View source for EMC AB6

{{Short description|Unique Diesel Railroad Locomotive}}
{{for|the United States Coast Guard patrol boat|USCGC Kangaroo (1917)}}
{{no footnotes|date=July 2016}}
{{Infobox locomotive
| name            = EMC AB6
| powertype       = Diesel-electric
| image           = CRI&P 751 (AB6) at Joliet, IL on October 16, 1966.jpg
| caption         = [[Chicago, Rock Island and Pacific Railroad|Rock Island]] {{Abbr|No.|Number}} 751 at Joliet, Illinois in October 1966
| gauge           = {{track gauge|ussg|allk=on}}
| builder         = [[Electro-Motive Diesel|Electro-Motive Corporation]] (EMC)
| builddate       = 1940
| totalproduction = 2
| aarwheels       = {{ubl|New: A1A-3|Later: A1A-A1A}}
| enginetype      = [[V12 engine|V12]] [[Two-stroke diesel engine|Two-stroke diesel]]
| primemover      = [[Electro-Motive Diesel|EMC]] [[EMD 567|12-567]], 1 off, later 2 off
| cylindercount   = 12
| poweroutput     = {{ubl|New: {{convert|1000|hp|kW|abbr=on}}|Later: {{convert|2000|hp|kW|0|abbr=on}}}}
| operator        = [[Chicago, Rock Island and Pacific Railroad|Rock Island]]
| fleetnumbers    = 750 and 751
| deliverydate    = June 1940
| retiredate      = mid-1970s
| disposition     = Both [[scrap]]ped 1973–74
}}
The '''EMC AB6''' was a type of [[diesel locomotive]] built exclusively for the [[Chicago, Rock Island and Pacific Railroad]] (the "Rock Island Line") by [[General Motors Corporation|General Motors]]' [[Electro-Motive Diesel|Electro-Motive Corporation]] and delivered in June 1940. Two examples were built, numbered #750 and #751.  They were built for the ''[[Rocky Mountain Rocket]]''   [[passenger train]], which travelled as a unified train from [[Chicago, Illinois]], to [[Limon, Colorado]], which then divided. One [[Section (rail transport)|section]] went to [[Colorado Springs, Colorado]], and the other to [[Denver, Colorado]]. The Rock Island desired a locomotive that could look like an integrated part of the train during the Chicago-Limon portion of the route, and could then be operated independently to take three cars to Colorado Springs.  A regular, cab-equipped A-unit could have been purchased, but that would have ruined the streamlined look of the train, so the RI had EMC build a flat-fronted locomotive based on an [[EMD E-unit|E-series]] [[EMC E6|E6]]B ([[B unit]]) but with an operating cab, headlight, [[pilot (locomotive attachment)|pilot]], and other features to enable it to operate as an independent locomotive.

Since the small three- and four-car trains the units would have to haul independently were very light, the AB6 pair were built with only one 1,000&nbsp;hp EMC 567 [[V12 engine]], and a baggage compartment where the second engine would have been. Later, with increasing trainloads, the baggage compartment was replaced with a second engine.

In 1965, the units had their [[Steam generator (railroad)|steam generator]]s replaced with [[head-end power]] and were reassigned to [[Push–pull train|push-pull]] suburban service in the Chicago area. In this form, they lasted until the mid-1970s and were eventually scrapped.

== References ==
* {{cite book| last=Marre| first=Louis A.| year=1995| title=Diesel Locomotives: The First 50 Years| page=123| publisher=Kalmbach Publishing Co.| isbn=0-89024-258-5}}
* {{cite book |author=Marre, Louis A. |year=1982 |title=Rock Island Diesel Locomotives 1930–1980| location=Cincinnati, Ohio |pages=93–94 |isbn=0-942192-00-1 |publisher=Railfax, Inc.}}

{{commons category|EMC AB6 locomotives}}
{{EMD cab and cowl}}

[[Category:A1A-3 locomotives]]
[[Category:A1A-A1A locomotives]]
[[Category:Electro-Motive Division locomotives|AB6]]
[[Category:Chicago, Rock Island and Pacific Railroad]]
[[Category:Passenger locomotives]]
[[Category:Diesel–electric locomotives of the United States]]
[[Category:Railway locomotives introduced in 1940]]
[[Category:Scrapped locomotives]]
[[Category:Standard-gauge locomotives of the United States]]