This group is for those people wishing to help compile a detailed list of as many of the 6,000 plus interlocking towers that once existed in the USA and Canada. Listings will be compiled of automatic interlockings and some non interlocked crossings as well. Please note this is a working group for active interlocking researchers rather than a general tower discussion group. Any information on any tower will be welcome here and we are looking for members who will share their ETT's and other information for the benefit of the project.

The picture is an interior shot of Alexis Tower by Charlie Whipp.