2ndAnnualEasternShoreCrabBoatEngineeringChallengeRuleshttps://www.umes.edu/Tech/CrabBoat.html

Sponsoredby:TheUniversityofMarylandEasternShoreTheU.S.ArmyTheUniversityofMarylandCenterforEnvironmentalScienceKelvin®EducationalGrades:9-12

Information/RulesMeeting:October12,2016CoachesDesign/BuildWorkshop:January11,2017RegistrationDeadlinewithNamesofAllTeamMembers:February17,2017WrittenReportandDesignDrawingsDue:April21,2017CompetitionDate:April28,2017from11am-2pmattheUniversityofMarylandCenterforEnvironmentalScienceinCambridge,MD.Directionsavailablehere.TeamSize:Minimumof4butnomorethan10students.ChallengeScenario:Design,develop,build,anddemonstratearadio-controlledscaledmodelofaChesapeakeDeadrisecrabboatintendedtoeconomicallycarry(collect)crabbasketsataChesapeakeBaylocation.Themodelwillberequiredtotravelempty(noballast)tothreecrabbasketcollectionlocations,demonstrateitscrabbasketcapacityandfullyloadedperformancebycarryingscaledbasketsthroughacourseandreturntothestartingpoint.

BoatSpecifications:Themodelmustbescaled1”=1-’0”(1:12)andconformtothefollowingspecifications:

• AnyChesapeakeDeadrisedesignisacceptableandthehullmaybeconstructedofanyrigidmaterial.

• Boatsmayinadvertentlycontact(strike)eachother,soabilitytowithstandminorcollisionsisaworthwhile(necessary)consideration–asisthewatertightintegrityandcushioningoftheradioreceiver/batterycompartment.

• Propulsionwillbeprovidedbyoneortwospecifiedelectricmotors(andbattery)operatingatnomorethantwelvevolts.

• Boathullmaximummeasurementsmustnotexceed:o Length40”includingrudderandpropo Beam12”o Maximumdraftofthehullitselfisnottoexceed2”whenempty

• BoatMotorandPropellerspecificationsare:o Motor9-12VDCo 12,500RPMo HighTorqueKelvin#850962

• Vesselsmustbepaintedormarkedforidentificationwithteamname–andthequalityofworkmanshipandfinishwillbeafactorinjudging.ThemodelwillbejudgedonhowsimilaritlookstoarealChesapeakeDeadrisecrabboat.(UseimagestohelpdeterminewhatarealChesapeakeDeadrisecrabboatlookslike.)

• Theboatswillbejudgedontheirreliabilitytocompletethecompetitionwhileincurringaslittledamageaspossibletothestructureandfunction.

• Boatsmaylosepointsforpurposefullystrikingothervessels.• Failuretoadheretotheaboverequirementswillresultinsignificantlossofpoints.• Itisrecommendedeachteamprovideafloorstandfortheirboatmodel,highenoughto

permitworkingontheirentryduringthechallenge.RequiredBoatElements:

• Theboatmustbemarkedwithamaximumloadlinethatisatleast2”belowthegunwalesedgemeasuredmid-hull.

• Thedesigndoesnothavetoincludeafulldeck;crabbasketscan(andforstabilityshould)bestackedcontinuouslyupfromthekeelandmayextend(4”)abovethegunwales(upperedgesofthehull),providedtheyareatleast1inchbelowthetopofdeckCabin.

• Theboatmusthaveacabinthatoccupiesatleast10%ofthehulloveralllength.Thiscabinmustextend5inchesabovethedeckandatleast1inchabovethetoplayerofthecrabbaskets.Nocargomaybeloadedinwayofthecabin.

• Atleast35%ofthelengthofthehullmustbefreeofcrabbaskets,potsandbuoys.Roomforworkspaceandcrabbaitmustbeprovided.Thisspacemaybesplitbetweenthecabinandtherestofdecktobeusedformachineryand/orelectronicsandbatteryaccess.

• Thescaledcrabbasketcontainerswhichwillbeusedaresuetbirdfeedcontainersmeasuring1-7/8”highx5”widex5-1/4”long.Theywillbefilledwith6-8largepebblessimulatingcrabs,rebar,andzincanode;andwhenfilledtheymustweighapproximately16ounces(450g)perbasket.Containersshouldbeprovidedbytheteamsfortheirowntesting.UMESwillhavealimitednumberofcontainersshouldteamsneedreplacements.

PerformanceDemonstrationExpectations:Theboatmustdemonstrateitscrabbasket-movingefficiencybytransportingasmany(nolessthan6)cagesfromeachofthe3designatedcrabcollectionlocationsoutinthelagoon,backtothedockacrossaspecifiedopenwatercourseofapproximately350’.Crabbasketsmustbeoff-loadedandtheboatmustreturntothestartingdockifmultiplerunsareplanned.Uponarrivalatthecompetitionsiteandafterthejudges’examinationoftheirentry,eachteammustdevelopaloadplantocarryasmanycrabbasketsaspossiblewithoutexceedingtheloadline,heightabovedeck,allowablecrabbasketspace,orstabilitylimits.Onceinthewater,eachcrabboatwillperformarungettingunderwayfromadock,tostopatdesignatedcrabbingstationsandaddingcrabbasketstotheirboat,andmaneuveringbacktothelaunchramp.Thegoalwillbetohavetheminimumbasketrate,whichisdeterminedbythefollowingformula:

• BasketRate=[(FixedCosts)+(OperatingCosts)]/(BasketsCarriedxDistanceTraveled)BR=(FC+OC)÷(BCxDT)

o FixedCosts(FC)=LengthxWidthxDraftLoadedx$10o OperatingCosts(OC)=timetoruncourseinsecondsx$10persecondxnumberof

propulsionmotorso BasketsCarried(BC)=totalnumberoffullsizedbasketso DistanceTraveled(DT)

Theboatmusthaveadequatestabilitywhenfullyloaded.Thisisimportant–testitbeforethechallengedate!Stabilityisdemonstratedby:

• Calculatingmetacentricheight(GM)inexcessof7.5’(3/4”)byplacingaonelb.weight4”oneithersideofthecenterlineandshowingnomorethan3degreesofheel,OR

• Havingarollperiod(left–right–backagain)oflessthan2seconds.Inevaluatingthevarioustrade-offsthatmustbemadeduringthedesignphase,keepinmindthatthecoursewillbeafewhundredfeetlong,andwillbeintheChesapeakeBay,subjecttowhateverweatherMotherNaturedecidestodeliverunlikeaswimmingpoolortestingtank.Remembertheobjectiveistomodelaboatthatcanreliablytransportasmanycrabbasketswithinthecourse.Maneuverabilityisessential,butthekeyistocollectthegreatestnumberofcrabbasketsfromthedesignatedstations.WrittenReportandDrawingsCriteria:EvaluationCriteria:Design/WrittenReport 20pointsDesignandConstruction 30pointsOralReport(atevent) 15pointsPerformanceDemonstration 35points*Theformatforthedesignandwrittenreportsaswellasajudgingrubricareprovidedonthewebsitetohelpguideteamsindevelopingthesedocuments.ForMoreInformation:PleasecontactDr.TylerLove,AssistantProfessor/CoordinatorofTechnologyandEngineeringEducationattheUniversityofMarylandEasternShore–tslove@umes.eduor(410)621-3448

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