Geoff,
Knees, breast hooks, and other curved pieces (such as frame components) were selected and cut from the forms that trees naturally took on as they grew, so a knee for example may be cut from the junction of the trunk and a branch thereby taking advantage of the strength in the natural wood form. There wasn't any manipulation of tree forms as they grew, just a good eye from the shipwrights to pick out the potential uses from the trees on offer. That is why as stocks of timber grew scarce in the UK iron knees and fastenings were increasingly in use from the latter part of the 18th century.
Gary
Geoff, Knees, breast hooks, and other curved pieces (such as frame components) were selected and cut from the forms that trees naturally took on as they grew, so a knee for example may be cut from the junction of the trunk and a branch thereby taking advantage of the strength in the natural wood form. There wasn't any manipulation of tree forms as they grew, just a good eye from the shipwrights to pick out the potential uses from the trees on offer. That is why as stocks of timber grew scarce in the UK iron knees and fastenings were increasingly in use from the latter part of the 18th century. Gary