Duplex was a chassis and fire apparatus builder located in Michigan and Ohio.


The Duplex Power Car Company was formed in Michigan in 1907, later renaming itself the Duplex Truck Company in 1915. Duplex specialized in the manufacturer of trucks, and some were used as fire truck chassis. In the late 1940s, the company introduced a conventional fire truck chassis and supplied it to various apparatus body builders, notably the General Fire Truck Corporation. In 1954, Oren Roanoke Corporation started using Duplex when the Corbitt chassis was no longer available. A new design was introduced in the mid-1950s, and it was used by apparatus builders Boardman, Howe (as its Defender model), Oren and others. In the 1970s, cab forward chassis were built using cabs from TCM.

In 1955, Duplex was acquired by Warner/Swasey. Warner/Swasey was in turn purchased by the Nolan Company and production moved to Ohio. In 1986, Duplex was purchased by the Simon Group of the UK and renamed Simon-Duplex Inc. This was around the same time that Simon also purchased LTI, creating Simon-LTI. Simon-Duplex LTI built complete pumper and aerial apparatus using the Olympian chassis.

The Simon Group sold LTI to Aerial Innovations Inc. in 1998 and closed the Duplex operation the same year.


  • McCall, Walter M.P. Illustrated Encyclopedia of American Fire Engine Manufacturers. Hudson, WI: Iconografix, 2009.