Des ign loads
The maximum mooring design load is specified by The
Ocean Cleanup as 3,600 kN. This load is obtained by multiplying
the maximum tension load in the Dyneema boom
of 1,000 m length, found using the equation given on page
207, by a factor of 2.5. The required ultimate pullout capacity
is doubled due to API RP 2SK recommended safety
factor for plate anchors. Therefore, the UPC is 7,200 kN.
Required Stevmanta VLA size
For the upper and lower bound (UB and LB respectively)
soil conditions the required anchor size and installation
depth are calculated by Vryhof.
The proposed 14 m² Stevmanta VLA, when installed with
an installation load of 187 tons at the anchor (i.e. shear
pin break load), will obtain the required capacity under
the assumed soil conditions. Table 3.21 summarizes the
anchor installation, capacity, and performance values.
The estimated drag length refers to the horizontal distance
between anchor drop points to the shear pin break
point during installation stage. After the shear pin has
broken there is no extra drag for the selected Stevmanta
VLAs up to its UPC of 7,200 kN.