FABRICATION OF BLOCKS

• OWNERS REQUIREMENT• DESIGN• CLASSIFICATION SOCIETY• PROCUREMENT• SURFACE PREPATION• CUTTING• FABRICATION • ERRECTION

OWNERS REQUIREMENT

• CONTRACT • WORKING SPECIFICATION• VESSELS PARTICULARS• MACHINERY AND EQUIPMENTS• PAINTING SPECIFICATION• CLASSIFICATION SOCIETY.

DRAWINGS

• DESIGN SECTION. BASIC DRAWINGCONSTRUCTIONAL DRAWING AS PER BLOCKSCUTTING PLAN (NESTING)

CLASSIFICATION SOCIETY

• BASIC DRAWING APPROVAL• CONSTRUCTION DRAWING APPROVAL• MATERIAL APPROVAL• WELDING PROCEDURE APPROVAL• WELDERS QUALIFICATION APPROVAL

PROCURREMENT OF MATERIAL(STEEL)

• CLASSIFICATION SOCIETY• DIMENSION AS PER DRAWINGS & CUTTING

PLAN• GRADE OF MATERIAL• AVAILABILITY.

STACKING OF MATERIALS

LOADING OF PLATE ON ROLLERS FOR SURFACE PREPARATION

• THE PLATE HAS TO BE DRY AND FREE FROM GREASE OIL ETC.BEFORE BLASTING.

SURFACE PREPARATION

• BLASTINGAbrasive used for

blasting sandCopper grit Iron grit• CLEANING

SHOP PRIMER PAINTING

• Shop primers are thin coatings which are applied to steel plates and profiles after blast cleaning to provide temporary corrosion protection during transport, storage and production.

PAINTING

PAINT DRYER

STACKING OF PLATES

CUTTING OF PLATES• CUTTING PLAN Nesting of plates as per

drawing. NOTE:-Nesting is done taking

in consideration the shrinkage area after welding.

Program is fed to the CNC cutting machine.

Plate placed on the cutting bed is as per the dimensions in the program fed.

Plate squareness is checked & cutting is proceeded according to the program.

PARTS CUT FROM PLATES

FLOORS MARKING ON FLOORS

EDGE PREPARATON

BENDING OF PLATES

TEMPLATES

BLOCK FABRICATION(e.g. Double Bottom)

• SUBASSEMBLYBottom panelTank top panel FloorsGirdersBulkhead Margin brackets

SUBASSEMBLY

BOTTOM PANEL TANK TOP PANEL

SUBASSEMBLY

• FLOORS• GIRDERS• MARGIN BRACKETS• BULKHEAD

UNIT ASSEMBLY

• Fitting & welding1. Tank top panel shifting2. Floor, girder, bulkhead and

margin bracket fitting to the tank top panel and its welding.

3. Pipe line fitting and welding accept end connections

4. Bottom panel fitting.5. Bilge plate fitting and

welding.

Bilge plate fitting and welding

Welding

• The block is toppled and welding of floors, girders, bulk head and margin brackets to the bottom panel is carried out ,this is done to change the position of welding from overhead to down hand. As down hand welding is faster then overhead and also consumable required is less.

• Dry survey is carried out .

STACKING OF BLOCKS

FABRICATED BLOCKS

Aft block. Bulbous bow

Erection of blocks

Joining of Mega Blocks

Test to check the soundness and water tightness of blocks

• NDTUltra sonic testingRadio graphic testingMagnetic particle testingDie penetrant testing/ Liquid penetrant testing.• WATER TIGHTNESSAir pressure testHydrostatic testHose test.

Painting of blocks

• Surface preparation as per painting specification.

Cleaning of surface from water, grease, oil etc.Blasting, buffing (power tooling).Cleaning of grit after blasting and surface

inspection.Painting as per specification.

Launching

• Pre launching ActivitiesUnder water surveyDrain plug fittingOver board valves to be closed.Anode fitting to be checked.Propeller to be locked.Rudder to be locked.Clearing the path of slipway etc.• Launching.

• Final out fitting• Sea trials• Delivery.