Component Two: Development of Conservation Plan for the Hieroglyphic Stairway
Copán was an important city-state during the Maya Classical Period (250-900). Since its rediscovery in the late 19th century, the site has been extensively investigated and excavated, revealing elaborate architecture and sculptural monuments. Copán is best known for its stone carving including its stelae, altars, and spectacular hieroglyphic stairway. At 10 meters wide by 24 meters high, the stairway is the longest text carved on stone from ancient Mesoamerica—comprised of 63 steps with over 1,000 intricately carved glyphs. This unique text recounts four centuries of Copán dynastic history.

The component consists of the application of a methodological approach to the conservation of the hieroglyphic stairway. The study focuses on evaluation of the condition of the stone, identification of the cause of decay and of the decay mechanisms of the building materials in order to propose appropriate measures for their mitigation.

Since 1999, a team of conservators and scientists from the GCI working with IHAH has undertaken a series of studies and analyses to better understand the conditions and the behavior of the materials which include a detailed condition survey and selection of control blocks for further monitoring, the characterization of building materials (stone and mortar), environmental monitoring, biological analysis of microorganisms, and the structural stability of the temple.

Protection of archeological remains often requires the building of protective shelters. At Copán, several types of shelters provide protection to carved stelae, decorated buildings, and to the stairway. While visitors are especially sensitive to the aesthetic impact of these added structures, it is important to understand what the effects of the protective shelters have in relation to their shape, form, and materials. To address this issue, treatment trials both for stone surface stabilization and mortar repointing were completed in order to establish a conservation strategy for the stairway that includes parameters for a shelter.

To support the mapping of the condition of the stairway stone blocks, a full photographic record was undertaken. Stereo photography (photogrammetry) was used to provide further comparison of the condition of the stone and to provide data for an eventual three-dimensional model of the stairway.

Building on the condition assessment and the evaluation of the treatment trials, the conservation plan will consider the need for stabilization of the stone blocks, surface repair/replacement of mortar, and parameter for shelter design. It will also consider preventive measures, short and long-term maintenance as well as a monitoring program to evaluate the condition of the stairway over time. Training in photographic monitoring of selected employees of IHAH at Copan has been carried out.

Work completed

• close-range stereo photography
• characterization of stone materials, mortar and decay products, as well as of repair materials used on the stairway
• detailed conditions of the stone blocks, recorded in digital format
• evaluation of the biological colonization of stone surfaces
• design and installation of on-site environmental monitoring system
• extensive archival research and annotated bibliography
• comparative analysis of photographs of selected blocks taken over time
• characterization of environment at the site and of microenvironment under the shelters
• research on locally available and potential treatment materials
• trials of repointing with lime mortars and of stone surface treatment
• schematic drawing of entire Stairway with numbering system

Work in progress

• production of conservation plan