Fishing Vesels stability

Discussion in 'Stability' started by Guillermo, Mar 8, 2008.

  1. Guillermo
    Joined: Mar 2005
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    Guillermo Ingeniero Naval

    Thanks Peter.
    The main problem I have encountered with the EU's GT regulations is that they somehow "encourage" designs with low moulded depth, as the boatowner usually desires more length and beam for the amount of GTs (volume) he has available to build a new boat.

    This makes the freeboard to become scarce thus compromising the fullfilment of the mandatory intact stability criteria (Full IMO's ones, applicable in Spain to boats down to 12 m of registered length) specially the maximum GZ occurring at 25 degress of heel or more. So boatowner asks the designer to design to not realistic operational load conditions, limiting fuel tanks and fish catches, specially if carried on deck.

    Then, in the real operation of the boat, the load conditions are greatly overpassed, with catches much bigger than studied carried on deck (as well as heavier fishing tackles) and even sometimes fitting out fuel tanks in places not allowed for in the design.

    Is somebody in other countries experiencing this same problem?

    Cheers.

    P.S.
    Peter, I see you are in Italy. Can you be of help help with the issue about building works management and liability, raised in http://www.boatdesign.net/forums/boat-design/personal-responsibility-ship-boatbuilding-26435.html ?
    Thanks in advance.
     
  2. mflapan
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    mflapan Junior Member

    Guillermo

    Back in the 1980s, we had a similar problem that the method for determining fishing units on vessels was not supportive of safe proportions. We wrote to the State Fishing agency highlighting our concerns on the matter and they eventually responded by changing the way they divided the total fishing effort.

    It was a long time ago, so I do not remember the details.

    Regards
    Mori
     
  3. Guillermo
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    Guillermo Ingeniero Naval

    Thanks Mori.
    This is been an important isue since several years ago around here, but I do not see movements towards the reconsidering of the EU's regulations on the matter. Perhaps it is because this is only a problem of Spain, that's why I'm asking, to try to find out what happens in other EU countries.

    Fishing effort has to be managed with allowed quotas for each fishing vessel/fleet/grounds, but not in GTs or HPs. This regulation, sumed to other encouraging the wellbeing of crews via bigger living spaces on deck, is producing (at least in Spain) dangerous boats which are suffering serious accidents with casualties, due to the mentioned overloading and other factors as clogged freeports, per example.

    Cheers.
     
  4. peter radclyffe
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    peter radclyffe Senior Member

    contact the FISHING NEWS, the industries U K paper, I read it for 20 years working in england, & it's very good, I remember some problems with rulebeaters being measured from sternpost to stem, some boats had unfeasibly long transoms which made them unsteerable in bad weather
     
  5. bremerjohn
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    bremerjohn Junior Member

    US regs compared with others

    Guillermo,

    I haven't studied the EU fishing vessel regulations carefully to compare, but it is my understanding that compared to the rules we have in the US, at least in Europe the rules are based on vessel volume (such as your GT reference) or hold capacity.

    Here in the US the National Marine Fishery Service, and also some states such as Alaska, regulate the size of fishing vessels (as it relates to the allowed fishery) almost entirely based on length of vessel. This has been frustrating for designers for years, and some of those on the management side as well. Your example of the rulebeaters plays out classically for example in Alaska where the 58 foot limit seiners have pushed the B/L ratio upwards. There have been dicussions within the North Pacific Fishery Management Council, including quite recently, to place ratio restrictions on these vessels. From the designers standpoint a capacity limit would be more constructive than a limit based solely on a principal dimension or ratio. The overall size limit has its place in some fisheries where there are many vessels in crowded waters, and where it is desired to keep large vessels from crowding out the others.

    While some valid arguments can be made against the high B/L ratioed vessels (i.e. running efficiency, roll accelerations), there are some merits to these vessels. In this era of quotas a wider vessel with more capacity allows an operator to make fewer trips to sea to catch his quota, thus realizing a net decrease in fuel consumption over a season. Fewer trips also means less exposure to icing and storms. The wider deck allows more crab pots to be carried for the crabbers. Again, they are under a quota system, so it isn't about catching more. It's about catching your share safely and efficiently. The beamier vessel, though being inherently stifffer because of typically higher GM, also requires a lot more wind/wave energy to make it roll in the first place. We've yet to have a customer complain that their vessel was too wide, and we've done plenty of "sponson" projects over the years in addition to new builds.

    I'm interested in studying the EU regulations to see what drives the design. It appears too that IMO is close to publishing some stability criteria for small fishing vessels, which might make an impact. The US Coast Guard is currently in a rulemaking process also to cover fishing vessels under 24m (79 feet). There are, at present, no mandatory safety and stability requirements for fishing vessels under this size in the US, and statistics (the Coast Guard's) have shown the majority of casualties are occurring in this smaller size range (40-79 feet registered length). Hopefully the Coast Guard will look closely at what IMO is doing. Historically this has not been the case.

    John
     
  6. bremerjohn
    Joined: Apr 2009
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    Location: Bremerton, WA

    bremerjohn Junior Member

    US regs compared with others

    Guillermo,

    I haven't studied the EU fishing vessel regulations carefully to compare, but it is my understanding that compared to the rules we have in the US, at least in Europe the rules are based on vessel volume (such as your GT reference) or hold capacity.

    Here in the US the National Marine Fishery Service, and also some states such as Alaska, regulate the size of fishing vessels (as it relates to the allowed fishery) almost entirely based on length of vessel. This has been frustrating for designers for years, and some of those on the management side as well. Your example of the rulebeaters plays out classically for example in Alaska where the 58 foot limit seiners have pushed the B/L ratio upwards. There have been dicussions within the North Pacific Fishery Management Council, including quite recently, to place ratio restrictions on these vessels. From the designers standpoint a capacity limit would be more constructive than a limit based solely on a principal dimension or ratio. The overall size limit has its place in some fisheries where there are many vessels in crowded waters, and where it is desired to keep large vessels from crowding out the others.

    While some valid arguments can be made against the high B/L ratioed vessels (i.e. running efficiency, roll accelerations), there are some merits to these vessels. In this era of quotas a wider vessel with more capacity allows an operator to make fewer trips to sea to catch his quota, thus realizing a net decrease in fuel consumption over a season. Fewer trips also means less exposure to icing and storms. The wider deck allows more crab pots to be carried for the crabbers. Again, they are under a quota system, so it isn't about catching more. It's about catching your share safely and efficiently. The beamier vessel, though being inherently stifffer because of typically higher GM, also requires a lot more wind/wave energy to make it roll in the first place. We've yet to have a customer complain that their vessel was too wide, and we've done plenty of "sponson" projects over the years in addition to new builds.

    I'm interested in studying the EU regulations to see what drives the design. It appears too that IMO is close to publishing some stability criteria for small fishing vessels, which might make an impact. The US Coast Guard is currently in a rulemaking process also to cover fishing vessels under 24m (79 feet). There are, at present, no mandatory safety and stability requirements for fishing vessels under this size in the US, and statistics (the Coast Guard's) have shown the majority of casualties are occurring in this smaller size range (40-79 feet registered length). Hopefully the Coast Guard will look closely at what IMO is doing. Historically this has not been the case.

    John
     
  7. Guillermo
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    Guillermo Ingeniero Naval

    Thanks for your information, John.

    As said, limiting the volume under deck as a criteria somehow "encourage" designs with low moulded depth (low freeboard), which may make the boats risky, so I do not like it. There are many voices around here (mine among them) saying it makes no technical sense to control the fishing effort by limiting whatever in the design of fishing vessels (note: vessels, not fishing gear).

    What needs to be limited is the fishing quota of each vessel, but of course this implies a bigger and more expensive inspecting effort which authorities don't like. Then, if an owner makes a boat too big or too small for his boat's quota he will go into problems, but that should be his risk as an entrepreneur.

    Other arising voices are saying the quota should not be individual but of the particular fishing ground and specie, so for a given existing fleet what needs to be limited is just the number of days the fleet can work in a certain period of time. As all FV are obligued to carry a "Blue Box" (Argos system) authorities can always know if a particular FV is fishing out of the allowed period of time. But this still leaves the problem of what the criteria should be when substituting an old unit.

    About the small commercial fishing boats stability criteria, we have the following in Spain:
    - Over 12 m of registering length, we use IMO's.
    - Under 12 m, we have now to use ISO 12217, which I do not like at all as I have encountered several problems of application because that particular ISO was conceived for recreational crafts not commercial fishing boats.

    Previous test and criteria for the very small ones was like this:

    - Boat in full load condition, this is full tanks, all crew aboard, fishing gear in its storage position (usually on deck) and an equivalent deck load to the pretended catch (or then in holds, but these boats use to carry catch on deck).
    - Heeling weights given by the formula: W = 0,065 Afl in tonnes (6,5% of floatation area in sqm) or then the weights given in a official table (as a function of B).
    - Weights are moved from B/3 at one side of the Center Line to B/3 to the other (or then to the sides and a linear correction is made). If the boat heels less than 14º and does not submerge the deck at any point, then the boat has acceptable stability.


    This has been working nicely from 1964, being a simple and cheap test to perform and having provided good safety levels to the fleet. So I do not know why they substituted it by the many times inaplicable and more expensive to test ISO. :mad:

    Cheers.
     
  8. comfisherman
    Joined: Apr 2009
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    Location: Alaska

    comfisherman Senior Member

    Alaska rule beaters

    As bremerjohn pointed out the brunt of Alaska fisheries are limited to length, The most popular being 32 in Bristol bay, and the aforementioned 58 limit seiners. The halibut fishery is broken down By length as well in i.e. D-class is 35, C-class is sub 60. Even our federal llp's for ground fish are broken down by length.

    Some fisheries are limited by limited entry permits only, some with length restrictions as well. Oregon does length and pot restrictions on their crab fishery, however it is able to go up or down a percentage of its overall length.

    The only fishery to my knowledge that tonnage plays a significant role in is the Alaska crab and Pollock drag fisheries. I believe that many of the sponson and lengthen jobs shoot for sub 200 net tons. The main reason is to avoid the need for licensed masters and mates.

    I am a bit of a fan of the rule beater boats, there has been a massive surge in 58' limit boats in the recent future and they are taking the role of much larger vessels. Most are fairly new and well built and quite seaworthy, there are isolated incidents of the crew pushing them to hard. For the most part however they are in quite a bit better shape then the assorted 80 foot gulf boats they are replacing.

    I fish a 32' limit bay boat, and while it is shallow draft for fishing the bay it is quite beamy at around 15.5" wide, but not the widest I have seen. It's ride is fair and it is a stable platform, it packs an admirable amount of fish with lots of extra free board. When the wide body boats came out it gave a definite advantage at first, however I am blessed to be in a country that gives me the freedom to build a bigger boat. After a while however the fishery went shallow and fast and it seems to have equalized a bit.

    I would be significantly concerned if enforcement decided to limit fishing impact based of tonnage. I like the fact that I can have a significant amount of free board. I would think, based of the sustainability we have achieved in many of the Alaska fisheries that the length+limited entry system would speak for its effectiveness.

    -Richard
     
  9. Guillermo
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    Guillermo Ingeniero Naval

    Very interesting, thanks. Perhaps we should think about such a system of length and entry limits. I'm going to comment it with people here.

    Cheers.
     
  10. Ad Hoc
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    Ad Hoc Naval Architect

    Guillermo

    What aspects of fishing vessel deisgn do you currently not like and why, and what would you like to see included, and why?
     
  11. Guillermo
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    Guillermo Ingeniero Naval

    I've said it: limiting by volume. See previous posts.

    Cheers.
     
  12. Ad Hoc
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    Ad Hoc Naval Architect

    G.
    that's what I thought, but just wanted to be clear.
    Well, then join the very long que. Since all vessels are limited by volume to a certain extent in their operations, all for very often stupid reasons too.

    The US 100 tonne rule, which is why many vessels try to be under 100tonne, why..decreases crewing!

    400 Tonne SOLAS for oily water separator etc

    There are many similar "bizarre" demarcations with tonnage, and the same applies for length too...why 24m?...or why ships with 'passengers' above 12 in total are called passenger ships, why not 20, what is 12 for? etc

    If there is a fundamental philosophy that is wrong with a particular rule, then that should be addressed. But a case needs to be built up as to why. Also not just why, but a replacement that satisfies the concerns, and can be demonstrated to still ensure the safety of previous vessels as well as future ones.

    We can't cherry pick rules, as much as we would like too, so the only way is to provide alternatives to the current legislation and showing why, and demonstrating the safety aspect is not only maintained, but enhanced.

    Otherwise you're on a hiding to nothing.

    I was on the UK IMO structures committee for the HSC code. We all knew there were deficiencies and errors in the original 1994 code, but just to bleat about them wasn't enough. We had to say why, where and then provide alternatives and demonstrate their effects, which we did. And eventually did get parts changed
     
  13. Çemberci
    Joined: Apr 2007
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    Çemberci Senior Member

    stability

    a literature for vessel stability " A best practices guide to vessel stability -Guiding fishermen safely in to the future-US Coast Guard"
    Oktay Çemberci
     

    Attached Files:

  14. Guillermo
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    Guillermo Ingeniero Naval

    Yes, I know that one, Çemberci, thanks.

    By the way, I take the opportunity to tell these forums members we are organizing a Seminar on "Commercial fishing vessels' crews and Stability". It will take place on November the 17th in Vigo, within the scope of the World Fishing Exhibition (http://www.worldfishingexhibition.com/index.php?lang=en).

    Panel of international experts is almost settled and I hope to soon be able to inform here about the program. All of you are invited to attend and also take some time to know our wonderful Rias, delicious dishes, sparkling wines and friendly people!

    Cheers :)
     

  15. Ad Hoc
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    Ad Hoc Naval Architect

    Guillermo

    I am in regular contact with several professors here at Osaka University; where i have also lectured at times. One Prof. focuses upon stability of fishing vessels and is also on the IMO committee for stability too, I'll ask him if he knows of this and make him aware.
     
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