77
1 INTRODUCTION
Firstcommercialdelivery206000 m3of LNGtothe
port ofŚwinoujście was made by tanker „Al‐
Nuaman”on17thofJune2016.SeachannelforLNG
tankers entering port ofŚwinoujście is presented in
Figure 1. It has been dragged to the draught 14.5
metersandwidthof220metersforsafenavigationby
alargegasta
nkers.
According to the Maritime Administration safety
regulations, the highest admissible dimensions of
LNGtankers(seeFigure2)enteringŚwinoujścieare:
Length=320meters,Breadth=51meters.,Draught
= 12.5 meters. Two pilots embark the ship at the
anchorageNo3orinpositionofN‐1buoy.Fourtugs:
two–per80tonseach,andtwoofminimum45tons
each, are necessary for help in manoeuvring the
vesselinLNGtermi
nal.VTSgivesthepermissionfor
berthing LNG tanker during the day time only. The
otherrestrictionsareasfollows:
Thewind speedhas tobe less than10 knots,the
wavehighhastobelessthan1.5m.,thevisibilityhas
tobemorethan1n.mile.
When LNG tanker navigates in the channel any
othervesselcannavigateinPomeranianBayor Port
ofŚwinoujście as per the VTS permission given on
VHFch.12.Allship’st
rafficisacceptedonlyoutside
thedeepseachannel.
Presented paper is dedicated to the ships which
are navigating outside the main channel, as per
MaritimeAdministrationregulations.
Some Notes on Safety Measures when Approaching
Port of Świnoujście
M.Szymoński
PolishNavalAcademy,Gdynia,Poland
ABSTRACT:ThepaperdescribesnewdirectionsinwhichthesafetyofnavigationinPomeranianBay(Pola
nd)
becameintoa newerasincetheLNGTerminalinportofŚwinoujściebeguntoattendtoalargegastankersat
around 32
0 meters length, 50 meters brea
dth, and draught
of 12.5 meters. For the safety of naviga‐tion in
PomeranianBay,theMaritimeAdministrationhasmodifiedthetrafficregulations,directingtheship’strafficto
thezonesoutsidethemainapproachingchannel.ForsomeoftheshipsnavigatingintoŚwinoujściethenew
regulationsmeanthenecessityofpassingthesha
llowwaters,withallconsequencesoftha
t.Themostimportant
effect, being predominating in shallow waters, it is the squat effect. This effect is causing the ship’s speed
reductiona
ndtheincreaseoffuelconsumption.Itisverydifficulttoselecttheinfluenceofthesquateffectfrom
others,likeweathercondit
ions,waveshighanddirection,andseakeepingqualitiesforshipsofdifferenttype.
Thispaperisgivingthecontributiontodeepanalysisoftheabove,andispresentingthetestre‐sultsdonefor
passenger/cargo Ferries, travelling as per regular service to the port ofŚwinoujście: M/F “G
ryf” and M/F
“Wolin”.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 12
Number 1
March 2018
DOI:10.12716/1001.12.01.08
78
2 SHIPSGOINGOUTSIDETHECHANNEL
Whenshipsarenavigatingoutsidethemainchannel,
inboundgoingvesselsareproceedingwestsideofthe
channel,whenoutboundvesselsare proceeding east
sideofthechannel.Theoutboundgoingvesselswith
the draught less than 7 meters should leave the
channelwhen
passingthepair buoys no.15‐16and
furthernavigatebetweenthelinelying0.5n.mileoff
theeastsideofthechannelandthewesternboundary
line of anchorages 1B, 2A, 2B and quarantine
anchorage. Vessels proceeding to the east are
navigating between the anchorages 1B and 2A
and
furtherby therecommended HELCOMship’s route.
The outbound vessels with the draught less than 9
meters should leave the channel when passing the
pairbuoysno.11‐12,asithasbeenshowninFigure1.
On the other hand, the vessels approaching
Świnoujście from the North
are navigating between
the line lying 0.5 n. mile off the west side of the
channelandeasternboundarylineofanchorage1A.
The vessels cannot crossing the channel between
theparallels53°57.5´Nand53°59.6´N.
Figure1. Approaching channel to LNG terminal in
Świnoujście(byauthor)
Therearesomeotherrestrictionsforthevesselsin
thevicinityofLNGtanker.Anyvesselnottobecloser
than:
1n.mileofftheLNGtankerwhensheisinthean‐
chorageNo.3;
0.5 n. mile off the LNG tanker when she is in
emergency
manoeuvringarea;
0.5n. mileoff the LNGtanker when she is navi‐
gatinginthechannelandothervessel‐withpilot
on board‐ispassing by east or west side of the
channel;
5n.milesaheadofLNGtankernavigating inthe
channeltothepair
ofbuoysNo.9‐10;
4n.milesaheadofLNGtankernavigating inthe
channelcloserthanthepairbuoysNo. 9‐10;
3n.milesasterntheLNGtankerapproachingthe
port;
2n.milesofftheLNGintheentrancetheport.
Figure2.LNGtankerinŚwinoujście(photobyauthor)
3 HYDRODYNAMICEFFECTSINSHALLOW
WATERWHENNAVIGATINGOFFTHE
CHANNEL
The passage through the deep see channel of
Pomeranian Bay has been analysed in details by
several authors (Chwesiuk, et al, 2007; Rutkowski,
2012)
WhentheexploitationofLNGterminalhasbegun,
MaritimeAdministrationbroughtnewtraffic
regulationsintoeffect.
Asithasbeendescribedabove
‐insection2,thevesselsapproachingorleavingthe
port ofŚwinoujście are obliged to navigate,
respectivelyinwestoreastsideofthemainchannel.
Navigation through the approaching channel is
reservedonlyforLNGtankers,vesselswithdraught
morethan9
metersorvesselswhichhasgottheVTS
permission.
Navigating west or east side of the approaching
channel the vessels are exposed to several effects
typical in shallow water. The above said effects are
definewhentheclearanceofwaterunderthekeelis
being analysed for safety of navigation.
Authors
(BarrasC.B.,RutkowskiG.,JurdzińskiM.)havebeen
describedseveraleffectsinfluentialonclearance“C”
of water under the keel for vessels navigating in
shallowwaters:
C=C1+C2+C3+C4+C5+C6+C7+C8+C9
where:
C1–
accuracyofdraughtdetermination;
C2–reactionondifferentkindofseabed;
C3–influenceofsealevel;
C4–influenceofrolling;
79
C5–influenceofpitching;
C6–influenceofyawing;
C7–effectofsurge;
C8–effectofsway;
C9–effectofheave;
C10–influenceofsquateffect.
The experience of exploitation the fast going
passenger/cargo Ferries or Container vessels in
shallow waters of Pomeranian Bay, allows
to state
thatthesquateffectispredominant whenthevessel
approachingŚwinoujście harbour out of the main
approachingchannel.
Passenger/cargo Ferries or Container vessels are
sailinginthisareawithspeedofaround14‐15knots.
Theory for hydrodynamic effects in shallow waters
shows,thatsquateffectis
usuallyfeltmorewhenthe
depth/draft ratio is less than four (Barras, 1978).
Ship’s velocity increasing interaction of a low‐
pressureareasothatshipispulleddownasshownin
Figure3.Thissquateffectresultsfromacombination
of vertical sinking and a change of trim that may
cause
thevesseltodiptowardsthesternortowards
thebow.
Squat effect is approximately proportional to the
square of the speed of the ship (Barras, 1978,
Rutkowski, 2012, Jurdziński, 2013) . Thus, by
reducingspeedbyhalf,thesquateffectisreducedby
afactoroffour.
Figure3. The hydrodynamiceffects in deepsea (1) and in
shallowwaters(2).(authorsWalke,SemhurWikipedia)
Duetothepredominantinfluenceofsquateffectin
the resistance of ship’s hull navigating in shallow
waters of Pomeranian Bay, the consequences of the
abovearedescribedbelow.Figure4showshowmuch
the increase of the resistance of ship’s hull is
producinganeffectofreductionofship’sspeed
and
increaseoffuelconsumption.
In nominal exploitation conditions the curve of
propeller K
s, shown in figure 4, makes the power
requirementdependentonship’sspeed.Atthesame
timethefuelsettingh
Nisgivinganominalquantity
offuelpertimeunit.PointAinfigure4corresponds
to the nominal power conditions N
N at the nominal
fuelsettingh
N,andnominalship’sspeedVN.
PointEinfigure4correspondstotheeconomical
powerconditions.In conditions,when theresistance
ofship’shullisraising,thepowerNandspeedVare
falling down, reaching the heavy curve of propeller
K
C.Atthesametimethefueladjusterisgivingmore
fuelpertimeunittoattainanominalsettingh
N.New
conditions of sailing correspond to the point C in
figure4.Innominalquantityoffueldistributionper
time unit we have the reduced power and speed of
ship.
Figure4. The propeller K and fuel h setting curves
(byauthor)
where
K
Ccorrespondstotheheavycurve,arisingincase
ofincreasedresistanceofship’shull.
K
Lcorrespondstothereducedresistance.CurveshN,
hE, hL correspond to the fuel settings: nominal,
economic,andlow,respectively.
Itisnopossibletosetmorefuelpertimeunitthan
characterizedbythenominalcurveh
N.Itmeans,that
incase of increased resistance of the ship’s hull,the
fullpoweroftheengineisnottouse:N
C<NN.
Tables1 and 2display theresultsof trial testsof
main engines, made on board the passenger/cargo
Ferries, serving on regular lines between ports of
Świnoujście and Trelleborg, M/F “Wolin” and M/F
“Gryf”.FerryM/F“Wolin”issuppliedwithfourmain
engines MAN B&W, type 6L40/45 with
nominal
powerof3300kWofeach.Thetotalaccessiblepower
is13200kW.FerryM/F“Gryf”issuppliedwithtwo
main engines Wartsila‐Sulzer, type ZA40S with
nominal power of 3960 kW of each. The total
accessiblepoweris7920kW.
Time schedule of such regular service is
very
restricted,andanybreakloadcausingtheincreasein
fuel consumption, as it was displayed in Tables 1
and2.
Table1.M/F“Wolin”,MANB&Wengine,type6L40/45
_______________________________________________
Power(%)25 50 75 85 100 110
Power(kW) 825 1650 2475 2805 3300 3630
Brakeload(kN) 18.7527.5 41.7546.7555 60.5
Fuelconsumption 201.3342.1487.4551.0646.7714.9
(Kg/Hr)
_______________________________________________
(testresultsforM/F“Wolin”)
80
Table2.M/F“Gryf”,Wartsila‐Sulzerengine,typeZA40S
_______________________________________________
Power(%)25 50 75 85 100
Power(kW) 990 1980 2970 3366 3960
Breakload(kN) 27.5 48.9 64.1 69.7 77.6
Fuelconsumption 215.0406.0591.0670.0910.0
(Kg/Hr)
_______________________________________________
(testresultsforM/F“Gryf”)
4 CONCLUSIONS
The general safety navigation regulations for
PomeranianBayship’straffic,done bythe Maritime
Administration, and caused by the beginning of the
large LNG tankers service in gas terminal of
Świnoujściehasbeenpresented.Astheresultofthese
new regulations implementation, the commercial
ships which are
navigating to, or from the port of
Świnoujście, are travelling outside the main
approaching channel. They are losing the fuel and
time passing the shallow sea waters of Pomeranian
Bay. Tests made for passenger/cargo Ferries M/F
“Gryf“andM/F“Wolin”areintroducingthescaleof
fuellosses.
Per
one year, one regularly serving Ferry ship is
consummingaround330metrictonsoffuelmoredue
toshallowwatereffectsofsquat.Foursuchshipsare
givingtotheownertheloss1320metrictons offuel
per year. These values are not to ignore taking into
accountthescale
ofship’strafficinPomeranianBay.
REFERENCES
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Liverpool.
Society of Naval Architects and Marine Engineers
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IIʺResistanceandPropulsionʺ
ChwesiukK.,WiśnickiB.,KlabachaM.,BorowiecA.,2007;
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świetle
zapisów„ZielonejKsięgi”politykimorskiejUnii
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