Winch Drum Capacity Calculations (1)

W

Cable Diam.

B h in inches

Cable Length in Feet

Cable Length in Meters

Case 1

18.00 24.00 10.00 Length based on my constant

0.250

25,635 23,119

7,813.71 7,046.67

Case 2

18.00 24.00 10.00 Length based on my constant

0.322

15,453 13,936

4,710.05 4,247.68

Case 3

18.00 24.00 10.00 Length based on my constant

0.500

6,409 5,780

1,953.43 1,761.67

Case 4

18.00 24.00 10.00 Length based on my constant

0.680

3,465 3,125

1,056.14 952.46

This calculation in this spreadsheet is based on the formula found in the UNOLS Handbook of Oceanographic Winch, wire and Cable Technology. L= (.2618 Wh (B+h) d2 This formula tends to overestimate the length of cable. The handbook also has a method of determining length using a factor for each different wire diameter. I back calculated from the factor to determine if there was a better constant than the .2618 value. The value I determined was .2361. The calculation shown on the second line is based on my

W

B

h

diam constant factor 0.2500 0.2361 3.7780 0.3125 0.2361 2.4179 0.3750 0.2361 1.6791 0.4375 0.2361 1.2336 0.5000 0.2361 0.9445 0.5625 0.2361 0.7463 0.6250 0.2361 0.6045 0.7500 0.2361 0.4198

3.7280 2.4320 1.6890 1.2410 0.9498 0.7505 0.6079 0.4222

0.05 (0.01) (0.01) (0.01) (0.01) (0.00) (0.00) (0.00) 0.00