ESSO OSAKA Maneuvering trials - shallow draft maneuvering of VLCC's

ARH1EF

1978 API Tanker Confexefl

October 1-4, 1978 Innisbrcok

Tarp1 Springs, Florida

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--E005AKA Man3vering Trials,

Sha11ii Draft Mariaivetiflq of VLCCS

W. 0.. Gray

coporatia..

Technische H Deift

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ESSO OSAKA ManeiveritjTrials

W. 0. Gray

Exxon Corporation

ESS OSAKA 5 a 278,000 dwt sirle screw VLCC

delivered in 1973 fran

the

Hitachi Shipyard in Japan. The OSAKA is cçerated ' Exxon International

Cixpany. flies

the Literiafl flag,

áni is manned ' Spanish of ficets and crew.

wring one intensive ek in July/kigist 1977 ESSO OSAKA was the "giinea pigs

for a

nprehenBive set of shallc" wàtà maiiawering trials. which are believed

to represent a

first.

The sponsors of these trials, which include eleven oil

and shipping calpanies undei the uthrella of the Amarican

Iristithte of

?r-chant Shipping (AIMS), the US. COast Gjatd and the U.S. MaritiiI

Administra-tion, undertcck sponsorship of the trials

With the foll'iii

purposes in mind: Inproving shiphnd1iñg emulator caçuter progran

by aauiring full

scale

ship trials ihformatiOfl,

particularly in shallo'

waters. It was believed that

there

re i

aifficiently cosprehenSiVé Sha11 water neuveriflg trial data

for a ncdern tanker

available anywhere in

the world to serve

this purpose.

With increasing nimbers of tanker owners relying

on training at

iandling

sinulatOrs for their

mariners, the proposed full scale

trial caild generate

hard data which

j1d provide a majot

iloprovesent in the

fidelity of the

sinulations of ship

behaviOr in sha1lwatr.

o Deepwater port design onsideratiCflS

ca1d be greatly facilitated by the

availabilitY of reliable,

caIç)reheflaiVe manaivering information for typical

large tankers.

The u.s. Coast

(iard has had a

special interest in this

aspect.

WOG DlO/A4

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o shiphandling maneuvering diagrama available for ccnnirv officers and pilots on ship bridges had been the subject of b'o IMCO* resolutions

and a recent

U.S. Coast Qard regilaticm. *ile it is possible to develop such information

with the necessary acoiracy for deepiater marJver5 wjtho.it further trials,

it

was not possible to do so for the nore inortant case of shallo'i water

behav-ior because no reliable ndel correlation with full, scale results

exists.

Further, it was not considered feasible in the shall water case to determine

such information by normal delivery trial proce)ireS.

One properly condicted set of trials for a typical vessel was

believed

suffi-cient to establish basic "model to ship

correlations needed by hydrodynami'

cists. Once such correlations had been established, as

was done marry years

ago in the speed/pJer field of ship design, naval

architects could predict

with confidence the maneuvering characteristics

for tankers over a wide range

of sizes.

B1CKGROUND

The concept of the OSAKA trials was first disaissed in the

author's coilpany in

1971 or 1972 as a lojical step in a tanker maneuvering research prcx3ram

begin

about 1966. The 1960's was a decade in which

hydrodynamicists and naval

architects brought the understanding and caloi lat ion of

ship's

maneuvering

behavior along quiddy, at least in deep water which is mathtiC1lY

rela-tively siffple by ccnparisOfl to shallci water.

With the first successful use

of real time ship emulators both for training and research

in 1970, the need

* IMCO is intergovernnntal Maritime Consultative Organization

for establishing an

acoirate rrelation between actual ship behavior and

sunilated predictions beme

obvicus. Nonetheless, because of the

st of

condict3.ng aich tria1s

together with the fact that

ship masters who evaluated sinulator response' "by

the seat of their pants"

declared them acoirate. it was

diffiojit to stimilate wi

interest in sud a project.

At abzt the same time, a gring

interest was being skn

in tanker

man-euverig by irxlivideals in bOth the piblic and regilatoty sectors

can be recalled by reereflCe to a auuber of significant events:

o In the

U.S., the Ports and

Waterways Safety Act of 1972 emerged from lengthy CngteSsional

hearings to

US. las,' whith stat

in part:

"That existing standatde for the design, construction,

alteraton, repair,

maintenance ai operation of suds vessels Dust be isproved for the adequate

protection of the rine environment."

and further that:

"&ch rules and' régilaticns

shall, to the extent possible, include bit rt

be limited to standards

to inrove vessel

manevering and stopping

abil-ity..."

It is perhaps ixt

surprising that the CongzeS8 adopted this law when Senate

committee hearin9s in regard to

improved maneuvering

i tankers Stated:

'The 'coumittee $ hearings' indicated that nu Ø

fore needs to be

dons in

ths area.

The stateof-theart

shoild be mproved

with the ecpectatir

of major advances made through the

investment of additional

research

G D1'O/A6

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and thrusters that woild reverse thrust, nust be explored, among other

possibilities.

One Coast Giard study canduded that pier ramming

caaial-ties 'and associated polluting incidents demand that future tanker design

incorporate SQUE mathod to prodice thrust atkniartships to assist in dodUng

and mansuvering. Lat.ecal thrusters, the report

concluded, aear to be the'

most effective matkd by whiCh to proàioe

this side force and their use is

reooáended in thture

designs. 1**atever the ultimate

]ution in this

area, it is clear that

not enoigh attention and priority are being assigned

to thIs problem.

It is hoped that

,enactflEnt of this

legislation will

aibstantiallY ehhanoe the attefltiOfl and priority being given the subject.

'

0 In 1974 a conprehensive edvance notice oi prgçioséd rulemakirv3 waS piblished

by the CoaSt Qiard covering a.zh inteztelatOd topice as navigational ecipip

itent, port entry criteria, bridge

mangivering informatiOn and vessel features

ihicth rniht hávé an influence upon maneiverability. As a part of its reaponse

to this notice,

AIMS proposed to rk with the USS GovetnuEnt to identify and

codify in regilations the "best recEnt

praiceR in regard to raor

charac-teristics of inpert. tnce

to aduate tnkèr

manei'vérability.

In the authors

recollection the thoight

hind this general suggest*Ofl

was that regilatry

proposals dealing

with øich matters as

rudder size, rudr

angle, back Lng

thrust aid speed

of zudde zroveneht iight

logically be included in

future

reg.ilationS. Technical representativeS for AIMS were of the opinion that' such an approach woild make good sense Whereas the re extreflE siggestions of

regJiriflg' ñultipië screws

and ruddets or, b

and stern thrusterS

woilci 'do

little, if anything, to

enhance manwveing safety.

(

o Despite

general agreennt in the

marine technical ccimUnity as evidencc1

at IMa) and in Coast Qard regilation making, pres1reS cx)ntirlied to bi ild to

içrove tanker

maneuverability. Typical

of this type of viewpoint are the

fo11QQiI. statønts from a

lead article entitled

"Controlling Ships in Heavy Thaffic" in a respected piblicatiOn of the (U.S.) ational Scienos Fojndatiofl:

"EspeciallY in the Sha1li

waters of t shOre and near harbors, large ships

can behave in unexpected ways." and "Especially

ladUng is detailed

knci-ledge of h

full-form, deepdraft

ships, sich as sipertankers,

behave in "ver:y shallcM" water - depths less

than three tines

their 60-foot and

deeper drafts."

With these factors as additional incentive, bit

still, with the preliminary

pirpose of obtaining

essential data for the best

"state of the art" shitii

ild-ing siuulatiOn, the basic prcOsal which resulted in the ESS) OSAKA trials was

presented to the U.S.

Govetnment and to AIMS

in the fall of

1976. 'By this tine with its èxoellent new CN)RF* facility caning on stream, MarAd had a keen

interest in obtaining

sinulator validation data. Coast Qiard, being

diect1y

responsible for licensing, of deepiater portSi

also bad a direct

interest in

obtaining information

that wo.1d be of

value in deciding on locationS and

characteristics of ach

facilities.

With both top managenent and financial

support fran these two brancheS of the U.S. Government most directly concerned with marine matters, the final additional 9Jpçort was quickly obtained thragh

AIMS fran 11 ccepanieS. The sponsoring organizations

are shfl on

Appendix A.

CoflpIter Mded Operations Research Facility, the shiphandling

SiflU-lator at Kings int, N.Y., U.S.A.

iX3 Dl0/A8

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Condicting full scale

trialS rjiteS good

good lud with the

Weather), and on both scores ESSO OSMA was fortunate.

Appendix A Stxws in addition to the sponsors the varic*S contractors and other

adviSorS having a role

in the project.

Special intion of certain of their

actIvitieS shoild be ude:

The David Wo Taylér Naval Ship R&D Center waS responsible for detailed data

collection. While the ship's a'm

instrudfltS were in nst instanceS

the basic

So.lrce of performance data,

it Was neisSaEy to cälibraté carefully and to

provide àontiiijais

recording facilities

for nESt key paranterS for

prepara-tion of aibseqient

figires shoiiflg total ship behavior in eacth mariver.

o Sippican

Corporation was reSponsi'té fbr

initial site selection,

hydro-graphic survey of the

test site, and for

installation of o.irrent

meters and

subseq.Ient analysis of currents d.lring the

trials.

Decca Si ry Systeme, Inc. was responsible fOr necesáary insttunentation to

use existing Decca Hi-Fix transmiSSiOns for contirLlo.35 position fixing with

reqiired preciSiCm.

o AMTEK

adaptedthe ship's

existing Dopplar sonar eqUi[1rIt to additionally provide contiruQis high resOlbtiOlk infornaitcfl uriderkeel clearance

dirii

the. tialS.

..

o Logistic support for the trials was

provided by EXXa Conpany U S A Marine

Department and a n.ntber of Coast Qiard ConmndS and

craft.

Coast (ujard's

7

handling of traffic, giarding of airrent meter inetallations, protecting

divers, and other functions which only they cwld supply, s excellent.

o Hydronautics, Inc. throigh SE* spoflsorship was responsible for pretrial

prediction of all àanejvers which flot only assisted in the planning of the

trial schedile and areas, bit also enabled an early test of the acoiracy of

their naneuveriflg prediction capability.

o Both the Massachusetts Institute of Tethnológf and Stevens Institute of

Tethnóloqy obtained, for the firSt tire, detailed full Scale sha.Ucw water

maneuvering informatich to assist in their ongoing hydrudynamic research

prograre fuhded by MarAd.

o Two panels Of the Soiety of Naval ArditectS and Marine Engineers with

reinbership from a broad sector of experts in the U.S. and abroad provided

excellent technical advi th diring ihitial preparation and final data

redition stages of the project.

Finally, all of the activities were condictéd under a contract issued by and

àdministèred by the Maiti1Te AdminiStration with EXxon International Corpany

serving as prime contractor.

OVerall project management and ccITpletia of the final rk program on

sche-die was the responsibility Of Messrs. p. M. Kimon and C. L. Crane, Jr. of

Exxon International Conpàny.

*Sti.E is Soiety of Naval ArchitectS and MarinO Engineers.

4

ThE SHIP, THE SITE AND THE TRIALS

Figure 1 has sketches of ESSO OSAKA'S hull form,' ruddBr and propeller, and includes as

U basic

diliensicnS and. other

significant paraflterS.

She is conSidered typical of ixidern VLCC's. Under the guidance of Captain

Bastar-rechea and her cr she perfornd satisfactorilY throighOit

the trial period.

Figure 2 gives a grauC

rep estation

of the ship's cross-seCti(X

in the

three basic water depths selected for

trial pirpos

including shallci, ñdiva%

and deep water.

Figire 3 shc*i'S the

site selected for

trials in the U.S. Qilf

of Mexico,

soith-west of Galveston, Texas and not far from one of the areas prcçcsed

for the

Seadodt dèepiater port. The three areas needed for deep, udium and shallaii water teSting are

indiôated, as are positions selected for

six seth of.

con-tiniws airrent

asureuént airing the

trials.

Caaial irpection of

th

darted water depths clearly shaws the very

uniform bottom côntcurs which prevail,

it is this featiré

which had made the Qjlf of Mexico a print

trial

site fran the earliest

thoights of the program. This characteristic, together

with the initial

bottom survey in the shalladeSt water gave confidence that

the VLCC, which had been ballasted to

her load draft

for the trials,

jld.nOt' run uncie

risk of striking

uncharted bottom obstruCtiOnS diring the

trial

prram.

Table 1 shcs the trial agenda listing

all mativers

condicted at the vari.iS

water depths and speeds needed to

Obtain siiailatOr input data.

Several 'observations of a geneta1 nathre abo.it

the 44 different runs

condJcted óJriIg

(

-9-the 8-day trial

period shaild assist in a final ui

erstandir

of the trials:

o All runs were

concI3cted with ESSO OSAKA

baflasted to nearly her full load

draft and no runs were undertaken

in a typical ballasted

condition. This decision was t&ken as it is nearly always a loa'd ship on an even keel which

nut be maneuvered into

increasirly Ehallri waters as it

arrives to discharge

its cargo.

The bailasted vessel with

trim by the stern is seldon

erated

with such low underkeel clearance, and With its rediced mass does not pose

shiphafldliflg. considerations

of as great interest as the

loaded tanker.

The fact that all trials

were uxicted with nderate to very

slow speeds

sisply reflects that these are

the speeds which Will (or

shald) .

selected

when nianeivering a ship in shálla.w water. Deep water trials were

in this case

coridicted at slow speeds rather than the higher speeds typical of deepwater

operationS since a main

objective of the trials was

cosparisons between

effects of deep, ndium

and shallow water performanCe

with other variables

such as speed and draft held constant.

ó In addition tothrhi

and stcçping maneiverS, which are readily understood

by non-hydrodyflami cists and mariners, Z' maneuvers and 0spiràl0 maneiverS

wre cor1icted as

these are the maans Selected by hrodynamiStS tO obtain

bjndamantal data on

directional stability (i.e. utendency

tog)

Straighta or

to "wajder).

o Finally, variis type

of turfling and stopping manoivers, acne of whith

will be. described low, were, of ociirSe, ndicted.

Even thoigh airrents

in the area selected

for the trials are

generally

con-sidered very moderate, elaborate steps were taken to monitor

oirrents ijrir*

the trials.

As will be seen

in aibsjuent

disaission of the resilts

even

rather moderate oirrents have a major iupact cn the "over the groind" behavior

of a maruveriflg ship proceeding at Slain speed. Acu)rdiflgly, at eath of the

six airrent

measuring points skn on

Fi9are 3 contirual

rerding of o.*rrent

strérth and directiOn

at both shall(

at4 deep locations was monitored. A

saiiple Of the type of iflfotmatiCm obtairád is sham

in Figsre 4.

Information

of this type then

had to be used, together with the

ship's position as

deter-mined by Decca Hi-Fix, to àorreCt for oirreflt both at deep and shafla' depths

to arrive at the

ship's path corrected for "set

and drift" of the

airrent.

TRIAL RESULTS

InspectiOfi of

of the major feathres of a iimber of

typical trial runs

under varying conditions shauld give an indication of the ccmprehensive

nare

of the information

ttathed.

This disaiSsiOn

will lodi into the

subject fran

the viewpoint

of birnir

ability, stçpiflg ability and steerirJ

controll

ability.

The pirpe of the

disoissiOn of the

sançlè results selected

is to

give a general iffVL'S iOfl rather thafl detailed specifios for whidi study of

the full trial

data is essential.

!NING ABIIITi .

Figures 5A and SB s ccitreheflSiVe data for a deep water jrning circle with

constant power needed for 7.8 knotS ship eed as the rnbeg3flS.

Figire SA shows both

path over the groind and as

corrected for set and drift.

It

clearly indicateS the

large effect of a ndest

wrrent, particularly as the

vessel's speed slaiis

dirir the turn.

Figire 5B sts the major

daracteris-tics of ship

behavior frau initial tiidder

der.

It indicates clearly the

aibstantial decredse in speed which acccipanieS a hard turn, ard the

fact that

shortly after oc'nu'ncing the turn, rate of turn becoaes

nearly ocristant.

Figires 6A ar 6B st

similar information, this tine

for a turn to the left

in èhaliow water. Once again the Oftëct Of current is readily apparent, as

is

a substantial increase in turning circle

path aS conpared with the deep water turn.

To give a better appreciatith of the effect Of watet

depth and underkeel

clearance on turs with constant pa'er, Figire

7 shois the first

2700 of

left turn maneuvers in deep, nedium and shall water. it confirms what has

been vI1 knin that a

Ship will turn in approximately

three tines its

in

length in deep Water, bit

so that this

figire increases considerably as

uiderkeèl clearance decreases.

F3.girS 8A and 83 depict a shallow water acCelerating turn". This manaiver

anneñces with the Ship

dead in the water, hard over

tudder and. "kiding

ahead° with the engine.

it ha been well kr

for years to shiardlers

that

they can achieve the tightest turn

with this type of maneuver which provides

maxinum rudder force with miflinum ship novenent ahead..

Figiré 9 shows a conparison

of aclerating thrn

in shallow and nedium water

depths.

G Dl0/A14

-An important feature of all

of these turning tests as a

function of water

depth or underkeel clearance is

that diring the initial

900

ooirse

alter-ations

there is not an inordinate increase in the

3vance, or distance along

the initial path with increasingly

shall' watà.

The nih

effect of water

depth only beccues especially noticeable when either a

irSe reversal, (half

circle) or a full circle,

is atteupted.

As a practical natter

rither of

these tró types at rnaruverS are

very fr.ient1y used in

handling large ships.

'10 rc*.rnd ait discussions

of turning, Figire 10

shas a comparison in shahlo"

water of "conventional birn with conStant poweru, an "accelerating turn" aid a "coasting turn'! Where the engihe is stcppèd at the tliue the helm is put over.

This figire shcs the

dramatic difference between

these different types

of

turns and clearly makes

the point that any sinulation

unable to distiniiSh

between these varicus types

of turns Will be grossly inaccurate for certain

types of actual manelvers.

SWPPING ABILITY

A variety of stopping mar.zverS were condicted with principal emphasis being given to the rocifl needed for Stcpping from variws maneuvering. speede. aid

ability to stop the ship

in a predetermined fashion.

Figres hA and .118 depict

the vessel's path afld stç1ng

behavior in shahL

water with full rudder

and steád

astern çer (abat

half the. total

avail-able) sinulating a maneuver

to st

the vessel pccipt1y wjttaJt concern for

directional control.

It can be sen that

the distance covered by the thip:.is

not very creat bit

that the vessel's

heading thabges L' nearly 90° cbring

this maneuver. .

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-Figures 12A and 12B

show a maneuver, also in shallow water,

wherein the

(

objective was to maintain vessel heading by oontiniing to uansuver both the

(

engins and the ridder.

The resilt is a stopping distance

little different

than in the previcus figires, bit

closely following the vessel's

original

(

racaheadingaashestcQs.

(

Figire 13 gives a conparison in deep water of stops fran manaivering speed of

(

3.5 knots indicating that when stopping withait regard to directional control,

the vessel

can be stopped in little nore

than her own length (using roaghly

(

half of total astern power) whereas

maintaining initial heading, aithaigh

(

entirely possible, ruires a considerably

greater distance to

ir the

vessel to a stop.

(

Finally, in Figire 14 the effects

of water depth on the ship's stopping path

( are shown.

Clearly fran this picture the

predominant effect of decreasing

(

water depth and underkeel clearance is a rotation of heading

braight abait by the assymnEtry of propeller forces

in a single screw ship.

Stopping distance

(

is hardly affected at all.

STEERING CCWLLABILITY

(

It is nct possible in a paper

of this type to do more than

taich upon

"con-trollability".

In layman's

terms this can be described as

the ability to

(

initiate and c*ied

a turn and can

be shown graphically in "Z maneuvers.

These are zigzag turns using 200 rudder angles.

(

Figa re 16 showS a portion of "Z" maijvers in shallow, nEdium and deep water.

It shows as ll mansuvers with the power maintainad and those with the ship

( allowed to coast withcut power.

( WOG DlO/A16

cCLJSIS.

Rather than attEpt

to draw my own ocnC]USlOflS cc

attEpt to interpret

those

readied by the

people actually cond3ctiflg the study,

t

official trials

conclusiOnS are repeated nearly verbatun as follows:

"1 The present txials provided a antitY of information not previoi sly ua-sured regarding the neuvering characteristics

of a ship in

shallow water.

Both research and operational type maj1verS keyed to large tankers were made.

In the process it was fcAind that the sing1&'scre1 EO OSAM, a 278,000

deed-weight ton tanker, was

able to marVer

reliably and predictablY

in all tested

water depths; even with engir stopped, as when sinulating nanawers

after a

prcçAilSiOfl failure.

"2. DistortiOns

of the flow

akxit the hill of a ship in

shallow water were foi rid to have

inportant effect on

manejveriIV notions. For exawple,

trial

nasureiiQflt5 indicated that:

"0 In shallow water, turning

circle tactical

diterS will increase

by as

nuch as 75% with 20% underkeel clearance, while drift angle and related

speed loss will red.ice relative to

turning in deep water.

With 50% underkeel clearance, the changes

from deep water are

significantlY

greater than

expected. based on previoiS nodel predictions and

full-scale trials.

"o Chedcing and (x)jnterturning ability are redic'ed as water depth decreases

to an

internediate depth (50% underkeel clearance

in the trials)

and then, with 20% underkee]. clearance,

these qialities

increase to better

%OG D1O/A21

15

-than in the deep water case

This is closely related to

the ap?areflt

reversal in maneivering dynamic

stability (with controls

fix, as is

azggested by the present spiral test

rea1ts.

Again, previcis ndel and

full-scale trials in shallow water failed to disclose this.

o The greatest effect

of decreasing water depth on

the stcççirxj of a

single screw tanker, fran slaii speed, awears to be an increase

in y

rotation to the right as it

s to a halt.

In the present trials the

heeding thange increased fran 18 to 50 to 88 degreeS in deep, nedium and shallow water, respectively.

"o Accelerating turns increased

in dianeter in shallow water,

bit to a

lesser extent than did

the conventional turns.

On the other hard,

coasting turns a ffered a trend reversal. The widest coasting turn path

was in the nedium water depth and the least was in deep water.

"3. Trials to show the

effects of a shitardler'S

control of propeller rpn

curing maneivers provided useful insights. For exan1e:

U

Accelerating turns cvnfirnd that

'kidcing" ahead the rpn when niving

at red.i speed significantly increases

turning ability.

"o The coasting Z-tuaneuver deixnstrated conclusively that this VLCC cwld

contirue maneivering in response to rudder actions even with the engine

stopped. It also showed that this large vessel could contirue

maneiver-ing while coastmaneiver-ing down to

speeds less than 1.5 knots.

This rea1t

shoild be enaxiraging to those concerned with the mareivering safety of

(

"0 As expected, rudder control on the single-screw vessel was eventl ally

lost airing stopping aanwvers

with constant astern rpn, although the

vessel's final orientation was

to scat extent

affected by early tudder

action.

Although the ship's

heading could be maintained

during a

"ontrol15d" stop by using various engine orders, it was at the expense

of increased stiflg

distance and greater

lateral &ift.

"Taken together, the points of Conclusion 3 ezçhasize that maniverabilitY

is inproved when rpn is increased and degraded when rediced. Kncwing this, the prudent shiç*andler

will ua3ally look

or the slcMest

safe speed in a

critical mane3verir3 area. If then regiired to speed up, maneuverability will

increase instead of

being degraded if

unexpectedly ru iced to

sli din.

"4. Other technical conclusions, which are mainly confirmatory, foll belari:

"o Speed of approach has a

mirir effect on the geaietry

of the conventional

b.irning circle of a large

tanker within the marivering speed range (5 to 10 knots).

U0 Asymnetry of maneuvers to

the Left and right

hand, ca.ised by

single-screw propeller

rotation, is greatest when rpn

ahead cc astern is large

relative to ship speed.

This is the case in sli

speed stopping and in

accelerating turns.

It is minor in the case

of cOnventioflal turns. "5. Technical data fran

the present trials

shoild be aduate for

validating

nodel and analytical

neths for predicting

ship maneuvering in deep and

shallai water under operational type cxnditiOflS

at sli speeds."

(

First, the ESSO OSAM trials provide

attesting to the

ability of

a typical

Sha1lci water at s1ri speed.

17

-One might

logically ask of what significance are these

findings and where

( shoild we go for the jb3re?

In aner to these

questicS and trying to

put

matters in

laymaEi'S langiage, I think

the folling points

shoild be made.

a wealth of

reliable technical data

VLCC to be maneuvered

predictably in

Next, tk ESS OSAKA trials tèpreseflt an excellent exanple of

the type of

cx)operation pssible between governeflt and irt&stry to undertake research of

nutual interest Which

might be beyond the means

of any single

entity to

ccnaict.

Finally, we hce that

it will be possible in

the near

thre for the

specific

trial data to serve as

the basis for

inroved mneuveriflg predict ons by

hydrodyflamiC latoratories

arid shitandling s$AilatOr facilities

aroind the

rld.

r

'bqJG DlO/A23

(

nso

U.S. Goverflflflt Agencies

U.S CoaSt Qiard, Departiflt of Transportation

Maritime AdministratiOn, Department of Cc roe

Tanker Opèràtors (Coordinated by American iflatibite of rt*iant Shippir)

Micb Shiij CQlpany

thev)n Shipping Colipafly

El Paso LNG Ccxpany

En Coupany, US.A.

Gilf Ttediig & TránsportatiDfl Conpany Inter State arx Ooeafl Transport CaLaJ%y

Mobil Shipii & Transportation Conpagj Shell Oil Conpany

Stariard Oil COsipany of Ohio

Sin Transport, lnc.

Tea, InCa

Cbntractór

Exxon International Conpany, Tanker Deparbflt

SiboontractorS

David W. Taylor Naval Ship R&D Center, 'll-Sale Trials Brantha Cärderod, Mayland

Sippican corptation, Sippican OcSarräPlic Division, Marion, Mássathisetts

Decca &iry Systens, Inc., Hastcn, Texas

AMETk(, Straza Division, El Cajon, California

Logistics 3iort

ar Advisors, Etc.

ixcn Conpany, U.S.A., BaytoEn Branc*i, Marir

tpartieflt

Hydronaition, Inc.

Maritime Administration, Department of ConiIPrOe Division of Maritime TeduE10gy

National Maritime Researdk Center

Steve rs Institute of TedUto1O'

The Society of Naval ArditeCts & Maraie EngirEers

Parl 11-10 (Controllability)

Pane] 0-5 (ANAL?MC Ship-Wave Relations) U.S. Coast Giard

Heaã]1arterS stff

Comarer Eighth Coast Qiard District

Ojtters BLPOTW)RN, DURABLE ar

I)D4T NE

Patrol Aircraft, Air

Station Coi.is Christ.i

FIGURE 1: SKETCUES OF ESSO OSAKA

Rudder, Propeller, Bow and Stern Profile and Lines Body Plan, Respectively

Ster Fbd WI. Trial WI. D - 28.3m H (Trial) - 21.7m Dispi. - 319,400int CB 0.831 L/B 6.31 B/H 2.44 90' - 35,000 Ridder Area/LH - 1.7%

ESSO OSAKA, 278 k DWT

FIGURE 2. MIDSHIPS SECTION RELATIVE TO BOTTOM IN THREE TRIAL WATER DEPTHS

DEEP

h/T =4.2

6 -.4 7 sh.noa Am . $

.-':.

, .- --- - -. I0 9 9...-' 3 12 .4 '4 4 a_a 'S U .oa 39 7, '10 5 4. 5 7 I I '2- ' 21 . 1 25 35,,$,-4 ' ii

.,''

2s 2' 24 33 . 01 ₇ 25 27 04

'/"P

25 ,'-'' , - '30 24 33 21 134 9O 2 17 33 22 #7 .19 13 IS 22 41_70 .4 .5 M.dlumm #. 'S .5 .2 _.,, .5

-:

_{P \ *' \.}

'

\'

4_. 44_. Si 14ó\ \. \ '06 ! II 71 .-.,... 1 S

:.

29 3. 27 2$. ---." 2S as 72 O 12 3, 2. 3$ I., Ill :.---75 'S. , F: -- I, 'J" ' .1 - --- -'- 15]I , .. _.-.--' S 20/ #5 5 ---2' %.-j U --- - .--- -$ _', -. -.30 -35 240 310 333' 265 49 3? - - . -

r:.

lkn*p'Ari II 34 .176 .- ' 220 320 SOS ISO 365 34 ' 36

:---4 - ---s---;.---44 4. '5 71

Figure 3 - Trial Sites

Ii .

IP

, 2 I. 4 .4 0 I -j I4 ' iL" I... b -, I IS 4$ .4. *4 0 'S .s .,,.,.L..,h...L.,, ,7i.. ' 3' 3% 2' --f. fl 61 104 '2 _'2 IS -''-AGNE-fl _/ -.-' I, '3 II 7 -2 .0 23 $0 $0 2' 220 35 3. 14 -4, ----1._-a' 21 -'6 .32 'SC 'S 'S. I 2' - 1R .5' *4 I 23 $2 "2 2. 0. -'4 320 305 : 215 3 I --0 . -a " 125 233 .0 420 22 9. -. ..." 25 70. ... -a S. 25 222 220 230 234 344 5. '7 S 240 2 0'- 14 24 l2 72 24 24 29 '9 27 I. _3. 34 75 27 25 I_S 52 0 245

2. CALIBRATION RUNS

Speed/rpm, taken during steady runs prior

to chosen maneuvers

TABLE 1 TRIAL AGENDA

constant heading 3.5, 6, 8.5 5, 7.5 7, 10 13 14 TOTAL RUNS 17

SPEED OF APPROACH TO MANEUVERS, KNOTS

TYPE OF MANEUVER OR RUN CALIBRATION DEPTH/DRAFT 1. 2 SHALLOW DEPTH/DRAFT 1.5 MED IUM DEPTH / DRAFT 4. 2 DEEP 1. MANEuVERS

Turn, port, 35° L rudder

Turn, stbd, 35° R rudder 5, 7 5, 7 7 7 7 7, 10 Turn, accelerating -350 R rudder 0+ 0+ Turn, coasting - 35° R rudder 5 5 7 5 7 Z mánéuver, 20/20 7 Z maneuver, 20/20 coasting 5 5 7 Z maneuver 10/10 7 Biased Z Maneuver Spiral Stop, 35° L rudder Stop, 35° R rudder 7 7 3.5 3.5 7 7 3.5 7 7 3.5 3.5 3.5

Stop,. controlled heading 3.5

1800 .00 1900 2000 2100 2200 2300 2400 100 00 300 400 500 600 700 800 900 1000 MOO i 200 Average Speed 26 31 26 42 31 11 04 17 31 July 1977 I August 1977 S

-1

Run Number 3723 Date: 2 August 1977

Time at Start: 17.03:44

Draft: 2.B r.(7l :5fi) (FM).

Average teptPl Under Kee' >68 C (22S ft)

ater 'Depth/Draft: 4.2

ind.frOC. 092 7 at 8.3 knots.

-DEEP WATER DEPTH TURNING' CIRCLE

(Rudder -36R Constant RPM)

Approach Speed ° 7.8 Kiots

Approach RPM 40.8 Approach Headiflg 272 T A Advance 1017 m (1112 yds)

B Transfer- 351 rn ('395 ds)

Tactical Diameter - ,924 (1010-yds)

- _a._.-. -- ._.___._ac__ $ -LEGEND o SMpCG- -'0 .Otecute-Pos1ton

§90.

Change of Heading 180' Change of Heeding Approzfmetely 1 mm CC Points Change of Heading (daIL.._.

r

0 43.2 91.6 133.8 178.2 224.8 .268.0 314.1 361.1 405.4 450.1 495'F 533.4 Point Ner At t.r Execute Time (mm) - .1

L73'

1 0 2. 3.10 3 5.52 4 7.92 5 10.68 6 13.80 7 16.88 8 20.33 9 24.13 10 27.92 -fl -. _32.QS__ 12 36.18 13 39.30

Path, Corrected for Set, Toward

.66.50 T Drift .73'Nrots

( ( ( (

(.

60 40 20 0 400 800 1200 TINE IN SECONDS 1600 2000 10 8

:1

0 0 2400 1.0

o.s!f

zo

o.so

100 Date: 2 Aug 77 Time at Start: 17:03:44 Wind from 092°T at 8.3 knOts

Draft: 21.8m (71.5 ft)

Rudder 35°R, Constant RPM Approach Speed = 7.8 knots Approach RPM = 40.8.

Approach Heading =272°T

Speeds Corrected for Set Toward 066T, Drift ia knots

RPM

hFWDSPEED-LATERAL. SPEED RUDDER ANGLE . CHANGE OF HEADING RATEOFTURN 1.0 - 0.SO_ 500

o.2s

400 - 0 300 0.2S (. Figure 5 (b) ( _40. ( 40 -400 0 (

POINT UNBEP Purl HU?9ber 4712 Date: 29 Ju1 1917 TIrEat Start: 13:51:02 Draft: 21.8 5 (71.5 ft) (F&A)

Average Depth Wtder Keel: 5.5 m (18 ft Water Depth/Draft: 1.2

Wind from 43'T at 9.5 KnotS

P,th. Measured Over Ground

SHALLOW WATER DEPTh TURNING CIRCLE

(Rudder 36L CONSTANT RPM) Approach Speed 7.0 Approach RPM 35.8 Approach Heading 065 A Advance - 1189 r (1300 yds) 8 Trensfer - 555 n (607 yds)

C Tactical Diuleter 1564 m (IflO yds)

Pith. Corrected for Sit, Tord 104' 1 Drift .34 Knots LEGEIW o ShIp CO Execute Position 90. Change of Heading 180' Change Of Heeding o ApproxlI*telY I sin CO Points

Point 2 3 4 S 6 7 8 9 10 11 12 -1.73 0 3.78 7.58 11.72 15.57 20.33 24.52 29.65 34.12 3862 43.15 47.57 Change of Heading (deg) AfterExecute Tlea (sin) 0 0 45 90.5 136.1 179.3 225.9 271.3 317.9 380.4 405.7 449.1 492.7

(

(

(. 60

(

40 20

t

4

I

4 .0 .0 .0 .0 0 1.0 0 O.5 0 1., hO 500 400 300 200 00 a. In I-14 14 0. In LO.s0 LO.25? 0.25 0.50 .

Run Number 4712 Water Depth/Draft: 1.2

Date: 29 Jul 77 Rudder 35°L, Constant RPM

Time at Start: 13:51:02 Approach Speed 7.0 knots

Wind from 043°T at 95 knots Approach RPM = 38.8

Draft: 21.8 m (71.5 ft) Approach Heading = 066°T

Speeds Corrected for Set Toward 104°T, Drift .34 knots

_

_

'Pu

t

RUDDER ANGLE

-I_ii1I1t-

RATE OF TURN

-UI

_{!I I_}

_

_

6"

CHANGE

rnda

OF HEADING

_p_

_

DEPTH 5

a

In, -500 500 1000 TIME IN SECONDS (. Figure 6 (b)

ESSO OSAKA, 278 k DWT

12km

1km

Rudder 350 Left

Approach Speed 7 Knots

FIGURE 7: WATER DEPTH. EFFECT ON TURNING CIRCLE PATHS

Date: 30 July 1977

Timeat Start: 06:51:36

Draft: 21.8 m (71.5 Vt)

Average Depth Under Keel': 5.5 m (18 Vt)

Water Depth/Draft: 1.2

Wind' from 013'T at 12.0 knotS

Path. Neasuret Over Ground 2 r..1....

Approach RPN 0 TermInal RPM 56.0

Approach Heading - 247'T

A Advaflce 49O.m (536yds)

B Transfer- 375 m (410 yds)

C Tactical Dlameter 106Cm (1160 3Jds)

Poth.CofreCt.diOrSSt. Toward o'T, Drift .SOlonot

OSMPt8 Execute Position Change of Heeding 180' CMnge of Heading o *pproxhimtely I mm CO Points Change of Heading (dog) Aftr Execute Time (minI Point Number 2 3 4. $ 6 1 8 .0.83 11.67 15.50. 18.97 22.78 25.27 29.13 32.52 0 88.0 133.0 177.0 225.0 210.0 317.0 353.0

Run Number 7012 Date: 30 Jul 77 lime at Start: 06:51:36 1nd from 013°T at 12.0 knots )raft: 21.8m (71.5 ft) 60 20 0 40 C, -Ui 5.-20 Ui 0 20 40

Speeds Corrected for Set Toward 060°T

-..

SHALLOW WATER DEPTH ACCELERATING TURN

I.

---

CHANGE OF HEADING I I I DEPTH 400 FWD SPEED RATE OF TUN Water Depth/Draft: 'I .2 Rudder 35°R

Approach Speed 0.3 knots

Approach RPM. 0 Approach Heading 247°T /LATERAL PEE Figure 8 (b) Drift .50 knot RUDDER ANGLE 0 2000 2400

I

200 100 C, Ui 0 (0 6.50 - 0.25 0 0.25 0.50 I. 8 6 4 3. 0 -400 800 1200 1600 TINE IN SECONDS

000

o'

o

cn '

..O.C'

r rl4- i....O a) wr4 c, . V)

FIGURE 9: WATER DEPTH EFFECT ON ACCELERATING TURN Shallow Vs. Medium Water Depth

1km

INITIAL HEADING

MEDIUM DEPTH

SHALLOW WATER

SALLOW WATER DEPTH ACCELERATING' 1IJRH

Run Nianber 7012

Date: 30 July 1977

Timeat Start: 06:51:36

Draft: 21.8 m (71.5 Vt)

Average Depth Under Keel': 5.5 m (18 Vt)

Water Depth/Draft: 1.2

Wind' from 013'T at 12.0 knotS

Path. Neasuret Over Ground 2 r..1....

(Rudder 35'R)'

Approach Speed- 0.3 tnots

Approach RPN 0 TermInal RPM 56.0

Approach Heading - 247'T

A Advaflce 49O.m (536yds)

B Transfer- 375 m (410 yds)

C Tactical Dlameter 106Cm (1160 3Jds)

Poth.CofreCt.diOrSSt. Toward o'T, Drift .SOlonot

OSMPt8 Execute Position Change of Heeding 180' CMnge of Heading o *pproxhimtely I mm CO Points Change of Heading (dog) Aftr Execute Time (minI Point Number 2 3 4. $ 6 1 8 .0.83 11.67 15.50. 18.97 22.78 25.27 29.13 32.52 0 88.0 133.0 177.0 225.0 210.0 317.0 353.0

000

o'

o

cn '

..O.C'

r rl4- i....O a) wr4 c, . V)

FIGURE 9: WATER DEPTH EFFECT ON ACCELERATING TURN Shallow Vs. Medium Water Depth

1km

INITIAL HEADING

MEDIUM DEPTH

SHALLOW WATER

60 6o

.IflG)

..

0r44

0:

Wr4 r4

.'-

j.

ESSO OSAKA, 278 k .DWT

6'

₀

er-4

FIGURE 9: WATER.DEPTH. EFFECT ON ACCELERATING TURN Shallow Vs. Medium Water Depth

1km

iNITIAL HEADING

MEDIUM DEPTH

60 6o

.IflG)

..

0r44

0:

Wr4 r4

.'-

j.

6'

₀

er-4

FIGURE 9: WATER.DEPTH. EFFECT ON ACCELERATING TURN Shallow Vs. Medium Water Depth

1km

iNITIAL HEADING

MEDIUM DEPTH

Advance, at 90 degree

twading change,-wete'a Transfer, at 90 degree

heading change, eaters

Tactical diameter, 'at 180 degree headipg change, 5015T8

PATH A PATH 8 PATH C

Coastini Chaoe Accelerating Chug

convene ton

1180 1615 +372

,

705 1075 +532 1590 incoeplete

* 1ative to cenventi011 turning results

A. CONVENTIONAL

'FIGURE 10: RPM EFFECT. ON TURNING CIRCLE PATH,.'IN SHALLOW WATER Coasting, Conventional Accelerating Turns

490 -592 315 -472 1060 -332

( ( ( ( ( +20 0 ( -20

(

-40 -60 ( ( 20 Th -40 ( ( ( ( 4 2 0 1.0 0.5k 0 600 500 400 300 200 100 0

I

2 It '-100 - 75 - 75 100 - 0.50

-0.zS1 ,, 0.50

SHALLOW WATER DEPTH STOPPING MANEUVER

Run Number 8512 Water Depth/Draft: 1.2

Date: 31 Jul 77 Rudder 35°R

Time at Start: 09:38:00 Approach Speed = 3.8 knots

,flnd from 025°T at 11.3 knots Approach RPM = 22.7 Draft: 21 .8 m (71 .5 ft Approach Head1n 246°T

Speeds Corrected for Set Toward 057°T, Drift .4 knot

1

U

J_1_..

-' SPEED F -

- - - -.

U...

U

-

CHANGE OF HEADING

-

_--

--

I

-!JIIIH

TU

I

I!J1:i_

-

DEPTH TE OF TURN

ar

_a.

I II

DISTACE TRAVELED -100 0 100 200 300 400 500 600 TIME IN stcois Figure 11 (b) ( (

Path. Measured Over Ground

-Pvint Number

SHALLOW WITER DEPTh STOPPING UtTh

Path ,Cirrected' for Set Tewad 097°T, DrIft .27 knot Point

CONTROLLED HEADING Point 1 2 3 After Execute Tima (mm) 4.22 11.13 Change of Heading (dog) 0 11.0 16.0

Run 'Number 11512 Date:

29 July 1977

Time etStbrt

20:56:04

Draft:

21.8 m (71.5 ft)

Averge0epth L'nder Keel:

4.9m (lift)

(Rudder 40'L)

LEGEND

Approach Speed u 3.2 knots Approach RPM

23.1, Astern RPM Varies

Approach Heading 2471 WInd from 024T at 10.6 knotS

o o o

Shipcc Execute Pe,ition(Met SImm) Approximately 1 un CO Points

60 40 20 0 -20 -40 -60 40 S 4 3 6

4;

I.1 w 0 1.0 .1 - 75

Date: 29 Jul 77 Rudder 40°L

Time at Start: 20:56:04 Approach Speed = 3.2 knots

Wind from 024°T at 10.6 knots Approach RPM = 23.1

Draft: 2L8 m (71.5 ft) Approach Heading = 247°T

Speeds Corrected for Set Toward O97°T Drift .27 knot.

_i.i

SPEED

uiIuI

CHANGE OF HEADING

_

.__.

a__s.

'-wlI V LATERAL -SPEED -- RUDDER ANGLE - - RATE OF TURN -. 1

_._

-'

DEPTH DISTANCE TRAVELED -1200 - 0.50 LI_I-I In 1000 O.2S I.- 0-L.a 800 a I.-600 'a t a 0.2S In 'a -- I-400 0.50 In 200 0 a I-_a u. 0 0-a 25 _a U a 0.5 I-i- 50 - 75 p-.n 0t.l

-.0 ₁₀₀ 500 750 TIME IN SECONDS Figure 12 (b) -250 0 250 1000 1250 1500

Esso OSAKA, 278 k DWT

SI MPLE :.STOPPING,. 35° RIGHT RUDDER

1km

STEERING, MAINL'4' 35° LEFT RUDDER

1km

CONTROLLED STOPPING:

CONTROLLED RUDDER AN:D PROPELLER RPM

.-.---- ----s

1km

FIGURE 13: CONTROLLED, SIMPLE AND STEERING STOPS IN DEEP WATER Approach Speed 3.5 Knots, 45 Rpm Astern Except For Controlled Stop

SHALLOW WATER, h/T= 1.2

-I

1km

MEDIUM DEPTH, h/T = 1.5 1km

DEEP WATER, hIT 4.2

1km

FIGURE 14: WATER DEPTH EFFECT ON STOPPING PATH

From 3.8 Knots, Wtth 350 R Rudder & 45 Rpm Astern (About 50% Of Available Astern Power, Ref. 9)

meters Knots to 3.8 Kts. to Deep Water meters meters On Ship

4.2 520 3.5 582 20 Scb 90S Sow 180 Right

1.5 575 3.8 575 -11 SO Port 200P Stern 50° Right

1km

1km

KILOMETERS

2 3

1km

FIGURE 15: COASTING EFFECT ON 200_200 Z-MANEUVER

IN THREE WATER DEPTHS

1 ESSO OSAKA, 278 k DWT Coasting SHALLOW, h/T 1.2 5 5

+

MEDIUM, h/T = 1.5 4 5 I ed