How do you prevent a drifting tanker or other disabled vessel from ending up on a beach or offshore oilrig? You arrest it..
Attaching a towline to a disabled vessels is never easy, and particularly not when you need it the most - in bad weather when she is drifting towards a lee shore or an oilrig. In order to remedy this a new tool for the emergency services has been developed - the ShipArrestor. This tool is 100% helicopter applied and consists of a chain lasso for connecting to the anchor windlass or similar strong point and a 200 m long towline. At the end of the towline a large scale sea anchor is fitted. This will reduce the driftrate, but more importantly it will put the cassualty's bow up against the weather and radically reduce the roll motion.
The developement of the ShipArrestor was funded by the Research For SMEs (Small and Medium sized Enterprises) program and started formally on October 1. 2008 and became a commercial product on December 1. 2010. This tool will:
- Put the vessel-in-distress' bow up against the weather
- Reduce the roll of the casualty and the associated wave impact forces
- Reduce the drift speed
- Allow towing of the casualty without putting rescue personnel aboard the vessel
Consequently the ShipArrestor can greatly reduce the risk of an environmental and economic disaster that is the potential outcome of tanker emergencies.
During the project phase a new lightweight chain, a heavy duty sea anchor for large ships and positioning mechanism have been developed. Full scale testing with the LNG tanker Arctic Princess and an Augusta Westland AW139 helicopter have proven the capabilities.