Seismic bracing, typically made of high-strength metal, is key component specifically designed to enhance the stability and safety of cable tray systems during earthquakes. For over 60 years, the mechanical, electrical, and fire protection trades have relied on TOLCO seismic bracing solutions. Why is seismic bracing important? International Building Code. Cable tray runs in seismic zones need more than normal hanger spacing. A standard trapeze support carries gravity load; it does not reliably stop lateral sway, longitudinal movement, anchor pullout, or cable spill during ground motion. We have decades of experience with real-world applications in severe seismic zones, supplying orld-class products and solutions.