo

iioS.3

.9t3

II

1.0.1

,,I0

P3

*0.1

5

93

109

ILSOI

SI

..p

ii4

33

20.3

1JlI

I,so

IPI.4

III

400

0 i

II.e

3$

PII O

lIC

loo

2.o,5

Jo/lo

i5

155,1

4lOI

15.3

I0

59

1140

ai

lOI

60.1;

31./la

'16

¡.9.8

¿39

lOt

21.5

i..o

ti

pp_

)3p

teL

10.9

3il.

Ill

L 11,4

642

*03

11.7

J,j

¡17

IIO.

SII

03

h.P

.i0*o

.13

131.2

341;

*04

91.0

J,,lS

1.37

ii3S

SII

104

IiI

JI5.0

'SS

lIt.8

055

lOS

21.1

liIea

IS

iI,._

lì

O5

3,4I

JiS.o

ii

!fr

I0

I 7.3

J431e

554

110.3

14

I0

J P.

'J

7.0

III

U,t

5.1

407

IDI

II$

51.7

Joli.

J47..

:(

SL

l.b.0

ll;.5

941

lot

A lit

120

.51710

us 35

p;4

144,5

,

1,54

153

71.9

.z, ,.e

15

141.

551

lOI

50.3

.41

O5)

II,I

SP

I11

023

.1jlk

.JI

(55*

0P

lO.2

.2,4

4I11

lIt.3

504

III

ill

13.3

2J..

Jq,

as

io:

isIs

1541

I5

5'o

liP

Il)

12.5

33.71

411W

41I.

II '55

I I 5J

J3P

P.3

33.'

4*oo

55.

Z'/5

'ils'

2t'T

4,,s

lolt

'56'

7*0

48s

ic2

114

16,3

J,0o

IGo,J

i.e

114

Ils

il'

6,4

I¡ç;Io

IS'

i1iÇÏ ta'

PIS

i ¡6

Propulsive Power Needed, Single-screw v.a.v. Twin-screw types

The difference in propulsive power needed for single-screw and twin-screw for obtaining the samespeed is marginal according to the latest prognosis (Fig. 17).

Intensive model testing shows only very little favour for the single-screw design, to the extent ofi % (within accuracy range). The modern extrapolation method using form factors concludes that thetwin-screw ship exceeds her single-screw counterpart slightly.

(Scale effect in wake, hull efficiency, scale effect in appendage resistance.)Thickness of boundary layer is proportionally 3 times larger in the model. Resistance of appendages

is about twice on model scale.

Propeller Diameter

Model testing for a big-sized vessel ought to be done with large slow-turning (97 RPM) type propel-lers for both designs, diameters of around 7300 MM for the twin screw design and around 8600 MMfor the single screw version. Even 75-90 rpm are becoming available.

Single screw Perils

In case of break-even or near break-even between the single-srew and twin-screw versions as topropulsive power, the single-screw ship might - notwithstanding lower investment costs - still looseher advantage if her propeller is designed with a relatively large blade surface area.

Such large(r) surface, however, may be necessary in view of reduction of cavitation, hull pressurefluctuations, vibrations, resulting noise et cetera.

The propeUer thus is to have a moderate skew'. mainly for reducing the higher harmonic(s)blade excitation. "Extreme skew" makes the fixed pitch propeller too vulnerable for going "astern"(Fig. 20). A few highly skewed propellers got ,,tulip"-shaped after a "crash-stop". Only c. p. propel-1ers can have extreme skew because of their uni-directiorial rotation.

Development of Large Celluiar Containervessels 261

5915 A Single screw For Erst contr.

5974 A 7.in screw Fo Erst conf r.

Fig. 16. Single screw versus twin screw

o 3 4 s lo

Fig

. I?.

kel

at iv

e co

mpa

nson

bel

wee

nhu

ll-re

sisl

ance

and

pro

puls

ive

effic

ienc

y¡

S-2

S-3

Scr

ew

t p a

iot

o ..

.t o

ty ,o

OtS

IlI.

r Il

LT0P

.G1

flWt

tA1

r P

SH

PL.

.I2

2 K

Ny

%LL

i1)

iO0

'oI0

O

.1.0

0

o65 o6,

..u.o

i

1032

0.68

0

0.69

7I4

3.-iu

---.

A,

c.00

D

.tS..

ZlS

B

:i:: .

.l.oa

70r

PV

*K 4

S-S

'1I J

I010

ILS

O 9

0 .i.

oö.i.

O3

.i08

I.0

o.rl9

46

o.7O

i.007

9.10

31Q

34

1.03

5

0.75

1

0.74

4

OC

144

-?

2.5

",o

102

oo..8

t's -

,2' e

NO

VIS

AT

I0N

S

i-oia

oW

AkE

PC

AK

25,

.ys

71/0

.o 5

.

2 5

I 0,1

804

5o7

os/ °

°o

0.51

010

4 sZ

PA

NM

A

i7.

__/

R5T

NO

0I0

00N

OS

.E, t

t"

.. .

0

woo

l non

4

o ,

sr a

etø

noV

,.. y

n.O

Cq,

'W

r3

S

00J0

50. 5

5J51

t

l00'

l' 08.5 -

- po

s.s

o.ao

f1i8

j7.,

HO

OR

N-H

OJf

r1A

N

4?'

...

NO

o,M

n001

S.S

¿17

0W05

F_

CO

OD

Ntl

sollo

-ip

Vo,

jo''.

°°"°

°

It..

,js..

2. S

F .

.5/7 l.)

l.o78

I 045

Soo

l07

04/5

4I 0

1709

910

JO

00M

, O"U

¿71

1

lNI1

sO1O

I*__

_.

.io

01 .o

ny.s

¿J0

0750

0.-_

_._

-.

wA

c

9s

0310

0004

71/

db. w

aTtN

-S,tt

..

I0 lO

I00

0649

0Ö_

t 4 0

54;'

0501

1. 4

7300

I._-

L:...

?._.

...0,

'-°'4

'1

OIL

S.

li M

>

ooo

HO

S.tl

*1I0

05

0

1.5

i00' A !7

0010

0004

41/0

1

0:t '

wO

O'

0005

o,f

lat.e

PI1

o0S

1019

010

lOO

son.

v.n

ar.0

01

MO

nI. S

ill'.l

bt 4M'

L7L

.° 1

17

_.. n

.....

loX

040

..,,,

a

Model No. 5915 A

b9

67

a


A

Model No. 59156

Crape off-so

50

II.looc lop

Fig. 18 ac. Reduction of wake peak by softening curvature ord. 4-3. This is most important for all single-screwships

Twm-screw Ship Experience Regarding Living Conditions and Reliabity of Service

Nedlloyd's experience with twin-screw ships is very favourable for this type as to fuel consump-tion level and especially the low vibration level. From that point of view. Nediloyd's NewbuildingDepartment would go 'the safe way' for twin-screw, especially in case of ready chances of higherspeed 'bursts'.

Also, the reliability in service with a twin-screw plant is higher than the single-screw propulsion.The twin-screw ship could sail with only one engine working whilst the other one is not working. itspropeller having been uncoupled and just 'windmihing'. The working propeller (fixed pitch) shouldnot overstrain the engine to which she is coupled, however.

The rudder will need about I to 2 degrees angle in order that the ship sails a straight course. Thisway, the inactivated engine could have maintenance or be repaired at sea without the ship beingdelayed too much or being tossed around by waves. Each engine to have a built-on "shaft generator".

Sailing on only one of two Engines

When not for maintenance or repair purposes, the twin-screw ship could sail - for economyreasons - on one engine.

Such could happen when late(r) arrival is wanted. By this method a too low load on both the mainengines is prevented and so troubles from bad combustion (liner wear, piston-ring breakage) will be


567ag

a

I 3S70 t600ir'T' t

.;QlDlo,

Qotshp ttiTr& lin g

i vi300

5.

Bese

edge riwcrdo.

2 3 TrQilingb Bossing pipes of nediloyd H edge upword

Fig. 19a and b. a) Twin-screw Fareast container vessel. Wide transom, so high stability, High speed, yet vibration-free. Wake peak about 25 . b) Twin-screw container vessel with similar propeller and rudder arrangement to Fig. a.Bossing pipes enclose shafting, thus prevent corrosion. NSMB model nr. 4751 "Otto". Engines 2 x 8RND9OM

Sulzer-type

less. However, speed then will be limited to some 15 knots only. Means for easily mechanicallydeclutching should be incorporated into the design should such use be the intention of the owner!operator.

Both engines to have a shaft generator. Auxiliary diesels to be I + I + 1)2, providing the ship witha capability for rnanoeuvring and also meeting the reefer load.

Twin-screw Versus Single-screw from Out-of-pocket Costs Viewpoint

The twin-screw ship will ask up to 4% more investment costs and does require more maintenancein the engine room.

But she will offer the feasibility of reaching about 23 knots - against only 22 knots of the single-screw version - should schedule backlog be met.

The single-screw version would be a cheaper proposition as to investment and maintenance costs.So, when service speed is definitely downgraded from 20.5 to 19.5 knots, the choice for the twin-screw can hardly be upheld. Although the feasibility for keeping schedule may be important. wecannot but emphasize the considerable reduction in fuel costs (and consequently slot costs) whenopting for the single-screw ship.

3O


_tejoFig. 20. Increase of ske' reduces "higher-harmonics"-excitation. Geometry of 4-bladed pTopeller model no. 5520.Nedlloyd Rochester: propeller diameter: D = 6500; pitch ratio at 0.7 R: P07/D = 0.907;expanded blade area rationAE/Ao = 0.726; chord length0 7/diameter c07/D = 0.420. thickness/chord length07 t/c07 0.0305. Dimensions

are given in mm for ship

(2) Hull Form - Single/Twin/Triple Screw

Introduction

The hull form of the fast sailing ship anno 1850, having a "cod's head" and a "mackerel-tail" hasdeveloped since into the present "seagoing motorlaunch" with a V-shaped forebody and a pram-typetransom stern - the container carrier. This form will provide sufficient seaworthyness and stability(Figs. 21-24).

Prismatic Coefficient

The optimum prismatic coefficient as function of speed-length ratio normally lies between 0.61and 0.68 (diagram of Benford). Higher fuel prices will tend to make ships of finer lines and in eachseparate case a remunerativeness calculation should be made.

Shortly after the oil crises, fuel costs rose to about one-third of the total exploitation costs and thepnsmatic coefficient reduced from .66 to .64. In case vessel has to bear a certain cargo-weight at atreshold draft, it pays to keep the fuller prismatic coefficient, however (limited draft in port).

Afterbody

From 1850 onwards, the transom stern developed into an elliptic stern. After 1920 the ellipticstern became a cruiser stern. As from 1968, the cruiser stern was cut off to a transom stern and in theyear 1970 the transom was widened to the full ship's breadth (Fig. 25). So we are back tothe 1850 "privateer".

The new afterbody is in fact a well approved old one as on fishing vessels. Buttocks' steepness tobe 9 to 11 degrees (maximum 12 1/2 degrees) and this should not be exceeded so as to prevent flowseparation.

One of the main advantages of the wide - pram-type - stern is the large stability provision withina given over-all length. Also hold space and notably deck space have thus been improved.

Also rolling angles are smaller in comparison to those of finelined cruiser-stern vessels under sameconditions of sea and swell.


0.90

0.85

0.80

'O.75Q)

- 070

0.500 06 OB 10 12 iL 1.6 18V (Vinkn)

'V[ )Lin ft.)

Fig. 21. Optimum prismatic coefficient on speei/tength ratio (Optimum on V/Jt) by Benford, U.S.A.

The drawbacks of the pram-type stern are there too, e.g.:- The larger frictionai surface - in comparison to a cruiser stern hull - when the stern is in the

water.- The slamming which sometimes may occur during heavy weather or when the vessel is laying in

a swell-bound roadstead.- A flat stern over the propeller also is more prone to transmit the propeller-excited pressure

fluctuations into the hull and superstructure, causing vibrations and noise hindrance to thecrew.

Midship Body

- A large bilge radius is favourable for obtaining low resistance. Nedlloyd prefers a soft bilgerather than inclined ship-sides with a hard bilge. (Difficulties with pilot ladder.)

- Rolling should in first place be kept within limits by loading the vessel to the right metacentricheight - preferably GM = 0.4 to 1.0 M. (This is the modern terminal shipplanners' duty') Anti-rolling fins have their drawbacks because of the high fuel prices as they require some threepercent of the fuel consumption and the lower service speed would ask for larger fins nowa-days in comparison to 10 years ago (then 25 knots, now 19 knots).

- Anti-rolling tanks should be very large to have sufficient effect. Adequate corrosion protectionof the tank walls against the heavy water-wash is not solved yet for a :5-years' lifetime of thevessel, Also, it is very difficult to design a sufficiently wide duct below the cargo hold for anunhampered cross-over flow.

Forebody

Originally, the ttss "Bremen/Hongkong Express" and "Nediloyd Delft/Dejima" (Fig. 26) had beendesigned in 1969 for 27 knots sea speed and many tanktests were carried out to the order of theowners in co-operation with the builder, Bremer Vulkan, for the purpose of obtaining a softly-increas-ing speedl power curve.

A cylindrical bulb, combined with a shoulderless forebody (iwo. section lito 13 - an idea byProf. lnui of Tokyo University) was adopted and indeed the vessels' hulls showed an almost complete

0.65

aso

0.55

a .jCTOtO.sp


Fig. 22 ac. Curves of sectional areas. a) Europe-Fareast L020 = 273 m; b) Safcon L0.20 = 247 m, draft = 12.00 rn;c) Safcon model (mmss Nedlloyd Hoorn/Houtman)

lack of bow wave at the 25-28 knots speed range in a calm sea. Lowest s.h.p. values at top speedwere attained with this hull (Fig. 1).However, after the fuel crisis of 1974, the service speed had to be reduced to a 20-21 knots level(max. peaks 23 kn) which new condition did require a considerably less massive bulb. Tanktesting in1980 learned that about 3 % fuel saving could be attained when replacing the original bulb by asmaller one and we decided to do so.We expect that speed loss due to bulb action - when the vessel is pitching in heavy headseas - wilialso be less.(Note: Many a model basin designs a bulb for full draft, calm sea and top speed only. In mostinstances this is because the shipyard has to fullfìll a minimum horsepower at a deep contract-draft'Such bulb type soon may act as a "brake" instead for the vessel in real service.)

268 Development of Laige Cellular Containervessels

The U-type fo r e body frame s hap e which is favourable at the high speed/length ratio(25 kn - 27 kn) should nowadays be redesigned into a more V-shape because the V-forebody givesmore lot-rn stability (KM value is considerably increased).

V-shape should not require more horsepower at the lower speed/length ratio's in comparision tothe U-bodied vessel (at high speed the U-shape is better).

Extra contaïners can be accommodated whilst keeping the original metacentric height. whichmeans that the earning capacity of the V-bodied foreship is larger.

A fine e n t r a n ce a ng1 e a t t h e load li n e is strongly advisable in order that the ship inrough weather may slice through waves easily.

Sufficient fr e e board a n d reserve bu o ya nc y should be designed into the forebody forkeeping the foredeck free from green water. Smaller vessels should have a long fo'cs'le. Buildersshould noi save steel-weight on this item!

Large amounts of w a t e r b a Il a s t in the ship's ends are to be omitted so as to reduce themoment of inertia.

Fuel oil t a n k s to have the centre of gravity rather far forward (0.4 L from F.P.P.) in order tokeep the ship at the proper trim without the necessity of large amounts of waterballast in the fore-body. This fact raises the problem of fuel-oil heating far away from the engine room.

Nediloyd has established that a flared forebody is advantageous in head seas.A k nu c k 1 e she e rl i n e in the higher part of the forebody will act as a wave breaker andmeanwhile create a box-type hull girder of sufficient compressive strength. on both sides of hatchesnumbers i and 2 - which is important when diving into a wave. Such knuckle - to our opinion - ispreferable to a wave-break on the deck mounted on a slun forebody.

By the way -- last but not least - the knuckle sheerline perhaps is the last rudiment of ship'sbeauty - a sheerless container vessel, blocked up with boxes is an awful sight.

Twin-screw Hull Form

The attractive feature in the line s of the twin-screw ships (block coefficient 0.60-0.68) is thestraightforward character of the desi-i (Figs. 22. 23. 29. 31).

A fishtail' deadwood, together with a skeg-rudder. a design that warrants good coursekeeping (even when sailing in following seas) also gives proper shallow-water and slow-speed direc-tional stability.

A wide 'pram'-shaped afte rbody - as said before - is ofgreat benefit to large container-ships and roro-vessels from stability and cargo carrying points of view. The immersion of the transom.however, should not exceed 0.6 M so as to limit extra fuel consumption by turbulence.

Free-flow propel I e rs. mounted on slender shafting. having a high entrance velocity willprovide a high propeller efficiency and - because of the low wake - there will be much less vibrationin comparison to single-screw ships.

Contrary to the vibration troubles experienced on the single-screw Autralia-run vessels of the firstgeneration containerships. it is noteworthy that the twin-screw Far East-run containervessels - evenwhen utilizing up to 2 x 40,000 shp for attaining a 27-knot sea speed - are quite free from vibration.This fact is greatly attributable to the slender pipe or bossing around the wingshafts resulting in anaxial wake of not more than 25 % to 30 .

Shafts should be enclosed in pipes in order to prevent corrosion. We intend to utilize Mannes-mann pipe, with oval section, unstiffened. Experience is excellent with a 1900 pipe on many ships!

Airwing-design b rack e t s, supporting the slender pipes, seem to have no harmful effects to thewake field and do not give cause to propeller-excited vibrations.

B o ss i n g s designed for creating contra-rotating water flow - for the purpose of increasing thepropulsive efficiency - should - as we see it - not be applied. The wake peak will be larger and willexcite cavitation and vibrations. As was experienced on a number of ships.

Sufficiently large t i p cl e a rance between the propeller and the ship's hull is also a 'must'for a good design in order to keep hull pressure fluctuations at a lowermost level.

The larger tip clearance will tend to have the position of the propellers far out and wellaft.

C

a

b

Fig. 23 a-c. Twin-screw hull. a) Europe-Fareast containership model 3956 for Nediloyd Dejima/Nedlloyd De],ft;h) Twin-cres Safcon ship lines (development stage) L0.20 = 247 M; c) Twin-screw Safcon ship lines (as built)L0.20 = 247 M. moddl 4751 "Otto", Nediloyd Hoorn Eur-Southern Africa, Nedlloyd Houtman Eur.-New Zealand

- - --.P4

Fig. 24 a-c. Single screw hull. a) Single screw safcon project in development stage L020 = 247 M; propeller onpipe; b) Single-screw Southern Africa - Fareast ntainer project 1975 L020 = 207 M; C) Pram with gondola,single-screw "Universal" containership project 1981 L020 = 202 M



Unfortunately this will cause the waterfiow (race) further out and so away from the single rudder,thus resulting in a poor steering capability.

On Nediloyds "Dejima/Deift" this deficiency is remedied by the ru dde r having been given agreat length (6 M on 290 M ship's length, i. e. 2.2% of Lpp) and a hard-over rudder angle capabilityof 45 degrees (instead of the commonly applied 35 degrees). Now, the rudder blade still can reachinto the propeller race if required for accurate steering in confined and shallow waters, especially atslow speeds.

From a manoeuvring point of view, the position of the propellers should preferably beclose to the skeg and well forward. This arrangement, of course, will result in strong hull pressurefluctuations, i.e. vibrations and noise hindrance, fracturing etc..

On these points - i.e. tip clearance versus manoeuvring feature - a compromise has to be foundfor the position of the propellers. Experience, up to now, obtained by Nedlloyd's "Dejirna/Deift" andalso by Hou tman/Hoorn has shown their stern arrangement to be a good compromise: proper steer-ing. no vibration. (Shafts should be kept parallel by all means in order to guarantee good manoeuvringcapabilities.)

&f t

bettsr tci

pru. witb prp.1iir oe pl- øt optt]. Sn- .ln. far forv.rd- WSld ts.rig

good

Fig. 25. Development afterbody 1968-1973

*i T

Development of Large Cellular Contarnervessels 271

Fig. 26. Nedlloyd DrIft

Single-screw Hull Form

On the conventional type fast cargo liners the propeller aperture developed already (1950-1965)from a narrow to a wider one (Figs. 25-28). After that period, the shaft-horsepower was nearlydoubled. The preference of Nediloyd is for the propeller-on-pipe arrangement so not for the SternBulb design. In this context we must mention that three vessels ("Abel Tasrnan", "Hollandia",

1970: 25- Z7kn

136

112rpm

1981

115rpm

9790rpm

- 22 kn

Fig. 27. Trend in propulsion of large containerships


a

C

ta.gerrtial

b

uuI

Fig. 28 a- r. Wake single-screw. a) Wake containervessel s.s. Abel Tasman/Sydney Express 32450 s.h,p.. i 10 RP\l.b) Results of 3-dimensional s'ake measurements on the Abel Tasman model. c) Variations of resultant spt'ed, strong

variations of angle of attack

"Zeelandia") having around 27,000 to 30,000 shp on their single propeller (block coefficient about0.60-0.64, some 1600 teu capacity) are all three suffering from aft-end vibration to a greater orlesser extent. This is directly related to the location of the engine "far aft". The design of such high-powered (single-screw) container-vessels -- as to keeping vibrations within bounds - is very difflult

-

Even more so this counts in case of roro-ships. Their aft hull is even more flat of shape over thepropeller. The trim balance of such vessels will require the Centre Of Buoyancy to be as far aft asfeasible, which means a full afterbody, whilst at the same lime the free flow into the propeller diserequires an afterbody as slender as feasible. As always in naval architecture, a compromise has 111

be reached: Engine foundation to be stiff, meanwhile the a ft e r h od y should he slender, fueland/or waterballast tanks should be positioned forward of l/2L.

C


N1

- .-..,..

Fig. 29 ac. Wake twin-screw, a) Wake Nediloyd Dejima. ' 1900. pipe + struts 86-ModeÇ c'i Far-East container sluris Nedlloyd Dejima; results of 3-dimensional wake measurements b S-hole Puoi tube

Approaches to Propeller

Some vessels, having a blunt afterbody inimediately ahead of the propeller and those having arather sharp turn-of-the-bilge in way of the engineroom, do suffer from separation of the water-flow towards the propeller (Figs. 32, 33).

Even slight afterbody variations have already strong influence on flowlines towards the propeller.The fullness - or rather slenderness - of the foot of sections 3 and 4. i.e. in way of the stern-endof the main engine, can be decisive in respect of separation of flow.

-T

T-'1' 'T î-:-:

7T 4

suu , .

a t.

tangential

b

274 De'welopment of Large Cellular Containervessels

Fig. 30. Left: Nice triple-screw arrangement of "Selandia"-Fareast containership. Right: fat bossings of tin-screpassenger-liner

Aperture Clearance

Other vessels have been designed with (too) smal] clearance in the upper part of the stern framejust ahead-and-above the propeller. This causes a wake peak in the "I 2-o'clock' position of thepropeller to a possible extent of 65% to 75% - with an inherent vibrations hindrance!

bF low

Fig. 31 a and b. a) Slender pipe with struts, pipe without internai stiffening (!). internal access up lo the sterntuhcseal, b) Development from o (circular) to O (oval) section in order to reduce resistance and wake

RoPo Model 5141D

Probably sepzotion

RoPo Mcdel 5190

o

RoRc Mode' 5247

2

2

3350

3

3

Engine should be positioned more forwardFig. 32. Flow lines towards propeller lip in top-position (l2o'cJock') showing the enormous influence of theshape of cross sections in way of ordinates 2-3-4 (where the main engine is posit onedi


RoRo Model 52O

wonderful flow

2 3


3

o

,oG

Fig. 33. Single-scre with engine "far-aft" often causes vibrations. Above is the outcome of 3-dimensional stakemeasurements by means of Pilot-tube on a toro ship model for three configurations of the ship's bottom (Gondola)in way of the main engine seating

Angle of Entrance to Propeller

In short, in case of flowlines towards the propeller having to make a sharp bend. separation of flossoccurs and a stagnated flow above the propeller can then activate bursts of hull vortex cavitation(mrnss "Straat Nagoya"-class. "Antilla Bay").

On certain vessels, suffering from Propeller-excited vibrations, a 'tunnel plate' has been mountedabove and ahead of the propeller which directs the inflow of water more accurately, shielding oft'the separation.Results often were very good (e.g. on "Sea-Land Economy". "Melbourne Express") enabling theuse of more horsepower at reduced vibration levels.However, there also is a case where a mal-designed leading edge of some kind of tunnel in the shellat an angle to the flowlines is acting as a water-stumbling barrage ("Encounter Bay"-class).

U 5 A ARAB'w.

RO-RO

'So. 0

'G303tMODE

FAT GONDOLA

5141MO SIIÑDfP'-wa 51410

r

.a NEOLLOYD OCS1E - AFT EPC ' ENGINE

the rudder ja 3% of 1_pp end the rudoer area is 28 erc.n of 1_pp a 10 n,.

MEDLLOV' 7TERDA'T


-Jo

r_'.2,_.-

-. T

Fig. 34. Location and foundation of engine; 1) too hard curve: floss -retarding 2 rnprovement for new designs

From experience, it has been found that ships with a propefler blade frequency of 5 x 130 13ôrevs/mm. and 6 x 106-110 revs/mm (Fig. 25). often suffer from full resonance of bulkhead panelvibrations in the afterbody The vessels suffering worst from such vibrations have been established tobe those with the accommodation right-aft and with propeller-tip speeds over 40 m'sec.

The higher harmonics, i.e. those of 3 and 4 times blade frequency. are the main culprits of thesevibrations. In these high frequencies exaci resonance predictions are almost impossible.

The results are vibration and connected noise hindrance to the crew and even damage to the struc-ture in the afterpeak area, damage to piping, bearings and instruments.

These troubles have frequently led to the practice of sailing at reduced power (and consequentlyless speed).

Vibrations in the first-generation class of containerships were at an acceptable level only if sail-ing below 27,000 shp. which habit resulted in a reduced service speed of 21 knots on the Europe-Australia and v.v. run,a reduction of one fufl knot of the normal capability.


For the naval architect it is a relieve now to have the possibility to apply lower propeller revolu-tions, i.e. 90-100 rpm, instead of the former 122 rpm. This allows for lower tip speeds.The flow of water should be kept "undisturbed" as far as feasible for (both twin- and) single-screw

vessels. Ifa wake peak of 55% is to be accepted or is unavoidable, thus causing cavitation and hullpressure fluctuations, a shock absorber over the propeller, mounted on the flat afterbody might betned (Tests at TPD-Delft and N.S.M.B.-Ede on this subject are done.) (Fig. 18).

Achievements 1971-1981 in Countering Vibrations

In 1971 we experienced the vibration-free propulsion with the twin-screw vessels. These vesselshad been fitted with propellers on shaftings enclosed in slender pipes and supported by stream-

a

05

b

go'

Flow sep5rtion

low speed Zone

High velocity -Motor

0°

50 w0

Fig. 35 ac. Flow around engine foundation, a) Flow lines Afihody with Gondola: h) Curves of constant velocits.model 5190, c) Results of 3-dimensional Pitot-tube measurements

1.0o

>

oC 0° 100go, 1BC, 270'

Development of Large Cellular Container-vessels 279

-

Fig. 36. Ceflular containership "Unen" design 1981. (For 'EMEC" service and 'EUROSAL" service

lined brackets. Following this good experience, we designed a similar arrangement for a subsequentproject (SAFCON), viz:

- One model fitted with twin-screws on pipe (Fig. 17).- One model fitted with one screw on a pipe (Figs. 24, 25).The wake belt on both models was very weak (about 25-30 only) and trouble from vibra-

tions not expected.The single-screw vessels, however, needed more horsepower for the same speed. This was caused

by the propeller being of a smaller diameter and larger blade area and thus of lower efficiency.The single-screw vessel lacked wake and therefore also the hull efficiency was low. ("No wake

no vibrations/no hull efficiency".) For good order's sake, we have to mention that al] conclusionshad been drawn without taking into account the Scale Effect (from model to ship) on wake andthrust deduction. 'Full Scale' will give a benefit to the free flow arrangements and a drawback tothe wake-adapted ones.


o.t

0.3 0.4 Q.)j5

E LDELINES LW EhJL.. Ax:. V5.)! Y CO ENS SI

AXIAL *lPEPT5

I 3O49C i 35 i83 lOP 725 270 3 5 35

TANGEPT1AL CO0OtE%iS

I0/.

.1

Fig. 37. Wake field measurements 'Universa containervesse! ('Unco". at 10.60 m draft. Ship model no. 5901 . i'tno. 39912. speed 19.0 kn., draft 10.6 m., model condition screw aperture I, bulbous bo I

The disappointing result on propulsion performance for the vibration-free single-scres pranl.type with propeller on pipe lead us to further developments in single-screw hut] form:We try to accommodate the diesel engine - which for reason of economy should be positioned

as far aft as feasible - in a streamlined bossing (we name it "Gondola") underneath the pram-hull.Tl-ijs bossing should be as slender as possible in order to reduce the wake peak (Figs. 34-37).Therefore the web frames on the tanktop should enclose the aft-end of the diesel engine, includ-ing the thrust block. The engine is 'hanging in a sling of shell plating and webs.Marine engineers should help the naval architects out of the quandary by making this engineseating a stiff one, yet allowing space for the fitting of filling pieces after lining up.Nedlloyd's "Universal" containership design (single-screw) is from 1981.The speed/power performance looks very good from predictions by tests at N.S.M.B.Wageningen.The "1 2-o'clock" wake peak is less than 50%.Contra-rotating vortexes appear to be relatively small and we expect that there will be only littleexcitation of vibrations.

0%

w* t

p

Development of Large CeUula.r Containervessels281

The Source of the Evil and a Guide to Avoidance

lt is the very first moment, when signing the building contract where length and deadweight areguaranteed, that the baby may be doomed to vibrate all her grown-up life:Engine far aft, a fat afterbody and a narrow propeller aperture are causing the evil:The building yard tries to offer the maximum carrying capacity - to the future owner/oper-ator - against the lowest feasible price and consequently shortest possible vessel.This ship then turns out to have a blunt afterbody, small aperture, high wake.Improvements of the hull form at a later stage after negotiations are often hardly feasible.Remoulding efforts by model basin and utilisation of wake-adapted (skew-back) propellers can hardlydo sufficient to soften the vibrations evil or the poor efficiency, as main dimensions remain in thewrong combination.So: Wrong dimensions are to be prevented at the contract stage! (Whichusually is far before tanktesting could be started!)In otherwords: tanktesting actually should be done before contract!

RefereaesNSMB Reports:

Contr. model 4248 October '78. Austr. contr. "Abel Tasman", ANZECS:model 3865 March '70. Far East contr. Deft/Dejíma. ScanDutch:model 3956 January '72; model 5902 Juni '81 ; Far East conti. DelftJDejima. Scandutch,model 4751 December '74, South Air. Europe Safcori conti. "Hoorn/Houtman"SEACSÍANZECS;model 5163 March '77, Container project, not built, ZAVO;model 5268-5308 March '77, Container Hongk.-Austr., AAE "Asian Jade";model 5655 Sept. '80:Contr. South Afr.-Far East, not built;model 5736 Sept. '80, Conti. South Afr.-Far East, MHI design;model 5901 Auf. '81, Conti. Universal typ - EMEC-Eurosal:model 5783 Oct. '81, Conti. Panmax:

model 5914 15. Sept. '81,Contr. Far East single twinscress,model 5943 June '82. Conti. "Keco"-design.Ro-Ro model 5100-5104 Sept. '76, RoRo contr. Austr.-Malaya, ANRO; "Anro Asia";model 5120-22 June '77; Shoribody version, for Middle East seice;model 5141-5131: model 5150; model 5190: model 5247 Febr. '79, Gooeseneck;model 5274 Nov. '77, Long-body version, NLL Rouen/Rosario:Calculation boundary layer flow around 3 RoRo afterbodìes. March 1979 Raven,Interim report simplified Hull forms August '78:model 5650 Nov. '80, Pass/Car ferry twin skeg-twin screw;model 5896 June '82. single skeg-single screw;model 6061 Sept. '82, heavy lift conti. RoRo carriermodel 5896 July '82, Trailer-passenger ferry.model 6901 Sept. '82, Trailer-passenger ferry.

Treatises by the same author on the subject of shìp's development:Verre Oosten Conrainerschepen. Nautisch Techniscti Tijdschrift. Aug./Sept. 1973.Developments of ship's afterbodies. Propellet-excited vibtattons, May 1973. Lips.Triliingshinder bij schepen. T.H. DeIft. mt. Periodical Press, 1977.Developments of afterbody or contr./roro vessels. 1978 translation by BSRA of ¡PP '77.Cost aspects in liner shipping. May '72 + Oct. '73. Ti-i Detft Symposium paper.Efficiency in liner shipping - Anno 1979. Nedlloyd/Europori.Nediloyd Lines' RoRo-concept for the Middle East. Holland Shipbuilding. Apr. '79.Ontwikkelingen in de lijnvrachtvaari. Juni 1980, De Ingenieur.DeIft-Dejima-Houtman-Hoorn. Aug. '75, Unieschakel.Containerschiff Bremen Express. Hansa, ¡972, iii concert with Br. Vulkan/Hapag Lloyd.Haven en Terminal Planning. T. H. AfdelingCiviek Tech,iek "Havertsl", 1980.Good Steering Properties for Conafrserships: The Motorship, 1979.Liner fleet re-tonnaging f Vessel development. ECT-conference, 1982.


Development of large cellular containerships

Summary

Under the influence of changing circumstances of living at the one hand and economic pressures on the otherhand il is of utmost importance to have proper tools of trade.

In shipping this means efficient yet liveable ships for the - necessarily capable - workforce needed to handlethem.

In this treatise we touch at a number of subjects encompassing both the efficiency and liveabil,tv.Efficiency items are eg. comparison of fuel consumption quantities of ship by type of main propulsive englne

(steam versus diesel), comparison by number of propeflers. Also by comparison of aft-ship configurations for theirinfluence on water-flow efficiency and avoidance of propeller-excited vibrations. Vibrations, besides giving habit-ability hindrance, may endanger structure and instruments.

However, vibrations cannot always be avoided because of certain demands put to ships form and lay-out onaccount of the cargo (viz, a wide afibody for stacking area and stability purposes). In order to arrive at next-best,the emphasis is laid on proper and repeated tanktesting. Outcome of many such tests are given, often by way of dia-

am for the specialists.

archief technische hogeschoo deift

Documents