CALM Buoy mooring chain

Discussion in 'Boat Design' started by Rian199, Nov 27, 2015.

  1. Rian199
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    Rian199 Junior Member

    Ufkigb
     
  2. TANSL
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    TANSL Senior Member

    With the help of this forum you are going to solve the problem that your boss raised. You'll only show him that you know how to use the internet facilities at our disposal. You'll fool your boss, sorry to be so rude, into believing that you have worked and thought a lot. Although you will fool, you know you have not acted properly and also have wasted the chance that your boss has given you to learn. Probably he does not needs you to solve that problem and he just pretended that you would learn to work, to take responsibility and deal with problems. Often it is not the right solution but to squeeze your brain.
    You are very free, of course, do what you want with your training but, in my opinion, you are not starting well.
     
  3. Rian199
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    Rian199 Junior Member

    I'm not trying to fool anyone, I'm doing research, and I'm not asking for step by step instructions. I have just never studied this sort of system before, and even some of the people at this office don't know exactly because they also haven't done this before, and the project manager is the only one who knows enough about it and he is away till next week, so am just eager to start. I have spent a lot of time researching this week and can't find what I am looking for. I have a few ideas but I just wanted to hear what some pointers from others who might know. Just to point me in the right direction. Plus these people are intelligent, I would be stupid to try and fool them, because they would see right through it, I just want to learn, that's all, and since we do have the internet available to us I thought I would just ask. One day when I have more experience I would like to help other people on here as well because I enjoy tutoring and teaching, if I know the content well enough to actually benefit someone. And at this point I don't which is why I'd like to know more. That's why I specified that I was a student. If I wanted to fool someone I'd pretend to be a professional or just asking out of interest, instead I was upfront about it, and I would tell my employers that I asked around to get the info. I don't take credit which isn't mine. You don't even know me, yet you just assume I am a fraud.
     
  4. TANSL
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    TANSL Senior Member

    There are two ways to ask for help on a topic:
    - Tell me everything you know about that topic and so I save myself a tough job.
    or
    - I've done all this and I'd like you to tell me what is right and what is wrong in my work, or how improve it.

    You amazed to see everything that appears when you type "mooring buoys systems" on any Internet search engine.
    Are you ashamed of what you said in your post # 1 ?. I'm surprised to see you've deleted.
     
  5. Rian199
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    Rian199 Junior Member

    I know who I am, and you can think what you want. I was just looking for peoples thoughts on this, I didn't want someone to do the work for me. Who I don't know is you. And I am not going to waste my time defending myself to someone who doesn't know me. That's why I am taking this down.
     
  6. TANSL
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    TANSL Senior Member

    That's what I wanted to say, that you are who must solve your problems and you must work to find solutions before calling for help.
     
  7. Poida
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    Poida Senior Member

    With respect TANSL, I don't see your logic.

    What you appear to be saying is, no one should ask for help or advice on this forum, they should look somewhere else.

    Poida
     
  8. bpw
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    bpw Senior Member

    Tansl,
    I have never heard of a boss who cared about how someone solved a problem, just that it was solved in an efficient manner. Unlike school, there are no points for effort in the working world. If I waste 4 hours at work doing research instead of picking up the phone and calling an expert it will not make the boss happy.

    If it bothers you so much perhaps you should just ignore the thread and let others help if they want to.
     
  9. TANSL
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    TANSL Senior Member

    Poida and BPW, both have your reasons for thinking as you do, and I respect them. I also have mine.
    Rian199 second time (second thread started by him), is asking for help without, apparently, having researched and worked hard on the issue concerned. It seems that it is difficult for him to find information but, in my opinion, in a few seconds is possible to find much information on the Internet. I find quite normal, and that's what many of us do in this forum, myself included, it is to expose a problem and say something like: "I know how to get here and do not know how to continue" or: "This is my solution , could you comment or improve it? ". I see no previous work by Rian199 and therefore, I conclude that asking for help without having invested, to study possible solutions, all the time he needs to invest. Here there are many students who ask for help and many professionals who ask for help but there are many people who claim that we're the ones who do his housework.
    If I was wrong, sorry, Rian199 have the opportunity to show how far it has come and I gladly, I'll be the first to help.
    BPW, I have no problem with the boss of Rian199 or with what he expects to receive from him. What I'm trying to say is that acting in this way, is Rian199 which will deceive himself, looking for shortcuts to do their jobs. And I repeat that myself, in this forum, I asked for help or explanations on some issues. Therefore, it seems to me very well that others seek help.
    I also apologize for not knowing better express myself.
    Greetings to all.
     
    Last edited: Dec 3, 2015
  10. gonzo
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    gonzo Senior Member

  11. TANSL
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    TANSL Senior Member

    Thanks, Gonzo, for supporting my words. As I said to Rian199 (not 999) in internet you can find lots of information.
    You, too, have given him wise counsel : "take initiative and do research". That's about the same as I told him. I would not have been able to express better. Thanks, again.
     
  12. Rian199
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    Rian199 Junior Member

    I understand where you're coming from TANSL, I know there are people who use other people for their work, but I can assure you that I do not do that. As for my previous thread, I didn't ask people again to do my work for me, again I asked for opinions and thoughts after doing my own research. It was my first unit in ship design, and is quite a different process to anything I have ever done before. The one member kept telling me to do a GA first, and when I first properly got into the design spiral it made more and more sense. The project counted 60% towards my final grade, and I putt a huge amount of hours into it, and eventually got 99% for it last week and I got over 80% for all my tests. I do my own research and my own study. You'l see I stopped asking for advice on that thread quite a while ago because as soon as they pointed me in the right direction I did the rest myself. That's all I wanted from this. The reason it might seem that I did not do much research on this is because I just briefly explained the situation, typing it on my phone on the train on my way back from work. That's why in my original post I said that I have more information if people needed it.

    And Gonzo, thanks, I have studied that document as part of my research and pretty much all of the first 3 or 4 pages of results you get when googling "CALM buoy" and "CALM buoy mooring maintenance" "SPM chain mooring" "chain mooring maintenance" etc. But yes that is exactly the system, I used that PDF and another one I found as well(http://petrofed.winwinhosting.net/upload/18Sep10/1.pdf) to learn how it functions and get a better visualization of what it consists of. I also have a lot of documentation of the buoy from the original builders and the companies who have previously done inspections and replacements of different parts. Though, as far as I can tell, this is first time that they are replacing the mooring chains in such a fashion. I am just unsure of how they will remove the chain and accurately re-install them again after inspection whilst still maintaining the buoy position offshore. From what I recall reading, it was originally designed to safely have 2 failures in the lines and still be able to take the worst-case scenario tension in the remaining chains. The project engineer really roughly doodled out what would need to happen just before he departed off-site, but with no real detail. What one of the other engineers mentioned was possibly having one or two other other boats moored to the buoy holding it in place by dragging the buoy to the opposite side off the chain being removed as to reduced the tension on the remaining buoys and keep the buoy position. I thought about it more afterwards and thought about how that would work, and I thought that if you had another boat moored to the mooring arm where the tanker normally would moor, you could just have the boat maneuvering around the buoy to either give slack or tension on the other chains. So say you want to remove one of the chains, pull the buoy in the direction of that chain to give slack to remove and detach it easier, then back again the other way to keep the buoy in position an relieve some of the extra tension distributed between the remaining chains. The maneuvering would be okay as well, I assume, since the arm swivels around the bearing? Though I assume care must be taken to avoid overloading that bearing. Then again it is designed to hold a 100kTonne tanker weathervaining around the buoy when taking on the cargo. I read another file on mooring systems and it mentioned installing spring buoys on the mooring lines can reduce the vertical load on the buoy but also offset the position of buoy and increase tension in the lines. I had an idea using these buoys to keep the CALM buoy in place, but I think that it is maybe over-complicated and impractical since there are a lot off other factors to consider like the time it takes to install additional buoys (vs just having a boat take dynamic control of the position of the buoy), the increased tension in the other lines, and if it is even possible or common practice.

    I'm also not sure where along the chain and how you would detach in from the anchor safely. Or even if you would detach the anchor at all. From what I have read it seems that it would not be easy to remove a drag embedded anchor once it is installed like this for permanent mooring, and the anchors are being re-used, they will not be replaced. I have found information on the actual inspection, and I have enough of an idea of how the chain and kenter shackles will be surveyed and replaced where necessary. But like I said, I don't have much to go in terms of the proper way to retrieve and re-install them. I have found some information on the initial installation of a mooring system, though fro what I can gather from the engineers sketch is that they look to do it one by one whilst the rest of the mooring chains are still in place. Though I could have misinterpreted that, since like I said, it wasn't very detailed. Again, let me know of any further clarification and information and I will provide. Though I am unsure of how much detail would be appropriate for me to share from a legal/work policies perspective
     
  13. gonzo
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    gonzo Senior Member

    A common way of removing anchors or moorings that are sunk in soft bottom is to use compressed air. Divers inject the air with a long pipe under and around it while there is tension on the chain from a crane or derrick. I am not an expert on these systems. However, I have worked on tugs and they can be made to stay in place. That means that a chain could be removed at a time with no danger. Of course, the weather should be calm.
     
  14. Rian199
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    Rian199 Junior Member

    Thanks gonzo, that actually makes a lot of sense, I will look into the method. The sketch the engineer did actually included a crane and a diver but with no further explanation, so that might be exactly what he was implying. Thanks a lot for that, that really helps :)
     

  15. TANSL
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    TANSL Senior Member

    Rian199, believe me when I say that I'm so glad you're progressing in your work. Gonzo's practical tips are valid many times. I just tried to tell you that without your own work you can get to get solution to your problems but never the right solution for you.
    Cheers.
     
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