Signal Maintainer Practice Test

When decoding these codes, think of three parts: position, device, and component. The first letter signals the turnout’s position, the middle letter names the device being operated, and the last letter identifies the hardware type. Normal is shown by N, a turnout is indicated by w for switch, and relay is shown by r. So Nwr literally means Normal switch operating relay, which matches the description of the item being asked for. The other codes don’t fit because their letter pattern would point to a different position, a different device, or a different component, not the combination described.