The appearance of CTC

The New York Central was the pioneering user of CTC. It is my
understanding that when the line to St. Louis was put under CTC, that
the CTC machine was located in the Big Four depot in Mattoon,
Illinois. When was this line "CTCed"? And what happened to the
interlocking towers? Was there any reason to keep them open? If
not, does anyone have the dates of when they closed? Specifically, I
am wondering about Karl Tower in Mattoon.

Thanks,
Thomas
French

When CTC first bacame practicable over long distances around 1930, interlocked crossings with another railroad usually couldn't be included, since the "op" at the crossing had to deal with two or more dispatchers, and might even be an employee of the "foreign" road. This was addressed in part by the development of "automatic interlockings" where the first train to arrive at the curcuit got a clear signal, and the later arrival had to wait.

When the push began to eliminate the final towers in the 1990's, the remaining roads conferred among themselves and agreements were worked out regarding the priorities involved.

I'm including a link to a new Yahoo group I think you'll find very interesting.

http://finance.groups.yahoo.com/group/A ... towerlist/