Interlocking: Diann Tower, Dundee, MI

Diann was an interlocked grade crossing of the Ann Arbor railroad main line (Toledo to Frankfort) and the Detroit, Toledo & Ironton railroad main line (Detroit to Ironton, OH) in Dundee Township about two miles south of the village of Dundee.

This crossing was created during Ford ownership of the DT&I and the main line was rerouted at the Malinta cut-off. Ford built a sturdy electro mechanical interlocking tower here, as well as a connection for both lines on the northwest and southeast quadrants. Both lines were block signaled at this location.

Photo Info: Top, Dianne Tower under construction September, 1926. 2nd photo, The tower after completion. 3rd photo, the interlocking machine at Diann; the 4th photo, the CTC machine in 1981 which controlled the line between Dundee and Flat Rock yard; 5th photo, the CTC machine at Diann Tower in 1973. [Greg Bunce]. 6th image, Diann Tower in 1987. [Charlie Whipp] 

Notes

The tower was originally equipped with a Union Switch & Signal Style "F" Model 14 electric interlocking machine.

The DT&I had a 7,780' controlled passing track north of the tower. The tower controlled the south entrance and the north entrance was North Diann at milepost 38.1.

This was one of the last new interlocking tower locations in Michigan.

Location: 41^o55.924'N / 83^o38.250'W.

Time Line

1926, The Detroit & Ironton has awarded a contract to the Union Switch & Signal Co, for the complete installation of a Type F electric interlocking at the intersection of the Detroit & Ironton and the Ann Arbor near Dundee, MI. The plant comprises 23 working functions using color-light signals controlled from a 15-lever frame Model 14, Type-F electric interlocking machine. The plant is being installed to eventually meet the requirements of alternating current propulsion on the D&I. [RSG-1926-09]

1928. The DT&I rebuilds the interlocking at Diann, adding 5 electric levers. [RSC-1929]

1968. The DT&I replaces the Style "F" machine with a US&S Traffic Control system for their single track main line between Carleton and Diann that was controlled by a new Type "C" panel in the tower. This panel also controlled the interlocking itself and the Model 14 machine was retired. [MRL-2023-6]

1972. The Ann Arbor railroad installed a separate US&S Type "C" panel in the tower to control their single track main line between Alexis and Diann. There was also hot-box printers in the tower.  [MRL-2023-6]

1988. August 31. Diann interlocking tower is closed. 

2023. January 18. The tower is torn down.