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The Ultimate Actionable Guide of Anchoring a Ship

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anchoring-a-ship Anchoring is as frequent operation on board as loading and unloading a cargo. But in spite of being a frequent operation, the number of incidents related to anchoring never seem to reduce. That is when many minor incidents never come to light to a wider audience. The truth is that even after being a routine operation, effective way of anchoring is not a child's play. Sure one can just somehow arrive at anchoring position and open the brake to anchor a ship. I am sure you would agree that it is not an effective way of anchoring. Don't you think so? In this post, let us discuss a practical way of anchoring. But before we do that, we need to discuss two things. First how an anchor holds the ship. And second what guarantees more holding power of anchor. 1. How an anchor holds the ship When an anchor is dropped, The crown of the anchor is the first to hit the sea bottom. As the ship moves back, the flukes take its position and embed itself into the seabed. It does not matter from what height the anchor is dropped, the crown will alway hit the bottom first. The flukes will only dig into the seabed once the ship moves aft and flukes are facing downwards into the sea bottom. As the ship moves back, the fluke takes its position and embed itself into the seabed.

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Comments (99)

  • karthick June 7, 2016
    Dear sir, very very useful . thank u soo much. we need something about what is squat , squat calculation, how to calculate ukc available etc.
    2
    Rajeev Jassal June 8, 2016
    Glad you found it useful Karthick.. I will definitely right on squat as this is another important topic.
    thulani August 24, 2018
    good day can you please send us your email address as well as contact details. Lastly the procedure of dropping anchors in any emergency in port
  • Rs Gill July 7, 2016
    I also believe that the weight should be on the chain stopper as it is designed to withstand much more than brakes. (Chain Stopper (Guillotine) = 80pct of Chain MBL Brake band = 45pct of Chain MBL). Plus I have witnessed, leaving a gap results in a high probability of deformation in the chain stopper as the slip distance is much higher (greater momentum) as compared to the cable snugly resting against the stopper in case the cable runs out under excessive load. The same is also recommended method for securing the cable, in the concerned publication.
    1
    Rajeev Jassal July 7, 2016
    That is a good point made there. While the OCIMF publication recommend having the chain rest on the stopper it does not however say that other way is incorrect. It compares and contrasts between two methods. But as I said I also prefers it to be resting on the chain stopper. Thanks for giving your valuable views on this.
  • Bob July 30, 2016
    Hi This is very good reading the only information on anchoring missing is which is best anchor to drop? Does it matter if either Port anchor or Starboard anchor is dropped taking into account strong (ish) shifting winds and tides, I would of thought the only reason for 2 anchors is to have a spare incase the first one was lost to the seabed etc, or is there another reason (or benefit) for having both Port and Starboard anchors? I'm sure it will be a rule for ships over a certain tonnage or size to have 2 anchors for safety reasons, I'm just curious of the benefits in bad weather (if there is any)
    1
    Rajeev Jassal July 30, 2016
    Hi Bob. In normal conditions It does not actually matters which anchor we use as finally vessel will be stemming the the resultant of all the forces (Current, wind, tide). In case of anchoring in a river closer to the shore (like in Mississippi) , we normally use off-shore anchor so that it can hold the ship from dragging into the shore..But we normally use anchors on alternate basis so that we are sure that both can be used when required. Regarding 2 anchors, Yes it is class requirement to have 2 anchors. Apart from having other anchor in case one cannot be used, we sometimes have to use both the anchors specially in river where we cannot allow the ship to turn because of less space or strong currents. We also use for turning the ship where tugs are not available and for that we may require anchor on a particular side. We also use anchor for mooring in the river ports so that while casting off the ship, it is easier to bring the ship off the berth which otherwise may be difficult because of current pushing the vessel onshore. There are plenty reasons to have one anchor on each side.
  • ASHISH ACHARYA August 10, 2016
    Dear Sir, I find information in your blogs very useful and very informative and to the point. However regarding anchoring procedure could you please elaborate on best anchoring time when we have some tidal range. for example if 0700 is LW and 1300 is HW and tidal range is 6 meter, what would be the best time to anchor and reason behind it.
    1
    Rajeev Jassal August 12, 2016
    Ashish, if you are looking for an objective answer to this, there is none. A ship can be anchored any time. If I had the privilege to choose the time I would choose just before the low water or just before the High water (Slack water time). The Tidal current would be minimum and I can handle the ship without any concern of strong current. Also the forces acting on the anchor while it is being brought up will be minimum. On the other hand if ship is going up river and need to drop anchor, it is easier as I can use the current to my advantage as with against current, I can always use the engine and not loose steering and still be able to maintain less ship speed. However I would avoid anchoring in time of strong tidal current if ship is bound down river as then I need to turn in the strong current.
  • Captain Md sadikul bari September 20, 2016
    Excellent
    1
    Rajeev Jassal September 20, 2016
    Thank you Captain Bari..
  • shishir kumar September 23, 2016
    this what i was looking since long..thnx
    1
    Rajeev Jassal September 29, 2016
    Glad it could be some help to you Shishir..
  • NICOLAS September 29, 2016
    A question about radar anchor function, I have always had a doubt about this. The radar antenna is situated over the bridge, so the reference is the bridge itself. We drop the anchor and when the total amount of cable is laid out we activate the function, so the bridge is making the swing circle... is it right ? otherwise if we activate the function at the very moment the anchor drops there is an error...wait for your comments...thank you
    2
    Rajeev Jassal September 29, 2016
    While calculating the turning circle of the ship at anchor, we take the length from the forecastle to the bridge into account. If we add this distance, it takes into account this error you are referring to.
    NICOLAS September 29, 2016
    exactly Sir, that's the point, the question is if you can input this data ( the lenght ) in the radar for this purpose.....thanks for your dedication...
  • Capt.Ali Ozcan October 4, 2016
    Very useful blog...thanx capt
    1
    Rajeev Jassal October 4, 2016
    Thank you Capt Ali..
  • AJAY October 19, 2016
    sir i have a doubt some in rough weather anchor will drop or not
    0
  • Adam November 17, 2016
    Dear sir, I've been tasked with putting a brief together to come to anchor. The scenario is! I have been away for 5 weeks travelling from Pardip (India) and arriving into the outer anchorage at the Thames in London. I need to propose, plan and execute this please can I have advice. Thank you
    1
    Rajeev Jassal November 18, 2016
    Hi Adam, The anchoring part is detailed in this post. Arriving from a long voyage would add checking & testing the anchoring equipments well before arrival for anchorage.
  • Adam November 17, 2016
    Please could someone look at my question I posted 6 hours ago. Kindest regards
    2
    Rajeev Jassal November 18, 2016
    Let me know if there is any further question on this subject.
    Adam November 18, 2016
    Thank you sir that's much appreciated. What I was really after was the full sequence of events leading upto this event happening, I need to put a proposal together and then execute the anchorage for my presentation. Would it be easier to email me info your time I'm very greatful for.
  • john April 18, 2017
    sir i have a doubt, in a condition when currents and winds are not from same direction which anchor should i prefer to drop
    1
    Rajeev Jassal June 9, 2018
    In practice, It does not really matter. We can use any anchor. Finally, the ship will adjust itself to the resultant of both the wind and the current.
  • Kelvin Brugge May 9, 2017
    I am teaching my class of students of the various anchoring methods - open moor, running moor, standing moor, Mediterranean moor and Baltic Moor. The thing is I have never met anyone or spoken to anyone that has ever carried out the Baltic Moor. Is this something you or any of your contemporaries have experience of or is it a leftover from a bygone era? In my own career I have experienced the Mediterranean moor and open moor, but none of the others. Thank you for your interesting blog
    1
    Rajeev Jassal June 9, 2018
    Same here Kelvin. I have never used Baltic Moor.
  • Capt. GNS June 6, 2017
    Capt Rajeev, Thanx for this blog. A week b4 my familiarization for my promotion I search for a blog regarding anchoring and I found yours. I read it over and over since yours was in detail. I was surprised when I went abroad for my familiarization because my answer to their anchoring problem (which i read and copied from yours) was exactly the slides they are using... And I cannot thank you enough... Pls continue to write blogs in our field because it is indeed a great help to us... Thanx. Capt. GNS
    1
    Rajeev Jassal June 9, 2018
    Thank you, Captain...
  • SANDEEP RANA July 8, 2017
    Recently during promotion interview to Master, a friend of mine was given a situation of anchoring a loaded VLCC, in Singapore anchorage while approaching from West. The current was setting at 3 kts, 330 degrees and wind experienced was force 4. What could have been the best approach heading and which side anchor would have been best to be used considering the above situation. Comments from experienced Captains would also be appreciated as i am having my interview and simulator test next month.
    1
    Rajeev Jassal June 9, 2018
    Head to the current. Ideally, you can use any anchor but in a very strong current, it is advisable to use two anchors. If I have to choose one anchor, I would choose the opposite of from where the wind is coming. If the wind of from the port side (when we head to the current), I would choose the starboard anchor so that the anchor does not allow the wind to turn the vessel and expose the ship's bow to the strong current.
  • Capt. Kayomarz Patel July 14, 2017
    Excellent post. Very detailed.
    1
    Rajeev Jassal June 9, 2018
    Thank you, Capt Patel...
  • Davy.Liao July 14, 2017
    Dear capt, A question about anchror operation to be fully automatic remote operation from bridge, I had a doubt about this function. Does it mean no seaman working on the fore mooring deck when automatic anchor operation from bridge ? does the anchor stopper need remote operation from bridge for meeting anchor fully automatic operation function? thanks.
    1
    Rajeev Jassal June 9, 2018
    I have never come across this but I guess this would be only on small ships or tugs. On bigger ships I don't think it would be safe to anchor without anyone forward.
  • fengyuan July 20, 2017
    Great article about anchoring a ship and it is very useful to know it. Thanks for your sharing and waiting for your new excellent articles.
    1
    Rajeev Jassal June 9, 2018
    Glad you found it useful Fengyuan...
  • fengyuan October 17, 2017
    There are different anchoring methods to suit different needs, and it is necessary to learn and know them before you do the anchoring work.
    0
  • Joost October 23, 2017
    Excellent article Sir. Would there be a guideline between anchor weight/size and vessel DWT you could share? Obviously depends on anchor type.
    1
    Rajeev Jassal June 9, 2018
    It is based on the equipment number of the vessel. Classification societies calculate the equipment number for the vessel and the weight of the anchor, as well as the length of the chain, depends on that.
  • Satyajit Dilip December 28, 2017
    Excellent post, one correction, the Scope of the anchor cable is the ratio of the length of the cable to the depth. Its vice versa in the article.
    0
  • Ercan Altay January 3, 2018
    Great article thanks very much for your all efforts
    1
    Rajeev Jassal June 9, 2018
    Glad you liked it Ercan...
  • Przemek January 26, 2018
    What is normal or good practice for securing anchors for sea and/or bad weathers? Should it be coupled in or not? Does any guides sais about it?
    1
    Rajeev Jassal June 9, 2018
    Both ways have its advantages and disadvantages. OCIMF mooring equipment guidelines recommend any of these methods.
  • indresh joshi January 29, 2018
    Very useful info. Sir. I have a ques? Suppose depth is 100 metre then what is the formula for putting shackles? And formula for making swinging and dragging cirle?
    1
    Rajeev Jassal June 9, 2018
    I have discussed the swinging circle on this blog. How to know if the anchor is dragging?
  • Bhavyadeep singh March 8, 2018
    very helpfull cap
    1
    Rajeev Jassal June 9, 2018
    Glad you found it helpful Bhavyadeep...
  • ankur behl March 11, 2018
    Sir can you please tell something about.. While in dry dock the company want you to lower the anchor and end to end the chain, what is the entire procedure? Thank you Sir
    1
    Rajeev Jassal June 9, 2018
    It is done with the help of shore crane. Ship staff needs to continue lowering the cable and someone from the drydock will signal when to stop lowering and resume lowering. Finally, the bitter end is released while the shore crane is holding the anchor chain.
  • S.Thirumalarkannan March 24, 2018
    Thank you so much sir.can u explain about boat note and different type of charterer
    0
  • David May 8, 2018
    I would like to know what is the rule of thumb "clearance of anchor chain stopper from the anchor chain.
    0
  • Dumith Abeyekoon June 8, 2018
    This has become the favorite learning site of mine. Presently I am doing my class II orals for chief mates and found this site is utmost important. Wish I could find all the answers to all my questions. Kindly add more topics. Best of luck sir..
    1
    Rajeev Jassal June 9, 2018
    Glad it is helping you. If you have any questions you can ask those on SEAQA section of the website.
  • muhammad alif danial abdullah October 28, 2018
    Sir, The question is.how many shackled of 35 dapth
    0
  • Lucille December 9, 2018
    What is the typical scope of chain veered for a ship anchoring in 12 fathoms of water? The answer is 70 fathoms. Can you explain why?
    0
  • Alessandro Chiurco March 20, 2019
    Hello Sir, could you explain how to weight the anchor? What happen if the scope is 4/5, the boat is at the maximum distance and you try to weigh the anchor? Is the windlass able to move the ship towards the anchor ?
    0
  • Anil March 24, 2019
    Dear sir, Your explanation was great,I have read navel architecture book so many times but still the concepts was not cleared fully , but yours way of explanation was excellent and clear up to point Thank you sir
    0
  • Prabhu Muthu April 29, 2019
    Your method of anchoring explained is so simple really excellent so far none of the author explained in such a easy and practical way.
    0
  • Nitesh thakur May 12, 2019
    Dear sir, could you please explain how to couple up both windlass in case if you have anchored in deep waters say 100 meters which is usual in fujairah.
    0
  • Ramo May 16, 2019
    Hi captain! how long anchor chain to drop, how is calculation captain? Please!
    2
    Tom May 21, 2019
    1.5x Sq.Root of Depth will give number of shackles to drop.
    Mathias May 24, 2020
    This formula does not account for windage area, nor wind strength. A better formula can be found here: https://trimaran-san.de/die-kettenkurve-oder-wie-ein-mathematiker-ankert/ Admittedly, it is for much smaller boats, but the mathematics is the same. You just need to scale the parameters.
  • Kuldeep May 20, 2019
    Can u also explain some thumb rules for Master,for picking up the pilot in congested waters such as singapore,and some thumb rules while navigating in congested waters such as cjk appeoach,
    0
  • Ronald Martin May 30, 2019
    Good day for u Dear Master, Pls let me know for how to calulation for drop anchor ,how many shackle to pay out for ship going to before drop anchor ...
    0
  • Ahmed July 12, 2019
    Sorry guys I need to know how the anchor directions is named by clock system like anchor direction is 11 clock and does it have any thing to do with the long and short stay.
    0
  • KAUSHIK DUTTA July 20, 2019
    sir thanks a lot for sharing so much of information. would you guide me on one question which has been asked recently in mmd i.e "how to secure anchor for a long voyage?" is it some thing about claws n all could explain it in a better way ?thank you
    0
  • Vijay Kumar Thakur August 4, 2019
    Hello Sir, As per Hazira port in India there is a very strong current.Sir pls explain how to approch during anchoring time and what is a suitable time for dropping and picking up anchor and why?
    0
  • Jonathan August 17, 2019
    Very useful capt. Similar article u discussed during my btm training. Keep on sharing ur expertise
    0
  • alfred February 17, 2020
    I'm wondering - what would the speed of anchor/chain when let go by opening brake ? In meters/second... BR AN
    0
  • Miramix April 3, 2020
    I what Know about anchor time?
    0
  • Twain.Dominic April 25, 2020
    I work hard, I insist, I will succeed
    0
  • Twain.Dominic April 25, 2020
    I work hard, I insist, I will succeed
    0
  • Amar anand May 3, 2020
    Great ...very informative
    0
  • Mathias May 24, 2020
    Hello, I could not agree more. Anchoring is too often a safety hazard than it should be. I am not playing in your league at all, my vessel is a small sailing vessel, but the mathematics of anchoring is the same. I spent some Corona time now to update my work on this, which you can find here: https://trimaran-san.de/die-kettenkurve-oder-wie-ein-mathematiker-ankert/ It covers what I call static anchoring (wind only) and dynamic anchoring (including swell). Important result is that a fixed scope like 6:1 or so is almost always a bad idea. In shallow water it underestimates the required chain length, in deep water it overestimates it. Happy to work out a digest with parameters of a huge vessel like you guys have!
    1
    Mathias January 27, 2021
    I have now created an app for iPhone/iPad/Android to work out the minimally required anchor chain length... albeit not for ships as huge as this one... https://trimaran-san.de/anchor-chain-calculator/
  • Mohammed Ali June 29, 2020
    Information on safe anchoring procedures
    0
  • Harjinder Singh July 16, 2020
    Thanks alot for making it look intersting and simple too
    0
  • Jose Manuel Yorac July 21, 2020
    sir can you give me 10 possible hazards for anchor party to consider prior commencing in anchoring operation?
    0
  • Shubroto kumar paul August 7, 2020
    Sir, i want to know clear idea about anchoring. What should do when i off windless break? Slowly or fast? When i off windless break it fall down its own weight and it is so fast. Is this speed harmful for anchor? If i fall down anchor with break slowly it will damage break of windless. Then what should do? Please sir reply in my email address. Thank you sir.
    0
  • Wooden Ship Kit - Ages Of Sail October 19, 2020
    That's really nice post. I appreciate your skills. Thanks for sharing
    0
  • khoa February 8, 2021
    Dear sir, Could you please explain for me how can i used SOG and COG during anchoring,I'm very confuse about that. As i know SOG during anchoring that purpose may we know vessel turning that correct or wrong ?? Thanks sir in avandce
    0
  • C/M Pagusara, Bryan T. February 10, 2021
    Excellent post, it is very helpful for me because i am preparing myself for promotion interview. Most of my Captian is using the method where they let go 3 shackles to the water and hold, wait for it to be brought up and let go again to the planned length for example 6 shackles in the water. What can you say about this method Sir?
    0
  • Brayan T. Pagusara February 10, 2021
    Dear sir thanks for this, its a big help for me as I am preparing for a promotion interview. Most of my Captain is using the method where they will let go 3 shackles in the water and hold on until it will be brought up or tight then let go the planned length for example 6 shackles in the water. What can you say about this method Sir?
    0
  • Capt charlie sasil June 5, 2021
    Very informative thank you for that.
    0
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  • Capt. Thet Moe Swe May 10, 2022
    Dear sir This article is the most pritical and smart way for anchoring.glad i found this article which is very helpful for my new carerer as Master.thank u so much sir.
    0
  • ANANT BHASKAR May 15, 2022
    Dear sir, very informative topic. Excellently explained. Plz confirm if the scope is ratio of length of cable deployed to the depth of seabed.
    0
  • SURESH KUMAR DHIANCHAND DHINGRA March 23, 2023
    How to decide which anchor to use - port or stba
    0
  • FRANK April 1, 2023
    Hi...actually vessel anchored in the Amazon where currents are abt 3 kts. Also other vessels are anchored close (0.5nm). We decided to turn the vessel around rather than passing between vessels. However the vessel was pushed more ahead due to 3 kts current...the vessel almost moved 0.75nm before it was turned completely (vsl in Ballast condition). So in a tight anchorage with strong currents & other vessels anchored close, what would be a best way to proceed.
    0
Capt Rajeev Jassal

About Capt Rajeev Jassal

Capt. Rajeev Jassal has sailed for over 24 years mainly on crude oil, product and chemical tankers. He holds MBA in shipping & Logistics degree from London. He has done extensive research on quantitatively measuring Safety culture onboard and safety climate ashore which he believes is the most important element for safer shipping.

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