Measurement Technology NW
LCI-90 Operator Manual
Page 61
11.0 Appendix C – Wrap Angle Calculations
1/2 WRAP ANGLE
1/2 WRAP ANGLE
LINE TENSION-TO FAIRLEAD
EXIT ANGLE
LINE TENSION-TO WINCH DRUM
ENTRY ANGLE
LOAD ON SHEAVE
Wrap Angle Correction Factor (WACF)
Angle
WACF
Angle
WACF
Angle
WACF
Angle
WACF
Angle
WACF
0
0.50000
38
0.52881
76
0.63451
114
0.91804
152
2.06678
2
0.50080
40
0.53209
78
0.64338
116
0.94354
154
2.22271
4
0.50030
42
0.53557
80
0.65270
118
0.97080
156
2.40487
6
0.50069
44
0.53927
82
0.66251
120
1.00000
158
2.62042
8
0.50122
46
0.54318
84
0.67282
122
1.01539
160
2.87939
10
0.50191
48
0.54732
86
0.68366
124
1.06503
162
3.19623
12
0.50275
50
0.55169
88
0.69508
126
1.10134
164
3.59265
14
0.50375
52
0.55630
90
0.70711
128
1.14059
166
4.10275
16
0.50491
54
0.56116
92
0.71978
130
1.18310
168
4.78339
18
0.50623
56
0.56629
94
0.73314
132
1.22930
170
5.73686
20
0.50771
58
0.57168
96
0.74724
134
1.27965
172
7.16779
22
0.50936
60
0.57735
98
0.76213
136
1.33473
174
9.55366
24
0.51117
62
0.58332
100
0.77786
138
1.39521
175
11.46279
26
0.51315
64
0.58959
102
0.79451
140
1.46190
28
0.51531
66
0.59618
104
0.81213
142
1.53578
30
0.51764
68
0.60311
106
0.83082
144
1.61803
32
0.52015
70
0.61039
108
0.85065
146
1.71015
34
0.52285
72
0.61803
110
0.87172
148
1.81398
36
0.52573
74
0.62607
112
0.89415
150
1.93185
LINE TENSION = LOAD ON SHEAVE * WACF
LOAD ON SHEAVE = LINE TENSION / WACF