Assessing the Damage
A “Difficult Access Team” from our engineering partners at Wiss, Janney, Elstner Associates, Inc., rappelled down the Cathedral to document damage across the building, making notes on iPads attached to their harnesses.
Once the assessment was complete, engineering crews ranked damage as severe, moderate or minimal.
- The four grand pinnacles of the central “Gloria in Excelsis” tower rotated. Each grand pinnacle is over 40 feet tall, weighs about 50 tons, and is topped by a four-foot-tall grand finial that weighs about 500 pounds. Three of the four grand finials fell to the tower’s roof; the top five courses of stone were shaken badly.
- Additional smaller pinnacles atop the tower were badly damaged and will need to be repaired or replaced.
- Dislodged stone struck a gargoyle and “decapitated” it. The gargoyle’s head was held in place only by the drainpipe that runs through the gargoyle to expel rainwater.
- One grand pinnacle was so damaged that it cannot be removed until funds are in place for its restoration. It will remain encased in scaffolding until it can be repaired.
- The grand pinnacles were so destabilized that workers could gently rock them back and forth on their bases.
- Several pinnacles skipped up and rotated like spinning tops, and several slender pinnacles collapsed entirely.
- The six freestanding flying buttresses of the east end—the oldest part of the Cathedral—swayed or moved, causing the flying buttress arches to stretch and move, resulting in cracking and separation of stones from one another.
- When construction began in 1907, there was no reinforcement used between stones. The seismic motion caused stones in the buttresses to shift and separate, and loosened and rotated the pinnacle stones.
- Rotation and movement along almost every exterior pinnacle on the Cathedral caused hundreds of spalled corners and stones (stones that have crumbled or flaked off), cracks, and fallen crockets and finials, requiring re-carving.
Immediate and Phase I Repairs
Immediately following the earthquake, the Cathedral was faced with the challenge of stabilizing the building, inspecting the damage, and beginning repairs—all while keeping the Cathedral open to worshippers and visitors.
Movable scaffolding erected 65 feet above the nave floor provided crews up-close access to the vaulted ceiling and stained glass windows. The unusual access allowed for inspection and cleaning of the intricate boss stones.
Crews also installed netting to protect from falling debris; the netting would remain in place for four years.
Crews began with the heavily damaged flying buttress on the Cathedral’s east end, drilling holes for stainless steel reinforcement rods.
The Cathedral raised $10.5 million for Phase 1 earthquake repairs between 2011 and 2015, and allocated the money toward stabilization, engineering and design, cleaning and resealing stained glass windows, masonry repair and repointing, and overall maintenance.
Despite these restoration efforts, some 87 percent of the Cathedral’s exterior awaits repair from the 2011 earthquake.