Video of the week

Originally posted by GK.LaserII .......would of thought the hull should be stronger than the backstay Great Vid

Depends how you measure strength, of course. And then there's big difference between the tension on the stay, and whatever the proper term for the mode of force on the hull is (fairly complex :P )

Rather embarrassed about the title but have a look at:

http://www.youtube.com/watch?v=Zrl4HodyWpk

I saw a presentation on finite element modelling of AC yacht hulls once.  They're designed to safety factors of about 0.9, so that means that if you meet the max strength winds and waves it will break.  It's a good way of ensuring you get a very light structure but you wouldn't want to design that way fro everyday use!

Originally posted by PeterV I saw a presentation on finite element modelling of AC yacht hulls once.  They're designed to safety factors of about 0.9, so that means that if you meet the max strength winds and waves it will break.  It's a good way of ensuring you get a very light structure but you wouldn't want to design that way fro everyday use!

I would use 1.5 (or 0.75% of yield strength) for a single part like a spring or bolt and more like 2 - 2.5 for an assembly to allow for material/assembly tolerance and a bit for misassembly (which applies a load somewhere unexpected). I heard at the time that a winch had failed so they lead it across the boat to another... and that the winch manufacturer was given a bit of a hard time!

haha, I know those boats are quick - but did they not have any bulkheads at all?!?!?!

glad they are on the save weight - less is more