Fortifying a Philadelphia Landmark While Maintaining its Historic Character

Project Background

• Designed by architect Gillette Woodman and built in 1901, the 23rd Street Armory is a massive granite building once used to store arms and ammunition; it is now home to the First Troop Philadelphia City Calvary while also serving as a rental space for musical productions, weddings, athletic contests, and other events
• The Armory includes an eastern side that is highly decorative and fortified and a western portion housing the drill hall that is more mundane yet still contains robust architecture
• The First Troop Philadelphia City Cavalry is the oldest military unit in the United States and the only unit that owns its own armory building; today’s members are part of the Pennsylvania Army National Guard and are appointed by election only
• Safety issues concerning the building’s exterior arose that required quick and appropriate measures be put in place to begin the repair effort
• Through exterior facade repairs, the restoration project was begun to restore the Armory’s historic character and enable it to better accommodate members, visitors, and tourists

Project Challenges

• This massive granite structure required in-depth structural repairs and special rigging to handle extremely heavy stones
• Deep historic steel bolstering and replacements were required
• Grouted anchors, each over two feet long, were needed to stabilize the embattled parapet

Project Approach

• Work proceeded in a logical and phased manner in close coordination with the engineer and owner to ensure a defendable and sustainable approach to the project and future building use
• To limit future deterioration and eliminate safety concerns, repairs to street-facing exterior walls and embattlements entailed the replacement of supporting steel along with the masonry itself
• Building block phases included initial assessment, detailed assessment with exploratory probes, overhead protection installation and pedestrian protection management, pilot phase repairs, and multi-year repair and preservation work phases