A short lesson on appreciating ancient ship construction


I received this unique lesson on  the first ships ever built from hydrodynamicist (one  who studies wave action) Sean Kery.  It’s fascinating,  even for a non-naval architect!

I recently finished a book called Uncorking the past that traces the invention of beer,wine and mead back to about 6000 BC if I remember right, and includes wrecks much older than this one.   There are a number of Books by Dr. George Gass and the late J.Richard Steffy that discuss dozens of these really ancient amphora wrecks and give a pretty good analysis of how the ships were constructed at that time.     I looked on alibris or amazon for used books on underwater archaeology and for less than 20 bucks bought 7 books.   The postage was actually about 5 bucks more than the cost of the books which range from coffee table books with lots of pretty pix to graduate school text books on the subject.

We are used to thinking about building wooden boats or ships by laying a keel, then adding lots of ribs and other framework then finally the planking.    Typically tarred rope called oakum is then forced between the plank edges to prevent leaks.

The oldest ships started with the keel then the planks were joined edge to edge using mortise and tendon joints that were pegged to hold them in place.   When the wood got wet, the planks swelled and sealed all the seams without oakum.   What little interior framework these old ships had was only added after the ship was completely built.   Several of those that were found sunk were an estimated 80 to 100 years from being new at the time of their sinking.   16th through 19th century wooden ships typically required extensive rebuilding every 10 years to keep them from rotting away.   The Mortise and tendon building method is very labor intensive and time consuming if you have to cut all those deep blind rabbets by hand, but it results in a much longer lasting ship.    Lastly one of the really ancient shipwrecks was found with the whole lower hull covered with tacked and soldered lead plates, dating from around 100AD.   The use of metal (copper) plates to stop the toredo worms (actually a weird type of clam) from eating tunnels through the wood, did not get reinvented until the 18th century.

History is such a weird and amazing place, It’s a big part of what lured me into studying shipwrecks in the first place

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SEAN KERY MS PE

Senior Hydrodynamicist

CSC  Fellow

 

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