Anyone who has ever heard the distinctive sound of a steam engine's whistle will never forget that sound. It provided the warning and announcement of the train's arrival. Wayside sign posts were erected to prompt the train engineer to blow the whistle. They were placed far enough in advance of grade crossings, towns and stations to provide sufficient notice. Known as "whistle posts" the sign was situated atop a post, generally concrete approximately four feet high, with a "W" on the sign. This sign post became a universal notice for all steam railroad operations.
The yard, in railroad terms, defines a system of tracks set aside for assembling trains and storing engines and cars. Yard limits refers to the designation of main railroad tracks as being part of the yard. A sign post entitled "Yard Limits" would be erected notifying the engineer of the approaching yard. Slow speeds and caution were required upon entering the yard so the sign post would provide the necessary advanced notice for the engineer to take appropriate measures.
Due to the danger of railroad tracks and yards, sign posts were erected informing the public to stay away. These signs also provided protection for the railroad in the event individuals ignored the signs and were subsequently injured.
These signs indicated location for steam engineer, letting him know how many miles the train had traveled, or how many miles it still had to go before the next stop. The engineer could then calculate whether the train was ahead of or behind schedule.
