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1 INTRODUCTION
Safetyofnavigationisoneofthekeyissuesaffecting
thetransportprocesses,whichareusedformaritime
transport. Among the many threats that could
undermine the proper course of the voyage,
accidentsrelatedtothemanfallingoverboardbelong
to a small group of events that can ta
ke place
regardless of the hydro‐meteorological conditions,
specificsoftheoperatedwaterarea,trafficintensity,
orotherexternalcircumstances.
Despite the tendency to constantly improve the
levelofsafetyforoverseavessels,correctresponseof
the ship navigator, resulting in the correct
implementation of the requiredʺman overboardʺ
manoeuvreisnotalwaysobserved.TheissueofPOB
(PersonOverboard)accidentsisthereforest
illvalid,
particularly that for a decade you can see steady
growthoftheworld merchant fleet, whichoverthe
last eight years has increased by 20 357 vessels
[EuropeanMaritimeSafetyAgency2005‐20013].
Figure1.Thenumberoftheworldmerchantfleetinyears
2005‐2013[EuropeanMaritimeSafetyAgency2005‐20013].
2 SIMULATIONSTUDIES
Becauseofthedirectimpactoftheʺmanoverboardʺ
manoeuvreontotherescueofhumanlifeatsea,the
membersoftheScientificSocietyʺWatchersʺactiveat
the Faculty of Navigation of Gdynia Maritime
Comparison of the Efficiency of Williamson and
Anderson Turn Manoeuvre
K.Formela,M.Gil&H.Śniegocki
GdyniaMaritimeUniversity,Gdynia,Poland
ABSTRACT:Thepaperpresentscomparisonofthe‘Personoverboard’manoeuvres.Thearticlewasbasedon
researchcon‐ductedonagroupofstudentsoftheFacultyofNavigationofGdyniaMaritimeUniversity.People
involved in studies previously conducted on board training on school training ships:ʺDar Młodzieżyʺ and
ʺHoryzont IIʺ, but did not have experience as an officers. Research was carried on the Polaris Ships Bridge
Simulator,locat
edatthefacultyofNavigation,ofGdyniaMaritimeUniversity.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 9
Number 4
December 2015
DOI:10.12716/1001.09.04.14
566
University,decidedtocarryouttherelevantresearch
inordertodeterminetheeffectivenessofindividual
manoeuvres.
Themeasurementpartconsisted,successively,of
theʺWilliamson Turnʺ and theʺAnderson Turnʺ
performed by two groups of 17 students of the
Navigation‐MaritimeTransportFaculty.Persons
involved in the studies previously underwent the
seagoing service onboard of training vessels‐
s/v
ʺDarMłodzieżyʺorʺHoryzontIIʺ.
Selectedfortestingwasnavigationand
manoeuvring simulator, POLARIS type,
manufactured by the Norwegian company named
Kongsberg. All devices operate on the basis of
complex mathematicalmodels that provide realistic
reactions of an individual and his environment. In
addition, they have DNV (Det Norske Verit
as)
certificate confirming the possibility of their use
during specialized courses for crews of merchant
ships).
Figure2. Simulators used for researches [Gil,Śniegocki
2015].
2.1 Objectivesandcourseofthestudies
According to the assumptions, each of the tested
individuals performed the exercise three times
manoeuvringtothestarboard.Allparticipantswere
operatinginthesamewaterareaandwiththesame
hydro‐meteorologicalconditions,whichareshownin
Table1.
Table1. Hydro‐atmospheric conditions simulated in the
researchedwaterarea[Gil,Śniegocki,2015].
_______________________________________________
Depth 100montheentireworkingarea
Windspeedand320°‐5kn(2°B)
direction
SeaState 1–Calm(rippled),0‐0,5m
Currentspeedand none
direction
Airtemperature21°C
Visibility 8–verygood–10Mm
CloudsNoclouds,clearvisiblesky
_______________________________________________
Toaccomplishtheta
sktheBULKC06Lmodelwas
selected–itisafullyloaded,215‐meterbulkcarrier
with a displacement of more than 60 000 tonnes
[KongsbergMaritime, 2015]. In ordertoshortenthe
exercise, it was beginning with a course 000 ° with
the settings of an engine order tel
egraph (E.O.T.)
ʺFULLSPEEDAHEADʺandthemaximumspeedof
theship‐15.9knots.
Inthedesignedtaskamanwasinitiallyheldata
distanceof380mfromthebowofthevesselsothat
thevessel,whenfloatingpastthemanʹsposition,was
positionedparalleltoit
.Theappliedsolutionmadeit
possible to simulate a situation in which the victim
has just fallen overboard. Information about the
initiationofthePOBalarmwassenttosteeringunits
with radio communications at a time when the
survivorhaspassedtherighttraverseoftheship.In
pra
ctice, this meant the circumstances in which the
distancefromtheinitialpositionofthevesseltothe
POB position was about 500 m. Simulations were
constructedinsuchawaysothatthemanplacedin
the water was not affected by the drift of wind,
making his position constant during the entire
manoeuvre.
Since none of the tested persons had previous
experience with the applied model of the ship, the
firsta
ttemptwascarriedoutinaccordancewiththe
description of the manoeuvre contained in the
ʺInternational aviation and maritime search and
rescueguideʺ(IAMSAR).
Figure3.„AndersonTurn”(a)and„WilliamsonTurn(b)as
perIAMSAR[InternationalMaritimeOrganization,2008].
IfasshowninFigure3,theguidecontainingthe
guidelines of the International Maritime
Organisation(IMO)suggeststhefollowingsequence
of action in case of an immediate manoeuvre – the
ʺAnderson Turnʺ [International Maritime
Organization,2008]:
Move the rudder on the side from which a man
fell;
Afterreachingachangeinthecoursebytheva
lue
of250°,settherudderintheʺzeroʺposition;
In the case of theʺTurn Williamsonʺ manoeuvre
IAMSAR recommends the following procedure
[InternationalMaritimeOrganization,2008]:
Move the rudder on the side from which a man
fell;
Afterreachingachangeinthecoursebytheva
lue
of60°,settherudderontheopposite side;
Whenthecoursereachesthevaluelowerby20°
thanthecountercourseascomparedtothe
initialsettingsofthevessel,settherudderinthe
ʺzeroʺposition.
Both at the first and the second manoeuvre, the
init
iationandintensityoftheprocessofstoppingof
the vessel was carried out at the discretion of an
individual performing the exercise. During the
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researchfurthertestswerecarriedoutonthebasisof
previous experiences of participants. At the time of
theexercisesexecution,thoseinvolvedintheexercise
modified the course of the manoeuvre‐in
accordance with their convictions based on the
analysis of the chart showing the route of the first
test. Each a
pproach was considered as completed
when the navigated vessel had reached a speed of
lessthantwoknots.Thatcriterionwasadopteddue
totherecognitionthatsuchspeedlevelwassufficient
forsafedeploymentofarescueboat.
During the exercise, at the position of an
instructor(atechnicaloperatorofthesimulator)they
recordedthefollowing real‐ti
medynamic