Commercial Vessel Designs

[boatsource]

Does anyone have recommendations for good designs/designers to work with for commercial vessels such as crew boats, patrol boats, tugs, barges, offshore vessels, various ferries and possibly ships, etc?

Monohull and cat designs would be good, aluminum and steel for materials, would be good if there were options for designs that are up to an IACS class standards and some without.

I've already had a preliminary discussion with Robert Allan but looking for further options and recommendations from the professionals.

[Bijit Sarkar]

At your service

[Hugh Westcoast]

Hi All
I want to build a boat for scuba diving/live aboard on the West Coast of South Africa. We do not have many decent harbours around our coast besides the larger commercial ones and none near the places I want to go to.
Therefore I need a boat that can be comfortable at anchour in fairly rough sea conditions. I need a stableplatform with decent accomadation and a fair deck area. I will not be carring heavy cargo.Cruising speed of 10 to 18 knots but fuel efficent
I skipperd( /diver /supervisor ) a 13.4 meter GPR Cat (Twin Hull ) on the West Coast for several years while diamond diving (commercial opperation) we (our family) built the boat using hired moulds. We modified the hull for our needs and ran a successful opperation from lamberts bay (South Africa ) to north of Luderitz in Namibia, living on the boat for months at a time. The "Cleavy" had bunks for 12 (crew + divers.)
We would stay out untill the sea conditions stopped us diving, up to 10 days at a time.In winter we often have very nice sunny , windless days but with 5m+ swells. ( usual conditions we will go out to sea in will normaly be less than 1 to 2 meters)The Cleavy was a great working boat and would have made a nice pleasure boat modified to accomadate 4 to 6 people. But not stable enough in some of the sea conditions we experience on the West Coast.
I have been looking at building a similiar sized SWATH (Tri Hull) type boat for the above operation. We have over the years built several smaller ski /fishing boats but this will be a scratch built, one off to see if it is feasible to raise the capital for a larger 20-30 metre (under 100 ton boat). This may never happen but one can dream, in the meantime I will build the smaller one.
I have many ideas but not the background to design my boat from scratch,the building + enginering does not worry me, we have built many diamond mining plants and have a small enginerring workshop.I would have to use steel as I would not want to make a mould for a one off design.
Any comments or advise on how or where to go for information to help with the design of my boat would be most appriciated.
I have rough sketches if it will help to visilize my idea.If someone can offer an alternative to the SWATH idea I am open to any imput.
Cheers and thanks
Hugh

[yipster]

Hello Hugh
SWATH I belive is one of the biggest renewals in history for wave going vessels and find them very interesting.
As you must know designing and building a good swath is an engineering marble, the heave response can be variable (like in any design) and more than with a regular boat size matters. Stresses on the legs, deep draft and the big wide surface can only be light loaden for stability.
Than there is dynamic stabilisation, swath needs long driveshafts often with transmission boxes or hard to acces way down machinery, designing and building is expensive to name a few down sides but yes, the concept is valid and I like to hear and see more, show us your sketches please

Some links http://en.wikipedia.org/wiki/Small_W...Area_Twin_Hull
http://en.wikipedia.org/wiki/CCGS_Frederick_G._Creed
http://en.wikipedia.org/wiki/Sea_Shadow
http://www.abeking.com/publish/english/flash.html
http://www.gizmag.com/stability-60-s...peryacht/8877/
have a look in my gallery for some pencilled ideas
and as ultimate there is even a computer stabilized one legged swath

I see swath in combination with a flying middle hull design a la incat
Lockheed martin makes a sort of triangle by making the front legs closer than the rear, read Leo Lazouskas site for multihull configurations and spacing.
I like triangling just about everything and want the legs stand out
simple straight developable surfaces i like but not like the sea shadow.
belive SWATH looks can be improved
as some of the sites above mentiond: there is development, experience and more to be considered designing and building a swath, a 10 million grand like some receive may be nice, here also some copies from jane’s high speed marine craft '95

[yipster]

you got a fine looking swath listed i see boatsource
read this for big grands and inovation ( virginia class fe )
even with a pic of another one legged swath

[john.G]

I have extensive experience with wavepiercer types to 37 m. incredible boats on paper but... in light load conditions they have a tendancy to pitch like bastards. Remember that the load line puts the middle hull in the water. Lightships with 6' of air under the middle they lack longtitudinal stability. heavily loaded they're phenominal. most commercial trawler types or fishing types are designed to be stable at sea. We got out for average of 30 days and don't stop moving. Maybe have a look at pearl support vessels or similar? Beyond my experience.
I reccomend a talk to McBride design in NZ. Exchange rate should work for you too. Picture of a mcBride longliner

[john.G]

remember the picture this time LOL

[john.G]

Just because there seem to be some linguistic differences to what I refer to as a wavepiercer, I'm adding a photo of my old "baby". Built by Incat/ Croether, the original designers of the type.

[yipster]

hi john, good to hear some experiece

I have extensive experience with wavepiercer types to 37 m. incredible boats on paper

that flying middlehull borders out exessive wavepiercing i was thinking

in light load conditions they have a tendancy to pitch like bastards

from what i remember they eventually added a big stabilizer against pitching

Remember that the load line puts the middle hull in the water. Lightships with 6' of air under the middle they lack longtitudinal stability. heavily loaded they're phenominal.

did not knew that, i've never seen that middle hull in the water exept for longtitudal stability an wavebreaking

[Hugh Westcoast]

Hi Yipster and John. G
My first choice was a Wave Piercer type boat and I contacted a company in Tasmania that build a boat similer to the one from John.G.
I need a boat that can also handle fairly rough and choppy seas while at anchour for the night. That is why I am looking at a SWATH craft.
Cheers Hugh

[brian eiland]

Originally Posted by boatsource

Does anyone have recommendations for good designs/designers to work with for commercial vessels such as crew boats, patrol boats, tugs, barges, offshore vessels, various ferries and possibly ships, etc?

Monohull and cat designs would be good, aluminum and steel for materials, would be good if there were options for designs that are up to an IACS class standards and some without.

I've already had a preliminary discussion with Robert Allan but looking for further options and recommendations from the professionals.

You should look up this fellow Chris Barry (CD Barry)
http://www.boatdesign.net/forums/profile/cdbarry.html
http://www.blogger.com/profile/06448283530872239211

He worked with the US Coast Guard for years I believe.

Link on to his name and you will find any number of postings by him to this forum