Emergency Contact Bulletin: Guidance on snap-back zones Home Latest updates Publications Bulletin: Guidance on snap-back zones 17 May 2016 Download page as PDF Sign up for alerts The Club would like to bring to Members’ attention the dangers of tensioned mooring lines and also highlight the concept of ‘snap-back’ zones. A snap-back is the sudden recoil of a mooring line as a result of its failure under tension. A snap-back zone on a mooring deck is the space where it is anticipated that the failed mooring line could recoil with great velocity, possibly resulting in injury or even death to crew present within this zone. Guidance and a review of the hazards associated with snap-backs are featured in industry publications such as the UK Maritime and Coastguard Agency’s Code of Safe Working Practices for Merchant Seafarers  ( COSWP ). Until recently, this guidance recommended the marking of snap-back zones on the mooring deck around the critical points such as the warping drum, roller fairleads and pedestal rollers. The aim of these markings was to warn the seafarers to avoid standing in these zones when mooring lines were under tension. However, recent studies have shown that the nature of snap-backs is more complex than initially perceived. This is due to various factors such as: • Mooring configurations • The nature of the mooring line used with regard to elasticity • Breaking strength which may influence the trajectory of a parted mooring line Hence the marking of snap-back zones on the deck, although convenient and simple, does not reflect the actual complex snap-back zone and may lead the seafarer into a false sense of security that they are safe as long as they aren’t standing in the highlighted area. The latest version of the COSWP dissuades the marking of snap-back zones on the deck . It recommends that the entire mooring deck should be considered as a potential snap-back zone and clear visible signage must be displayed to warn crew. It is also recommended