QUESTION: Why is the Double-Lock Chainplate System™ so strong?
ANSWER: This method of attaching the chainplate insures a strong connection between the chainplate and the deck/hull structure. It is attached to both the deck and the hull to locking them together. This labor intensive construction system spreads the loads of the sail rig throughout the hull, avoiding concentrated loading.

Double-Lock Chainplate System™

From "Offshore Yachts" by John Rousmaniere
               “The mast step must distribute mast compression fore and aft to floors. A bulkhead close to the mast is a desirable feature. Chain-plate loads should be spread by a hull attachment that is as longs as possible--a structural bulkhead is ideal.”
From "Further Offshore: A Practical Guide for Sailors" by Ed Mapes
               “The chainplates, port and starboard and on the stem and transom, should be attached to solid structural members that distribute the rigging loads to the vessel’s backbone without causing local distortions. Ideally, for strength and redundancy, each stay and shroud should have its own chainplate.”