I was just thumbing through the June 2007 issue of Railroads Illustrated. On page 47 there is a photo of Southern Railways southbound Southerner at Woodstock, Alabama in July 1970. In the photo caption it says that "some 19 years earlier, near this very site, the same train was involved in a disastrous head-on collision with the Crescent that claimed 17 lives. The detouring Crescent rounded the curve at track speed coming up to the east end of Woodstock siding only to find that the northbound Southerner had overshot the siding and was sitting in the ‘OS’.
First of all, what is meant by the term “OS”?
Secondly, does anyone know the story of this wreck or where I might read about it. My father worked for Southern on this same stretch of track and it is close to home for me so I am interested.
This is just speculation and so, subject to correction but, if the accident happened in CTC territory the OS would refer to that section of track in which the remote controlled switch was located. It would be represented on the CTC board by a red light(as opposed to yellow for the track sections, sometimes miles in length, between controlled switches). The red lighted track sections would be those used to denote the time the train arrived for entry onto the train sheet (hence On Sheet).
It sounds like the one train entered the siding after the second passed the approach signal and overran the switch at the end of the siding. If so, it couldn’t back into the clear and the opposing train would have expected at least an approach signal at that point
The term OS originally meant On Schedule. It came to mean the message sent by the operator at a train order station to the dispatcher reporting that a specific train had passed his station at a certain time, e.g. “Extra 1251 south OS Mansfield at 2:43 pm”.