Published on: August 18, 2026
Safeguarding Historic Architecture and Maintenance Personnel
Hazard: Existing single-point anchors failed structural pull tests, leaving workers exposed to steep-pitch leading-edge falls on a 4:12 sloped roof without compliant tie-off points.
Solution: A 2,849-linear-foot Kee Line horizontal lifeline system mounted across 145 custom-placed posts toggled directly to the metal deck substrate.
Benefits: Replaced compromised anchor posts with fully certified fall arrest protection, preserved the weatherproofing and aesthetic integrity of irreplaceable historic slate tiles, and ensured full OSHA compliance across complex roof ridges.
The Challenge: Navigating Brittle Substrates and Structural Failures
During a comprehensive site assessment at the ExxonMobil campus in Las Colinas, Texas, engineering evaluations revealed that the facility’s existing anchor system was structurally compromised. Rigorous pull tests on posts spaced 40 feet apart failed load certifications, exposing personnel to critical risks along the roof perimeter. In addition to mitigating the 4:12 pitch fall hazard, the site presented extreme architectural constraints. The facility features the largest commercial slate roof in Texas, constructed with rare, finite replacement tiles that could easily fracture under dynamic loads or improper penetrations. Moore Industries required a fall protection specialist capable of engineering a high-capacity arrest system without cracking the fragile stone or causing building envelope leaks.
The Process: Trade Coordination and Specialized Masonry Integration
Selected through a competitive bidding process among four safety providers, FLS partnered directly with general contractor Moore Industries and original roofing master slaters Scottie Ballantyne Roofing. Engineering teams reviewed detailed architectural sketches to calculate cable tensions, line deflections, and structural loads across multiple roof planes.
Field execution required precise coordination between fall protection installers and master roofers. Ballantyne Roofing carefully removed slate sections and prepped replacement tiles from a strictly limited supply. FLS technicians aligned every anchor post to sit centrally on the body of each tile, preserving natural watershed properties and avoiding weak fracture lines. Posts were toggled through to the metal decking below before the roofing team sealed each penetration and reinstalled the surrounding slate courses.
The Solution: Precision Kee Line Cable Infrastructure
FLS delivered a turnkey active fall arrest solution designed around the facility’s complex footprint:
- Continuous Cable Footprint: 2,849 linear feet of 8mm 7×7 grade stainless steel cable spanning the full ridge and valley layout of the campus.
- Custom Deck Connections: 145 engineered posts anchored via high-capacity toggle-bolt assemblies directly into the structural metal decking beneath the slate.
- Watershed Preservation: Custom post spacing and centered tile penetrations designed specifically to protect stone integrity and prevent water infiltration.
- In-Line Shock Absorption: Advanced energy-absorbing brackets installed at system terminations and corners to limit load transfer into the building structure during a fall event.
Summary: A Long-Term Compliance Partnership
Through meticulous multi-trade synchronization, FLS successfully mitigated hazardous fall conditions while respecting the historic masonry craftsmanship of the ExxonMobil campus. The project closed severe safety vulnerabilities and delivered an unobtrusive, durable safety asset that protects maintenance technicians for years to come.
To preserve long-term compliance and structural integrity, the facility’s active fall protection infrastructure is enrolled in the FLS safety lifecycle program for recurring annual inspections and certifications.
Ready to enhance safety and efficiency at your facility? Contact Flexible Lifeline Systems for a comprehensive safety audit and let our team of experts help you find the perfect solution for your work at height.
