Although the process of anchoring, from laying to hoisting, is a routine job, it requires skill and experience. Doing it well is critical for the safety of crew and vessel, as well as for the health of marine life and the seafloor. The EU-supported AnchorGuardian project developed a device which, with accuracy to less than a metre, sounds an early warning alarm if an anchor is dragging. To avoid false alarms triggered by factors such as wind and tide, the system’s sensors work independently of any ship movement. The first prototypes have been developed, manufactured and tested in several sea trials, resulting in displacement accuracy between 80 % and 100 %, when compared to the actual displacement. Swiss Ocean Tech, the project host, has received several grants and has just successfully completed the first financing round with investors. They have also secured international patents specifically for AnchorGuardian.
Upgrading a centuries-old industry
Today’s anchor alarms cannot tell in real time if an anchor is still holding or already dragging, so early and accurate detection is paramount. Otherwise the situation can lead to collisions, groundings and oil spills, potentially causing environmental and economic disaster and even deaths. Current alarms work by tracking a vessel’s movement and then extrapolating potential anchor movement from that. But the GPS tracks the antenna on the ship, not the anchor, so calculations are based on where the GPS antenna was at the instant of the alarm, not where the anchor’s final resting place is. Getting this right matters because sailors have to set a security zone around a boat, which is the electronic area the boat may manoeuvre within without tripping an alarm. AnchorGuardian has a sensor module inserted between the anchor and its chain, and a module in the boat hull, which communicates by ultrasound. A display keeps crew updated in real time about the anchor’s position and hold. The display can be as a standalone on a vessel’s bridge or integrated within a pre-existing Electronic Chart Display and Information System (ECDIS) or GPS Plotter through the maritime electronic signals standard known as NMEA 2000 / 0183. Whilst the anchor is lifted or dropped, AnchorGuardian can also provide additional essential information, such as when the anchor has reached the seafloor or its exact position.
Safer sailors, ships and seas
Anchor dragging has caused several oil spills. For example, in 2018, Indonesia declared a state of emergency after a coal ship’s anchor dragged a pipeline more than 100 m, spilling oil over an area of nearly 13 000 hectares and polluting 60 km of coastal ecosystems. “As well as providing an anchor dragging early warning system, AnchorGuardian collects information useful to the scientific community about where anchoring should be better regulated. This increases safety, minimises environmental impacts and reduces economic loss,” says Thomas Frizlen, founder of Swiss Ocean Tech. Next, the team will focus on developing close-to-production prototypes which will be validated by a group of captains. The captains will test them on their vessels for 3 months, providing feedback for the pilot series design and manufacturing in Switzerland. After certification, AnchorGuardian is anticipated to enter the market in 2021 and be available through shipyards, manufacturers and boat accessory shops for all kinds of vessels, including merchant ships, leisure boats and fishing vessels.
AnchorGuardian, anchor, sailor, crew, anchor dragging, ships, early warning system, oil spills, leisure boats, fishing vessels, collisions, groundings, maritime, seafloor