DL 105DL 105Marine SurvivalMarine Survival

DavitsDavits

BT ElliottBT Elliott

20112011

DavitsDavits A system to move a lifeboat from the stowed A system to move a lifeboat from the stowed position, outboard for launching and recoveryposition, outboard for launching and recovery

Radial Radial ObsoleteObsolete

Mechanical Mechanical ObsoleteObsolete

GravityGravity

Radial DavitsRadial DavitsManually swung out, first one then the other, Manually swung out, first one then the other, manila falls, two person operationmanila falls, two person operation

Mechanical DavitMechanical DavitHand cranked out, manila falls, 2 man op.Hand cranked out, manila falls, 2 man op.

Gravity DavitsGravity Davits Industry StandardIndustry Standard One man operationOne man operation Wire rope fallsWire rope falls No power needed to launchNo power needed to launch Brake controlled lowering speedBrake controlled lowering speed Electric winch for hoistingElectric winch for hoisting Manual cranking gear with safety deviceManual cranking gear with safety device Launch able with vessel listing and trimmingLaunch able with vessel listing and trimming

Types of Gravity DavitsTypes of Gravity Davits

Roller Gravity Roller Gravity

Single PivotSingle Pivot

Multi-PivotMulti-Pivot

Free-FallFree-Fall

FixedFixed

Roller GravityRoller Gravity

Single PivotingSingle Pivoting

Multi-PivotingMulti-Pivoting

Multi-PivotingMulti-PivotingUsed when height is restricted, deck aboveUsed when height is restricted, deck above

Free FallFree Fall

Free FallFree Fall

FixedFixedDrill rigs, no concerns about listing and Drill rigs, no concerns about listing and trimmingtrimming

Training ShipTraining Ship

Lifeboats 1, 2, 3, 4 use Roller Gravity DavitsLifeboats 1, 2, 3, 4 use Roller Gravity Davits

Lifeboats 5, 6 use Single Pivot Gravity Lifeboats 5, 6 use Single Pivot Gravity DavitsDavits

Roller Gravity DavitRoller Gravity DavitLifeboats #1, 2, 3, 4Lifeboats #1, 2, 3, 4

Pivoting DavitPivoting DavitLifeboats # 5, 6Lifeboats # 5, 6

Roller Gravity DavitsRoller Gravity Davits

Most common on TSGBMost common on TSGB

Style of Davit that the USCG is basing their Style of Davit that the USCG is basing their testing ontesting on

Main ComponentsMain ComponentsTrack way and Davit ArmTrack way and Davit Arm

Track WayTrack Way

Each supports and Each supports and guides an armguides an arm

Transfers weight and Transfers weight and forces to shipforces to ship

Provides mounting Provides mounting surfaces accessories surfaces accessories such as winches, such as winches, grips, locking bar and grips, locking bar and limit switchlimit switch

Davit ArmDavit Arm

Moving part of system Moving part of system using rollersusing rollers

Cradles lifeboatCradles lifeboat

Attachment point for Attachment point for wire sheaves, span wire sheaves, span wire and tricing wire and tricing pendentpendent

Electric WinchesElectric WinchesNot needed to launchNot needed to launch Track way or Deck MountTrack way or Deck Mount Closed gearingClosed gearing 2 Drums2 Drums Centrifugal Brake 120 Centrifugal Brake 120

ft/minute maximumft/minute maximum Dead Man brakeDead Man brake Overhauling WheelOverhauling Wheel Emergency cutoff switchEmergency cutoff switch Operating Controls on Rail Operating Controls on Rail

DrumsDrumsSized for 6x19 wire, Fleet Angle Sized for 6x19 wire, Fleet Angle ≤≤ 8 8 ۠۠

Davits 1, 2, 3, 4Davits 1, 2, 3, 4

Centrifugal BrakeCentrifugal Brake

Dead man BrakeDead man Brake

Manual Cranking with Manual Cranking with Safety deviceSafety device

Overhaul Wheel Overhaul Wheel

Emergency Cutoff Emergency Cutoff Operating ControlsOperating Controls

GripesGripesSecures lifeboat to Davit Arm in stowed positionSecures lifeboat to Davit Arm in stowed position

Tricing Pendent: brings boat alongside for loadingTricing Pendent: brings boat alongside for loadingFrapping Line: replaces tricing and controls boat Frapping Line: replaces tricing and controls boat

while loweringwhile lowering

Limit SwitchLimit SwitchCuts power to winch before final SecuringCuts power to winch before final Securing