can anyone suggest, how to calculate volume of forepeak tank

Discussion in 'Boat Design' started by appusree888, Dec 18, 2014.

  1. TeddyDiver
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    TeddyDiver Gollywobbler

    Just fill the tank and see how much it takes :p
     
  2. doug9694
    Joined: Dec 2014
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    doug9694 Small Engine Mechanic

    re-3: Calculate tank size

    I made a mistake. The area is not the 1/4 x for this shape. The 1/3 x is correct.

    Here is another formula: http://zobayer.blogspot.com/2009/11/volume-of-irregular-tetrahedron.html

    If you don't want to figure the volume then I suggest to do what TeddyDiver said.
    That is if there is a tank there. I was under the impression that it is an empty space and you want to put a tank there.
    You can buy a tank, or have one made, slightly smaller then the space and use that spray in foam to fill in around and support the tank. I have done this at the side of a sail boat where the side bows out and the bottom came to a point.
     
  3. appusree888
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    appusree888 Sreenath

    Tansl....this is more than enough.....now I got a clear picture.....sometime am like a tube light :). Thank you tansl
     
  4. appusree888
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    appusree888 Sreenath

    Thanks douge
     
  5. TANSL
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    TANSL Senior Member

  6. rwatson
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    rwatson Senior Member

    If you have the sizes in CAD, you must expect the ability to have it 'tell' you the volume with the Volume Function. Why do you need all the handraulic math ????
     
  7. Rabah
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    Rabah Senior Member

    Hi appusree 888,
    That you do not speak about computer model means that again the question is remodeling an existing ship what the case your preceding thread for tank calibration of a tug was.
    If you were the specialist - shipbuilder would know that the volume of a forepeak can be calculated on too methods as well as volume of the whole hull - through an integration on a length /on frames/ as have clarified Tansl, and through an integration on height /on water-lines/. On both methods it is necessary to receive the close sizes. Absolute coincidence will fail as it is an approximated method for integration.
    I guess that following your problem will be how receive ullage foot tables for volume at different levels of filling of the forepeak tank. And if it is necessary to calculate intact stability and the ballasting in a forepeak will be necessary, must to know for definite levels and a centroid of ballast on X and Z /I guess Y=0/. It is necessary as well at unsinkability calculations.
    In that case I recommend calculate integration on the second alternative - on water-lines. So it will be easier to receive outcomes for change a centroid of ballast.
    It is better to calculate X of ballast from forepeaks bulkhead than from AP or FP.
     
  8. TANSL
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    TANSL Senior Member

    sampeeter, what length are you talking about ?. LOA, waterline length, between perpendiculars, tonnage length?. It is very important to define this term.
    Peaks not have to be tanks, whether as "tank" we mean a space that can hold liquids.
     
  9. appusree888
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    appusree888 Sreenath

    Can anyone suggest how to calculate Load line for a Flat Barge habing Length as 19.90m, Breadth as 10.00m and Depth as 2.00m
     
  10. Rabah
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    Rabah Senior Member

    Hi Sreenath,
    Your question is incomplete!
    Надо уточнить следующее:
    1. Если это существующая баржа - с каким объемом располагаем для размещения перевозимого груза.
    2. Тип баржи – сухогрузная с трюмом, баржа – площадка для колесной техники или наливная
    3. Какой груз перевозим и с каким относительным весом

    Потом надо сделать следующие расчеты:
    1. Вычисляется кривая водоизмещения в зависимости от осадки – предполагаю что это прямая наклоненная линия с исключением в нижней части
    2. Вычисляется максимальный вес который можно перевозить
    - Если это наливный или сыпучий груз – наличный объем умножается на относительный вес груза
    - Если это тяжеловесная крупногабаритная техника или контейнеры – по их расположению в проекции План в трюме или на палубе и по числености
    3. На линии водоизмещения отмечается максимальный вес и получается максимальная осадка Tmax
    4. Вычисляется площадь и сопротивительный момент поперечного сечения баржи
    5. Принимаем что баржа это простая балка, свободно опертая в концах на две опоры и нагруженная равномерно распределенным грузом и вычисляем максимального изгибающего момента и максимальные срезывающие усилия
    6. Вычисляем нормальные от изгиба и тангенциальные напряжения от среза и сравниваем с допустимыми
    7. Если все в порядке, тогда T=Tmax и это будет грузовая ватерлиния
    8. Если поперечное сечение не выдержит надо уменьшить максимального веса и повторить расчеты.
    8a. Если проект новый и баржа сейчас проектируется – тогда надо увеличить площадь и сопротивительный момент поперечного сечения. Как? Например: переборка в ДР по всей длине грузовой части; двойное дно и двойные борта; увеличение тольщины обшивки днища, бортового ширстрека и палубного стрингера; увеличение размеров продольных конструктивных связей. Алтернативный вариант – применить более качественная низко легированная сталь, для которой допустимые напряжения будут большими.

    Если надо быть точными, то Правила классификации судов требуют и расчеты прочности при погрузке и разгрузке.
    Best Regards,
    Razmik Baharyan
    Naval Architect
     
  11. TANSL
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    TANSL Senior Member

    Rabah, please, you're going to allow me somewhat silly question. The answer you gave to Sreenath, it is likely that interests many people. Your degree probably is of no interest to most people. So why do you write the answer in a language many do not understand and you put your degree in a language that everybody understands ?. Thank you in advance for your explanation.
     
  12. saraa.fenwick
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    saraa.fenwick New Member

    Hi,
    Considering you shape or the design, we can ensure good strength with less cost & material which should carry & support heavy weight & achieve stability , talking about the equation , we can use Equation of newton's 2nd law, ie. F=ma, where f is force, m is mass & a is acceleration & to ensure the proper weight & balance the total force in vertical direction should be zero.
     

  13. alan white
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    alan white Senior Member

    Fill with packing peanuts, drop into cardboard box of measured dimensions, measure height. Why torture yourself?
     
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