1956 U.S. Patent for the Original Tetrapod
Life with Tetrapods: The Nature of Concrete in Okinawa
1956 U.S. Patent for the Original Tetrapod
Figure 1. Illustrations from the U.S. patent for “Artificial Blocks for Structures Exposed to the Action of Moving Water”—the original Tetrapod—granted in October 1956. Source: Google Patents: https://patents.google.com/patent/US2766592.
