More on Interlocking signals

NW Mailing List nw-mailing-list at
Wed Oct 30 17:43:44 EDT 2013

Back before ditch lights, some trainmen referred to the Restricting aspect
as a "ditch light."

Grant Carpenter

> Date: Sat, 5 Oct 2013


> Jim:

> If I'm deciperhing this diagram correctly, the signal at the entring

> end of the siding is displaying an APPROACH DIVERGING. The

> bottom target shows three amber lights pointed toward the main.

> The center amber light shouldn't be there. Bear in mind that not

> all sidings were bonded and therefore couldn't detect if the siding

> was occupied or if there were track defects or a switch not properly

> line. For non-bonded sidings, the signal at the entering end of the

> siding would desplay RESTRICTING. On the Pittsburgh Division, the

> W&LE had a multitude of non-bonded sidings and maximum

> authorized speed to enter was 15 MPH. N&W's Safety Department

> ID'ed restricitng signals by noting that the diagonal signal on the

> bottom target point to the ditch and if you don't comply with the

> indication, the ditch is exactly where you're going. Harry Bundy

More information about the NW-Mailing-List mailing list