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8/11/2019 25 Meter HSV
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Intact Stability Calculation
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0 General Particulars
Name of Vessel : 25 Meter Hydrographic Survey Vessel
Owner : BIWTA
Type of Vessel : Survey Vessel
1 Principal Particulars & Dimension
Particulars
Length Overall 25.0 Meter
Length of Hull 25.0 Meter
Breadth 06.5 Meter
Depth 03.0 Meter
Engine 02X300 hp
Maximum Speed 12.5 Knots (Full Load, 100% MCR)
Cruising Speed 11 Knots (Full Load, 90% MCR)
Fuel 9000 Liter
Fresh Water 1500 Liter
Grey Water 300 Liter
Waste Water 300 Liter
Lightship 59.60 Tonne
Full Load Displacement 71.31 Tonne
Draught at Lightship 0.97 Meter
Draught at Full Load 1.15 Meter
Generator 02X38 kVA
Endurance 2000 nm @ Cruising Speed
2 Nomenclature
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AP Aft Perpendicular
BG Longitudinal distance between Center of Buoyancy and Center of Gravity0 Height of Initial Metacenter above Center of Buoyancy in transversecondition Displacement in metric tons (t)
LOA Length overall of shipLBP Length between perpendiculars.
B Breadth Moulded Block Coefficient Prismatic Coefficient Midship Coefficient Water Plane CoefficientD Depth
d Mean draft from Base Line
FSC Free Surface correction
GM Transverse metacentric height (m)
GZ Righting lever (m)LCB Longitudinal center of Buoyancy
LCF Longitudinal center of floatation
VCB Vertical center of buoyancy over base line (m)
LCG Longitudinal center of gravity from aft end or mid ship
VCG Vertical center of gravity over base line (m)
KG Same as VCG
KB Same as VCB
KG KG corrected for free surface effects (m) Longitudinal metacentric height (m) Transverse metacentric height (m)
Angle of heel (deg.)MCT Moment to change trim one cm (t-m/cm).
TPC Tons per cm immersion
WS Wetted Surface Area (m2)
3 Stability Criteria Applied
General
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The vessel was evaluated by the rules & guidelines set by IMO A.749(18) Ch3 (Code for
Intact Stability & Design Criteria Applicable to All ships).
4. Brief description of Stability Criteria
1. Minimum requirements for stability of Inland Ships
Except Barge, Pontoon and floating equipments, all ships, having length greater than 24
meters should comply with any one standard between the following two standards at any
loaded conditions.
Standard 1
The area under the GZ curve is not to be less than 0.055 m-radian heeling angle up
to 300 and not less than 0.09 m-radian for the heeling angle 400 or the angle of
flooding which one is less. Beside the area under the curve of GZ is not to be lessthan 0.03 m-radian at the heeling angle 300 and 400 or if the angle of flooding at
300 is less than that of 400.
GZ is to be at least 0.20 m at an angle of heel equal to or greater than 300.
The heeling angle is to be not less than 250, at which GZ is maximum.
The initial metacentric height must not be less than 0.15 m for L>70 m and is to be
not less than 0.35 m for L= 70 m and is to be
not less than 0.35 m for L< 70 m.
The highest righting lever should occur at the heeling angle greater than 150.
The Effect of Free Liquid Surface
For the free surface liquid surface effect, the initial metacentric height and GZ curves should be
corrected as per following assumptions.
The free surface must be considered for liquid in tanks including ballast water tank for identifying
the effect of liquid on stability.
Tanks should be either empty or full as far as possible.
For identifying the correction of free surface, those tanks should be considered which are able to
create the maximum free surface moment
can be calculated for each tank by the following formula =
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Where, = free surface moment (meter-ton) = total capacity of tank = molded breadth of tank = Specific weight of tank liquid, ton/
3
= block coefficient of tank = h = molded depth of tank
l = maximum length of tank in meter
k = coefficient from the following table as per b/h ratio
Table of Coefficient K
b/h 5 10 15 20 30 40 50 60 70
10 0.01 0.11 0.12 0.12 0.11 0.1 0.09 0.07 0.05
5 0.04 0.07 0.1 0.11 0.11 0.11 0.1 0.08 0.05
3 0.02 0.04 0.07 0.09 0.11 0.11 0.1 0.09 0.08
2 0.01 0.03 0.04 0.06 0.09 0.11 0.11 0.1 0.09
1.5 0.01 0.02 0.03 0.05 0.07 0.1 0.11 0.11 0.11
1 0.01 0.01 0.02 0.03 0.05 0.07 0.1 0.12 0.13
0.75 0.01 0.01 0.02 0.02 0.04 0.05 0.08 0.12 0.15
0.5 0 0 0.01 0.01 0.02 0.02 0.05 0.09 0.016
= sin12 (1 + 2
2 )
= cos8 1 + tan
cos
12()2
(1 + 22
)
Where, cot