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Playing CSI on a windlass failure

Discussion in 'Technical Discussion' started by C4ENG, Mar 27, 2009.

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  1. C4ENG

    C4ENG Senior Member

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    Muir vert windlass VCR11000
    The deck crew was raising the anchor when a hydraulic line failed. The anchor was about 3 meters from being completely raised up into the vessel when a line blew off at a swedge fitting suppling hydraulic power to the windlass hydro motor. Upon arrival of the situation, the windlass was secured with the brakes on tightly and the anchor right at the water line. I am thinking that maybe the deck crew did not release the brakes properly and rode the anchor up as such causing the failure with excess hydraulic PSI. Question is.. If a hydraulic line opens with a load on the windlass.. should that allow the anchor to free fall back down? Or does the windlass still hold the anchor/load even with an open hydraulic line?
    If it does free fall with a broken line, then that would mean that they did leave the brakes on..
  2. AMG

    AMG YF Moderator

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    I am not sure, but think that all stations in a hydraulic system has their own back pressure valves, so a leak should not affect all items.
  3. Marmot

    Marmot Senior Member

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    Uh, you might want to do some reasearch into how your hydraulic system works chief ...
  4. C4ENG

    C4ENG Senior Member

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    What do you think I am doing right now???

    If I was so smart that I knew exactly how everything worked..
    I would probably own the boat that I am working on now...

    Is that the best you have to offer in my research here Marmot?
  5. Codger

    Codger YF Wisdom Dept.

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    Not familiar with this specific product.
    That being said... It's completely dependent on whether the system is designed to "fail open" or "fail closed". There should be a check valve accessible that will have what looks like a butterfly valve etching or label with an arrow indicating flow direction , the position of which indicates the fail mode. If that information isn't there then only recourse is to check with the manufacturer.
  6. C4ENG

    C4ENG Senior Member

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    Yes I did read the tech book from Muir but it was weak, more opperation than anything else. I wanted to call Muir but they were in Australia, so I sent an email.
  7. dennismc

    dennismc Senior Member

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    Anchor winch pulling anchor, hydraulic fitting fails, fluid
    pisses out, apply brake all stop. YES

    If the brake had been partially on during lift, would that "possibly"
    cause overpressure and fitting failure? WELL IT CERTAINLY WOULD CAUSE
    "MORE" PRESSURE THAN IF THE BRAKE WAS OFF, MORE FRICTION MORE PRESSURE TO
    OVERCOME.

    If the anchor stopped coming up when the fitting failed and did not free
    fall, would that prove brake partially on or would anchor just stop
    where it was?? DEPENDS ON THE TYPE OF ANCHOR WINCH IF WORM GEAR DRIVE IT
    WOULD NOT FREE FALL NO MATTER WHAT, IF PINION GEAR IT WOULD, ONE WOULD
    THINK, OR COULD FREE FALL EXCEPT FOR FRICTION MOST OF WHICH COULD HAVE BEEN
    CAUSE BY THE BRAKE. BY CHANCE DOES THE WINCH HAVE A GEAR "DOG" AS MY OLD
    FASHION ONE DOES IF SO IT WOULD CATCH AND STOP FREE FALL.
  8. K1W1

    K1W1 Senior Member

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    This is only in an integrated Hydraulic System.


    By and large and the original poster should know if he actually holds a Chief Engineers CoC. A hydraulic system has a system pressure, changes in the system pressure cause a flow in the fluid to the source of low resistance( a leak) a total loss of pressure can often set off some Non Return Valves in the system.

    I seriously doubt that a simple system like an anchor windlass which for all intents and purposes is a simple hydraulic motor taking the place of an Electric Motor doing the same job, has anything more in way of protection for free running other that the manual friction lining equipped brake band.

    A generous application of ample elbow grease to the actuating wheel of this would have averted any problem and rendered th8s thread unnecessary.

    A blown hose on a properly hydraulic system should result in an alarm for loss of system pressure and a stop for the pump section by section in an integrated system but definitely all over in loss of discharge pressure which in an extreme case is caused by loss of Fluid at the intake port(s) of the pump
  9. C4ENG

    C4ENG Senior Member

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    A lic engineer should know everything? I already stated my opinion about knowing everything...I am not sure if you knew the answer either...

    I definetely do know enough not to go taking apart perfectly good functioning equipment while at anchor to find answers that can be located in other ways..
  10. dennismc

    dennismc Senior Member

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    Just fix the bad fitting and get on with cruising.document the failure, take pics, have a cold one .
  11. C4ENG

    C4ENG Senior Member

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    Done and done.
    Cheers
  12. K1W1

    K1W1 Senior Member

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    Hi,

    I suggest you read what I wrote before your offhand comments are transmitted by keyboard to screen.

    By the way- What Marine Chief Engineers License do you actually have?
  13. Marmot

    Marmot Senior Member

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    Well chiefy, first off it is inconceivable that your boat has a hydraulic system that lacks a feature to control pressure or flow. What do you think all that hydraulic power does when you don't have the control valve on that windlass open? Does the system explode whenever some consumer is not rotating? Does the anchor drop whenever the control valve is not set to raise or lower? I don't think it does. Haven't you ever operated the system so you know how it works so you can troubleshoot it or at least understand what the deckies are talking about?


    So, before you get too upset at being tweaked because you blamed the deckies for something you are obviously clueless about and as "chief" should at least know how your systems work, how about just thinking about the system for a moment while you are looking for the hydraulics drawings which it appears like you have never bothered to look at.

    Does the windlass hydraulic motor have a brake of its own? If it does, hydraulic pressure first releases the brake then turns the motor. Loss of pressure as would happen if the supply line broke (you never said which one failed, if you even know) would allow the brake to set and lock the system. Most windlasses let the anchor freefall by disconnecting the drum from the drive (ask a deckie to explain it to you) because the worm gearing used on most will prevent it from lowering unpowered under load. But some might be geared differetly and that is why some may have the motor brake. This also applies to electric driven units. If there is no motor mounted automatic brake then the windlass most likely will not freefall under load due to the type and ratio of gearing.

    But back to basics, most hydraulic systems built since the late 1800s have overpressure relief valves and flow controls. If your pump is an axial piston pump (as is likely on all but the smallest boat) it most likely has a contol device (a servo) which controls the pressure and flow up to the system limit. When there is no flow the pump only moves a tiny amount of oil to maintain set pressure. When pressure drops as when a consumer (your windlass) is put online the pump increases output to meet flow and pressure demand. The pressure is limited by the controls and blocking flow will not blow up the system. In the event the pressure control failed a system pressure relief valve would open to prevent the deckies from blowing up the system. This is really basic stuff that anyone who has the nerve to call himself "chief" should know and that is why you are getting the flack over this. It embarrasses all the real chiefs out there.
    Last edited: Mar 28, 2009
  14. C4ENG

    C4ENG Senior Member

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    This use to be a pretty cool place to bring your questions and stories to share with others, things that could also benefit others who want to read these threads for learning.. But then people seem to want to ridicule others with words like “Chiefy” being questioned on your documentation for your position, so and so on, because you didn’t know an answer to something..?

    Dennismc.. Thanks for your help.. With your guidance I figured out the answer. The windlass has a worm driven gear box so the answer is "NO" the windlass would not free fall the load with a open hydro line…

    As far as blaming deck crew.. It was only theory for the curiosity of learning, not to try and hurt another for making a mistake.. It would not serve me, but it did serve me to play CSI as I learned quite a lot.. Maybe one day I will grow up and be real smart like some other people:)
  15. Capt J

    Capt J Senior Member

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    You could try releasing the brake on it now and see if it free falls.

    There are many reasons why the line may have broke. Being that it broke with the anchor so close, its possible the anchor was caught underneath a rock and the extra force to lift it vertically could have put excess pressure on it. It's possible the line is just old. If the brake was on partially it would have had to have been fairly tight to blow a line and, it would have been fairly apparent and either smelled the material or slowed the anchor coming in enough. but who knows with some crew members. Regardless, fixing a blown line is not the end of the world.
  16. Marmot

    Marmot Senior Member

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    It still is and folks who have questions get answers and advice. The problem with your question and the way it was presented is that you describe yourself as a chief engineer but your question and the way it was presented clearly labeled you as a poseur with little knowledge of how the systems on the boat operate and very little knowledge of the fundamentals that should be part of the toolbox of anyone calling himself an engineer much less claiming the title of chief.

    That post and your other one about the "charge" leaking out of a generator really do call your qualifications into question. This makes a real engineer whinge with embarrassment because it cheapens the currency.

    If you had claimed to be a boat owner or crewmember who was interested in learning what might have happened or how the windlass works then it would have been different. A simple answer would have been supplied and your ignorance wouldn't have been highlighted. Your asking that question that way was like a doctor asking someone to explain blood pressure ... if you lack the fundamentals how can you look your employer in the eye and claim to have earned a paycheck? And how on earth can you claim to be a chief engineer and blame the deckies if you don't even know how the thing works? That is what pushed my button.

    It is a chief engineer's role to help other crewmembers understand how to operate machinery properly and why, not to blame them when he doesn't even know his own job. Until you learn that there is little point in trying to teach you anything about engineering.
  17. Capt Bill11

    Capt Bill11 Senior Member

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    The above is all correct and very informative stuff. It's just to bad you felt the need to add the sarcasm and condescension. It really takes away from what you have to offer. And other than making you feel/look superior adds nothing to the discussion.
    Take a tip from another sarcastic, condescending wise ass, myself, consider biting your lip more often. That way people are more likely to really hear what you have to say. Instead of reacting to how you say it.

    But you're right of course, it is basic hydraulic stuff that a "chief" engineer should know and understand. But at least he had the smarts to admit what he didn't know and ask for help. Hopefully C4ENG will now study up on the subject as opposed to being turned off to it by your "teaching" methods.
  18. Capt J

    Capt J Senior Member

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    Marmot, regardless of what C4ENG position is on the vessel. There is no need to go on with this dialogue of what he should and shouldn't know and judging the guy.

    Why is it that you cannot just answer the guys question and go on with your day. None of this blabber answered the guys question, it's just chatter. I am sure there are some engineering things that you don't know as well. Some of us actually work and don't have the loyalty to spend an entire day reading up about it. Also it wouldn't be money well spent for the owner to waste an entire day finding out about one thing, meanwhile we could be fixing 5 different things, and go to someone for the answer on the one thing. Nobody can know every single thing on every single system on every single yacht that they work on. While an engineer should be knowledgable about most everything on a private yacht, there are so many different systems from yacht to yacht that it's almost impossible to do so. Keep in mind you're talking about an engineer on a private yacht with many different off the wall gadgets and toys, not a cruise ship or commercial ship.
  19. Marmot

    Marmot Senior Member

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    You are quite correct, if I were the captain or the owner I wouldn't have gone on with the dialogue, I would have fired him moments after the event. He should have gone to the manuals not the internet, and more importantly, he should have known such incredibly basic engineering before accepting the position he is obviously not qualifed to hold.

    If it sounds like I have no patience for fraudulent engineers it is because I don't. Engineers don't have to know everything but they must know what is installed on their boat and where to find the information on how it works if they accept a chief's paycheck. Why should I be nice and keep my opinion to myself? I have to deal with the amazing screwups of amateur engineers and the cost it imposes on owners nearly every day. Paying high salaries to unqualified and incompetent engineers is the sort of thing that drives owners away from the industry, and effects all of us.

    Sarcastic and condescending? Perhaps, but the subject hasn't earned much more and trying to defend such ignorance and blame others is hardly worth much more. We can't afford that type of "engineer" in this business and no owner should accept that level of performance. I am not going to apologize for telling it like I see it and have no qualms about ridiculing the ridiculous.

    What are you trying to say CaptJ, that just because it's a yacht the guy doesn't have to know his job or the very basic machinery he is paid to maintain? That doesn't cut it either. The hydraulic system and windlass is not a "gadget or toy" peculiar to a single yacht. His paycheck probably far exceeds what one of his skill level and "expertise" would demand on a commercial vessel or cruise ship even if he had the training or certification to hold any position on one of those vessels. So, don't play the "only a yacht" card. That is like saying it's only a yacht so the captain doesn't need to know how to read a chart.
  20. Seafarer

    Seafarer Senior Member

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    What CaptJ is saying is that you're making yourself look bad, not C4ENG. He's right.

    You can feel strongly without being so strident.