Seafastening Design Calculation - Transportation Loads

SEAFASTENING DESIGN CALCULATION - TRANSPORTATION LOADS Barge motion Typical transportation barge motion criteria (depends on barge beam) Barge beam = 20 m Roll  = deg ; T = 10 s 25 Pitch  = deg ; T = 15 10 s Heave H = 0.2 g ; s .. Angular acceleration in roll, .. = 0.172 rad/s2 Angular acceleration in pitch,  = 0.103 rad/s2 .. Heave acceleration,  = 1.962 m/s2

Pitch

Y

Roll

X Z

Vessel Data weight m = 76.00 tonne; i.e. w = d0 = d1 = d2 =

8.60 2.30 1.00

m m m

X (COG) = 16.18 m Y(COG) = 4.62 m Z (COG) = 3.14 m

745.56

kN c0 = c1 = c2 =

Vessel dimensions ?

2.486 2.04 4.00

(from amid barge, longitudinal distance) (from barge freeborad, vertical distance h) (from amid barge, transverse distance b)

m m m

Distances to turning axis ?

C.O.G

b Y

h C.O.R

Calculation of Motion Forces: Roll + Heave Vessel Self Inertia Moment Mr =

Z 328.5

kNm

..

- Maximum Forces: Fh = *m*Z+(1+H)*sin()*m*g .. Fv = +*m*Z+(1+H)*cos()*m*g Fh = 438.6 kN Max Fv = 852.0 kN Min Fv = 769.7 kN

O/T moment = Fh x c0 + Mr = Restoring moment =Fv x c1/2 = FOS against O/T =

1418.9 785.1 0.6

kNm kNm < 1.0 => Tension will develop, Vessel to be held down

1105.5 509.4 0.5

kNm kNm < 1.0 => Tension will develop, Vessel to be held down

728.1 1474.2 2.0

kNm kNm > 1.0 => No Tension

536.2 898.1 1.7

kNm kNm > 1.0 => No Tension

..

- Minimum Forces: Fh = *m*Y+(1-H)*sin()*m*g .. Fv = +*m*Z+(1-H)*cos()*m*g Fh = Max Fv = Min Fv =

312.6 kN 581.7 kN 499.5 kN

O/T moment = Fh x c0 + Mr = Restoring moment =Fv x c1/2 = FOS against O/T =

Pitch + Heave Vessel Self Inertia Moment Mr =

62.3

kNm

..

- Maximum Forces: Fh = *m*Y+(1+H)*sin()*m*g .. Fv = +*m*Z+(1+H)*cos()*m*g Fh = 267.8 kN Max Fv = 991.3 kN Min Fv = 737.1 kN

O/T moment = Fh x c0 + Mr = Restoring moment =Fv x c2/2 = FOS against O/T = ..

- Minimum Forces: Fh = *m*Y+(1-H)*sin()*m*g .. Fv = +*m*Z+(1-H)*cos()*m*g Fh = Max Fv = Min Fv =

190.7 kN 703.2 kN 449.0 kN

O/T moment = Fh x c0 + Mr = Restoring moment =Fv x c2/2 = FOS against O/T =

Lateral Load FHR (kN) +Roll + Heave (max) -Roll +Heave +Roll -Heave -Roll -Heave (min) +Pitch +Heave (max) -Pitch +Heave +Pitch -Heave -Pitch -Heave (min)

438.6 317.6 312.6 191.6 267.8 195.3 190.7 118.1

Vertical Load FVR (kN) 852.0 769.7 581.7 499.5 991.3 737.1 703.2 449.0

O/T Moment (kNm) Restoring Moment (kNm) 1418.9 869.0 1118.1 785.1 1105.5 593.3 804.8 509.4 728.1 1982.6 547.7 1474.2 536.2 1406.4 355.8 898.1

FOS against O/T 0.6 0.7 0.5 0.6 2.7 2.7 2.6 2.5

Tension

< 1 (Yes) < 1 (Yes) < 1 (Yes) < 1 (Yes) (No) OK (No) OK (No) OK (No) OK