D
Dave
Collisions
Lead is extremely soft and ductile. In a collision with a rock it will deform and absorb energy so less chance of hull damage. Cast iron is brittle and will fracture and the force will transmit to a greater extent to the hull so greater chance of a hull crack. Lead keels can be hammered back into shape, not much can be done for an iron keel other than filler and fairing compound.
Lead is extremely soft and ductile. In a collision with a rock it will deform and absorb energy so less chance of hull damage. Cast iron is brittle and will fracture and the force will transmit to a greater extent to the hull so greater chance of a hull crack. Lead keels can be hammered back into shape, not much can be done for an iron keel other than filler and fairing compound.