Anchor Dragging


A recent study from DNV indicates that there has been an increase in anchor related incidents. The chart below shows the trend over the last 6 years. The Swedish Club and GARD also show rising numbers of claims due to anchor incidents and losses. So, what causes these incidents and how can we help prevent them?

*The above chart was obtained from a webinar on the topic “Anchoring losses on a negative trend – how to improve?” This webinar was a joint webinar from DNV, Gard and The Swedish Club

Major causes

Bad Weather has been identified as the most prominent reason for anchor related incidents.

The various incident investigations conducted by DNV, highlight that hesitation or delay in decision making has led to:

  • Late response to heave the anchor
  • Forced an error in anchoring procedure
  • Exceedance of environmental limitations
  • Anchor holding compromised

Major consequences

There can be various dangers and consequences due to anchor loss and anchor dragging incidents. Direct consequences include anchor replacement, recovery cost, off hire and service delays. Indirectly, it may also cause ship grounding, collision, damaged subsea equipment – including pipelines and cables, oil spills and more.

Alpha ori approach


Potential Anchor dragging observed has been added to the notification library for various ships. Since this addition, SMARTShip has been able to provide advanced notifications to various ships enabling safer navigation.

This type of notification was developed by incorporating the below logic:

  • Vessel’s distance traveled from anchored position > swinging circle radius)
  • (SOG at anchorage >= 0.4 kts (AND) difference between vessel’s COG & heading is within range of 165 to 195 degrees)

Case example from a vessel – oil tanker

The vessel concerned is a newly built Oil/Chemical Tanker. Its carrying capacity is around 77,500 t DWT. Its length overall (LOA) is 228 meters and its width is 38 meters. The vessel was doing a series of short voyages along the various coastal cities of The Philippines during the month of July, 2021 and has been at anchorage near Zamboanga.

SMARTNotifications “Potential Anchor Dragging” activated on 12/07/2021 at 0238 UTC


  • The vessel was at anchor and swinging continuously leading to vessel going out of swinging circle
  • Vessel was alerted immediately by shore staff
  • Anchor was heaved up and re-anchored as a precautionary measure.

Potential consequences and impact

  • High chances of Anchor getting dragged.
  • Chances of collision and grounding.

The SMARTShip™ System detected the speed (SOG) of the vessel was greater than that of 1 NM while the ship was at anchorage.

Upon further analysis, it was found that Ship had traveled from the ship’s anchored position to 0.19 nm while its swinging circle radius is 0.15 nm. The system also detected that the ship’s speed over ground was also higher than that of the defined threshold of 0.3kn. Hence SMARTShip triggered the alert. Other parameters like ME RPM, STW etc were also plotted to analyze the data.

After the Master received the alert in the SMARTShip portal, he reviewed the same in ECDIS, which further confirmed that the ship had dragged from its original anchored position. The below screenshot shows the Vessel status during the anchorage.

The above use cases demonstrate how ships equipped with the SMARTShip platform and SMARTNotifications application, have contributed to a reduction in navigational incidents that detect any anomaly to normal behavioral trends and provide leading indicators.

With SMART Notifications, vessel operators, charterers and other maritime executives have real-time access to ship operations providing instantaneous value realization to all stakeholders through integrated insights, transparency, and enhanced collaboration. The initiative has led to a reduction of incidents onboard the ship. We have experienced over 100+ reported use cases in the below categories:

  • Improved vessel reliability and availability
  • Lead safer navigation
  • Improved regulatory compliance
  • Loss prevention


To summarize, with SMART Notifications users have:

  • Virtual access to the ship anytime
  • 24/7 visibility into ship and equipment condition
  • Reduced dependency on ship crew for condition monitoring
  • Ability to assist ship crew better during emergencies

The ability to receive SMART Notifications through the SMARTShip Go mobile application is an added benefit for the user. This ensures that safety and compliance of the vessel is maintained through-out the year and at any given point of time.

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