timber shakes

[Freebee]

I have just watched a TV program on Sky PBS channel about the restoration of American clipper Coronet, in the series Ultimate restorations. Its a great documentary, but in watching the restoration crew had to find large bulks of timber for keel, Stem and stern replacements. A lot of the new timber had cracks I think they are called shakes running through them. is that typical for this type of construction?? or does it lead to weakness in the structure??

 

[Rum Run]

Shakes / cracks running with the grain of a large timber do not reduce the bending strength. Shakes across the grain are a definite no-no.
I believe it is common to push some very soft stopping into the shake so as to prevent water getting in and encouraging rot. Hard filler makes the shake open up and can split the timber completely. The cheapskate would have used a mixture of asphalt and asbestos fibres intended for gutter joints in the past - don't try this at home kids!