Keystone Ingenuity Contributes to U.S. Cold War Submarine Memorial

 

The submarine?EUR??,,????'???s hull is constructed of Keystone straight-faced Compac units (mortarless masonry).

Planners of the U.S. Cold War Submarine Memorial at Patriots Pointe in Charleston, South Carolina had the design challenge to recreate the smooth black hull of a submarine to support the 55-ton conning tower and fairwater planes from the decommissioned USS Lewis and Clark. The fabricated hull had to mesh seamlessly with the conning tower. Robbie Boland of Keystone believed a hull made of Keystone straight-faced Compac units (mortarless masonry) would work, and a planning group of retired Navy admirals, architects and contractors agreed.

?EUR??,,????'??If conventional masonry had been used, the mortar joints would have been visible,?EUR??,,????'?? explained Boland. A black masonry stain had to be mixed to match the color of the conning tower. Soil conditions were another problem. The site near Charleston Harbor is fill from harbor dredging. The solution was to support the submarine with 40 12-inch precast driven piles interconnected with a precast pile cap. The conning tower and fairwater planes are supported with cast-in-place concrete walls and attached to the Keystone units with a geogrid connection to steel angles.

The Keystone Compac walls are assembled in the near-vertical pin position with the wall footings angled toward the inside of the structure. This 14-degree ?EUR??,,????'??tilt?EUR??,,????'?? mimics the taper of a submarine without showing the staggered setbacks typical of segmental retaining wall construction. The top deck of the submarine is constructed with clay paving bricks, also tinted black with masonry stain.

This unique wall application was a welcome challenge for project contractor Jay Foreman of Colony Construction Company. ?EUR??,,????'??I could tell it was going to be a very different kind of job during the bidding,?EUR??,,????'?? he said. ?EUR??,,????'??We had never done anything remotely like it before, but it still turned out to be one of my favorite jobs. It has gotten a lot of positive recognition.?EUR??,,????'??

According to Boland, a Keystone design was selected for the project because Keystone proposed a team approach and coordination between them and the wall engineer, soils engineer, wall installer and general contractor.