naval architect Project Report

7/30/2019 naval architect Project Report

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INDEX

1. Introduction 41.1 Ship design 4

1.1.1 Concept design 5

1.1.2 Preliminary design 5

2.Aim of the project 5

3.Glossary of terms 6

4.Owners requirement 7

5.Parent ship data and analysis 96.Algorithm 10

7.Estimation of main dimensions & coefficients 12

7.1 Main dimensions 12

7.2 Form coefficients 13

7.2.1 Block coefficient 13

7.2.2 Midship coefficient 14

7.2.3 Prismatic coefficient 14

7.2.4 Coefficient of water plane area 15

7.3Calculations 16

8. Sectional area curve 18

9. Lines plan 19

9.1 Body plan 19

9.2 Half-breadth plan 20

9.3 Profile plan 21

10. Bonjean curves 22

10.1 Bonjean calculation 22

11. Hydrostatic curves 23

11.1 Hydrostatic calculations 23


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11.1.1 Longitudinal Center of Buoyancy 24

11.1.2 Vertical Center of Buoyancy 29

11.1.3 Longitudinal Center of Floatation 32

11.1.4 Tonnes Per Centimeter immersion 3811.1.5 Moment to Change Trim by 1 cm 38

11.1.6 Metacentric height in transeverse and

longitudinal section 38

12. General Arrangement 50

12.1 Introduction 50

12.2 Frame spacing & bulkhead disposition 50

12.3 Sketches 5112.4Superstructure 52

12.5 Accommodation 53

12.6 Painting and Cathodic protection 54

12.7 Pipe work colouring 56

12.8 Life savings and fire fighting equipment 56

12.9 Navigation lights 56

13 Detailed Capacity Calculations and Drawings 58

13.1Introduction 58

13.2 loading Calculation 59

14 Conclusion 62


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1.Intoduction

A tugboat (tug) is a boat that maneuvers vessels by pushing or towing them. Tugsmove vessels that either should not move themselves, such as ships in a crowded

harbor or a narrow canal or those that cannot move by themselves, such as barges,

disabled ships, log rafts, or oil platforms. Tugboats are powerful for their size and

strongly built, and some are ocean-going. Some tugboats serve as

icebreakers orsalvage boats. Early tugboats had steam engines, but today most

have diesel engines. Many tugboats have firefighting monitors, allowing them to

assist in firefighting, especially in harbors

1.1 Ship Design

Ship design is a complex process. The principle fact in this process is the

creativity involved in designing a good functional unit, the ship which meets the

various regulatory body requirements and the design practices and meet the owners

requirement.

Basic design involves the determination of major characteristics affecting

cost & performance.

(1)Main dimensions: L,B,T,D

(2)Hull form: Lines design

(3)Power: Resistance & propulsion

(4)Preliminary General Arrangement

(5)Major structure.

The proper selection of the above should satisfy the following mission

requirements

(1)Good sea keeping performance.

(2)Maneuverability

(3)The desired speed.

(4)Endurance

(5)Cargo capacity

(6)Dead weight.
http://en.wikipedia.org/wiki/Icebreakerhttp://en.wikipedia.org/wiki/Salvage_tughttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Deluge_gunhttp://en.wikipedia.org/wiki/Deluge_gunhttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Salvage_tughttp://en.wikipedia.org/wiki/Icebreaker


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The project involves the basic design of double skin PSV vessel with specifications

and encompasses:

(a)Concept design

(b)Preliminary design

1.1.1 Concept design

This translates the mission requirements into Naval Architecture & Engg.

characteristics. It includes the technological feasibility studies to determine the

fundamental elements of the proposed vessel such as Length (L), Breadth (B),

Draught (T), Coefficients (CB, Cw, CM, Cp), Power or alternative sets of

characteristics which meet the required speed, dead weight. It includes preliminary

light ship weight estimates. The selected concept design forms the basis of

obtaining approximate cost.

1.1.2Preliminary design

It defines the major ship characteristics affecting cost & performance.

Certain controlling factors like Length, Beam, Horsepower & DWT are not

expected to change upon completion of this phase. Its completion provides a

precise definition of the vessel that would meet the mission requirements.

2.Aim of the project

The main aim of this project is to design a Harbor, Ocean Towing Tug &also is to make a hydrostatic curve for a harbor tug with a bollard pull of 20tons.,


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3.Glossary of terms

LOA : Length Overall

B : Breadth

D : Depth

T : Draft

LWL : Load Water Line

LBP : Length between Perpendicular

DWT : Dead weight of ship

LWT : Light Weight of ship

CB : Block coefficient

CM : Midship Coefficient

CP : Prismatic Coefficient

AM : Area of Midship

AWL : Area of water line

(CW) : Coefficient of fineness of the waterplane area

(LCB) : Longitudinal centre of buoyancy

(VCB) : Vertical centre of buoyancy

(LCF) : Longitudinal centre of floatation

(TPCi) : Tones per centimeter immersion

(MCTi) : Moment to change trim by one centimeter

(BMT &BML): Metacentric height in transverse & longitudinalsections


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4.Owners requirement

The main aim of this project is to design a: Harbor, Ocean Towing Tug with

20 tons bollard pull . It has the following specifications.

TYPE : Harbor, Ocean Towing Tug

Service speed : 11knots

Classification : R.I.NA. Registro Italiano Navale

LOA : 21 metres

LBP : 19metres

Moulded Breadth : 8 metres

Moulded Depth : 3.8metres

Summer Load Draft : 2.8 metresGross Tonnage :


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Accomodation

Single cabin :0Double Cabin :4Crew messroom :1

Total accommodation : 8

Navigation & Communication

Depth recorderGPS Navigator

Radars x 2N 1 Radar X Band GEM SC 1210 NRadio systems Sailor system 4000 HT 4520

Autopilot SteeringTelephone System Mobile

VHF DSC SAILOR RT 4822 DSCAIS - Navtex FURUNO NX 500


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5. Parent ship data and analysis

The relevant data of 15-40 bollard pull were analysed & ratios are

calculated. They are expressed in the tabular form below.

NAME DIMENSIONS Assumed

Velocity

Bollard

Pull

(Metric

Tonnes)

LOA Depth Deep Draft Gross Registered

Tonnage

Ft In LBP Meter Ft Meter Ft Meter Ft Meter Tonnes InternalVolume

Knots m/s

1 SIGNETRANGER

82 19.995 25.0 26 7.925 11 3.3528 9 2.7432 98 277.4 15 7.7166 36

2 JIM COLLE 78 19.02 23.8 27 8.23 11 3.3528 8 2.5654 145 410.5 9 4.63 29.1

3 SIGNET

COURAGEOUS

90 21.946 27.4 28 8.534 15 4.572 12 3.6576 152 430.3 12 6.1733 44

4 SIGNET

CHALLENGER

104 25.359 31.7 36 10.97 16 4.8768 13 4.1148 379 1073 15 7.7166 46.5

5 SIGNET

VOLUNTEER

70 17.069 21.3 26 7.925 11 3.3528 9 2.7432 146 413.3 13 6.6877 13.5

6 NATALIECOLLE

81 6 19.873 24.8 32 9.754 16 4.8768 13 3.9624 215 608.7 11.5 5.9161 42.5

7 DANIEL

COLLE

81 6 19.873 24.8 32 9.754 16 4.8768 13 3.9624 215 608.7 11.5 5.9161 42.5

L/B B/D L/D B/T

2.523077 2.363636 5.963636 2.888889

2.311111 2.454545 5.672727 3.207921

2.571429 1.866667 4.8 2.333333

2.311111 2.25 5.2 2.666667

2.153846 2.363636 5.090909 2.888889

2.0375 2 4.075 2.461538

2.0375 2 4.075 2.461538


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Analysis of ratios

Range Average

L/B 2.032.57 2.27

B/T 2.33-3.2 2.70

L/D 4.075-5.96 4.98

B/D 1.8-2.45 2.18

6.Alogorithm

As mentioned in the aim we started research about the different types of

ship. It may lead us to find out most of the ship details and we aware about the

different types of bulk carrier.

We started researching on different apparent ships from those ship details we

find out a desirable detail for our ship. From those values we get the following

details.

Fig: Basic concept of ship


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Length overall (LOA)

Length of a ship measured horizontally from foremost part of stem to

foremost part of bow.

Length between perpendiculars (LBP)

It is often abbreviated as LPP, LBP orLength BPP is a term describing the

length of a ship. LBP refers to the length of a vessel along the waterline from the

forward perpendicular to the aft perpendicular.

Beam or Breadth (B)

It is the maximum width along the midship.

Depth (D)

It is the maximum depth of a ship.

Draft (T)

It is the depth of a ship measured from keel to waterline.

Loads water line (LWL)

It is an imaginary line drawn along the surface of water measured from

intersection of contour to forward perpendicular and the aft perpendicular.

Dimension ratios

Dimensions of the underwater body are sometimes referred to in ratio form.

These are noted below, with approximate ranges for each:

Ratio of length to breadth = L/B Approx. range 2 to 8.

Ratio of length to draft = L/T Approx. range 6 to 30.Ratio of breadth to draft = B/T Approx. range 1.8 to 5.


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Under water volume or displacement

An object that sinks displaces an amount of fluid equal to the object's

volume. Thus buoyancy is expressed through Archimedes' principle, which states

that the weight of the object is reduced by its volume multiplied by the density of

the fluid. If the weight of the object is less than this displaced quantity, the object

floats; if more, it sinks. It is the same for a ship

To find the underwater volume we have to analyze the formula

Density = mass /volume

Volume = mass/density

Mass = considering the ships total weightDensity of sea water (approx. = 1.025 T/m3)

7.Estimation of main dimensions & coefficients

7.1 Main dimensions

The main dimensions have a decisive effect on many of the ship characteristics. It

affects

Stability

Hold capacity

Hydro dynamic qualities such as resistance, maneuvering, sea keeping

Economic efficiency

Determining the main dimensions, proportions and form coefficient is one of

the most important phases of overall design.

Platform supply vessel are essentially moderate speed ship carrying dry

cargo. Demand for the dry bulks in offshore field has increased tremendously.

Hence the need for economic optimality in design, capacity etc is necessitated.

Symbols list


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DWT Dead weight

Displacement

LBP Length between perpendiculars

V Velocity

g Acceleration due to gravity

B Moulded breadth of the ship

D Moulded depth of the ship

T Draft of the ship

CB Block coefficient of the ship

Fn Froude number

7.2 Form coefficients

7.2.1Block coefficient (CB)

Block coefficient (CB) is the volume (V) divided by the LWL x B x T. If you

draw a box around the submerged part of the ship, it is the ratio of the box volume

occupied by the ship. It gives a sense of how much of the block defined by the

LWL, beam (B) & draft (T) is filled by the hull. Full forms such as oil tankers willhave a high CB where fine shapes such as sailboats will have a low CB.


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Fig: Block coefficient

7.2.2Midship Coefficient (CM)

Midship coefficient (CM orCX) is the cross-sectional area (Ax) of the slice

at Midship (or at the largest section for CX) divided by beam x draft. It displays the

ratio of the largest underwater section of the hull to a rectangle of the same overall

width and depth as the underwater section of the hull. This defines the fullness of

the underbody. A low CM indicates a cut-away mid-section and a high CM

indicates a boxy section shape. Sailboats have a cut-away mid-section with low CX

whereas cargo vessels have a boxy section with high CX to help increase the CB.

7.2.3Prismatic Coefficient (CP)

Prismatic coefficient (Cp) is the volume (V) divided by LBP x Ax. It displays

the ratio of the immersed volume of the hull to a volume of a prism with equallength to the ship and cross-sectional area equal to the largest underwater section

of the hull (midship section). This is used to evaluate the distribution of the volume

of the underbody. A low or fine Cp indicates a full mid-section and fine ends, a

high or full Cp indicates a boat with fuller ends. Planing hulls and other high-speed

hulls tend towards a higher Cp. Efficient displacement hulls travelling at a low

Froude number will tend to have a low Cp.


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Fig: Prismatic coefficient

7.2.4Coefficient of fineness of the waterplane area (CW)

Water plane coefficient (CW) is the waterplane area divided by LPP x B. The

waterplane coefficient expresses the fullness of the waterplane, or the ratio of the

waterplane area to a rectangle of the same length and width. A low C W figure

indicates fine ends and a high CW figure indicates fuller ends. High CW improves

stability as well as handling behavior in rough conditions.

Fig: Water plane coefficient


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7.3 Calculations

LOA = 21mtr

LBP = 19mtr

Breadth = 8 mtr

Depth upto deck = 3.8 mtr

Draft (Design) = 2.8mtr

LWT = 145 T

CB is in th range of 0.5 - 0.8 in case of harbor tug.

After correction CB value = 0.60

CB =

Under water volume = CB x L x B x T

= 0.60 x 19 x 8 x 2.8

= 255.36 m3

FN=


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(1 KNOT = 0.5144 m/s)

Assuming CW value = 0.84

CW =

Water Plane Area = 0.84 x 19 x 8

= 127.68m2

Assuming Cm=0.91

Cm =

Midship Area = 0.91 x 2.8 x 8

= 20.3844m3

CP=

=

Displacement = Dead weight + Light weight ship

Displacement = Under Water Volume x Density

=255.36 * 1.025 = 261.744T

Dead weight = Displacement - Light weight of the ship

= 261.744145

= 116.744T


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8.Sectional area curveA fundamental drawing in the design of a ship particularly relative to resistance

is the sectional area curve, for a ship with some parallel middle body. The sectional

area curve represents the longitudinal distribution of cross sectional area below the

DWL.

The ordinates of a sectional area curve are plotted in distance-squared units.

Inasmuch as the horizontal scale, or abscissa, represents longitudinal distances

along the ship, it is clear that the area under the curve represents the volume of

water displaced by the vessel up to the DWL, or volume of displacement.

Alternatively, the ordinate and abscissa of the curve may be made non-dimensional

by dividing by the midship area and length of ship, respectively. In either case, the

shape of the sectional area curve determines the relative "fullness" of the ship. The

sectional area curve and the half breadth are drawn keeping the underwater volume

and the form coefficients kept in mind.

Fig: Sectional area curve


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9.Lines planThe lines plan are drafted for each ship according to the unique feature of

the ship involved. Makin the lines plan is the first stage of the design spiral and is

one of the most important part of the entire design process since these line plansare provided to the operator and are constantly referred as part of the operation of

the ship.

The body plan is generate from the sectional area curve and the half breadth.

The lines are fared to avoid any kinks in the lines and also to make sure that the

lines are in perfect curves. The final underwater area and volume are calculate and

corrected to the previously corrected values.

9.1 Body Plan

Fig: Body plan

Planes parallel to the front and back of the imaginary box are called stations.There are three important stations. The intersection of the stem of the ship at the

design water line is called Forward Perpendicular (FP). The intersection of the

stern at design water line(immersed transom) or the rudder stock is called the Aft

Perpendicular (AP). The station midway between the perpendiculars is called the

midship stations.


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Each station plane will intersect the ship's hull and form a curved line at the

points of intersection. These lines are called sectional lines and are all projected

onto a single plane called the Body Plan.

The body plan takes advantage of the ship's symmetry. Hence only half thesection is show; the sections forward of amidships are drawn on the right side, and

the sections aft of the amidships are drawn on the left side. The amidships section

is generally shown on both sides of the body plan. The vertical line in the center

separating the left and right half of the ship is called the centerline.

9.2 Half-Breadth Plan

Fig: Half Breadth plan

The bottom of the box is a reference plane called the base plane. The base

plane is usually level with the keel. A series of planes parallel and above the base

plan are imagined at regular intervals, usually at every meter. Each plane will

intersect the ship's hull and form a line at the points of intersection. These lines are

called waterlines and are all projected onto a single plane called the Half-Breadth

Plan.


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Each waterline shows the true shape of the hull from the top view for some

elevation above the base plane. The water lines referred to here has nothing to do

with where the ship actually floats. There waterlines are the intersection of the

ship's hull with some imaginary plane above the base plane. Since ships are

symmetric about their centerline they only need be drawn for the starboard or port

side, thus the name Half-Breadth Plan.

9.3Profile Plan

Fig: Profile plan

A plane that runs from bow to stern directly through the center of the ship

and parallel to the sides of the imaginary box is called the centerline plane. A

series of planes parallel to one side of the centerline plane are imagined at regular

intervals from the centerline. Each plane will intersect the ship's hull and form acurved line at the points of intersection. These lines are called buttock or butt lines

and are projected onto a single plane called the Sheer Plan.


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Each buttock line shows the true shape of the hull from the side view for

some distance from the centerline of the ship. The centerline plane shows a special

butt line called the profile of the ship.

10.Bonjean Curves

The curves of cross sectional area for all body plan stations are collectively

called Bonjean Curves. One of the principal uses of Bonjean Curves is determining

volume of displacement of the ship at any level or trimmed waterline.

10.1 Bonjean calculations

Fig: Bonjean curve

In the Bonjean calculation the sectional area and moment of each station up

to each waterline is calculated. This enables the calculation of Displacement, LCB

and VCB for any waterline for even keel and also trimmed condition.

The uses of Bonjeans are:

1) Hydrostatic calculations.

2) For flooding calculations.

3) Launching calculations.

4) Longitudinal strength calculations.


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11.Hydrostatic Curves

It is customary in the design of a ship to calculate and plot as curves a

number of hydrostatic properties of the vessel's form at a series of drafts. Such

curves are useful in loading and stability studies during the design phase. Largescale plots of these curves for a newly built ship are then made for the assistance of

the vessel's operating personnel. Such curves are known as the vessel's curves

of form, or synonymously, hydrostatic curves.

11.1 Hydrostatic calculations

It is mandatory in the design of a ship to calculate and plot as curves a

number of hydrostatic properties of the vessels form at a series of drafts. Th rough

out its life a ship changes its weight, trim & freeboard. Its condition at any state of

circumstances can be found from hydrostatic curves. Hydrostatic particulars

corresponding to different waterlines are calculated.

List of formulae used.

1)Awp = 2/3 x h x f(A)

2) Mx = 2 x h2/3 x f(M)

3) LCF, x = h x f(M)

f(A)

4) IL = (2h3/3) x f(IL)

5) IT = (2 x h/9) x f(IT)

6) TPC = (Awp x 1.025)

100

7) BMT = IT/

8) BML = IL/

9) MCT = x GML


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100 x LWL

10) KM = BM + KB

11) CB =

LBP x B x T

12) CM = A/(B x T)

13) CW = AWP / (L x B)

14) CP = CB/CM

11.1.1 Longitudinal Centre of Buoyancy (LCB)

Longitudinal centre of buoyancy (LCB) is the longitudinal distance from a

point of reference (often midships) to the centre of the displaced volume of water

when the hull is not moving. Note that the longitudinal centre of gravity or centre

of the weight of the vessel must align with the LCB when the hull is in

equilibrium.


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Calculation table

WATERLINE 0.5 WATERLINE 1

STATION HALF AREA AREA SM f(V) LEVER f(M) STATION HALF AREA AREA SM f(V) LEVER f(M)

00 0

10

00

00 0

10

00

10 0

40

10

10 0

40

10

20 0

20

20

20 0

20

20

30 0

40

30

30 0

40

30

40 0

20

40

40 0

20

40

5

0 0

4

0

5

0

5

0.829 1.66

4

3.3

5

16.57

61 1.92

22

611.5

62.575 5.15

25.2

630.9

71 2.76

46

738.6

73.144 6.29

413

788.02

81 2.76

23

822.1

83.144 6.29

26.3

850.3

91 2.76

46

949.7

93.144 6.29

413

9113.2

101 2.76

23

1027.6

103.144 6.29

26.3

1062.87

11

1 2.76

4

6

11

60.7

11

3.144 6.29

4

13

11

138.3

121 2.76

23

1233.1

123.144 6.29

26.3

1275.45

131 1.87

44

1348.6

132.435 4.87

49.7

13126.6

140 0.96

21

1413.4

141.649 3.3

23.3

1446.18

150 0.68

41

1520.4

151.253 2.51

45

1575.18

160 0.44

20

167.02

160.888 1.78

21.8

1628.42

170 0.18

40

176.05

170.638 1.28

42.6

1743.4

180 0

10

180

180.013 0.03

10

180.234

34 339 87 895.7

LCB 10.08 LCB 10.2

VOLUME 11.09 VOLUME 28.9


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STATI

ON

HALF

AREA AREA SM

f(V

)

LEVE

R

f(M

)

STATI

ON

HALF

ARE

A AREA SM

f(V

)

LEVE

R f(M)

0 0 0 1 0 0 0 0 0 0 1 0 0 0

1 0 0 4 0 1 0 1 0 0 4 0 1 0

20 0

20

20

20.38 0.759

20.7

62

1.51

88

30 0

40

30

30.99

2 1.9844

3.9

73

11.9

04

40 0.94

20.

94

3.7

74

1.94 3.882

3.8

84

15.5

2

52 4.77

49.

55

47.

75

4.14 8.284

16.

65

82.8

6 4 8.76 2 8.8 6 52.5 6 6.27 12.54 2 12.5 6 75.24

75 10.1

420

7141

77.01 14.02

428

7196.

28

85 10.1

210

880.

68

7.01 14.022

148

112.

16

95 10.1

420

9181

97.01 14.02

428

9252.

36

105 10.1

210

10101

107.01 14.02

214

10140.

2

115 10.1

420

11222

117.01 14.02

428

11308.

44

12 5 10.1 2 10 12 121 12 7.01 14.02 2 14 12

168.

24

134 8.22

416

13214

135.89 11.78

423.

613

306.

28

143 6.26

26.

314

87.

614

4.77 9.542

9.5

414

133.

56

153 5.06

410

15152

154.03 8.06

416.

115

241.

8

162 3.88

23.

916

62.

116

3.26 6.522

6.5

216

104.

32

172 3.06

46.

117

10417

2.65 5.34

10.

617

180.

2

180 0.78

10.

418

7.0

618

1.01 2.021

1.0

118

18.1

815

3

157

7

23

1 2349

LCB 10.3 LCB

10.

2

VOLU

ME

50.5

5

VOLU

ME

76.

3


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WATERLINE 2.5 WATERLINE 2.8

STATI

ON

HALF

AREA AREA SM

f(V

)

LEV

ER

f(M

)

STATI

ON

HALF

AREA AREA SM

f(V

)

LEV

ER f(M)

00.704 1.4082

10.

70

00

1.449 2.8981

1.

40

0

11.142 2.2836

44.

61

4.5

71

2 44

81

8

21.75 3.5

23.

52

72

2.7 5.42

5.

42

10.8

32.538 5.076

410

330.

53

3.56 7.124

143

42.7

2

43.667 7.334

27.

34

29.

34

4.771 9.5422

9.

54

38.1

7

56.01 12.02

424

5120

57.16 14.32

429

5143.

2

6

8.22 16.44

2

16

698.

6

6

9.42 18.84

2

19

6

1137

9 184

367

2527

10.2 20.44

417

285.

6

89 18

218

8144

810.2 20.4

220

8163.

2

99 18

436

9324

910.2 20.4

441

9367.

2

10 9 18 2 18 10 180 10 10.2 20.4 2 20 10 204

119 18

436

11396

1110.2 20.4

441

11448.

8

129 18

218

12216

1210.2 20.4

220

12244.

8

13 7.75 15.5 4 31 13 403 13 8.89 17.78 4 36 13 462.3

146.533 13.066

213

14183

147.64 15.28

215

14213.

9

155.68 11.36

423

15341

156.74 13.48

427

15404.

4

164.75 9.5

29.

516

15216

5.7 11.42

1116

182.

4

173.885 7.7706

416

17264

174.65 9.3

419

17316.

2

181.728 3.456

11.

718

31.

118

2.17 4.341

2.

218

39.0

6

32

2

317

6

38

0

368

8

LCB

9.85

5 LCB

9.7

1

VOLU

ME

106.

4

VOLU

ME

12

5


28/62

28

WATERLINE 3 WATERLINE 3.5

STATI

ON

HALF

AREA AREA SM

f(V

)

LEV

ER

f(M

)

STATI

ON

HALF

AREA AREA SM

f(V

)

LEV

ER f(M)

01.984 3.968

12

00

03.39 6.78

13.

40

0

12.6 5.2

410

1 10.4

14.23 8.46

417

1 16.92

23.36 6.72

26.

72

13.

42

5.12 10.242

102

20.4

8

34.27 8.54

417

351.

23

6.1 12.24

243

73.2

45.52 11.04

211

444.

24

7.46 14.922

154

59.6

8

5 7.94 15.88 4 32 5 159 5 9.9 19.8 4 40 5 198

610.22 20.44

220

6123

612.22 24.44

224

6146.

6

7 11 22 4 44 7 308 7 13 26 4 52 7 364

8 11 22 2 22 8 176 8 13 26 2 26 8 208

9 11 22 4 44 9 396 9 13 26 4 52 9 468

10 11 22 2 22 10 220 10 13 26 2 26 10 260

11 11 22 4 44 11 484 11 13 26 4 52 11 572

12 11 22 2 22 12 264 12 13 26 2 26 12 312

139.66 19.32

439

13502

1311.64 23.28

447

13605.

3

148.39 16.78

217

14235

1410.34 20.68

221

14289.

5

157.47 14.94

430

15448

159.36 18.72

437

15561.

6

166.37 12.74

213

16204

168.09 16.18

216

16 258.9

175.18 10.36

421

17352

176.51 13.02

426

17442.

7

182.47 4.94

12.

518

44.

518

3.23 6.461

3.

218

58.1

4

41

9

403

5

51

8

491

5

LCB

9.63

7 LCB

9.4

9

VOLU

ME

138.

2

VOLU

ME

17

1


29/62

29

WATERLINE 3.8

STATION

HALF

AREA AREA SM f(V) LEVER f(M)

0 4.26 8.52 1 4.3 0 0

1 5.27 10.54 4 21 1 21.1

2 6.22 12.44 2 12 2 24.9

3 7.23 14.46 4 29 3 86.8

4 8.63 17.26 2 17 4 69

5 11.09 22.18 4 44 5 222

6 13.42 26.84 2 27 6 161

7 14.2 28.4 4 57 7 398

8 14.2 28.4 2 28 8 227

9 14.2 28.4 4 57 9 511

10 14.2 28.4 2 28 10 284

11 14.2 28.4 4 57 11 62512 14.2 28.4 2 28 12 341

13 12.83 25.66 4 51 13 667

14 11.53 23.06 2 23 14 323

15 10.53 21.06 4 42 15 632

16 9.17 18.34 2 18 16 293

17 7.31 14.62 4 29 17 497

18 3.69 7.38 1 3.7 18 66.4

579 5449

LCB 9.419

VOLUME 190.9

11.1.2.Vertical centre of buoyancy (VCB)

Is the geometric centre of the ships under water area at a particular draughtfrom the vertical section from keel and its position will change with draught. The

position of the VCB determines where is the buoyancy of that particular draft

remains in the hull.


30/62

30

Calculation table

WATERLINE 1 WATERLINE .5WATER

LINE

AR

EA SM

f(v

)

LEV

ER

F(

M)

WATER

LINE

AR

EA

S

M f(v)

LEV

ER

F(M

)

WL.5

58.

8 5

29

4 0.5 147 wl0 0 5 0 0 0

WL1

79.

86 8

63

9 1

638

.9 WL.5

58.

8 8

470

.4 0.5

235.

2

WL1.5

91.

15 -1

-

91

.2 1.5

-

137 WL1

79.

86 -1

-

79.

9 1

-

79.8

684

2

649

.2

390

.5

155.

34

VC

B

0.7

71

VC

B

0.3

98

WATERLINE 2 WATERLINE 1.5

WATER

LINE

AR

EA

S

M

f(v

)

LEV

ER

F(

M)

WATER

LINE

AR

EA

S

M f(v)

LEV

ER F(M)

WL.5

58.

8 1

58

.8 0.5

29.

4 WL.5

58.

8 1

58.

8 0.5 29.4

WL1

79.

86 3

24

0 1

239

.6 WL1

79.

86 4

319

.4 1

319.

44

WL1.5

91.

15 3

27

3 1.5

410

.2 WL1.5

91.

15 1

91.

15 1.5

136.

725

WL2107

.2 110

7 2214

.4469

.4485.565

67

9

893

.5

VC

B

1.

32

VC

B

1.0

34


31/62

31

WATERLINE 2.8 WATERLINE 2.5

WATERLI

NE

ARE

A

S

M f(v)

LEV

ER

F(M

)

WATERLI

NE

ARE

A

S

M f(v)

LEV

ER F(M)

WL.5

58.

8 1

58.

8 0.5

29.

4 WL.5 58.8 1

58.

8 0.5 29.4

WL1

79.

86 4 319 1

319

.4 WL1

79.8

6 4

319

.4 1

319.4

4

WL1.5

91.

15 2 182 1.5

273

.5 WL1.5

91.1

5 2

182

.3 1.5

273.4

5

WL2

107

.2 3 322 2

643

.1 WL2

107.

19 4

428

.8 2

857.5

2

WL2.5

122

.2 3 367 2.5

916

.3 WL2.5

122.

17 1

122

.2 2.5

305.4

25

WL2.8

125

.9 1 126 2.8

352

.6

111

1

1785.

24

1375

2534

VC

B

1.8

4

VC

B

1.6

06


WATERLI

NE

ARE

A SM f(v)

LEVE

R

F(M

)

WATERLI

NE AREA SM f(v)

LEVE

R F(M)

WL.5 58.8 1

58.

8 0.5 29.4 WL.5 58.8 1 58.8 0.5 29.4

WL1

79.8

6 4 319 1

319.

4 WL1 79.86 4

319.

4 1

319.4

4

WL1.5

91.1

5 2 182 1.5

273.

5 WL1.5 91.15 2

182.

3 1.5

273.4

5

WL2

107.

2 4 429 2

857.

5 WL2

107.1

9 4

428.

8 2

857.5

2

WL2.5

122.

2 2 244 2.5

610.

9 WL2.5

122.1

7 2

244.

3 2.5

610.8

5

WL2.8

125.

9 3 378 2.8

105

8 WL2.8

125.9

4 4

503.

8 2.8

1410.

53

WL3.

128.

1 3 384 3

115

3 WL3.

128.1

1 1

128.

1 3

384.3

3

WL3.5

132.

4 1 132 3.5

463.

5

186

6

3885.

52

212

8

476

5

VC

B

2.2

4

VC

B

2.08

3


32/62

32

WATERLINE 3.8

WATERLINE AREA SM f(v) LEVER F(M)

WL.5 58.8 1 58.8 0.5 29.4WL1 79.86 4 319 1 319.4

WL1.5 91.15 2 182 1.5 273.5

WL2 107.2 4 429 2 857.5

WL2.5 122.2 2 244 2.5 610.9

WL2.8 125.9 4 504 2.8 1411

WL3. 128.1 2 256 3 768.7

WL3.5 132.4 4 530 3.5 1854

WL3.8 133.6 1 134 3.8 507.6

2657 6631

VCB 2.5

11.1.3Longitudinal centre of floatation (LCF)

Longitudinal centre of flotation (LCF) is the geometric centre of the ships

water-plane area at a particular draught and its position will change with draught.

The position of the LCF determines how the change of trim will be apportioned

between the forward and aft draughts.


33/62

33

Calculation table

WATERPLANE 0.5 WATERPLANE 1

STAT

ION

halfBREA

DTH

fullbrea

dth

SMf(A

)

LEV

ER

f(

M)

STAT

ION

halfBREA

DTH

fullbrea

dth

SMf(A

)

LEV

ER

f(

M)

0 0 0 1 0 0 0 0 0 0 1 0 0 0

1 0 0 4 0 1 0 1 0 0 4 0 1 0

2 0 0 2 0 2 0 2 0 0 2 0 2 0

3 0 0 4 0 3 0 3 0 0 4 0 3 0

4 0 0 2 0 4 0 4 0 0 2 0 4 0

50 0

40

50

52.8 5.6

422.

45

112

62.91 5.82

211.64

669.

86

3.46 6.922

13.84

683

7 3.3 6.6 4 26.4 7 185 7 3.65 7.3 4 29.2 7 204

83.3 6.6

213.

28

106

83.65 7.3

214.

68

117

93.3 6.6

426.

49

238

93.65 7.3

429.

29

263

103.3 6.6

213.

210

132

103.65 7.3

214.

610

146

113.3 6.6

426.

411

290

113.65 7.3

429.

211

321

123.3 6.6

213.

212

158

123.65 7.3

214.

612

175

132.69 5.38

4 21.52

13 280

133.22 6.44

4 25.76

13 335

141.8 3.6

27.2

14101

142.73 5.46

210.92

14153

151.3 2.6

410.

415

156

152.27 4.54

418.16

15272

160.9 1.8

23.6

1657.

616

1.75 3.52

716

112

170.63 1.26

45.0

417

85.7

171.5 3

412

17204

180 0

10

180

180.27 0.54

10.5

418

9.72

178.2

1858

242

2507

LCF10.43 LCF

10.36

AREA

58.81

AREA

79.9


34/62

34

WATERPLANE 1.5 WATERPLANE 2

STATI

ON

half

BREADT

H

full

bread

th

SMf(A

)

LEV

ER

f(M

)

STATI

ON

half

BREADT

H

full

bread

th

SMf(A

)

LEV

ERf(M)

0 0 0 1 0 0 0 0 0 0 1 0 0 0

1 0 0 4 0 1 0 1 0 0 4 0 1 0

20 0

20

20

22.37 4.74

29.4

82

18.9

6

30 0

40

30

32.79 5.58

422.

33

66.9

6

42.49 4.98

29.9

64

39.

844

3.25 6.52

134

52

53.35 6.7

426.

85

1345

3.64 7.284

29.

15

145.

6

63.71 7.42

214.

86

89.

046

3.75 7.52

156

90

7

3.71 7.42

429.

7

7207

.8

7

3.75 7.5

4

30

7

210

83.71 7.42

214.

88

118

.78

3.75 7.52

158

120

93.71 7.42

429.

79

267

.19

3.75 7.54

309

270

103.71 7.42

214.

810

148

.410

3.75 7.52

1510

150

113.71 7.42

429.

711

326

.511

3.75 7.54

3011

330

123.71 7.42

214.

812

178

.112

3.75 7.52

1512

180

133.47 6.94

427.

813

360

.913

3.64 7.284

29.

113

378.

56

143.14 6.28

212.

614

175

.814

3.41 6.822

13.

614

190.

96

152.81 5.62

422.

515

337

.215

3.15 6.34

25.

215

378

162.42 4.84

29.6

816

154

.916

2.82 5.642

11.

316

180.

48

172.05 4.1

416.

417

278

.817

2.37 4.744

1917

322.

32

181.09 2.18

12.1

818

39.

2418

1.36 2.721

2.7

218

48.9

6

27

6

285

6

32

5

3132

.8

LCF

10.

3 LCF

9.6

44

ARE

A

91.

2 AREA

107

.2


35/62

35

WATERPLANE 2.5 WATERPLANE 2.8

STATI

ON

half

BREA

DTH

full

bread

th

S

M

f(

A)

LEV

ER

f(M

)

STATI

ON

half

BREA

DTH

full

bread

th

SMf(

A)

LEV

ERf(M)

02.33 4.66

14.

660

00

2.33 4.661

4.

660

0

12.72 5.44

421

.81

21.

761

2.98 5.964

23

.81

23.8

4

23.03 6.06

212

.12

24.

242

3.26 6.522

132

26.0

8

33.32 6.64

426

.63

79.

683

3.5 74

283

84

43.6 7.2

214

.44

57.

64

3.74 7.482

154

59.8

4

53.81 7.62

430

.55

152

.45

3.87 7.744

315

154.

8

63.81 7.62

2 15.2

6 91.44

63.87 7.74

2 15.5

6 92.88

73.81 7.62

430

.57

213

.47

3.87 7.744

317

216.

72

83.81 7.62

215

.28

121

.98

3.87 7.742

15

.58

123.

84

93.81 7.62

430

.59

274

.39

3.87 7.744

319

278.

64

103.81 7.62

215

.210

152

.410

3.87 7.742

15

.510

154.

8

113.81 7.62

430

.511

335

.311

3.87 7.744

3111

340.

56

12

3.81 7.62

215

.2

12182

.9

12

3.87 7.74

215

.5

12185.

7613

3.77 7.544

30

.213

392

.113

3.85 7.74

30

.813

400.

4

143.63 7.26

214

.514

203

.314

3.75 7.52

1514

210

153.44 6.88

427

.515

412

.815

3.6 7.24

28

.815

432

163.1 6.2

212

.416

198

.416

3.25 6.52

1316

208

172.54 5.08

420

.317

345

.417

2.6 5.24

20

.817

353.

6

181.46 2.92

12.

9218

52.

5618

1.5 31

318

54

370

3312

382

3399.8

LCF

8.

95 LCF

8.9

08

ARE

A

12

2

ARE

A

125

.9


36/62

36

WATERPLANE 3 WATERPLANE 3.5

STATI

ON

half

BREADTH

full

breadt

h

SMf(A

)

LEVE

Rf(M)

STATI

ON

half

BREADTH

full

breadt

h

SMf(A

)

LEVE

Rf(M)

02.72 5.44

15.4

40

00

2.88 5.761

5.7

60

0

13.1 6.2

4 24.8

124.8

13.38 6.76

427

1 27.04

23.39 6.78

213.

62

27.1

22

3.62 7.242

14.

52

28.9

6

33.58 7.16

428.

63

85.9

23

3.72 7.444

29.

83

89.2

8

43.81 7.62

215.

24

60.9

64

3.89 7.782

15.

64

62.2

4

53.9 7.8

431.

25

1565

3.94 7.884

31.

55

157.

6

63.9 7.8

215.

66

93.66

4 82

166

96

73.9 7.8

431.

27

218.

47

4 84

327

224

83.9 7.8

215.

68

124.

88

4 82

168

128

93.9 7.8

431.

29

280.

89

4 84

329

288

103.9 7.8

215.

610

15610

4 82

1610

160

113.9 7.8

431.

211

343.

211

4 84

3211

352

123.9 7.8

215.

612

187.

212

4 82

1612

192

133.89 7.78

431.

113

404.

613

3.97 7.944

31.

813

412.

88

143.82 7.64

215.

314

213.

914

3.94 7.882

15.

814

220.

64

153.69 7.38

429.

515

442.

815

3.87 7.744

3115

464.

4

163.34 6.68

213.

416

213.

816

3.55 7.12

14.

216

227.

2

172.63 5.26

421

17357.

717

2.68 5.364

21.

417

364.

48

181.51 3.02

13.0

218

54.3

618

1.53 3.061

3.0

618

55.0

8

38

8

344

6

40

1

3549

.8

LCF

8.8

8 LCF

8.84

6

AREA

12

8 AREA 132.4


37/62

37

WATERPLANE 3.8

STATIONhalf

BREADTH

full

breadthSM f(A) LEVER f(M)

0 2.91 5.82 1 5.82 0 0

1 3.52 7.04 4 28.16 1 28.162 3.72 7.44 2 14.88 2 29.76

3 3.8 7.6 4 30.4 3 91.2

4 3.91 7.82 2 15.64 4 62.56

5 3.96 7.92 4 31.68 5 158.4

6 4 8 2 16 6 96

7 4 8 4 32 7 224

8 4 8 2 16 8 128

9 4 8 4 32 9 288

10 4 8 2 16 10 160

11 4 8 4 32 11 352

12 4 8 2 16 12 192

13 3.98 7.96 4 31.84 13 413.9

14 3.96 7.92 2 15.84 14 221.8

15 3.93 7.86 4 31.44 15 471.6

16 3.64 7.28 2 14.56 16 233

17 2.68 5.36 4 21.44 17 364.5

18 1.54 3.08 1 3.08 18 55.44404.78 3570

LCF 8.8202

AREA 133.58


38/62

38

11.1.4.Tones per centimeter immersion (TPCi)

It is the amount of load in tones required to change of draft in 1 cm. Sincecompared to ships size 1cm is approximately equal to the water plane at particular

draft.TPCi = ( area of waterplane x 1cm) x density of sea water.

11.1.5.Moment to change trim by one centimeter (MCTi)

The MCT 1 cm is the moment required to change the trim of the vessel by 1

cm and may be calculated by using the formula:

MCT 1 cm = W x GML/100L

Where, W = The vessels displacement in tonnes

GML = The longitudinal metacentric height in metersL = Vessels length (LBP) in meters.

11.1.6.Metacentric height in transverse & longitudinal sections (BMT &BML)

The metacentric height (GM) is a measurement of the initial static stability

of a floating body. It is calculated as the distance between the centre of gravity of a

ship and its metacentre. A larger metacentric height implies greater initial stability

against overturning.


39/62

39

The metacentre is considered to be fixed for small angles of heel; however,

at larger angles of heel the metacentre can no longer be considered fixed and other

means must be found to calculate the ship's stability. The metacentre can be

calculated using the formulae:

KM = KB + BM

BM = I/V

KB orVCB- The centre of buoyancy (height above the keel)

I - The Second moment of area of the waterplane in m4

V - The volume of displacement in m3.

KM - The distance from the keel to the metacentre.

23

All of these calculation helps to draw the hydrostatic curves


40/62

40

Fig: Hydrostatic curve


41/62

41

Hydrostatic parameters for different water level is shown in tabular form.

WATERPLANE 0.5

STATIONhalf

BREADTH

full


0 0 0 1 0 0 0

1 0 0 4 0 1 0

2 0 0 2 0 2 0

3 0 0 4 0 3 0

4 0 0 2 0 4 05 0 0 4 0 5 0

6 2.91 5.82 2 11.64 6 69.84

7 3.3 6.6 4 26.4 7 184.8

8 3.3 6.6 2 13.2 8 105.6

9 3.3 6.6 4 26.4 9 237.6

10 3.3 6.6 2 13.2 10 132

11 3.3 6.6 4 26.4 11 290.4

12 3.3 6.6 2 13.2 12 158.4

13 2.69 5.38 4 21.52 13 279.76

14 1.8 3.6 2 7.2 14 100.8

15 1.3 2.6 4 10.4 15 156

16 0.9 1.8 2 3.6 16 57.6

17 0.63 1.26 4 5.04 17 85.68

18 0 0 1 0 18 0

178.2 1858.5LCF 10.429

AREA 58.806


42/62

42

WATERPLANE 1

STATIONhalf

BREADTH

full


0 0 0 1 0 0 0

1 0 0 4 0 1 0

2 0 0 2 0 2 0

3 0 0 4 0 3 0

4 0 0 2 0 4 0

5 2.8 5.6 4 22.4 5 112

6 3.46 6.92 2 13.84 6 83.04

7 3.65 7.3 4 29.2 7 204.4

8 3.65 7.3 2 14.6 8 116.8

9 3.65 7.3 4 29.2 9 262.8

10 3.65 7.3 2 14.6 10 146

11 3.65 7.3 4 29.2 11 321.2

12 3.65 7.3 2 14.6 12 175.2

13 3.22 6.44 4 25.76 13 334.88

14 2.73 5.46 2 10.92 14 152.88

15 2.27 4.54 4 18.16 15 272.4

16 1.75 3.5 2 7 16 112

17 1.5 3 4 12 17 204

180.27 0.54

10.54

189.72

242 2507.3

LCF 10.36

AREA 79.87


43/62

43

WATERPLANE 1.5

STATIONhalf

BREADTH

full


0 0 0 1 0 0 0

1 0 0 4 0 1 0

2 0 0 2 0 2 0

3 0 0 4 0 3 0

4 2.49 4.98 2 9.96 4 39.84

5 3.35 6.7 4 26.8 5 134

6 3.71 7.42 2 14.84 6 89.04

7 3.71 7.42 4 29.68 7 207.76

8 3.71 7.42 2 14.84 8 118.72

9 3.71 7.42 4 29.68 9 267.12

10 3.71 7.42 2 14.84 10 148.4

11 3.71 7.42 4 29.68 11 326.48

12 3.71 7.42 2 14.84 12 178.0813 3.47 6.94 4 27.76 13 360.88

14 3.14 6.28 2 12.56 14 175.84

15 2.81 5.62 4 22.48 15 337.2

16 2.42 4.84 2 9.68 16 154.88

17 2.05 4.1 4 16.4 17 278.8

18 1.09 2.18 1 2.18 18 39.24

276.22 2856.28

LCF 10.3406

AREA 91.1526


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WATERPLANE 2

STATIONhalf

BREADTH

full


0 0 0 1 0 0 0

1 0 0 4 0 1 0

2 2.37 4.74 2 9.48 2 18.96

3 2.79 5.58 4 22.32 3 66.96

4 3.25 6.5 2 13 4 52

5 3.64 7.28 4 29.12 5 145.6

6 3.75 7.5 2 15 6 90

7 3.75 7.5 4 30 7 210

8 3.75 7.5 2 15 8 120

9 3.75 7.5 4 30 9 270

10 3.75 7.5 2 15 10 150

11 3.75 7.5 4 30 11 330

12 3.75 7.5 2 15 12 180

13 3.64 7.28 4 29.12 13 378.56

14 3.41 6.82 2 13.64 14 190.96

15 3.15 6.3 4 25.2 15 378

16 2.82 5.64 2 11.28 16 180.48

172.37 4.74

418.96

17322.32

18 1.36 2.72 1 2.72 18 48.96

324.8 3132.8

LCF 9.6441

AREA 107.2


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WATERPLANE 2.5

STATIONhalf

BREADTH

full


0 2.33 4.66 1 4.66 0 0

1 2.72 5.44 4 21.76 1 21.76

2 3.03 6.06 2 12.12 2 24.24

3 3.32 6.64 4 26.56 3 79.68

4 3.6 7.2 2 14.4 4 57.6

5 3.81 7.62 4 30.48 5 152.4

6 3.81 7.62 2 15.24 6 91.44

7 3.81 7.62 4 30.48 7 213.36

8 3.81 7.62 2 15.24 8 121.92

9 3.81 7.62 4 30.48 9 274.32

10 3.81 7.62 2 15.24 10 152.4

11 3.81 7.62 4 30.48 11 335.28

12 3.81 7.62 2 15.24 12 182.8813 3.77 7.54 4 30.16 13 392.08

14 3.63 7.26 2 14.52 14 203.28

15 3.44 6.88 4 27.52 15 412.8

16 3.1 6.2 2 12.4 16 198.4

17 2.54 5.08 4 20.32 17 345.44

18 1.46 2.92 1 2.92 18 52.56

370.22 3311.84

LCF 8.9456

AREA 122.1726


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46

WATERPLANE 2.8

STATION

half

BREADTH

full

breadth SM f(A) LEVER f(M)

0 2.33 4.66 1 4.66 0 0

1 2.98 5.96 4 23.84 1 23.84

2 3.26 6.52 2 13.04 2 26.08

3 3.5 7 4 28 3 84

4 3.74 7.48 2 14.96 4 59.84

5 3.87 7.74 4 30.96 5 154.8

6 3.87 7.74 2 15.48 6 92.88

7 3.87 7.74 4 30.96 7 216.72

8 3.87 7.74 2 15.48 8 123.84

9 3.87 7.74 4 30.96 9 278.64

10 3.87 7.74 2 15.48 10 154.8

11 3.87 7.74 4 30.96 11 340.56

12 3.87 7.74 2 15.48 12 185.76

13 3.85 7.7 4 30.8 13 400.4

14 3.75 7.5 2 15 14 210

15 3.6 7.2 4 28.8 15 432

16 3.25 6.5 2 13 16 208

17 2.6 5.2 4 20.8 17 353.6

18 1.5 3 1 3 18 54

381.66 3399.76

LCF 8.907824

AREA 125.9478


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47

WATERPLANE 3

STATION

half

BREADTH

full

breadth SM f(A) LEVER f(M)

0 2.72 5.44 1 5.44 0 0

1 3.1 6.2 4 24.8 1 24.8

2 3.39 6.78 2 13.56 2 27.12

3 3.58 7.16 4 28.64 3 85.92

4 3.81 7.62 2 15.24 4 60.96

5 3.9 7.8 4 31.2 5 156

6 3.9 7.8 2 15.6 6 93.67 3.9 7.8 4 31.2 7 218.4

8 3.9 7.8 2 15.6 8 124.8

9 3.9 7.8 4 31.2 9 280.8

10 3.9 7.8 2 15.6 10 156

11 3.9 7.8 4 31.2 11 343.2

12 3.9 7.8 2 15.6 12 187.2

13 3.89 7.78 4 31.12 13 404.56

14 3.82 7.64 2 15.28 14 213.9215 3.69 7.38 4 29.52 15 442.8

16 3.34 6.68 2 13.36 16 213.76

17 2.63 5.26 4 21.04 17 357.68

18 1.51 3.02 1 3.02 18 54.36

388.22 3445.88

LCF 8.876101

AREA 128.1126


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48

WATERPLANE 3.5

STATIONhalf

BREADTH

full


0 2.88 5.76 1 5.76 0 01 3.38 6.76 4 27.04 1 27.04

2 3.62 7.24 2 14.48 2 28.96

3 3.72 7.44 4 29.76 3 89.28

4 3.89 7.78 2 15.56 4 62.24

5 3.94 7.88 4 31.52 5 157.6

6 4 8 2 16 6 96

74 8

432

72248 4 8 2 16 8 128

9 4 8 4 32 9 288

10 4 8 2 16 10 160

11 4 8 4 32 11 352

12 4 8 2 16 12 192

13 3.97 7.94 4 31.76 13 412.88

14 3.94 7.88 2 15.76 14 220.64

15 3.87 7.74 4 30.96 15 464.4

16 3.55 7.1 2 14.2 16 227.2

17 2.68 5.36 4 21.44 17 364.48

18 1.53 3.06 1 3.06 18 55.08

401.3 3549.8

LCF 8.846

AREA 132.43


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49

WATERPLANE 3.8

STATIONhalf

BREADTH

full


0 2.91 5.82 1 5.82 0 01 3.52 7.04 4 28.16 1 28.16

2 3.72 7.44 2 14.88 2 29.76

3 3.8 7.6 4 30.4 3 91.2

4 3.91 7.82 2 15.64 4 62.56

5 3.96 7.92 4 31.68 5 158.4

6 4 8 2 16 6 96

7 4 8 4 32 7 224

8 4 8 2 16 8 1289 4 8 4 32 9 288

10 4 8 2 16 10 160

11 4 8 4 32 11 352

12 4 8 2 16 12 192

13 3.98 7.96 4 31.84 13 413.92

14 3.96 7.92 2 15.84 14 221.76

15 3.93 7.86 4 31.44 15 471.6

16 3.64 7.28 2 14.56 16 232.96

17 2.68 5.36 4 21.44 17 364.48

18 1.54 3.08 1 3.08 18 55.44

404.78 3570.24

LCF 8.820199

AREA 133.5774


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12.3 Sketches

A typical general arrangement of the vessel is given below. The drawings are not

the scale.


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Accommodation Ladder

Two accommodation ladders, one on each side, are provided on the upper deck as

ahown in the G.A plan. They are of the vertical self-stowing type.

Material Al alloy

Width Approx. 800 mm

Windows

The sizes of windows fitted are:

Square windows : Approx. 400 x 600 mm in accommodation roomsApprox. 600 x 700 mm in public rooms

Material : Aluminium alloy.

12.5 Accommodation

The requirements should includes

1. Crew accommodation fwd.

2. All bulkheads should be of steel. If in contact with weather they have to be

gas tight and watertight. Means for closing the opening to be provided.

3. Bulkheads connecting crew space with store, cargo spaced tanks etc should

be watertight, gas tight.

4. Bulkheads connecting two galleys, sanitary space, laundry etc should be

gastight and watertight up to a certain height.

5. Floors to be properly covered.

6. Protection:

a) Protection of crew against injury.

b) Protection of crew against weather.

c) Insulation from heat and cold.


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d) Protection from moisture.

e) Protection from effluent originating in various compartments.

f) Protection from noise.

7.No direct opening between accommodation and stores.

8. Side scuttles can be opened in sleeping rooms, mess rooms, smoking rooms

and recreation rooms.

9. Separate sleeping rooms for officers, chief engineers etc.

10.Mess room should be able to accommodate all officers at the same time.

11.Recreation room should accommodate 1/3rd

of the officers.

12.Recreation are on the open deck.

officers : 2member

crew : 6member

Total : 8 member

GALLEY

1. 1 single bowl stainless steel sink with

2. 1 stainless steel 2 doors refrigerator

3. 1 air ventilator diameter 8

4. 3 spare power point.

5. loose galley equipment such as pot, pan cutlery, for 8 crews.

12.6 PAINTING AND CATHODIC PROTECTION

PAINTING GENERALAll steel plate are to be shot blasted Sa 2.5 and primed with one coat epoxy primer

before fabrication (about 20 microns dry film thickness) or Care must be taken toensure the surfaces are free of all kinds of contamination.


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PAINTING SCHEMES

Following specifications based on Hempel Coating System are for guidance. Other

specifications of equal standard would be acceptable.

Keel to Waterline Dry Film Thickness

1 coat Epoxy 15039 30mic 1 coats Epoxy 45889 50mic

2 coats Antifouling 80900 125mic

Waterline to Deck

1 coat Epoxy 15309 30mic

2 coats Epoxy 15139 150mic

Main Deck

1 coat Epoxy 15309 30mic

2 coats Epoxy 45889 100mic

F.W. Tanks


Bilge, Void Spaces, Chain Locker & SWB Tanks


F.O. Tank

1 coat Red Oxide 25mic

Exterior/ Interior of Superstructure, crew Accommodation, Engine Room & Stores& Steering Gear.

1 coat 15309 30mic

1 coat Enamel White 52140 60mic


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CATHODIC PROTECTION

Zinc anodes are to be bolted the immersed loaded hull rudders and inside of the seachest, total of 8kg x 20pcs zinc anode or equal

12.7 PIPEWORK COLOURING

All exposed piping system are to be identified with color bands in accordance with

the following schemes:1) Bilge & ballast : black

2) Fire main : bright red

3) F.W. System Cold : blue

4) Fuel Oil : brown5) Lub Oil : yellow

6) Hydraulic Oil : purple7) Sea Suctions : green

8) Seawater cooling : light green

12.8 LIFE SAVING AND FIRE FIGHTING EQUIPMENT

LIFE SAVING EQUIPMENTTo be accordance with Requirement of Singapore Marine Department for as per

safety plan Tug Boat with a total complement of eight men.Life Raft = 2 x 8men inflatable life raft

Life Buoys = Eight (8) life buoy

Life Jacket = Fourteen (8) life jackets complete with light and whistle

FIRE FIGHTING EQUIPMENTFire Main = Three (3) x 1 fire hydrant with coupling and nozzles

Fire Man Outfit = One (1) complete set .

Fire Extinguisher = 8 x 9kgs dry chemical and 1 x 40 Ltr. Wheeled Form Or

as per Safety plan

Portable emergency Diesel Pump = One(1) unit 1

ELECTRICALElectrical fittings use to be of good quality wiring system are comply withclassification societys requirements.


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AC SupplyFrom 2 x 28 kw diesel driven generator set. 415/ 4/ 50 running in single.

DC SupplyFrom batteries, 2x 150 N and 2X150 N as per classification requirement.

12.9 Navigation lights

Navigation lights provided as per SOLAS requirements

1) Masthead light one on forward mast and one on navigational mast.

2) Side lights Red light on port side and green light on starboard.

Fitted on the sides of navigation bridge.3) Anchor lights All round white light at forward mast.

4) Stern light White light at extreme aft.

5) Towing light Yellow light at forward mast.

The tug shall be fitted with the following equipment which must be maintained in

good working order: -

1. Compass2. Facility to take compass bearings

3. RADAR with plotting facility

4. Echo sounder

5. Rudder Angle, RPM, variable pitch and bow thrust indicators (if fitted)

6. Marine VHF radiotelephone installation

7. Electronic Position Fixing Receiver

8. Mobile telephone


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13 Detailed Capacity Calculations and Drawings

13.1 Introduction

The cargo hold capacity is estimated for checking to carry out capacity of

the vessel. Aside from their relationship to ship operating revenue, capacity

calculations include locating center of gravity of all spaces containing significant

dead weight items. The weights and center of gravities of these items are

indispensable to stability and trim studies.

Table shows tank capacity & centre of gravity.

TANK NAME LOCATION (between stations) VOLUME LCG VCG

BWT(PORT)1 0-2 3.25 0.984 2.47

BWT(STARBOARD)2 0-2 3.25 0.984 2.47

FOT(PORT)1 2--5 9.59 3.44 2.3

FOT(STARBD)2 2--5 9.59 3.44 2.3

DT(PORT)1 5--6 0.99 5.41 2.34

LUBE OIL TANK 5--6 0.99 5.41 2.34

FOT(PORT)3 12--16 16.4 13.78 0.74

FOT(STARBD)4 12--16 16.4 13.78 0.74

FWT(PORT,WINGS)1 16--17 6.33 16.2 1.476

FWT(STARBD,WINGS)2 16--17 6.33 16.2 1.476

FPT(PORT)1 17--19 4.44 17.45 1.32

FPT(STARBD)2 17--19 4.44 17.45 1.32

SWT(PORT) 7--9 4.12 7.87 0.35

BWT(PORT)3 5--7 5.45 5.9 1.28

BWT(STARBOARD)4 5--7 5.45 5.9 1.28

BWT(PORT)5 6--7 1.27 6.39 0.39

BWT(STARBOARD)6 6--7 1.27 6.39 0.39

BWT(PORT)7 4--5 2.06 4.42 1.57

BWT(STARBOARD)8 4--5 2.06 4.42 1.57

HYROLIC OIL TANK 5--6 0.37 5.71 0.48

BWT(STARBOARD)9 7--9 4.12 7.87 0.35


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The capacities of tanks/compartments are determined using computer softwares

like Autocad/MS excel. Table indicates the moulded capacities of respective

tanks/compartments along with their location and centre of gravity.

13.2 Loading conditions

Procedure

The LCG of the lightship mass is known. The mass and center of gravity of

cargo, stores and ballast water are to be determined. Therefore, displacement at any

loading condition is the sum of the corresponding weight components. Since the

displacement at each condition is known.

The range of loading conditions which a ship might experience varies with

its type and the service in which it is engaged.

1) Fully loaded departure condition with 90% component

Loaded departure

Sr No component weight(T)

Light weight 145

Total fresh water (90%) 9.234

Total ballast water (90%) 34.218

Total Fuel oil tank (90%) 38.9376

Total sewage 0Human weight 1.02

Food(10days) 1.5

LUBE OIL TANK (90%) 0.784971

Dirty oil tank 0

TOTAL WEIGHT 230.6946


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2) Arrival condition with 10% component

Loaded arrival


1 Light weight 145

2 Total fresh water (10%) 1.026

3 Total ballast water (90%) 34.218

4 Total Fuel oil tank (10%) 4.3264

5 Total sewage (90%) 3.888

6 Human weight 1.02

7 Food(10days) 0

8 LUBE OIL TANK (10%) 0.087219

9 Dirty oil tank (50%) 0.41184


3) Ballast departure condition with 90% component

Ballast departuresr No component weight(T)

1 Light weight 145




5 Total sewage 0

6 Human weight 1.02

7 Food(10days) 1.5

8 LUBE OIL TANK (90%) 0.7849

9 Dirty oil tank 0



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4) Ballast arrival condition with 10% component

Ballast arrival

sr No component weight(T)

1 Light weight 145




5 Total sewage ( 90%) 3.888

6 Human weight 1.02

7 Food(10days) 0

8 LUBE OIL TANK (10%) 0.087

9 Dirty oil tank (50%) 0.41184


5) Ballast arrival condition with 10% component

Light ship


1 Light weight 145

2 Total fresh water 0

3 Total ballast water 0

4 Total Fuel oil tank 0

5 Total sewage 06 human weight 0

7 food(10days) 0

8 Lube oil tank 0

9 Dirty oil tank 0

TOTAL WEIGHT 145


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14. Conclusion

One of the principal uses of Bonjean Curves is determining volume of

displacement of the tug at any level or trimmed waterline.

Hydrostatic curves are useful in loading and stability studies during the

design phase.

While we making the hydrostatic curve of Harbor, Ocean Towing Tug , we

also study the tug structure, stability, shape, uses of bonjean curve, etc.

Loading condition of Harbor tug provides a ship's stability, and hence may

vary considerably during the course of a voyage, or from one voyage to the

next.

Documents

naval architect Project Report