Annex 10 – Requirements for Extent of Thickness Measurements at those Areas of Substantial Corrosion of Bulk Carriers with Double-Side Skin Construction within the Cargo Length Area
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.744(18) – Guidelines on the Enhanced Programme of Inspections During Surveys for Bulk Carriers and Oil Tankers – (Adopted on 4 November 1993) - Annex A - Guidelines on the Enhanced Programme of Inspections During Surveys for Bulk Carriers - Part B – Guidelines on the Enhanced Programme of Inspections During Surveys of Bulk Carriers Having Double-Side Skin Construction - Annex 10 – Requirements for Extent of Thickness Measurements at those Areas of Substantial Corrosion of Bulk Carriers with Double-Side Skin Construction within the Cargo Length Area

Annex 10 – Requirements for Extent of Thickness Measurements at those Areas of Substantial Corrosion of Bulk Carriers with Double-Side Skin Construction within the Cargo Length Area

TABLE 1 − BOTTOM, INNER BOTTOM AND HOPPER STRUCTURE
Structural member Extent of measurement Pattern of measurement
Bottom, inner bottom and hopper structure plating Minimum of three bays across double bottom tank, including aft bay Measurements around and under all suction bell mouths Five-point pattern for each panel between longitudinals and floors
Bottom, inner bottom and hopper structure longitudinals Minimum of three longitudinals in each bay where bottom plating measured Three measurements in line across flange and three measurements on the vertical web
Bottom girders, including the watertight ones At fore and aft watertight floors and in centre of tanks Vertical line of single measurements on girder plating with one measurement between each panel stiffener, or a minimum of three measurements
Bottom floors, including the watertight ones Three floors in the bays where bottom plating measured, with measurements at both ends and middle Five-point pattern over two square metre area
Hopper structure web frame ring Three floors in bays where bottom plating measured Five-point pattern over one square metre of plating
Single measurements on flange
Hopper structure transverse watertight bulkhead or swash bulkhead − lower 1/3 of bulkhead − five-point pattern over one square metre of plating
− upper 2/3 of bulkhead − five-point pattern over two square metre of plating
− stiffeners (minimum of three) − For web, five-point pattern over span (two measurements across web at each end and one at centre of span). For flange, single measurements at each end and centre of span
Panel stiffening Where applicable Single measurements

TABLE 2 − DECK STRUCTURE INCLUDING CROSS STRIPS, MAIN CARGO HATCHWAYS, HATCH COVERS, COAMINGS AND TOPSIDE TANKS
Structural member Extent of measurement Pattern of measurement
Cross deck strip plating Suspect cross deck strip plating Five-point pattern between under deck stiffeners over 1 metre length
Under deck stiffeners Transverse members Five-point pattern at each end and mid span
Longitudinal member Five-point pattern on both web and flange
Hatch covers Side and end skirts, each three locations Five-point pattern at each location
Three longitudinal bands, outboard strakes (2) and centreline strake (1) Five-point measurement each band
Hatch coamings Each side and end of coaming, one band lower 1/3, one band upper 2/3 of coaming Five-point measurement each band i.e., end or side coaming
Topside ballast tanks a) watertight transverse bulkheads: Five-point pattern over 1 sq. metre of plating
- Lower 1/3 of bulkhead Five-point pattern over 1 sq. metre of plating
- Upper 2/3 of bulkhead Five-point pattern over 1 metre length
- Stiffeners  
Topside ballast tanks b) two representative swash transverse bulkheads: Five-point pattern over 1 sq. metre of plating
- Lower 1/3 of bulkhead Five-point pattern over 1 sq. metre of plating
- Upper 2/3 of bulkhead Five-point pattern over 1 metre length
- Stiffeners  
Topside ballast tanks c) three representative bays of slope plating: Five-point pattern over 1 sq. metre of plating
- Lower 1/3 of tank Five point pattern over 1 sq. metre of plating
- Upper 2/3 of tank  
Topside ballast tanks d) Longitudinals, suspect and adjacent Five point pattern on both web and flange over 1 metre length
Main deck plating Suspect plates and adjacent (4) Five-point pattern over 1 sq. metre of plating
Main deck longitudinals Suspect plates Five point pattern on both web and flange over 1 metre length
Web frames/transverses Suspect plates Five-point pattern over 1 sq. metre

TABLE 3 − STRUCTURE IN DOUBLE-SIDE BALLAST TANKS
Structural member Extent of measurement Pattern of measurement
Side shell and inner plating:    
− Upper strake and strakes in way of horizontal girders − Plating between each pair of transverse frames/longitudinals in a minimum of three bays (along the tank) − Single measurement
− Single measurement
− All other strakes − Plating between every third pair of longitudinals in same three bays  
Side shell and inner side transverse frames/ longitudinals on:    
− upper strake − Each transverse frame/ longitudinal in same three bays − Three measurements across web and 1 measurement on flange
− all other strakes − Every third transverse frame/ longitudinal in same three bays − Three measurements across web and 1 measurement on flange
Transverse frames/ longitudinals: Minimum of three at top, middle and bottom of tank in same three bays Five-point pattern over area of bracket
− brackets    
Vertical web and transverse bulkheads:    
− strakes in a way of horizontal girders − Minimum of two webs and both transverse bulkheads − Five-point pattern over approx. two square metre area
− other strakes − Minimum of two webs and both transverse bulkheads − Two measurements between each pair of vertical stiffeners
Horizontal girders Plating on each girder in a minimum of three bays Two measurements between each pair of longitudinal girder stiffeners
Panel stiffening Where applicable Single measurements

TABLE 4 − TRANSVERSE BULKHEADS IN CARGO HOLDS
Structural member Extent of measurement Pattern of measurement
Lower stool, where fitted − Transverse band within 25 mm of welded connection to inner bottom − Five-point pattern between stiffeners over one metre length
  − Transverse bands within 25 mm of welded connection to shelf plate − Five-point pattern between stiffeners over one metre length
Transverse bulkheads − Transverse band at approximately mid height − Five-point pattern over one square metre of plating
  − Transverse band at part of bulkhead adjacent to upper deck or below upper stool shelf plate (for those ships fitted with upper stools) − Five-point pattern over one square metre of plating
Parent topic: Part B – Guidelines on the Enhanced Programme of Inspections During Surveys of Bulk Carriers Having Double-Side Skin Construction
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