idea for what became the Crandall Cabs began shortly after Amtrak began
operations on May 1, 1971. As the new national passenger carrier
sorted through its fleet of either worn down or simply worn out
locomotives it attempted to trim down its size. Much of its handed-down
diesels were EMD E8As/Bs and E9As/Bs, which while having logged
hundreds of thousands of miles were generally reliable. One of the
first things the company did was to retire these units as quickly as
possible and replace them with the new SDP40F starting in 1973
(unfortunately, this model proved unreliable in passenger service and
forced Amtrak to purchase new units just a few years later in 1976, the
F40PH). Since Amtrak was offering the locomotives at very affordable
prices and the C&NW needed power for its commuter operations around
Chicago (this was before the service became state-funded) the railroad
grabbed six B units and five A units in the spring of 1973.
All of these locomotives, as mentioned above were ex-UP, and the C&NW gave them road numbers of 501 through 511; #501-#506 included four E9Bs and two E8Bs while #507-#511 were all E8As except for one which was an E9A (EMD had built these units for UP between 1950 and 1962). Between April 3rd and August 16th, 1973 the C&NW began rebuilding the covered wagons with either updated 12-567C prime movers (giving them all a horsepower rating of 2,400) or other new features like Automatic Train Control, Automatic Train Stop, and Head End Power (or HEP, this replaced the antiquated steam generators). However, the railroad a problem with its B units in trying to figure how to retrofit them into self-contained units that could then be used in commuter service.
The answer to this came from the company's then Assistant Superintendent
of Motive Power, M. H. Crandall. He proposed to construct a home-built
cab on one end and add a control stand. The idea worked and what
resulted was a rather ugly, but utilitarian, cowl look that became known
as Crandall Cabs after their creator. In truth, the cabs of these
units somewhat resembled the special wide versions built for the
Canadian roads over the years like the SD50F, SD60F, M420, and M636 with
a tapered nose and flat front windshield that angled at the corners
(although the glass itself did not). Interestingly enough, the design
still looks similar to the present wide-cabs used by Electro-Motive since roughly the 1980s.
For whatever reason the Chicago and North Western chose not to give these unique locomotives a name and they were only ever listed as E8Bs and E9Bs. As the 1970s wore on the RTA had been in operation since 1973 and began to increasingly subsidize commuter rail services around Chicago. As the C&NW began to wind down its personal obligation in this regard it sold its 11 Crandall Cabs and E8As/E9A to the RTA on December 31, 1977 which subsequently leased them back to the railroad. In doing so the units began to be repainted into RTA colors, which was completed by November of 1980. They continued to operate in this fashion until the spring of 1983 when the RTA retired all of the Crandall Cabs and the As between March and May of that year except for E8 #510 and E9 #511, which continued to see service until March 19, 1989.
After their retirement in 1983 the Cabs were sold to Naporano Iron & Metal of Naporano, New Jersey between June and July of 1985. After this point the units were subsequently scrapped. Despite the locomotives' unpopular look they operated as intended and saved the Chicago & North Western a significant amount of money, particularly when it had no interest by the 1970s in continue to operate commuter trains but was forced to do so. Additionally, being an EMD locomotive of the period with and featuring 12-567C model prime movers made them highly reliable.
For more reading about the 'North Western, Chicago & North Western Railway from Tom Murray is another of MBI's "Railroad Color History" series and provides an excellent general history of the C&NW from its humble beginnings to purchase by Union Pacific in 1995, all the while stuffed full of colored photographs (typical of "Railroad Color History" publications). Also, for more on the history of Electro-Motive's covered wagons noted historian Brian Solomon has published a book entitled, Electro-Motive E-Units and F-Units: The Illustrated History of North America's Favorite Locomotives, which superbly details the entire line from its early days in the mid-1930s to the end of production.