What is STS Mooring Operation ?

During an STS operation, no other activity is to be permitted for e.g., bunkering, de-slopping etc.

The vessel must carry out a STS drill at least 24 hrs prior arrival at the trans-shipment location and record this in the deck log books.

For vessels carrying out STS whilst underway, the speed of own vessel must not be greater than 5 knots, keeping in line with the recommendations in the STS guide.

For vessels carrying out STS operations with the mother vessel at anchor:

1. A tug should be used to hold the anchored ship on a steady heading. If no tug is available, postponement of this operation should be considered.
2. For both berthing and unberthing operations, tugs are to be used at all times.

In accordance with the OCIMF STS transfer guide, it should be agreed by the masters of both ships, before the operation starts, which individual will have overall advisory control of the STS operation. However, this does not relieve either master from his responsibility to ensure the safety of his own vessel.