We found this interesting page on the Skuld website – Skuld are a “world leading” marine insurance provide- they know what they are talking about – if you are in any doubt that STS is safe, read this please:
https://www.skuld.com/topics/cargo/liquid-bulk-cargo/sts-transfer/ship-to-ship-transfer-safety/
Their section on previous incident is particularly enlightening – we’ve reproduced it below:
Previous incidents / accidents
The most common incident to occur during STS operations is a collision between the two ships while manoeuvring alongside each other or sailing. Collisions between the two ships typically occur for reasons which include the following:
- Incorrect approach angle between the manoeuvring vessel and constant heading (mother) ship
- The manoeuvring ship approaching at excessive speed
- Failure of one or both ships to appreciate meteorological and/or tidal conditions
- The mother vessel failing to control excessive swinging while at anchor and/or manoeuvring ship failing to appreciate the swing
- Miscommunication between the vessels during manoeuvring
Engine failure of one of the tankers, particularly during mooring and un-mooring, can also result in a collision between the two ships. The failure of a ship’s main engine to start at a crucial point has also been a common cause of accidents.
Failure of mooring lines can occur because the mooring equipment is in poor condition. Excessive speed during mooring manoeuvres, extreme ship motion during the STS transfer operation and a poor mooring arrangement leading to chaffing of the lines can also lead to mooring line failure. Mooring line failure can cause fatal injuries to crew members, as well as damage or failure of the cargo hose(s).
The integrity of the fenders can be compromised by the manoeuvring vessel landing too heavily on the mother tanker.
The event of pollution can arise from situations, which might include:
- Failure of cargo hoses and/or mooring lines
- Deterioration of the weather conditions and/or sea state
- Damage to the cargo hose(s)
- Cargo overflow
- Machinery failure on one of the oil tankers
- Failure of pressure release valves, leading to tank explosion
- Securing and/or disconnecting of cargo hoses in a seaway and
- Cargo pump, valve or line failure on one of the oil tankers
The event of spillage of hydrocarbons can in turn lead to fire and/or explosion.
The possibility of explosion exists during the transfer of lower flash point oils.
A risk to the safety of the crew also exists in the form of gas accumulations because airflows around the decks of ships involved in STS operations are prone to eddies that prevent normal dissipation. In this regard, normal tanker safety precautions should be maintained during cargo transfer operations.
Now what did the CFPA say? Something like….. it’s perfectly safe, it goes on all over the world every day, no-one is concerned about it, it’s just like filling up your car…..
