Similar-size VLCC STS… looking for practical views
I have written a detailed reconstruction of one STS incident where two similar-size VLCCs parted after being all fast alongside.
A squall was one of the reasons… but I do not think weather alone gives the full answer.
After all fast, the whole STS setup is still changing. One ship is rising. The other is settling. Mooring leads change. Fender loading changes.
That is the part I found most interesting while writing this.
If anyone here has handled, supervised, or seen similar VLCC STS operations, I would be interested to hear your view. Especially on what tends to get underestimated in these operations.
My experience with ship break aways was on a not a VLCC but a 600 ft tanker moored to an all-concrete refinery island in the middle of San Francisco bay.
The orientation of the pier was northeast in a striates where the currents can run six knots plus on a normal day depending on ebb and flood tides. During storm conditions the runoff from this river striates can exceed 8 knots.
The current at the time was at a swift ebb and the mooring lines were a little slack and not attended. The current caught the bow of the vessel (facing upriver) on the inboard side (pier side), snapping all the mooring lines from bow aft, all but the stern lines before the crew could put the anchor down.
It was chalked up to not doubling up on the mooring lines and inattention by the crew.
