ask : Bow Design?

Dear friends, I'm Gafaruddin. I'm a mechanical engineering student. Now I take my final project. As the topic, I take a bow design. Now I need some answer about the reasons of choosing bow design. what are the important aspects of choosing bow design for a ship?
Thank you..

 

For me, I sail inland mostly, so dealing with Lake Michigan chop versus ocean swells makes a difference, as well as buoyancy. I like to sail somewhat dry too, so the bow needs to cut into a wave, to a point, and deflect the water...or rise, but not rock too much.

My ideal is are the bows of the proa Amatasi and catamaran Nice Pair, shown below.

 

There is bows design.

https://www.google.co.uk/search?q=s...NF-a10QXPj4HQCA&ved=0CGwQsAQ&biw=1143&bih=688

http://www.stowmasters.com/xbow.htm

http://en.wikipedia.org/wiki/Bow_(ship)

http://www.google.co.uk/imgres?hl=e...85&start=12&ndsp=20&ved=1t:429,r:3,s:12,i:123

Then there is bow design.

http://compare.ebay.co.uk/like/160772521720?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla

Use Google, then you'll understand why humans build boats in many different shapes.

Good luck.

 

Could not disagree, Pericles. And, like lots of things, to each for each, as needs dictate. Amazing stuff, really. Lad will have much fun editing that work.

 

Gafaruddin

A very long way from Surabaya is Douarnenez in the west of France.
The town just celebrated its Festival four days ago. Here are two videos. There are many more on Youtube, so you can view how other maritime nations built their ships.

http://www.youtube.com/watch?v=RJVRT1NRriA

http://www.youtube.com/watch?v=WLURzV8HYZM

Best wishes.

 

To : Pericles

ehm, basically I'm not a sailor. I just take bow design as my final project. I try to analyze the tension stress in each type of bow design. But I love ship. When I was child my father made me a boat from bamboos arrangement and it was nice to me..

By the way thank's for your information...

Warm regards from Surabaya, Indonesia..

 

Ok, thank you. how about bow design in tankers? it's seem has a big resistance? but what is the the important consideration of choosing this bow design? why the designer don't use a raked bow or another bow design which is more efficient in water resistance?

something lke this

By the way thank's for your time to answer my questions..

 

You should strongly study and understand commercial boat's hull design, They are different from the average boat, so learn why they are used.

There are lots of different types of sailors, many different ideas of the best types of boats..... yet many commercial boat hulls look similar when they are designed by companies that run them and pay the fuel bill.

 

Maybe like how you want to drive a Cadillac at home, but at work you drive a rough riding heavy duty truck that is designed for work, and work above all else.

 

A large tanker or bulker speed-length ratio is so low and the vessel so large compared to most seaways that it really doesn't matter. So increasing the block coefficient for more cargo and simplifing the construction to reduce cost are the driving factors. Almost all large (100,000+ DWT) tankers have ellipitical or cylinderical bows with little or no flare up high and use a breakwater on deck to proctect the manifolds.

Smaller product carriers in the 150-200m range have "regular" atlantic bows like most ships.

 

If you want to consider the structure in the bow region (which you have alluded to), you first need to understand the Naval Architecture of the boat as a whole. When considering vessel shapes (in totality (you can't really separate out just the bow for comparison)), you have to understand the hydrodynamic forces it must withstand, as well as the economic pressures which drive the design. Sometimes the hydrodynamics wins (racing yachts etc.) and sometimes the economics wins (cargo vessels). Detailed shape within the boat may have other drivers (e.g. comfort and wetness).

Without understanding the design factors, it is very hard to draw any comparison at all, let alone a meaningful comparison. Without understanding the naval architecture, you're not going to get representative loads for your stress analysis.

Tim B.