This document contains calculations for the midship section modulus and moment of inertia of a ship. It provides the dimensions, areas, section moduli, and moments of inertia for various structural elements both above and below the assumed neutral axis. The total section modulus at the keel is 4639.59 cm^3 and at the main deck is 9279.19 cm^3. The actual neutral axis is located 17.22 cm above the assumed axis.

1. 59 m = 5942 cm
11 m = 1100 cm
5 m = 500 cm
2.5 m = 250 cm
Above Assumed Axis
Area (cm
2
) Lever (cm) AY AY
2
Ah
2
/12
A Y cm3
cm4
cm4
Expansion Trunk deck plate 8 mm 319.82 349.38 111738.71 39039271.06
Hatch Coaming Plate 12 mm 103.20 304.38 31412.02 9561189.43 796765.79
Deck Stringer plate 10 mm 153.29 104.79 16062.79 1683204.50
Shearstrake Plate 10 mm 61.00 225.50 13755.50 3101865.25
Side Shell Plate 8.5 mm 165.75 97.50 16160.87 1575684.70 131307.06
Inner Shell plate 9 mm 230.59 128.10 29537.94 3783809.92
Center line BHD Plate 8 mm 141.19 176.50 24919.94 4398352.78
Side Stringer Plate 8 712.00 90.40 64364.80 5818577.92
Deck longitudinal 1 HP 180 X 8 18.84 341.60 6437.32 2198986.93
Deck longitudinal 2 HP 180 X 8 18.84 340.54 6417.28 2185322.49
Deck Girder T 250 X 100 X 10 34.00 334.13 11360.56 3795948.02
Deck longitudinal 3 HP 180 X 8 18.84 336.73 6345.50 2136709.03
Deck longitudinal 4 HP 180 X 8 18.84 333.98 6293.68 2101951.27
Deck stringer longitudinal HP 160 X 7 14.59 243.60 3553.88 865725.27
Outer Shell longitudinal 1 HP 160 X 7 14.59 219.35 3200.10 701941.31
Outer Shell longitudinal 2 HP 160 X 7 14.59 154.35 2251.86 347580.72
Outer Shell longitudinal 3 HP 160 X 7 14.59 24.30 354.51 8614.66
Inner Shell longitudinal 1 HP 160 X 7 14.59 219.35 3200.10 701941.31
inner Shell longitudinal 2 HP 160 X 7 14.59 154.35 2251.86 347580.72
nner Shell longitudinal 3 HP 160 X 7 14.59 24.30 354.51 8614.66
Center Line BHD plate Long. 1 HP 180 x 8 18.85 281.70 5308.92 1495507.34
Center Line BHD plate Long. 2 HP 180 x 8 18.85 219.26 4132.17 906008.76
Center Line BHD plate Long. 3 HP 180 x 8 18.85 154.26 2907.17 448451.96
Scantling (mm)
Rule Length of Ship, L =
Breadth of Ship, B =
Depth of Ship, D =
Assumed Neutral Axis height from Keel
Item
MidShip Section Modulus Calculation

2. Center Line BHD plate Long. 3 HP 180 x 8 18.85 24.25 457.06 11084.57
Center Line BHD Horizontal Stiffener T 350 X 150 X 10 44.00 90.50 3982.00 360371.00
2217.72 376761.04 87584295.55 928072.84
Below Assumed Axis
Area (cm2
) Lever (cm) AY AY2
Ah2
/12
A Y cm3
cm4
cm4
Center line BHD Plate(8mm) 8 mm 3.20 4.00 12.80 51.20
Center line BHD Plate(9mm) 9 mm 109.34 129.50 14159.53 1833659.14
Keel Plate 10 mm 59.97 249.40 14956.52 3730155.59 310846.30
Bilge plate 8.5 mm 18.35 192.37 3529.59 678974.04 28290.59
Bottom plate 8.5 mm 306.22 241.70 74012.76 17888736.44
Side plate 8.5 mm 89.25 52.50 4685.63 245995.31
Inner shell plate 9 mm 937.80 52.10 48859.38 2545573.70
Slope plate 9 mm 53.75 127.00 6826.25 866933.75
Inner Bottom plate 9 mm 380.81 149.55 56950.14 8516892.76
Side Girder-01 8 mm 74.32 196.50 14602.67 2869381.74
Side Girder-02 8 mm 67.76 192.35 13032.61 2506808.83
Side Stringer Plate 8 mm 73.12 104.60 7648.35 800017.62
Outer Shell longitudinal 4 HP 160 X 7 14.59 14.59 212.84 3105.11
Inner Shell longitudinal 4 HP 160 X 7 14.59 14.59 212.84 3105.11
Side Stringer Plate Long. HP 160 X 7 14.59 114.67 1672.92 191833.81
Bilge Long. HP 180 X 8 20.64 200.86 4146.59 832867.84
Inner Bottom Longitudinal 1 HP 160 X 7 14.59 159.68 2329.52 371970.05
Inner Bottom Longitudinal 2 HP 160 X 7 14.59 159.68 2329.52 371970.05
Inner Bottom Longitudinal 3 HP 160 X 7 14.59 159.68 2329.52 371970.05
Inner Bottom Longitudinal 4 HP 160 X 7 14.59 159.68 2329.52 371970.05
Bottom Longitudinal 1 HP 160 X 7 14.59 235.60 3437.11 809770.07
Bottom Longitudinal 2 HP 160 X 7 14.59 230.87 3368.15 777600.25
Bottom Longitudinal 3 HP 160 X 7 14.59 228.50 3333.59 761724.52
Bottom Longitudinal 4 HP 160 X 7 14.59 226.14 3299.18 746081.80
Center line BHD Longitudinal 5 HP 180 X 8 18.85 40.74 767.83 31283.01
Center line BHD Longitudinal 6 HP 180 X 8 18.85 105.74 1992.80 210718.37
Scantling (mm)Item

3. Bottom transvesr Long. HP 160 X 7 14.59 193.20 2818.73 544567.86
Ceter line BHD Longitudinal (One Side) HP 160 X 7 14.59 206.00 3005.54 619141.24
= 2421.87 296862.43 49502859.27 339136.88
A AY AY2
Ah2
/12
2217.7207 376761.0362 87584295.55 928072.8444
2421.87433 296862.4291 49502859.27 339136.8842
4639.59503 79898.60713 137087154.82 1267209.729
+ 1267209.73
138354364.55
= 4639.59503 cm2 = 0.463959503
= 9279.19006 cm2 = 0.927919006
17.22 cm
= 0.17 m
2.67 m
= 267.22 cm
= C m
= D m
138354364.55 cm
4
136978428.21 cm
4
273956856.41 cm
4
Section Modulus at Keel = AA cm3
BB cm
3
Total
Total
Above Assumed NA
Now, Location of Actual Neutral Axis above Assumed Neutral Axis =
Below Assumed NA
Total Area (Half Areax2)
Half Area
Section Modulus at Main Deck =
Location of Actual Neutral Axis above Base =
Now, Moment of Inertia about assumed Axis =
Now, Moment of Inertia about Actual Axis (one side) =
Now, Moment of Inertia about Actual Axis (both sides) =
Y to keel =
Y to Deck=