The kinetic energy, which is transmitted onto the yacht by wind and waves, needs to be absorbed by the docking system.
It can be calculated with the following mathematical formula.
E kin = m v ² / 2 = Braking force x braking distance
E kin … kinetic engery [ Joule ]
Braking force … [ N ]
Braking distance … [ m ]
Example 1:
2 stern lines, 1 mooring line
Ropes' specification: breaking force 7 200 kg, 15 % max. elongation. Stern line 4 m, Mooring line 6 m.
Suspension element | Braking force [kg] | Braking distance [m] | Kinetic engergy [Joule] |
Stern line | 1.500 | kg | 0,12 | m | 883 | Joule |
Mooring line | 1.500 | kg | 0,18 | m | 1.324 | Joule |
| Total damping capacity: | 2.207 | Joule |
Example 2:
2 diagonal stern lines , 1 mooring line.
Ropes' specification: Breaking force 7 200 kg, 15 % max. elongation. Stern line 10 m, mooring line 6 m.
Suspension element | Braking force [kg] | Braking distance [m] | Kinetic energy [Joule] |
Diagonal stern line | 1.500 | kg | 0,3 | m | 2.207 | Joule |
Mooring line | 1.500 | kg | 0,18 | m | 1.324 | Joule |
| Totel damping capacity: | 3.532 | Joule |
Example 3:
DualDocker & securing lines
Diagonal stern lines; 10 m each, Spring lines to mid ship; 16 m each
Supension element | Braking force[kg] | Braking distance [m] | Kinetic energy [Joule] |
DualDocker shock absober (push) | 1.500 | kg | 0,1 | m | 736 | Joule |
DualDocker shock absorber (pull) | 1.500 | kg | 0,2 | m | 1.472 | Joule |
DualDocker side force | 1.000 | kg | 0,1 | m | 491 | Joule |
Diagonal stern line | 1.500 | kg | 0,33 | m | 2.428 | Joule |
Spring line to mid ship | 1.500 | kg | 0,25 | m | 1.839 | Joule |
| Totel damping capacity: | 6.965 | Joule |
