Lesson 1Welding processes for ship repairs: SMAW, GMAW/MIG, FCAW, and submerged arc—process selectionLooks at main welding processes used in ship repairs, comparing SMAW, GMAW, FCAW, and SAW for speed, access, position ability, and quality, and guiding choice for usual structural 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 plating and guides choosing local renewals, patches, and double-skin fixes, with focus on class rules, load paths, drainage, 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-resistant alloys, and welding materials, focusing on matching strength, toughness, rust behaviour, and weldability in usual ship repair cases.
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 accurate removal of damaged parts using oxy-fuel, plasma, and CNC thermal cutting, dealing with tool setup, cut quality, heat-affected areas, and reducing bending and redoing 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 measurement ways, template making, edge prep, tolerances, and aligning to cut down onboard fitting time and welding bending.
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 repair, including welder training, WPS following, NDT methods, acceptance rules, and repair limits, ensuring 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 structured way from first damage check to repair choice and scope setting, mixing class needs, risk, cost, downtime, 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 training WPS for ship steels, including preheat and interpass control, postheat, and PWHT choices, with care for hydrogen cracking, 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 fatigue life, covering shape changes, soft joins, backing details, weld shapes, and aligning 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 fatigue crack ways and repair choices, including stop-holes, weld removal, full-penetration welds, splice plates, doublers, and redesign of details to better fatigue 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
