hull design

[Guillermo]

Originally Posted by shoaib_jaff

...i thought that you could help me with the parent ship data, thats all

1 day voyage for a 50m stern trawler and a 3800 m trawling depth sound quite weird to me. I do not know if there is net handling machinery for such an extreme depth. What's the intended base port and fishery? As you probably know, a moratory on deep sea bottom trawling is being internationally considered, due to its pernicious effect on some habitats (http://news.bbc.co.uk/1/hi/sci/tech/4308156.stm)
Please, do not post information little by little about your design determining factors, or I'll not be happy about helping (And probably others either). Just post all you already know or want to know about. That's more fair.
Cheers.

P.S.
“In recent years in India, the major thrust in fisheries development has been on optimizing production and productivity, augmenting export of marine products, generating employment and improving the welfare of fishermen and their socio-economic status. Fishing efforts are largely confined to the inshore waters through artisanal and mechanized sectors. About 90 per cent of the present production from the marine sector is within a depth range of up to 50 to 70
metres and the remaining 10 per cent from depths extending up to 200 metres. While 93 per cent of the production is contributed by artisanal and motorized sectors, the remaining seven per cent is contributed by deep sea fishing fleets confining their operation mainly to the shrimp grounds in the upper east coast."

On indian fisheries:
http://www.hinduonnet.com/businessli...s/080305g1.htm
http://www.fao.org/documents/show_cd...E/y4849e09.htm
http://countrystudies.us/india/107.htm

From the Indian "Integrated Fisheries Project":
"Experimental Deep Sea Fishing to test commercial feasibility:
As more and more fishing effort to be diverted to areas beyond traditional fishing limits, the expertise available with the Project has to be deployed to conduct intensive fishing operations in grounds where sizeable resource potential is indicated through exploratory surveys by vessels of Fishery Survey of India. Such intensive fishing would generate data needed to make investment decisions by entrepreneurs besides demonstrating to the industry the technology suitable for exploitation of such reserves."

Cheers.

[RANCHI OTTO]

Guillermo is a precious source of informations..thanks!

[khokan]

Can anyone help me with the basic fundamentals of Ship Hull Detail Design? i want to know about Ship Hull Detail Design in detail. if u have any softcopy of books/documents

Thanx in advance for ur reply.
Regards
Khokan

[PNACS]

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[SailDesign]

Originally Posted by ranchi otto

Guillermo is a precious source of informations..thanks!

I'd like to add my vote to that one. Guillermo is amazing.
Steve

[Guillermo]

Stev & Ranchi: Thanks a lot, but stop the crawling....

shoaib: Something for you: Not within your strange specs, but a modern deep sea stern trawler (You'll have to learn some Spanish, sorry )

DESCRIPCIÓN: Pesquero congelador de arrastre por popa
AÑO DE CONSTRUCCIÓN: 2002

CARACTERÍSTICAS PRINCIPALES
Eslora total 55,64 m.
Eslora entre perpendiculares 49,45 m.
Manga 11,60 m.
Puntal a la cubierta principal 7,90 m.
Puntal a la cubierta segunda 5,20 m.
Calado de trazado 5,20 m.
Arqueo bruto (1969) 1.222 GT
CLASIFICACIÓN
LRS+100A1, Stern Trawler, + LMC, UMS
CAPACIDADES
Bodega 884 m³
Combustible 211 m³
Capacidad de agua dulce 76 m³
Aceite 3,4 m³
POTENCIA Y VELOCIDAD
Motor principal WARTSILA 2.760 Kw
Velocidad en pruebas 14,00 nudos
Autonomía 6.500 millas
Grupos auxiliares 2 x 632 Kw
Alternador de cola 1200 Kw
TRIPULACIÓN
Dotación 18
PLANTA DE CONGELACIÓN
Capacidad para congelar 77 Tons. por día en 11 armarios de placas de 15 Tons. por día en túnel de congelación

[shoaib_jaff]

guillermo,
thanks for the valuable information!
i have couple of questions regarding the design problem (dont misunderstand me i am a learner)

which one is better sections for trawler: normal/ knuckle / u / v?

which one is used bulbous / racked bow for trawlers in modern design?

why a slight rack is given for a keel in trawlers? ( i have seen in some design)

do we use a skeg for better maneouverability in modern design of trawlers? (now-a days bow thrusters are mostly used)

which one is used in modern design: a sheer deck or a forecastle deck?

is camber necessary for trawlers?

[PNACS]

Hi Shoib,

Being a Naval Architecture Student you shoud be able find answers to all these questions by yourself from basics you have learnt over last 6-7 semesters. For example, raked Bow OR bulbous bow?. You could find the answers from basics you have learnt in resistance part of Naval architecture (Remember..... or flip back to those chapters in PNA, the advantage of bulbous bow is for a certain rage Froud Number). Cant you work out hull form by iterating/optimizing between effect of LCB on resistance, Required forward hold volume, angle of entrance etc etc).? The Skeg is for directional stability. Skeg will not add to maneouverability of your vessel. Based on Class rules, find minimum bow height required & decide if u need a forecastle deck.

All the Best!!

[Guillermo]

shoaib_jaff:

which one is better sections for trawler: normal/ knuckle / u / v?
which one is used bulbous / racked bow for trawlers in modern design?

U sections. Bulbous bow for long rangers, but as you are talking about a 1 day trip , you really don't need it.

why a slight rack is given for a keel in trawlers? ( i have seen in some design)

To create space to locate a big diameter propeller, if I understood your question correctly.

do we use a skeg for better maneouverability in modern design of trawlers? (now-a days bow thrusters are mostly used)

If you use a rudder, you usually use skegs to support it with this type of vessels, if I properly understood your question.

Ducted propeller, rudder and bow thruster are nowadays commonly used.

which one is used in modern design: a sheer deck or a forecastle deck?

Or even a full length sheltered working deck with net whinches forward. Depends on net handling system and working space needings. You have to work out that.

is camber necessary for trawlers?
For weather decks, yes. Usually it's given to all decks.

Attached find a present for you. The lines of a 36 m LOA stern trawler.

Hope this is useful. I think you now ow me $.20

Cheers.

[SailDesign]

I'll give Guillermo an A for this homework assignment

[shoaib_jaff]

i thank everybody for helping me in one way or the other

special thanks to GUILLERMO

i had enough from him for starting my project, now no more question will be asked by me.
i will contact you again guillermo, if needed.........
you helped me from the scratch....
with all your support i will be able to design a better trawler
regarding the $0.2, i can send you a copy of my project when its complete, just send me our mailing address.
thanks again...............