The CNcyclopedia online says the unit was modified for snowplow service by adding removable windshield screens and covers for the radiator fans.
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The metal boxes were to keep snow from getting into the engine compartment while plowing.  Note the screens over the front windows, as well.
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It was modified for snowplough duties in southern Ontario, hence the radiator fan cover and windschield grilles.
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| Posted by K100DS on January 8, 2014  |  |   
I think they were having a contest to figure out if it was possible to make an F-unit ugly. Success!
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Her sister, 9164, lives on at the back lot of NRE in Silvis, IL.  She also has the extra metal added.  Here is a link as I shot her in 2012.
http://www.rrpicturearchives.net/showPicture.aspx?id=3668494
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Looks ugly, but sounds AWESOME!
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