Lime kilns have been used for centuries with little change to their construction or functioning, as the produced lime has been an important component in mortars throughout history. The lime kiln on Hassel Island was constructed to produce lime in a convenient location to create mortar for the construction of the historic structures and pavements.
The kilns produce lime by heating limestone, stacked between layers of coal. Because St. Thomas had no limestone deposits, this kiln utilized crushed coral and probably shells for the initial component of the lime recipe rather than limestone. The typical historic mortar recipe consisted of three parts of sand to one part of lime. Large pieces of coral were also utilized as building materials in many historic structures throughout the islands.
The firebricks lining the kiln are stamped with the name of a company that began operation in 1851. Until 2014 the kiln was in desperate need of restoration.
In June, 2014 the Trust was awarded a grant from the Office of Insular Affairs, Department of the Interior for the restoration of the lime kiln. The contract for the restoration was given to Stone Masonry, LLC, a firm with extensive experience in historic restoration of stone structures, headquartered in St. John, U.S. Virgin Islands.