Ladder Trays: The trays appear to be a bunk bed ladder. I would always suggest heavy power cables since heat is the greatest killer of electricity. Fire-resistant cable trays are designed to maintain their structural strength and support cables under high-temperature conditions. They help prevent cables from falling, short-circuiting, or losing functionality during fire exposure. In high-rise buildings, these systems are especially important. Cable tray installation must comply with specific technical standards to ensure electrical safety, system reliability, and long-term maintainability. Materials like steel. 1. 1* This standard shall cover life safety from fire and fire protection requirements for fixed guideway transit and passenger rail systems, including, but not limited to, stations, trainways, emergency ventilation systems, vehicles, emergency procedures, communications, and control systems. 2. Electrical cable tray wall penetration firestopping Scope: Firestopping for busway, cable trays, cables, and trunking passing through walls in enclosed electrical installations. Where cables pass through shafts, walls, slabs, or enter electrical panels or cabinets, openings shall be tightly sealed. The primary rulebook used in the safe use of cable trays is NEC Article 392.