bULK cARRIER PRESENTATION
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Transcript of bULK cARRIER PRESENTATION
1
BULK CARRIER
Hull Structural approach
2
SUMMARY
1.Introduction
2. Damage to Bulk Carrier
3. Bulk Carriers hull design
with IACS UR
4. BV approach
3
Introduction
4Bureau Veritas
Introduction
CapesizeBulk Carrier+80,000dwt527 ships of
82.5 million dwt
PanamaxBulk Carrier60-80,000dwt888 ships of
61.5 million dwt
HandymaxBulk Carrier40-60,000dwt976 ships of
44.9 million dwt
HandysizeBulk Carrier10-35,000dwt2,945 ships of
78.7 million dwt
Iron oreCoal
Grain Salt
Iron oreCoalGrain
BauxitePhosphate
Graincoal
Steel prod.CementPotash
RiceSugar
GypsumForest prod.
ScrapSulphur
Combined Carriers151 Ships of15.1 M. dwt
► The Bulk Carrier Market
5Bureau Veritas
Introduction
HEAVY BULK
MULTIPURPOSE
LIGHT BULK
► Type of Loading
6Bureau Veritas
Introduction
► Single side bulk carrier
7Bureau Veritas
Introduction
► Double side bulk carrier
8
Damage to Bulk Carriers
9Bureau Veritas
Damage to Bulk Carriers
► Trends of Losses at Sea
0
0.5
1
1.5
2
2.5
dwt
1970 1974 1978 1982 1986 1990 1994 1998
Combos
Bulkers
Tankers
10Bureau Veritas
Damage to Bulk Carriers
► Bulk carrier losses
A crew safety problem
LOSS OF LIVES
0
20
40
60
80
100
120
140
160
180
200
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
Years
No
. li
ves
lost
BULK CARRIERS LOST
0
5
10
15
20
25
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
Years
No
. ve
sse
ls l
ost
Source: Intercargo
11Bureau Veritas
Primary causes of casualties
Considering data from 1999 to 2000, primary causes of fatalities are:
1. Hull damages2. Navigation error3. Fire and explosion4. Machinery failures
Oil tankers
0%
5%
10%
15%
20%
25%
30%
35%
Bulk carriers
Ma
chin
ery
fa
ilure
na
vig
atio
n e
rro
r
fire
an
d e
xplo
sio
n
hu
ll fa
ilure
mis
cella
neo
us
0%
10%
20%
30%
40%
50%
60%
70%
80%
Machinery failure
navigation error
fire and explosion
hull failure
miscellaneous
Damage to Bulk Carriers
12Bureau Veritas
0.00E+00
5.00E-04
1.00E-03
1.50E-03
2.00E-03
2.50E-03
3.00E-03
Hatchcover Pipes&valves
Side Shell Side Shell(Collision)
Bottom Shell Deck Side ShellPenetration
categories of incidents
fre
qu
en
cy
of
inc
ide
nts
pe
r s
hip
y
ea
r
Mini
Handysize
Handymax
Panamax
Cape size
Damage to Bulk Carriers
13Bureau Veritas
Damage to Bulk Carriers
► Type of Damages
• cracking at hatch corners;
• plate panel buckling of cross deck strips and stiffening structure;
• cracking of hatch coamings;
• cracking at the intersection of the inner bottom plating and the hopper/stool platings
• grab and bulldozer damage to the main frames lower brackets
14Bureau Veritas
Damage to Bulk Carriers
► Type of Damages
• cracking at main frame bracket toes
• corrosion within topside tanks, of the tranverse bulkheads, the frames and brackets
15Bureau Veritas
Damage to Bulk Carriers
► Type of Damages
16Bureau Veritas
Damage to Bulk Carriers
► Type of Damages
17Bureau Veritas
Damage to Bulk Carriers
► Type of Damages – Hatch Covers
• 1 or 2 case of missing/lost hatch cover per year (excluding ships which sunk)
• N°1 hatch cover ten times more likely to be damaged than hatches from amidships to aft
18Bureau Veritas
Damage to Bulk Carriers
► Rules into force - Conclusion
• IMO (SOLAS Ch. XII) : Safety
• IACS Requirements : strength of hull and stability
regulation URS 12,17,18,20,21,25,27…
• BV Rules April 2005 or CSR rules
includes IACS and IMO requiremetns
19
Bulk Carriers Hull designIACS UR requirements
20Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► IACS Rules for New Bulk
UR S12
- Requirements forSIDE STRUCTURES in single side skin (following UR Z11) Bulk Carrier
UR S17
- LONGITUDINAL STRENGTH of Hull girder in flooded condition
0,125 h
0,125 h
h
UR S18
- Scantlings requirements for Transverse corrugated watertight bulkheads in flooded condition for each hold (only single side skin B/C following URZ11)
UR S1/1 A
- Requirements for loading conditions, loading manuals, loading instruments and loading sequences
21Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► IACS Rules for New Bulk
UR S20
- Scantlings requirements for Double Bottom in flooded condition for each hold (only single side skin B/C following URZ11)
Ex UR S24 replaced by SOLAS Ch. XII Reg. 12 and 13 (Resolution MSC 134 (76) and MSC 145 (77)) + UI SC 179/180
-Cargo hold, ballast and dry space water level detectors (REG. 12) – (regardless date of construction)-Dewatering of forward spaces of B/C (REG. 13) – (regardless date of construction)
UR S21
- Strength requirements for Hatch Covers and coamings located forward of 0.25 L from the fore perpendicular
22Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► IACS Rules for New Bulk
UR S25
- harmonized notations and corresponding design loading conditions including Mass Curves definition
UR S27
- Strength requirements for fore deck fittings (Ventilator and air pipes) and equipments (Windlasses)
UR S26
- Strength and securing of SMALL HATCHES on the exposed fore deck
UR S28
- Requirements for the fitting of a FORECASTLE
23Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S1 and UR S1A : Loading Instrument and Manual
• Loading Instrument
• all existing bulk carriers of both single and double side skin construction
• Loading Manual
• all existing single side skin bulk carriers
• all new bulk carriers, ore carriers and combination carriers
• includes Loading sequences for single side skin bulk carriers >= 150m built before 1/7/98
• includes Loading sequences for all new bulk carriers >= 150m built after 1/7/98
24Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S12 : Side Structures
• Minimum thickness of frame web :
t w,min = C(7 + 0.03 L) (+ 15% in foremost hold)
• Minimum thickness of side shell :
• Requirements for construction of upper and lower brackets
• Welding requirements
• No combined load « cargo + sea water » considered
0,125 h
0,125 h
h
0,125 h
0,125 h
h
25Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S17 : Longitudinal Strength of Hull Girder in Flooded Condition
• Flooding of any hold in any loading condition :
• equilibrium calculation: MSW and FSW in flooded condition
• calculation of under MSW + 0.8 MW
under FSW + 0.8 FW
Typical reinforcements induced by UR S17 > adm increase of section modulus in midship area
(increase of deck thickness)
> adm increase of side shell thickness in way of
transverse bulkhead
26Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S18 : Corrugated transverse watertight bulkhead
• Calculation of pressure induced by flooding
(design load= cargo + sea water):
bending moment and shear force acting on the bulkhead
• Checking of section modulus of the corrugation under the bending moment (taking into account
gussets or shedder plates)
Gusset PlatesGusset Plates
27Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S18 : Corrugated transverse watertight bulkhead
• Checking of shear stress in web of the corrugation with requirement for shear buckling
• Strength of plate under local pressure
• Requirements for construction of upper and lower stools and alignment conditions
► Typical reinforcements induced by UR S18
• Increase thickness of flange / web of corrugation
• Gusset or shedder plates
28Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S20 : Allowable hold loading
• Calculation of shear strength of the double bottom to obtain the allowable hold loading considering hold flooding
• Sum of shear areas of floors and girders taking into account holes if any
► Typical reinforcements induced by UR S20
• Increase thickness of flange / girders at their ends
• Add partial floors / girders
• Remove holes
29Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S21 : Hatch Cover• Design load based on green sea on deck
• Only hatch covers located forward of 0.25 L from the fore perpendicular
• Direct calculation of primary members (with effective width for compression flanges) under pressure
• Allowable stresses: a = 0.8 F (yieldstress)
a = 0.45 F
2 5 . 72 5 . 7
pp ( P a )( P a )5 6 . 55 6 . 5
8 2 . 28 2 . 2
0 . 2 5 L 0 . 1 L F P
2 5 72 5 7
8 8 . 68 8 . 6
5 8 . 85 8 . 8
P ( P a )P ( P a )
2 5 . 72 5 . 7
pp ( P a )( P a )5 6 . 55 6 . 5
8 2 . 28 2 . 2
2 5 . 72 5 . 7
pp ( P a )( P a )5 6 . 55 6 . 5
8 2 . 28 2 . 2
2 5 . 72 5 . 7
pp ( P a )( P a )5 6 . 55 6 . 5
8 2 . 28 2 . 2
0 . 2 5 L 0 . 1 L F P
2 5 72 5 7
8 8 . 68 8 . 6
5 8 . 85 8 . 8
P ( P a )P ( P a )
0 . 2 5 L 0 . 1 L F P0 . 2 5 L 0 . 1 L F P
2 5 72 5 7
8 8 . 68 8 . 6
5 8 . 85 8 . 8
P ( P a )P ( P a )
2 5 72 5 7
8 8 . 68 8 . 6
5 8 . 85 8 . 8
P ( P a )P ( P a )
2 5 72 5 7
8 8 . 68 8 . 6
5 8 . 85 8 . 8
P ( P a )P ( P a )
30Bureau Veritas
Bulk Carriers Hull design with IACS UR requirement
► UR S25 : Harmonized notations and corresponding design Loading conditions for B/C
• Definition of notation
• BC-A dens>1t/m3, + specified empty hold at maximum draught, + BC-B conditions.
• BC-B dens>1t/m3, + no empty hold, + BC-C conditions.
• BC-C dens<1t/m3
• Definition of design loading conditions for checking of rules criteria regarding longitudinal strength
• Definition of design loading conditions for checking of rules criteria regarding local strength (primary and secondary members)
• Definition of the hold mass curves to be included inside Loading Manuel and Instrument.
31
BV approach
32Bureau Veritas
BV approach
► Critical Point
Members Connection with
Inner bottom plating Sloping and /or vertical plate of lower stool
Sloping plate of hopper tank
Inner side plating Sloping plate of hopper tank
Transverse bulkhead Sloping plate of lower stool
Sloping plate of upper stool
Frames of single side bulk carriers
Upper and lower wing tank
Ordinary stiffeners in double bottom
Floors in way of transverse bulkheads
Hatch corners Free edges of hatch corners
Hatch coaming ends Upper deck
Hatch cover stopper Fx, Fy, Fz Stopper
33Bureau Veritas
BV approach
► Critical Point
Double bottom in way of transverse bulkheads
CONSTRUCTION NDE :
• Misalignment (median lines) between floor and bulkhead (or stool) plating t /3.
• Cut-outs for connections of the inner bottom longitudinals to double bottom floors to be closed by collar plates welded to the inner bottom.
The following NDE are required :
• VE 100%,
• UE 35% of full penetration weld for absence of cracks, lack of penetration and lamellar tears
34Bureau Veritas
BV approach
► Critical Point
Double bottom in way of hopper tanks
CONSTRUCTION NDE :
• Misalignment (median lines) between girder and sloping plate tA /3.
• Misalignment (median lines) between floor and hopper transverse web tB/3.
The following NDE are required :
• VE 100%,
• UE 25% of full penetration weld for absence of cracks, lack of penetration and lamellar tears
35Bureau Veritas
BV approach
► Critical Point
Lower part of inner side (In case of double hull)
CONSTRUCTION NDE :
• Misalignment (median lines) between hopper tank top plate and hopper tank sloping plate tA /3.
•. Misalignment (median lines) between members above and below hopper tank top plate tB /3.
• If not full penetration welding of hopper tank top plate to inner side, the weld preparation is to be indicated on the approved drawings.
• Butt welds between inner side and hopper tank sloping plate at a distance greater than 500mm from the hopper tank top plate.
The following NDE are required :
• VE 100%,
• UE 25% of full penetration weld for absence of cracks, lack of penetration and lamellar tears
36Bureau Veritas
BV approach
► Critical Point
Lower part of transverse bulkheads with lower stools
CONSTRUCTION NDE :
• Misalignment (median lines) between corrugation flanges and stool side plating tA /3.
•. Misalignment (median lines) between lower edge of shedder plates and stool side plating tB /3.
• Knuckled shedder plates are to be avoided.
•Corrugation radius according to Ch 4, Sec 7, [3.1.3].
The following NDE are required :
• VE 100%,
• UE 35% of full penetration weld for absence of cracks, lack of penetration and lamellar tears.
37Bureau Veritas
BV approach
► Critical Point
Transverse corrugated BHD with upper stool or top side tank
CONSTRUCTION NDE :
Misalignments between :
• Transverse web or intercostal reinforcement fitted inside the upper wing tank and corrugation flanges,
• Transverse web or intercostal reinforcement fitted inside the upper wing tank and upper stool side plating,
• Upper stool side plating and corrugation flanges, are to be t /3.
The following NDE are required :
• VE 100%, with particular care for fillet shape and undercuts on the plating,
• UE 100% of full penetration weld for absence of cracks, lack of penetration and lamellar tears
38Bureau Veritas
BV approach
► Critical Point
Side frames with hopper and topside tank
CONSTRUCTION NDE :
• Misalignment (median lines) between flame web and the connecting brackets inside hopper tank and upper wing tank t /3, where t is the minimum thickness among those of the connected elements.
• Soft toe : tapering of frame flange at ends : thickness 1:3, width 1:5.
The following NDE are required :
• VE 100%, with particular care for fillet shape and undercuts on the plating at the soft toes,
• ME or dye penetrant depending on the results of VE.
39Bureau Veritas
BV approach
► Critical Point
Double bottom longl. In way of transverse BHD stool
CONSTRUCTION NDE :
• Misalignment between webs of bottom and inner bottom longitudinal with floor stiffener t /3.
• In case of fillet weld, misalignment may be as necessary to allow the required fillet leg size, but 10mm.
Visual examination 100%.
40Bureau Veritas
BV approach
► Critical Point
Hatch corner
CONSTRUCTION NDE :
• Corners of insert plates to be rounded, unless corresponding to joints of deck strakes.
• Insert cut edges to be carefully executed.
The following NDE are required :
• VE 100%,
• RE / UE in areas indicated in the sketch.
41Bureau Veritas
BV approach
► Critical Point
Ends of longl. Hatch coamings
CONSTRUCTION NDE :
• Misalignment between bracket and under deck longitudinal tB /3.
• Soft tow : tapering of bracket flange at ends : thickness 1:3, width 1:5
The following NDE are required :
• VE 100%, with particular care for the weld shape and undercuts on deck plating,
42Bureau Veritas
Priorities for bulk carrier safety
• PRIORITY 1 strengthen the side shell to prevent flooding
• PRIORITY 2 avoid progressive flooding
• PRIORITY 3 alert the crew to the occurrence of flooding at the very first stage
BV approach
43Bureau Veritas
►Rules entered into force after July 1st, 1998 : Existing & New Ships
BV approach
44Bureau Veritas
We are ready to go!
45Bureau Veritas