E "'

PHILIPPINE TRIGON
SHIPYARD
..
CORPORATION
,,,.,,..
••c • 1t.a*'OTI', ,.... IC.GO Jtl..r • -.- S,i,.t
IS l'lr.QIOOI.,:

SCANTLING CALCULATIONS HULL 19-001

FORMARINAAPPROVAL

OWNER'S COPY I
MARITIME INDUSTRY
 PAGE
SECTION CONTENT
NO.
I INTRODUCTION 1
II DEFINITION 2
DIAGRAM A – SCANTLING LENGTH 2
DIAGRAM B – FREEBOARD LENGH 3
DIAGRAM C – SCANTLING DRAFT 5
DIAGRAM D – GENERAL ARRANGEMENT PLAN 6
DIAGRAM E – MIDSHIP SECTION PLAN 7
DIAGRAM F – TRANPOSED SECTION MODULUS 8
LONGITUDINAL SCANTLING AT MIDSHIP SECTION
TABLE 1 – CALCULATION OF EQUIVALENT SECTION MODULUS OF THE 9
MIDSHIP SECTION USING AUTOCAD PROGRAM “MASSPROP”
ABS 9 SECTION MODULUS CALCULATION 10
GRAPH 1 – ABS STANDARD TABLE FOR WAVE HEIGHTS 11
III DEFINITION OF LOAD BENDING MOMENTS 12
TABLE 1 – LOADCASE NO. 1 BALLAST DEPARTURE 12
TABLE 2 – LOADCASE NO. 2 BALLAST ARRIVAL 17
TABLE 3 – LOADCASE NO. 3 FULL LOAD DEPARTURE 22
TABLE 4 – LOADCASE NO. 4 FULL LOAD ARRIVAL 27
IV LONGITUDINAL STRENGTH CALCULATION 32
V SCANTLING CALCULATION OF LOCALIZED SECTIONAL MEMBERS 40
VI SUMMARY OF SECTION MODULUS FOR ACTUAL LOADCASES 49
I - INTRODUCTION :
Ship structure is considered as the material that provides the strength and stiffness of sea-borne structure allowing it to withstand
the loads it is expected to be subjected to during the course of its deployment. Hull girder is the structure which resist longitudinal
bending. This structures include primarily the shell plating, decks, inner bottom, girders and longitudinal bulkheads. It is generally
accepted assumption that the maximum bending moment extends over the midship portion of the ship. Accordingly, the
classification societies ordinarily require the maintenance of the midship scantlings throughout the midship portion. This particular
structural review will primarily make reference to the American Bureau of Shipping (ABS) Rules for Building and Classing Offshore
Support Vessels (2016), which require the midship scantlings to extend throughout the midship 40% of the scantling length. Hence,
this review is limited only to the local loads which are pressures and forces directly applied to the individual structural members:
plating panels, ordinary stiffeners and primary supporting members and hull girder loads that are forces and moments which result
as effects of local loads acting on the vessel as a whole and considered as a girder as defined in accordance to the prescribed and
applicable ABS Rules.

For the purpose of establishing the bending moments, actual load draughts associated with each cargo and ballast distribution are
calculated using MAXSURF Software. Local loads are calculated on the basis of the vessel draught corresponding to the cargo or
lightship distribution while being subjected to the ABS “standard wave heights” (Graph 1). The vessel draught is to be taken as the
distance measured vertically on the hull transverse section at the middle of the length from the base line to the waterline in full load
condition as defined in “Load Case No.3” in the “Intact Stability Assessment” and light ballast condition established as “Load Case
No. 2”.

1|Page
SECTION II - DEFINITION :
1 Application - The following definitions of symbols and terms are to be understood (in the absence of other
specifications) where they appear in these Rules.

2 Scantling Length (L) L is the distance in meters on the summer load line from the fore side of the stem to the centerline
of the rudder stock. For use with these Rules, L is not to be less than 0.96 and need not be greater than 0.97 of the length on the
summer load line. The forward end of L is to coincide with the fore side of the stem on the waterline on which L is measured. In
ships with an unusual stern and bow arrangement the length, L, is to be specially considered. See Diagram A.

Diagram A - Scantling Length

 3 Freeboard Length (Lf) Lf is the distance in meters (feet) on a waterline at 0.85 of the least molded depth measured
from the top of the keel from the fore side of the stem to the centerline of the rudder stock or 0.96 of the length on that waterline,
whichever is greater. Where the stem is a fair concave curve above the waterline at 0.85 of the least molded depth and where the
aftermost point of the stem is above the waterline, the forward end of the length, Lf, is to be taken at the aftermost point of the
stem above that waterline. See Diagram B.

Diagram B – Freeboard Length

 4 Breadth (B) B is the greatest molded breadth in meters.

5 Molded Depth (D) D is the molded depth at side in meters measured at the middle of L from the molded base line to
the top of the freeboard-deck beams. In vessels having rounded gunwales, D is to be measured to the point of intersection of the
molded lines of the deck and side shell plating. In cases where watertight bulkheads extend to a deck above the freeboard deck and
are to be recorded in the record as effective to that deck, D is to be measured to the bulkhead deck.

6 Scantling Depth (Ds) The depth Ds for use with scantling requirements is the distance in meters (feet) from the molded
base line to the strength deck.

7 Molded Draft (d) The molded draft d, is the distance in meters from the molded base line to the summer load line.

8 Scantling Draft (ds) The scantling draft ds is the maximum draft, in meters , at which the strength requirements for the
scantlings of the ship are met. The draft, ds, for use in scantling requirements is the molded draft to the deepest load line to which
the vessel is designed to operate in service. For the purpose of these review, scantling draft ds should not be taken less than 0.67Ds.
See diagram C.
DIAGRAM C – Scantling Draft
DIAGRAM D – General Arrangement Plan
DIAGRAM E - Midship Section Plan
DIAGRAM F - Transposed Section Modulus Longitudinal Scantling at midship section.
TABLE 1 - CALCULATION OF EQUIVALENT SECTION MODULUS OF THE MIDSHIP SECTION
USING AUTOCAD PROGRAM “MASSPROP”
Note : Measurement are in centimeters

Neutral axis from keel 244.2966 cm

Moment of inertia at the neutral axis 224,816,377.1885 cm^4
Section modulus from the top 747,634.97 cm^3
Section modulus from the bottom 920,259.95 cm^3
ABS 9 Section Modulus Calculation
9.1 Items Included in the Calculation In general, the following items may be included in the calculation of the hull
girder section modulus, provided that they are continuous.:

• Deck plating (strength deck and other effective decks)

• Shell and inner bottom plating

• Deck and bottom girders

• Plating and longitudinal stiffeners of longitudinal bulkheads. Horizontally corrugated longitudinal bulkheads can
be included in the hull girder strength calculation for bending strength but not for shear strength. Vertically
corrugated longitudinal bulkheads are to be excluded from the hull girder bending strength calculation but may
be considered for shear strength.
• All longitudinals of deck, side, bottom and inner bottom

• Continuous longitudinal cargo rails and/or walkways.

10 | P a g e
GRAPH 1 - ABS Standard Table for Wave Heights

Graph 1 - The 1.1 √L currently used by Lloyds Register and by the US. Navy Bureau of Ships and 0.6(L 0.6) used in certain investigations by the American Bureau of Shipping

11 | P a g e
SECTION III - DEFINITION OF LOAD BENDING MOMENTS :
TABLE 1 - LOAD CASE NO. 1 – Ballast Departure
Loading Condition Arrangement Displacement = 1,071.53 T
Draft Fwd = 1.904 M
Draft Aft = 3.192 M
Draft Mid = 2.548 M
Trim = 1.289
 Item Name Quantity Unit Mass Total Mass Unit Volume Total Volume Long. Arm Trans. Arm Vert. Arm
tonne tonne m^3 m^3 m m m
Lightship 1 675.000 675.000 -4.133 0.000 4.141
Subtotal 675.000 -4.133 0.000 4.141
COT No. 4 (P) 0% 138.390 0.000 153.972 0.000 -15.635 -0.293 0.950
COT No. 4 (S) 0% 138.383 0.000 153.965 0.000 -15.635 0.293 0.950
COT No. 3 (P) 0% 154.326 0.000 171.702 0.000 -6.643 -0.293 0.950
COT No. 3 (S) 0% 154.326 0.000 171.702 0.000 -6.643 0.293 0.950
COT No. 2 (P) 0% 144.610 0.000 160.892 0.000 2.972 -0.293 0.950
COT No. 2 (S) 0% 144.610 0.000 160.892 0.000 2.972 0.293 0.950
COT No. 1 (P) 0% 130.613 0.000 145.320 0.000 11.965 -0.293 0.950
COT No. 1 (S) 0% 130.609 0.000 145.315 0.000 11.965 0.293 0.950
Subtotal 0% 1135.868 0.000 1263.760 0.000 0.000 0.000 0.000
F.O.T. No. 2 (P) 96% 17.210 16.521 20.488 19.668 -18.176 -3.404 3.009
F.O.T. No. 2 (S) 96% 17.210 16.521 20.488 19.668 -18.176 3.404 3.009
F.O.T. No. 1 (P) 96% 9.056 8.694 10.781 10.350 -18.821 -1.230 0.598
F.O.T. No. 1 (S) 96% 9.056 8.694 10.781 10.350 -18.821 1.230 0.598
Subtotal 96% 52.531 50.430 62.537 60.035 -18.398 0.000 2.178
W.B.T. No. 10 0% 41.969 0.000 40.945 0.000 -16.843 0.000 0.000
W.B.T. No. 9 100% 36.398 36.398 35.510 35.510 -8.710 0.000 0.549
W.B.T. No. 8 (P) 100% 22.355 22.355 21.809 21.809 -4.237 -2.400 0.549
W.B.T. No. 8 (S) 100% 22.355 22.355 21.809 21.809 -4.237 2.400 0.549
W.B.T. No. 7 100% 45.221 45.221 44.118 44.118 0.550 0.000 0.549
W.B.T. No. 6 (P) 100% 19.788 19.788 19.305 19.305 5.050 -2.427 0.549
W.B.T. No. 6 (S) 100% 19.788 19.788 19.305 19.305 5.050 2.427 0.549
W.B.T. No. 5 100% 44.533 44.533 43.447 43.447 9.532 0.000 0.549
W.B.T. No. 4 100% 30.508 30.508 29.764 29.764 13.710 0.000 0.545
W.B.T. No. 3 100% 28.633 28.633 27.935 27.935 17.537 0.000 0.538
W.B.T. No. 2 100% 16.573 16.573 16.169 16.169 21.415 0.000 0.538
W.B.T. No. 1 100% 10.073 10.073 9.827 9.827 25.091 0.000 0.544
A.P.T. 0% 11.212 0.000 10.939 0.000 -28.975 0.000 0.000
Subtotal 84.78% 349.405 296.223 340.882 288.998 5.640 0.000 0.547
F.W.T. No. 1 (P) 100% 24.392 24.392 24.392 24.392 24.484 -1.236 3.370
F.W.T. No. 1 (S) 100% 24.392 24.392 24.392 24.392 24.484 1.236 3.370
F.P.T. (FWT) 0% 18.132 0.000 18.132 0.000 27.509 0.000 0.000
F.W.T. No. 2 (P) 100% 1.095 1.095 1.095 1.095 -25.985 -2.220 3.902
Subtotal 73.34% 68.011 49.878 68.011 49.878 23.376 -0.049 3.381
L.O.S.T. 0% 2.648 0.000 2.879 0.000 -24.036 0.000 0.000
B.O.T. 0% 1.372 0.000 1.475 0.000 -27.040 0.000 0.000
Subtotal 0% 4.020 0.000 4.354 0.000 0.000 0.000 0.000
Total Loadcase 1071.532 1739.544 398.912 -0.822 -0.002 3.020
Still-water Bending Moment

Maximum Bending Moment = 1,912.174 Tonne-m

Wave Induced Bending Moment (Sagging Condition)
Wave Height = 2.0M
Wave Length = 61.8 M

Maximum Bending Moment = 957.247 Tonne-m

Wave Induced Bending Moment (Hogging Condition)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 2,899.243 Tonne-m

16 | P a g e
TABLE 2 - LOAD CASE NO. 2 – Ballast Arrival
Loading Condition Arrangement Displacement = 981.464 T
Draft Fwd = 1.645 M
Draft Aft = 3.072 M
Draft Mid = 2.358 M
Trim = 1.427 M
 Item Name Quantity Unit Mass Total Mass Unit Volume Total Volume Long. Arm Trans. Arm Vert. Arm
tonne tonne m^3 m^3 m m m
Lightship 1 675.000 675.000 -4.133 0.000 4.141
Subtotal 675.000 -4.133 0.000 4.141
COT No. 4 (P) 0% 138.390 0.000 153.972 0.000 -15.635 -0.293 0.950
COT No. 4 (S) 0% 138.383 0.000 153.965 0.000 -15.635 0.293 0.950
COT No. 3 (P) 0% 154.326 0.000 171.702 0.000 -6.643 -0.293 0.950
COT No. 3 (S) 0% 154.326 0.000 171.702 0.000 -6.643 0.293 0.950
COT No. 2 (P) 0% 144.610 0.000 160.892 0.000 2.972 -0.293 0.950
COT No. 2 (S) 0% 144.610 0.000 160.892 0.000 2.972 0.293 0.950
COT No. 1 (P) 0% 130.613 0.000 145.320 0.000 11.965 -0.293 0.950
COT No. 1 (S) 0% 130.609 0.000 145.315 0.000 11.965 0.293 0.950
Subtotal 0% 1135.868 0.000 1263.760 0.000 0.000 0.000 0.000
F.O.T. No. 2 (P) 10% 17.210 1.721 20.488 2.049 -17.677 -3.054 1.461
F.O.T. No. 2 (S) 10% 17.210 1.721 20.488 2.049 -17.677 3.054 1.461
F.O.T. No. 1 (P) 10% 9.056 0.906 10.781 1.078 -18.997 -0.739 0.103
F.O.T. No. 1 (S) 10% 9.056 0.906 10.781 1.078 -18.997 0.739 0.103
Subtotal 10% 52.531 5.253 62.537 6.254 -18.132 0.000 0.993
W.B.T. No. 10 0% 41.969 0.000 40.945 0.000 -16.843 0.000 0.000
W.B.T. No. 9 100% 36.398 36.398 35.510 35.510 -8.710 0.000 0.549
W.B.T. No. 8 (P) 100% 22.355 22.355 21.809 21.809 -4.237 -2.400 0.549
W.B.T. No. 8 (S) 100% 22.355 22.355 21.809 21.809 -4.237 2.400 0.549
W.B.T. No. 7 100% 45.221 45.221 44.118 44.118 0.550 0.000 0.549
W.B.T. No. 6 (P) 100% 19.788 19.788 19.305 19.305 5.050 -2.427 0.549
W.B.T. No. 6 (S) 100% 19.788 19.788 19.305 19.305 5.050 2.427 0.549
W.B.T. No. 5 100% 44.533 44.533 43.447 43.447 9.532 0.000 0.549
W.B.T. No. 4 100% 30.508 30.508 29.764 29.764 13.710 0.000 0.545
W.B.T. No. 3 100% 28.633 28.633 27.935 27.935 17.537 0.000 0.538
W.B.T. No. 2 100% 16.573 16.573 16.169 16.169 21.415 0.000 0.538
W.B.T. No. 1 100% 10.073 10.073 9.827 9.827 25.091 0.000 0.544
A.P.T. 0% 11.212 0.000 10.939 0.000 -28.975 0.000 0.000
Subtotal 84.78% 349.405 296.223 340.882 288.998 5.640 0.000 0.547
F.W.T. No. 1 (P) 10% 24.392 2.439 24.392 2.439 24.455 -1.026 1.355
F.W.T. No. 1 (S) 10% 24.392 2.439 24.392 2.439 24.455 1.026 1.355
F.P.T. (FWT) 0% 18.132 0.000 18.132 0.000 27.509 0.000 0.000
F.W.T. No. 2 (P) 10% 1.095 0.109 1.095 0.109 -25.739 -1.995 3.415
Subtotal 7.33% 68.011 4.988 68.011 4.988 23.354 -0.044 1.400
L.O.S.T. 0% 2.648 0.000 2.879 0.000 -24.036 0.000 0.000
B.O.T. 0% 1.372 0.000 1.475 0.000 -27.040 0.000 0.000
Subtotal 0% 4.020 0.000 4.354 0.000 0.000 0.000 0.000
Total Loadcase 981.464 1739.544 300.240 -1.118 0.000 3.025

18 | P a g e
Still-water Bending Moment

Maximum Bending Moment = 1,540.812 Tonne-m

Wave Induced Bending Moment (Sagging Condition)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 827.327 Tonne-m

20 | P a g e
Wave Induced Bending Moment (Hogging Condition)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 2,470.208 Tonne-m

21 | P a g e
 TABLE 3 - LOAD CASE NO. 3 – FULL LOAD DEPARTURE

Loading Condition Arrangement

Displacement = 1,898.532 T
Draft Fwd = 4.112 M
Draft Aft = 4.328 M
Draft Mid = 4.220 M
Trim = 0.216 M
 Item Name Quantity Unit Mass Total Mass Unit Volume Total Volume Long. Arm Trans. Arm Vert. Arm
tonne tonne m^3 m^3 m m m
Lightship 1 675.000 675.000 -4.133 0.000 4.141
Subtotal 675.000 -4.133 0.000 4.141
COT No. 4 (P) 98% 138.390 135.623 153.972 150.893 -11.066 -2.005 3.145
COT No. 4 (S) 98% 138.383 135.616 153.965 150.885 -11.066 2.005 3.145
COT No. 3 (P) 98% 154.326 151.239 171.702 168.268 -1.856 -2.088 3.090
COT No. 3 (S) 98% 154.326 151.239 171.702 168.268 -1.856 2.088 3.090
COT No. 2 (P) 98% 144.610 141.718 160.892 157.675 7.442 -2.087 3.091
COT No. 2 (S) 98% 144.610 141.718 160.892 157.675 7.442 2.087 3.091
COT No. 1 (P) 98% 130.613 128.001 145.320 142.413 16.337 -1.810 3.155
COT No. 1 (S) 98% 130.609 127.997 145.315 142.408 16.337 1.810 3.155
Subtotal 98% 1135.868 1113.150 1263.760 1238.485 2.451 0.000 3.118
F.O.T. No. 2 (P) 96% 17.210 16.521 20.488 19.668 -18.174 -3.404 3.009
F.O.T. No. 2 (S) 96% 17.210 16.521 20.488 19.668 -18.174 3.404 3.009
F.O.T. No. 1 (P) 96% 9.056 8.694 10.781 10.350 -18.793 -1.234 0.597
F.O.T. No. 1 (S) 96% 9.056 8.694 10.781 10.350 -18.793 1.234 0.597
Subtotal 96% 52.531 50.430 62.537 60.035 -18.388 0.000 2.178
W.B.T. No. 10 0% 41.969 0.000 40.945 0.000 -16.837 0.000 0.000
W.B.T. No. 9 0% 36.398 0.000 35.510 0.000 -10.773 0.000 0.000
W.B.T. No. 8 (P) 0% 22.355 0.000 21.809 0.000 -6.550 -0.170 0.000
W.B.T. No. 8 (S) 0% 22.355 0.000 21.809 0.000 -6.550 0.170 0.000
W.B.T. No. 7 0% 45.221 0.000 44.118 0.000 -1.780 0.000 0.000
W.B.T. No. 6 (P) 0% 19.788 0.000 19.305 0.000 2.972 -0.171 0.000
W.B.T. No. 6 (S) 0% 19.788 0.000 19.305 0.000 2.972 0.171 0.000
W.B.T. No. 5 0% 44.533 0.000 43.447 0.000 7.213 0.000 0.000
W.B.T. No. 4 0% 30.508 0.000 29.764 0.000 11.965 0.000 0.000
W.B.T. No. 3 0% 28.633 0.000 27.935 0.000 15.585 0.000 0.000
W.B.T. No. 2 0% 16.573 0.000 16.169 0.000 19.826 0.000 0.000
W.B.T. No. 1 100% 10.073 10.073 9.827 9.827 25.091 0.000 0.544
A.P.T. 0% 11.212 0.000 10.939 0.000 -28.975 0.000 0.000
Subtotal 2.88% 349.405 10.073 340.882 9.827 25.091 0.000 0.544
F.W.T. No. 1 (P) 100% 24.392 24.392 24.392 24.392 24.484 -1.236 3.370
F.W.T. No. 1 (S) 100% 24.392 24.392 24.392 24.392 24.484 1.236 3.370
F.P.T. (FWT) 0% 18.132 0.000 18.132 0.000 27.509 0.000 0.000
F.W.T. No. 2 (P) 100% 1.095 1.095 1.095 1.095 -25.985 -2.220 3.902
Subtotal 73.34% 68.011 49.878 68.011 49.878 23.376 -0.049 3.381
L.O.S.T. 0% 2.648 0.000 2.879 0.000 -24.036 0.000 0.000
B.O.T. 0% 1.372 0.000 1.475 0.000 -27.040 0.000 0.000
Subtotal 0% 4.020 0.000 4.354 0.000 0.000 0.000 0.000
Total Loadcase 1898.532 1739.544 1358.226 0.227 -0.001 3.450
Still-water Bending Moment

Maximum Bending Moment = 654.563 Tonne-m

Wave Induced Bending Moment (Sagging)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 898.252 Tonne-m

Wave Induced Bending Moment (Hogging)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 1754.841 Tonne-m

 TABLE 4 - LOAD CASE NO. 4– FULL LOAD ARRIVAL

Loading Condition Arrangement

Displacement = 1808.464 T
Draft Fwd = 3.847 M
Draft Aft = 4.240 M
Draft Mid = 4.044 M
Trim = 0.392 M
 Item Name Quantity Unit Mass Total Mass Unit Volume Total Volume Long. Arm Trans. Arm Vert. Arm
tonne tonne m^3 m^3 m m m
Lightship 1 675.000 675.000 -4.133 0.000 4.141
Subtotal 675.000 -4.133 0.000 4.141
COT No. 4 (P) 98% 138.390 135.623 153.972 150.893 -11.071 -2.004 3.145
COT No. 4 (S) 98% 138.383 135.616 153.965 150.885 -11.070 2.004 3.145
COT No. 3 (P) 98% 154.326 151.239 171.702 168.268 -1.861 -2.088 3.090
COT No. 3 (S) 98% 154.326 151.239 171.702 168.268 -1.861 2.088 3.090
COT No. 2 (P) 98% 144.610 141.718 160.892 157.675 7.438 -2.087 3.091
COT No. 2 (S) 98% 144.610 141.718 160.892 157.675 7.438 2.087 3.091
COT No. 1 (P) 98% 130.613 128.001 145.320 142.413 16.332 -1.811 3.155
COT No. 1 (S) 98% 130.609 127.997 145.315 142.408 16.332 1.811 3.155
Subtotal 98% 1135.868 1113.150 1263.760 1238.485 2.446 0.000 3.118
F.O.T. No. 2 (P) 10% 17.210 1.721 20.488 2.049 -17.639 -3.057 1.460
F.O.T. No. 2 (S) 10% 17.210 1.721 20.488 2.049 -17.639 3.057 1.460
F.O.T. No. 1 (P) 10% 9.056 0.906 10.781 1.078 -18.828 -0.756 0.101
F.O.T. No. 1 (S) 10% 9.056 0.906 10.781 1.078 -18.828 0.756 0.101
Subtotal 10% 52.531 5.253 62.537 6.254 -18.049 0.000 0.992
W.B.T. No. 10 0% 41.969 0.000 40.945 0.000 -16.843 0.000 0.000
W.B.T. No. 9 0% 36.398 0.000 35.510 0.000 -10.773 0.000 0.000
W.B.T. No. 8 (P) 0% 22.355 0.000 21.809 0.000 -6.643 -0.171 0.000
W.B.T. No. 8 (S) 0% 22.355 0.000 21.809 0.000 -6.643 0.171 0.000
W.B.T. No. 7 0% 45.221 0.000 44.118 0.000 -1.780 0.000 0.000
W.B.T. No. 6 (P) 0% 19.788 0.000 19.305 0.000 2.972 -0.171 0.000
W.B.T. No. 6 (S) 0% 19.788 0.000 19.305 0.000 2.972 0.171 0.000
W.B.T. No. 5 0% 44.533 0.000 43.447 0.000 7.213 0.000 0.000
W.B.T. No. 4 0% 30.508 0.000 29.764 0.000 11.965 0.000 0.000
W.B.T. No. 3 0% 28.633 0.000 27.935 0.000 15.585 0.000 0.000
W.B.T. No. 2 0% 16.573 0.000 16.169 0.000 19.826 0.000 0.000
W.B.T. No. 1 100% 10.073 10.073 9.827 9.827 25.091 0.000 0.544
A.P.T. 0% 11.212 0.000 10.939 0.000 -28.975 0.000 0.000
Subtotal 2.88% 349.405 10.073 340.882 9.827 25.091 0.000 0.544
F.W.T. No. 1 (P) 10% 24.392 2.439 24.392 2.439 24.472 -1.024 1.354
F.W.T. No. 1 (S) 10% 24.392 2.439 24.392 2.439 24.472 1.024 1.354
F.P.T. (FWT) 0% 18.132 0.000 18.132 0.000 27.509 0.000 0.000
F.W.T. No. 2 (P) 10% 1.095 0.109 1.095 0.109 -25.723 -1.999 3.415
Subtotal 7.33% 68.011 4.988 68.011 4.988 23.370 -0.044 1.400
L.O.S.T. 0% 2.648 0.000 2.879 0.000 -24.036 0.000 0.000
B.O.T. 0% 1.372 0.000 1.475 0.000 -27.040 0.000 0.000
Subtotal 0% 4.020 0.000 4.354 0.000 0.000 0.000 0.000
Total Loadcase 1808.464 1739.544 1259.554 0.115 0.000 3.475
Still-water Bending Moment

Maximum Bending Moment = 653.438 Tonne-m

Wave Induced Bending Moment (Sagging)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 1251.595 Tonne-m

30 | P a g e
Wave Induced Bending Moment (Hogging)
Wave Height = 2.0 M
Wave Length = 61.8 M

Maximum Bending Moment = 1355.871 Tonne-m

31 | P a g e
SECTION IV - LONGITUDINAL STRENGTH CALCULATION

ABS 3.3 Longitudinal Strength for Vessels 61 m (200 ft) in Length and Over
ABS 3.7 Bending Strength

3.7.1 Hull Girder Section Modulus 3.7.1

(a) Section Modulus. The required hull girder section modulus for 0.4L amidships is to be
the greater of the values obtained from the following equation or 3-2-1/3.7.1 (b)

SM = Mt/fp cm3
where:

Mt = total bending moment, as obtained below

fp = nominal permissible bending stress in metric ton / cm2

240−𝐿
= 1.663 − [ ] 𝑡⁄
1620 𝑐𝑚2

The total bending moment, Mt, is to be considered as the maximum algebraic sum of still-
water bending moment and wave-induced bending moment, as follows:

Total Bending Moment (Mt) = Ms + Mws + Mwh

where:

Ms = still-water bending moment in kN-m (ton-m) as obtained per actual load

Mws = wave-induced bending moment in kN-m (ton-m) in sagging condition

per actual load.
Mwh = wave-induced bending moment in kN-m (ton-m) in hogging condition

32 | P a g e
A-1 - MINIMUM SECTION MODULUS REQUIREMENT BASED ON ABS RULES

A-1-1 Still Water Bending Moment

Ms = Cst x (L)2.5 x B x (Cb+ 0.5)

Where

Cst = [0.618 + 110−𝐿

] 𝑥 10−2
462

Cst = [0.618 + 110−63.59 ]

462
𝑥 10−2

= 0.007184

Cb = 0.664 ; L = 63.59 m ; B = 10 m

Ms = 0.007184 x (63.59)2.5 x 10 x (0.666 + 0.5)

Ms = 2,701.077 tonne-m

A.1.2 Wave Induced Bending Moment

Mw = C 2 x L 2 x B x H x K b

where;

Cb = 0.666 ; L = 63.59m ; B = 10 m

C2 = [2.34 𝑥 𝐶𝑏 + 0.2]𝑥 10−2

= [2.34 𝑥 0.666 + 0.2]𝑥 10−2

C2 = 0.01758
 Kb = 1.4 – 0.5 x Cb

= 1.4 – 0.5 x 0.666

Kb = 1.067

H = 0.0172 x L + 3.653

= 0.0172 x 63.59 + 3.653

H = 4.747

Mw = [0.01758 x 63.592 x 10 x 4.747 x 1.067]

Mw = 3,600.64 tonne-m

A.1.3 Total Bending Moment

MT = M S + M W

= 2701.077 + 3600.64

MT = 6301.717 tonne-m

fp = nominal permissible bending stress in metric ton / cm 2

240−𝐿
= 1.663 − [ ] 𝑡⁄
1620 𝑐𝑚2

240−63.59
= 1.663 − [ ] 𝑡⁄
1620 𝑐𝑚2

= 1.663 − [0.10889] 𝑡⁄
𝑐𝑚2

= 1.55411 𝑡⁄
𝑐𝑚2
A.1.4 Section Modulus Requirement

SM = MT / fp

6301.717 𝑚𝑒𝑡𝑟𝑖𝑐
𝑡𝑜𝑛−𝑚𝑒𝑡𝑒𝑟 100 𝑐𝑚
SM = 𝑥 𝑚
1.55411 𝑚𝑒𝑡𝑒𝑟𝑖𝑐 𝑡𝑜𝑛/𝑐𝑚2

SM = 405,487.192 cm3

As Installed Minimum Section Modulus (smallest section modulus)

Sm = 747,634.97 cm3 . . . . . . compliant

405,487.192
Safety Factor =100% -
747,634.97

= +45.76%
A.2 - MINIMUM SECTION MODULUS REQUIREMENT FOR LOADCASE 1 (WAVEHEIGHT =
2m)
Mt = Ms + Mws + Mwh

= (1,912.174 + 957.247 + 2,899.243)

Mt = 5,768.664 metric ton-meter

Where

fp = nominal permissible bending stress in metric ton / cm 2 for mild steel

= 1.5805 metric ton/cm2

Section Modulus Needed at Ballasted Departure with 2 m wave height

Sm = 5768.664 𝑚𝑒𝑡𝑟𝑖𝑐 𝑡𝑜𝑛−𝑚𝑒𝑡𝑒𝑟 100 𝑐𝑚

1.5805 𝑚𝑒𝑡𝑒𝑟𝑖𝑐 𝑡𝑜𝑛/𝑐𝑚2 𝑥 𝑚

= 364,988.54 cm3

As Installed Minimum Section Modulus (from the top)

Sm = 747,634.97 cm3 . . . . . . compliant

364,988.54
Safety Factor =100% -
747,634.97

= +51.18%
A.3 - MINIMUM SECTION MODULUS REQUIREMENT FOR LOADCASE 2 (WAVEHEIGHT =
2m)
Mt = Ms + Mws + Mwh

= (1,540.812 + 827.327 + 2,470.208)

Mt = 4,838.347 metric ton-meter

Where

fp = nominal permissible bending stress in metric ton / cm 2 for mild steel

= 1.5805 metric ton/cm2

Section Modulus Needed at Ballasted Arrival with 2 m wave height

Sm = 4,838.347 𝑚𝑒𝑡𝑟𝑖𝑐 𝑡𝑜𝑛−𝑚𝑒𝑡𝑒𝑟 100 𝑐𝑚

1.5805 𝑚𝑒𝑡𝑒𝑟𝑖𝑐 𝑡𝑜𝑛/𝑐𝑚2 𝑥 𝑚

= 306,127.617 cm3

As Installed Minimum Section Modulus (from the Top)

Sm = 747,634.97 cm3 . . . . . . compliant

306,127.617
Safety Factor =100% -
747,634.97

= +59.05%
A.4 - MINIMUM SECTION MODULUS REQUIREMENT FOR LOADCASE 3 (WAVEHEIGHT =
2m)
Mt = Ms + Mws + Mwh

= (654.563 + 898.252 + 1,754.841)

Mt = 3,307.656 metric ton-meter

Where

fp = nominal permissible bending stress in metric ton / cm 2 for mild steel

= 1.5805 metric ton/cm2

Section Modulus Needed at Full Load Departure with 2 m wave height

Sm = 3,307.656 𝑚𝑒𝑡𝑟𝑖𝑐 𝑡𝑜𝑛−𝑚𝑒𝑡𝑒𝑟 100 𝑐𝑚

1.5805 𝑚𝑒𝑡𝑒𝑟𝑖𝑐 𝑡𝑜𝑛/𝑐𝑚2 𝑥 𝑚

= 209,279.09 cm3

As Installed Minimum Section Modulus (from the top)

Sm = 747,634.97 cm3 . . . . . . compliant

209,279.09
Safety Factor =100% -
747,634.97

= +72.01%
A.5 - MINIMUM SECTION MODULUS REQUIREMENT FOR LOADCASE 4 (WAVEHEIGHT =
2m)
Mt = Ms + Mws + Mwh

= (653.438 + 1,251.595 + 1,355.871)

Mt = 3,260.90 metric ton-meter

Where

fp = nominal permissible bending stress in metric ton / cm 2 for mild steel

= 1.5805 metric ton/cm2

Section Modulus Needed at Full Load Arrival with 2 m wave height

Sm = 3,260.90 𝑚𝑒𝑡𝑟𝑖𝑐 𝑡𝑜𝑛−𝑚𝑒𝑡𝑒𝑟 100 𝑐𝑚

1.5805 𝑚𝑒𝑡𝑒𝑟𝑖𝑐 𝑡𝑜𝑛/𝑐𝑚2 𝑥 𝑚

= 206,321.04 cm3

As Installed Minimum Section Modulus (from the top)

Sm = 747,634.97 cm3 . . . . . . compliant

206,321.04
Safety Factor =100% -
747,634.97

= +72.40%
SECTION V - SCANTLING CALCULATION OF LOCALIZED SECTIONAL
MEMBERS

ABS 3-2-5/1.7 Standard Frame Spacing

S = 2.08L + 438 mm

= 2.08 (63.59) + 438 mm

S = 600.00 mm

as installed;

S = 600 mm

ABS 3-2-2/5.1 Side Shell Plating Amidship

𝑠√ℎ
t= mm
268

where;

s = frame spacing

h = depth, in mm but not less than 0.1L or 1.18d, whichever is greater

= 4.5 m

d = draft for scantlings

0.1 (63.59) = 6.359 m

1.18 (4.3) = 5.074 m

600√6.359
t= 268 mm

40 | P a g e
 = 5.645 mm

As installed;

t= 11 mm

ABS 3-2-2/3.3 Bottom Shell Plating

𝑠√ℎ
t= + 2.5 mm
254

600√6.359
t= + 2.5 mm
254

= 8.457 mm

As installed;

t = 11.0 mm

ABS 3-2-3/3.1 Deck Plating Thickness

𝑠√ℎ
t= + 2.5 mm
254

where;

s = 600 mm

h = 0.028L + 1.08 m

= 0.028 (63.59) + 1.08

= 2.860 m

41 | P a g e
 600√2.860
t= + 2.5
254

= 6.49 mm

As installed;

t = 7 mm

ABS 3-2-10/1.3 Keel Plate

t = the thickness of the plate keel throughout the length of the vessel is to be not
less than the bottom shell thickness

tBottom = 11.0 mm

t = 12 mm

ABS 3-2-4/1.3.1 Center Girder Thickness Amidship

t = 0.056L + 5.5 mm

= 0.056 (63.59) + 5.5

t = 9.06 mm

as installed;

t = 10 mm

ABS 3-2-4/1.3.3 Center Girder Depth/Tank Top Depth

hg = 32𝐵 + 190√𝑑 mm

where;
 B = 10 m; d = 4.3 m

hg = 32(10) + 190√4.30

hg = 713.99 mm

Actual Height;

hg = 950 mm

ABS 3-2-4/1.5 Thickness of Side Girders

t = 0.036L + c

where;

c = 4.7 mm

t = 0.036 (63.59) + 4.7 mm

t = 6.99 mm

as installed;

t = 8 mm

ABS 3-2-4/1.13 Thickness of Inner-Bottom Plating

t = 0.037L + 0.009s + c mm

where;

L = 63.59 m; s = 600mm; c = -0.5mm

t = 0.037 (63.59) + 0.009 (600) – 0.5 mm

 t = 7.252 mm

as installed;

t = 10 mm
ABS 3-2-4/5.1 Solid Floor Thickness

t = 0.036L + 4.7 + c mm

where;

c = 0 mm; transversely framed

t = 0.036 (63.59) + 4.7 + 0 mm

t = 6.989 mm

as installed;

t = 8 mm

ABS 12.7.3 Corrugated Bulkhead

SM = 7.8chs𝑙2 cm3

Where;

C = 0.56

𝑙 = distance between supporting members

s = a + b = 0.60

h = 2.10 m

SM = 7.8 x 0.56 x 2.10 x 0.60 x (3.0)2 cm3

= 49.53 m3
As Calculated:

SM = 𝑡𝑑2
𝑎𝑑𝑡
6 + 2

b a b

d
t

Where;

t = 10 mm / 0.1 cm

a = 48 cm

b = 12 cm

d = 30 cm

2
SM = 0.1𝑥30 40𝑥30𝑥0.1
6 + 2

= 75.0 cm3
ABS 5C-2-2/15.3.1 Structural Sections/Deck Longitudinal

SM = 7.8chs𝑙2 cm3

where;

c = 1.25 ; h = 0.6375

s = 0.6 ; 𝑙= 2.4

SM = 7.8 x 1.25 x 0.6375 x 0.6 x 2.4 2

Sm = 21.48 cm3
 Y

48 | P a g e
SECTION VI - SUMMARY OF SECTION MODULUS FOR ACTUAL LOADCASES

SUMMARY OF SECTION MODULUS REQUIREMENTS

ACTUAL LOADCASES
Actual Section Installed
Permissibl
Modulus Section
Bending Moment e Bending Margin
Requirement Modulus
Stress
from Top
Still Water Sagging Hogging
(t/cm2) (cm3) (cm3) %
(t-m) (t-m) (t-m)
Ballast Arrival
1,912.17 957.24 2,899.24 1.5558 364,988.54 747,634.97 +51.18
(Wave Height 4.0m)
Full Load Departure
1,540.81 827.33 2,470.21 1.5558 306,127.617 747,634.97 +59.05
(Wave Height 2.5m)
Ballast Departure
654.563 898.252 1,754.84 1.5558 209,279.09 747,634.97 +72.01
(Wave Height 2.5m)
Ballast Departure
653.44 1,251.60 1,355.87 1.5558 206,321.04 747,634.97 +72.40
(Wave Height 4.0m)

SECTION MODULUS REQUIREMENT BY ABS

Actual Section Installed
Permissibl
Modulus Section
Bending Moment e Bending Margin
Requirement Modulus
Stress
from Top
Wave Enduced
Still Water (t-m) (t/cm2) (cm3) (cm3) %
(t-m)
ABS RULE 2,701.077 3,600.64 1.55411 405,487.192 747,634.97 +45.76

49 | P a g e
Revision No. Revision Summary Date

-------------------- ooo ---------------------

Computer calculations for the present data have been reviewed by:

GLENN DELA TORRE

------------------- ooo -------------------