When it comes to providing protection against falls associated with fixed ladders, there are two main options - vertical ladder lines and ladder cages.
Cages for Fixed Ladders Are No Longer Acceptable Under OSHA
VERTICAL LADDER WITH SAFETY CAGE SECURITY SYSTEM, Vertical ladders with safety cage
Adjustable Safety Cage Ladder #18509-243, 5-9', All-Terrain Wheels & Wheel Lift / Little Giant
Vertical Access Cat Ladder Kit - Ladder Warehouse
Cotterman - F28SC Fixed Steel Wall Ladder w/ Safety Cage, 2 Sections
Jess Wilkinson - Height Safety Engineers
VERTICAL LIFELINE ON LADDERS, VERTIGRIP ON LADDER
Jess Wilkinson - Height Safety Engineers
Ladder Safety Cage Vertical Bolt-On Ladder Protection Cage
Safety systems, Design and install