The Fish Rock Watch Tower is a 35-foot old-world round Irish tower resting on the ridge overlooking Anchor Bay, CA. It is designed and built by master mason Patrick McAfee with numerous stone masons from around the world joining in to work on it for 3 week periods, biannually, for over 5 years. The Fish Rock Tower has many elements common in traditional Irish round towers: a 40:1 batter, a spiral staircase, arched windows, battered doors with lintels and relieving arches, string courses, embrasures, and a conical stone roof with stone shingles.  The tower uses hot lime mortar made of hot lime, brick dust, sand and oystershell. The primary wall stone for the Fish Rock Tower is mica quartzite schist that was quarried in California. The stair treads, window and door surrounds, string courses, and other features are cut from Academy Black, a granite also quarried in California.”

The idea for a tower was born at the end of a gathering of masons, who had been working on other projects around the property by the red house. At that point, the property was 5 acres, but the neighboring property was available for sale and Peter was interested to purchase. The new property went up the hill from the red house and spanned across the street where it featured a raised wood platform to reveal the expansive ocean view. As the crew climbed the ladder to the elevated platform, the idea struck as if it were lighting.   Almost in unison as if it were planned.. 

“We should build a tower here!”   

“Yes we should.” was Peter’s reply

Hot lime mortar is unique in that it has self-healing capabilities brought on every time it rains. From MIT university: “During the hot mixing process, the lime clasts develop a characteristically brittle nanoparticulate architecture, creating an easily fractured and reactive calcium source, which, as the team proposed, could provide a critical self-healing functionality. As soon as tiny cracks start to form within the concrete, they can preferentially travel through the high-surface-area lime clasts. This material can then react with water, creating a calcium-saturated solution, which can recrystallize as calcium carbonate and quickly fill the crack, or react with pozzolanic materials to further strengthen the composite material. These reactions take place spontaneously and therefore automatically heal the cracks before they spread.” Furthermore, MIT’s team has proven that Roman concrete was made using the hotlime method. “To prove that this was indeed the mechanism responsible for the durability of the Roman concrete, the team produced samples of hot-mixed concrete that incorporated both ancient and modern formulations, deliberately cracked them, and then ran water through the cracks. Sure enough: Within two weeks the cracks had completely healed and the water could no longer flow. An identical chunk of concrete made without quicklime never healed, and the water just kept flowing through the sample. As a result of these successful tests, the team is working to commercialize this modified cement material.”