> Erie Lackawanna had several Interlocking Towers
> with CTC Panels inside them !!! The tower operator
> had to take instructions from the dispatchers
> office -- no big deal.

There really isn't a whole lot of difference (at least as far as the technology used) for a MANUAL interlocking (powered, not armstrong) and CTC. If you think about it, in CTC you basically have control points which are interlocked, and the intermediate signals aren't much more than an ABS system. For many years the track between Truckee and Norden was listed as a manual interlocking with the operator at Norden, so I presume they had to work closely with the dispatcher to know what trains were coming through off or on to the ABS double track on both sides. I believe when the Norden operator was discontinued, control was transferred to the dispatcher as CTC. I don't think they really did anything but extend the control from Norden to the dispatcher's office, no field changes at the signals required.


> One interesting fact of Interlocking Towers is
> that the first railroad to build through the
> location usually made the second railroad involved
> build, maintain, and STAFF the Tower. This often
> had undesired consequences in that the 2nd
> railroad could decide who went first !!!

True. Even worse, the second railroad was stuck with maintaining the diamonds too. In some cases, the first railroad has assumed maintenance and operating responsibility of a junction just to gain control.

Typically automatic interlockings are "first come, first served" so there isn't any prejudice.