(narrator) Over time, the elements, especially the cycle of freezing and thawing, slowly deteriorated these walls. To preserve the structure, in 2015, it was time for a restoration. Twelve tons of clean, crushed oyster shell were delivered to the site.

(Describer) Hands add materials to a machine.

The mixture is sand, lime, Portland cement, coloring, water, and finally the oyster shells.

[mixer churning]

First, the original surface is wet to ensure a good bond. The new tabby is worked into the original tabby by hand. Forms are built for the gun embrasures. A similar device was used during the original construction. Once the tabby is set but not cured, the forms are removed. Water pressure models the new material to blend with the original structure. After a few years in the Low Country heat and humidity, the color will be very close to the original fort walls,

(Describer) Accessibility Provided by the US Department of Education.

and Fort Frederick will stand for another century.