why does this 1986 steel Junk have holes in rudder?

[Tiny Turnip]

This is fascinating stuff - thanks for all the great information everyone! I found this in a 2006 thread on junks in the boat design archives:

http://www.boatdesign.net/forums/archive/t-11449.html

It comes from an earlier wikipedia edit, now gone, so it may be questionable:

Also, from sometime in the 13th-15th centuries many junks incorporated "fenestrated rudders" (rudder with holes in them), an innovation adopted in the West in 1901 to decrease the vulnerability of torpedo boats rudders when manoeuvering at high speed. Likewise the Chinese discovery - which probably came about through fortuitous weaknesses in knotted pine - was probably adopted because the reduced stresses helped cope with the weak and vulnerable mountings of junk rudders.

Somewhere in my surfing, but I forget where! sorry! I read that the combination of bow dagger plate and large rudder developed to allow a large clear space for cargo centrally, whilst still providing balanced lateral resistance.

Many, many great pictures of Junks on Karsten Petersen's Global Mariner website, mostly from the early and mid seventies:

http://global-mariner.com/index111ChineseJunks.html

Incidentally, the entire, splendid blue book on Vietnamese Junks can be downloaded free here, but no fenestrated rudders!

http://www.junkbluebook.com/

[rwatson]

Originally Posted by Angélique

Interesting bow dagger . . . . .

Are there uses for bow boards nowadays . . ? ?

Cheers,
Angel

Heck - Alfa Romeo, the "worlds fastest super yacht"

and most of the canting keel yachts have them

http://www.gizmag.com/go/3164/picture/6741/

[Yobarnacle]

Foochow Pole Junk
http://www.tara.bz/index.asp?page=viewitem&ma=7