Which code denotes the north stick relay route locking?

• A. Nlp
• B. Ns
• C. Nvp
• D. Nwc

Answer: (B)

In signaling practice, routes are locked using specific devices, and each locking method has a code. Ns denotes north stick relay route locking. This means the locking of the route is accomplished through a north stick relay in the interlocking system, which latches the route once set so that signals and points cannot be changed until the lock is released. This code is used to identify that exact locking method on diagrams, reports, and maintenance notes. The other codes correspond to different locking devices or schemes and do not describe the north stick relay route locking, so they’re not the correct designation in this context.