Lesson 1Welding processes for ship repairs: SMAW, GMAW/MIG, FCAW, and submerged arc—process selectionLooks at main welding methods used in ship fixes, comparing SMAW, GMAW, FCAW, and SAW for speed, reach, position ability, and quality, and guiding choice for usual structure fixes.
SMAW setup and shipyard applicationsGMAW and MIG variants in repairsFCAW self-shielded and gas-shieldedSubmerged arc for panel renewalsProcess selection decision factorsDistortion and heat input controlLesson 2Corrosion repair for bottom shell plating: local renewals, patch plating, and double-skin/trim patch solutionsExplains rust damage ways in bottom shell plates and guides choosing local fixes, patches, and double-skin solutions, stressing class rules, load paths, water flow, and long-term rust protection.
Corrosion types in bottom shell regionsCriteria for local plate renewalsDesign of insert and patch platesDouble-skin and trim patch conceptsScantling checks and class approvalCoating, anodes, and sealing detailsLesson 3Use of advanced materials and consumables: higher-strength steels, corrosion-resistant alloys, and consumable selectionLooks at choosing and using stronger steels, rust-proof alloys, and welding materials, focusing on matching strength, toughness, rust behaviour, and weldability in usual ship fix situations.
Grades of higher-strength ship steelsCorrosion-resistant alloys in repairsMatching and overmatching consumablesHydrogen-controlled consumable typesStorage and handling of electrodesDissimilar metal joint strategiesLesson 4Cutting and removal: oxy-fuel, plasma, and CNC/high-precision thermal cuttingExplains safe and exact removal of damaged parts using oxy-fuel, plasma, and CNC heat cutting, dealing with tool setup, cut quality, heat zones, and reducing bend and re-do work.
Selection of cutting process by taskOxy-fuel cutting setup and safetyManual and mechanized plasma cuttingCNC and template-guided cuttingControl of HAZ and edge qualityDistortion control during removalLesson 5Prefabrication and modular panel replacement: templates, edge preparation and tolerancesCovers planning and making modular replacement panels, including measure methods, template making, edge prep, tolerances, and lining up to cut down on-ship fitting time and welding bend.
Damage survey and panel mappingTemplate methods and digital scanningShop fabrication and fit-up checksEdge preparation and root gapsDimensional tolerances and fairnessLifting, handling, and positioningLesson 6Weld quality control: welders qualification, NDT acceptance criteria, and repair limitsCovers weld quality checks in ship fixes, including welder training, WPS following, NDT methods, allowed levels, and fix limits, making sure structure strength and rule following.
Welder qualification and continuityVisual inspection and weld gaugesUltrasonic and radiographic testingMagnetic particle and dye penetrantAcceptance criteria and defect limitsRepair welding and reinspection stepsLesson 7Damage assessment to repair decision framework and scope definitionGives a clear frame from first damage check to fix decision and scope setting, mixing class needs, risk, cost, down time, and long-term structure performance.
Initial inspection and data collectionUse of NDT and thickness measurementsResidual strength and buckling checksTemporary versus permanent repairsRepair scope and work package definitionCoordination with class and ownerLesson 8Welding procedure specifications (WPS), preheat/postheat, PWHT considerations for common ship steelsDescribes making and checking WPS for ship steels, including pre-heat and between-pass control, post-heat, and PWHT choices, watching for hydrogen cracks, hardness limits, and class papers.
Essential WPS variables and rangesPreheat and interpass temperature controlPostheat for hydrogen diffusionPWHT need, methods, and limitsHardness and microstructure controlWPS qualification and recordsLesson 9Joint design improvements to reduce stress concentrations and extend fatigue lifeFocuses on joint design changes to cut stress points and lengthen tiredness life, covering shape changes, soft joins, backing parts, weld shapes, and lining up to best load passing.
Assessment of existing joint detailsNotch effects and stress raisersSmooth transitions and tapersBacking bars and run-on tabsOptimized weld profiles and toesAlignment and fit-up tolerancesLesson 10Fatigue crack repair strategies: stop-holes, full-penetration welds, splice plates, doublers and redesign of detailsDetails tiredness crack ways and fix choices, including stop-holes, weld removal, full-welds, splice plates, doublers, and detail redesign to better tiredness life and follow class advice.
Identification of fatigue-prone detailsCrack sizing and monitoring methodsStop-holes and crack arrest drillingFull-penetration weld repair stepsUse of splice plates and doublersDetail redesign to reduce hotspots
