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Vessel Outside Diameter Do = 1219 mmWrapper Plate Thickness tr = 9.53 mm (A 516M Gr.485)Saddle Included Angle 2 = 120 DegWrapper Plate Included Angle = 132 DegWrapper Plate Width Wr = 250 mmHeight from Saddle base to Vessel CL H = 1390 mmSaddle Stiffener Thickness ts = 9 mm (A 36M OR EQ.)Web Plate Thickness tw = 9 mm (A 36M OR EQ.)Saddle Width Ws = 150 mmBase Plate Width Wb = 250 mmDistance from Saddle CL to outer Anchor Bolt CL B = 450 mmBase Plate Thickness tb = 15.875 mm (A 36M OR EQ.)Base Plate Length Lb = 1125 mmDistance from Outer Stiffener CL to Vessel CL L2 = 350 mmDistance from CL of web to CL of Anchor Bolt L3 = 60 mmDistance from edge of Web to edge of Base L4 = 25 mm

Height from Saddle base to outer stiffener H1 = 1080 mmH - ((Do/2) + tr)) x Cos

Outer Stiffener Height H2 = 864 mmH - ((Do/2 + tr)^2 - L2^2)^0.5 - tb

Inner Stiffener Height H3 = 755 mmH - (Do/2 + tr) - tb

Overall Length of Saddle L1 = 1072 mm2 x Sin x (Do /2 + tw)

Cross Sectional Area of Saddle Stiffeners As = #REF! mm^23 x (ts x (Ws-tw) + (tw x L1)

Minimum Saddle Section Modulus Zxx = #REF! mm^3(3 x ts x (Ws^2/6)) + (Lb - (3 x ts x (tw^2/6))

Minimum Saddle Section Modulus Zyy = #REF! mm^3(tw x (Lb^2/6)) + (5 x (Ws - tw)/L x (tw^2/6))

Base Plate Section Modulus Zb = 10501 mm^3Wb x tb^2/6

2 (g + a)

a ag g

H

Lb

tr

tb

L2 B

H2H3

Wb

L4

L1

y

y

x xWs

tw

tsL3

L4

(Typ.)

a

a

H1

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STRESSES IN SADDLE WRAPPER PLATE

Ref BS5276 Pt 2

Wrapper Plate Inside Radius Rr = 609.53 mm

Angle b = 120 Deg = 2.094 Rads180 -

Maximum Reaction Load at Saddle R = #REF! N(FPSO Motion)

Consider a 1mm wide strip of Wrapper Plate

Load/unit Width P = #REF! N/mm widthR/Rr x (1 + Cos )/(( 3.14159 - ) + ( Cos ) x ( Sin ))

Load per unit area of Wrapper Plate q = #REF! N/mm^2P/Wr

Ref Roark & Young Table 26 Case 9a for a = 341.0 mmb = 70.5 mm

a/b = 4.837b1 = 0.718

Maximum Bending Stress in Wrapper Plate fbr = #REF! N/mm^2 #REF! x q x b^2/tr^2

Shear Stress in Saddle Wrapper Plate fsr = #REF! N/mm^2 #REF!P/(2 x tr)

Bearing Stress in Wrapper Plate fpr = #REF! N/mm^2 #REF!P/tw

STRESSES IN BASE PLATE (Compressive Loading)

Assume that the saddle is sufficiently rigid to distribute the compressive load uniformly over the total base plate area.

Consider a 1mm wide strip of Base Plate

Load per unit width of Base Plate P = #REF! N/mm widthR/L

Load per unit area q = #REF! MPaP/Wb

Ref Roark & Young Table 26 Case 10a for a = 341.0 mmb = 70.5 mm

a/b = 4.837b1 = 2.105

Maximum Bending Stress in Base Plate fbb = #REF! N/mm^2 #REF! x q x b^2/tb^2

Shear Stress in Saddle Base Plate fsr = #REF! N/mm^2 #REF!P/(2 x tb)

Bearing Stress in Base Plate fpr = #REF! N/mm^2 #REF!P/tw

ab

b bbb

b1

b1

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Lateral Tensile Stress in Saddle

Horizontal Load in Saddle is given by Fh = W x K9

Saddle Included Angle 2 = 120 Deg

Hence K9 = 0.88 (Ref BS5500 App G.3.3.2.6)

Therefore Fh = #REF! N

Maximum Saddle Height that can resist Fh H4 = 203Do/6

Actual Height used for calculation of Tensile Stress H5 = 203Min. of H4 or H3-tb

Area resisting Fh Ash = 1829 mm^2H5 x tw +Wr x tr

Tensile Stress in Saddle fts = #REF! N/mm^2 #REF!Fh/Ash

WEB PLATE

Maximum Height of Web and Outer Stiffeners H1 = 1065 mm

Ref. BS 449 Clause 27f for Grade 43 steel

Minimum permissible thickness of Web tw(min) = 5.91 mm OKH1//180

Note :A 516M Gr.485 A 36M OR EQ.

Min. Yield Stress Sy = 262.00 N/mm^2 248.22 N/mm^2Min. Allowable Stress Sa = 137.89 N/mm^2 114.46 N/mm^2

Allowable Bending Stress Sb = 172.92 N/mm^2 163.83 N/mm^2Allowable Compressive Stress Sc = 157.20 N/mm^2 148.93 N/mm^2Allowable Shear Stress Ss = 110.31 N/mm^2 91.57 N/mm^2Allowable Bearing Stress Sbr = 220.62 N/mm^2 183.13 N/mm^2Allowable Tensile Stress St = 157.20 N/mm^2 148.93 N/mm^2

a