What is necessary for establishing OOS Limits beyond interlockings?

Establishing Out-of-Service (OOS) limits beyond interlockings requires a barricade and its location specified in the Form D. This is essential because a barricade serves as a physical and visible indicator of the point at which trains should not proceed. It helps ensure safety by clearly delineating the boundaries where train movements are prohibited or limited due to maintenance work or other hazards.

Additionally, documenting the location of the barricade in the Form D provides formal authorization and communication to all relevant crew members and dispatchers, ensuring everyone is aware of the established limits. This process is vital for maintaining safety and operational integrity on the railway, as it prevents unauthorized movement through areas that may present danger or in which trains are not allowed to operate.

Other options, while they may seem relevant in different contexts, do not directly address the specific needs for establishing OOS limits beyond interlockings. For instance, a valid train order and verbal confirmations serve different administrative and operational purposes, while written consent from crew members is not a necessary requirement for establishing OOS limits.