SHIP-TO-SHIP TRANSFERS PROCEDURES & PROTECTION

BEST PRACTICES IN SHIP-TO-SHIP TRANSFER: ACHIEVING OPERATIONAL EXCELLENCE AT SEA

It’s a transfer of Crago between two ships, either while the Vessels are Stationary or it is underway. The process of moving cargo, usually oil or liquified gas, between two ships is known as ship-to-ship (STS) transfer. An STS tanker vessel is frequently used as the receiving vessel and another vessel is used as the delivering vessel in an STS transfer operation.

Heightened risks are associated with these operations, where skill and experience play crucial roles. Also, many risks are involved in maneuvering the ships while they are underway and being ready to abort the operation should circumstances change while ships are doing STS operations. Tanker Ships will have a Ship-to-Ship Transfer Operation Plan (STS plan) approved by their flag

1. STS Operation Overview

Goal: To transfer cargo between ships with impractical or unavailable port infrastructure. Generally carried out while at anchorages or in open sea.
Cargo Types: These could be refined petroleum products, crude oil, or LPG / LNG.
Participants: Two vessels, fendering equipment, and specialized staff (STS service provider).

2. Key Procedures for STS Operations

Pre-Transfer Preparations:

Approval and Clearances: Ensure adherence to national and international regulations (MARPOL, SOLAS) and secure the required authorizations from maritime authorities. Taking permission from the relevant port state authority.
The properties of the Cargo involved are mentioned in MSDS with its UN number.
Risk Assessments are to be carried out before starting STS operations. Transfer plan after conducting a comprehensive risk assessment.
Weather: Keep an eye out for ideal weather; wind, rain, and high seas can make operations unsafe.
STS Location Selection: Go for the approved STS location which offers plenty of open area for movement of both vessels and has some protection from prevailing winds and currents.
Fender requirements: Generally, a minimum of 4 jumbo fenders is a standard requirement to protect the vessels during the transfer. That will depend on per size of the vessels & requirements. The fenders can be rigged on either vessel, but a common arrangement is to rig on the maneuvering ship

Vessel mooring:

Positioning: To prevent direct contact between the 2 vessels, the vessels are positioned side by side with fenders in between. Also to clarify which ship will maintain course and speed during the operation (the Constant heading ship) and which ship will be the Manoeuvring ship
Mooring Lines: Make sure the mooring lines are properly aligned and tensioned. Strong lines that can support the weight and motion of both vessels are required.
Mooring arrangement: Moorings should be ready for rapid deployment, with all lines led through class-approved, closed fairleads. Spare moorings should be kept ready in case of failure. Unmooring should not commence until all maneuvering; navigational and communication equipment have been confirmed in good order.
Communication Protocol: Method of communication to be agreed upon and function tested. A common language should be agreed upon, and alternative means of communication prepared should the primary means fail. Should also provide a specific channel of communication for ships and STS coordinators on land.

Cargo Transfer:

Hose Connection: The cargo manifolds of the two ships are connected by flexible hoses. To make sure there are no leaks, hoses should be tested.
Pumping Operations: Start the transfer process at a steady pace. Continuous monitoring of tanker pump pressure and rates is necessary.
Tank Monitoring: Keep an eye out for overfill and irregularities in temperature or pressure in cargo tanks.
Emergency Protocols: Establish spill containment protocols and an emergency shut-down system (ESD).

3. Safety and Protection Measures

Personal Protective Equipment (PPE): All participants should wear the proper PPE, such as helmets, gloves, goggles, and clothing that can withstand flames.
Risk of Fire and Explosion: To lower the risk of fire, use inert gas in cargo tanks. Keep extinguishers and firefighting supplies on hand.
Firefighting and oil spill equipment are to be present and the crew is to be well-trained to use them in an emergency.
Anti-spill measures: These include having oil spill response gear on hand and deploying booms. Make sure that the International Convention for the Prevention of Ship-related Pollution (MARPOL) is followed.
Crew Training: Safety, emergency response, including oil spill management, and STS transfer operations should all be covered in crew training.
Constant Monitoring: Keep an eye on the operation's environmental factors, cargo transfer rates, and vessel movement.
Contingency Plan: Have an emergency plan in place for quick action in the event of a spill, equipment failure, or unanticipated bad weather.
Wind velocity and direction: There is a defined threshold for wind velocity, often set at 30 knots, with even lower limits for larger ships. The wind direction can make maneuvering difficult, particularly if in opposition to any tidal currents
Constraints on swell: Restrictions on swell conditions, typically around 3 meters, are implemented, although VLCC transfers may observe a reduced limit of 1.5 meters
Meteorological predictions: Weather forecasts must remain within acceptable parameters, and allowances for potential time extensions should be made to account for unforeseen delays

4. Final and Post-Transfer Inspections

Disconnection: To prevent spills, carefully disconnect the hoses after the transfer is finished.
Deballasting and Final Tank Checks: Verify that tanks are secure and that cargo levels are within acceptable bounds.
Tracking the Operation: Fill out the transfer log and make sure that all pertinent paperwork, such as risk assessments and certificates, is filed correctly.
Mooring Release: Release the mooring lines and move the vessels as needed after the operation has been verified as thorough and safe.
Abort criteria: For example, should the environmental conditions change, or a piece of essential equipment fail.