What a retard Oz is turning out to be.

It's clear the man never even heard of inertia.

He seems to think a lead keel has the same inertia
as a cast iron keel. He doesn't know or remember
the law of physics that states a body in motion
tends to remain in motion and a body at rest tends
to remain at rest.

When attached to a hull a keel is a body at rest
with respect to the hull. A cast iron keel will
stop faster if it hits an immovable object whereas
a lead keel (of identical mass) will stop slower.

It follows that the forces imparted to the hull
are less with a lead keel than a cast iron keel.

I guess Oz never heard of the benefits of crush
zones in automobile engineering that protect the
passengers by slowing the vehicle and passengers
down in not such an abrupt manner.

Simple physics but beyond a New Zealander's
ken.

S.Simon