There was a small ice house at the south end of the platforms, beyond the express facility, at Wichita Union Station.  It was probably there for the purpose of icing passenger cars as needed.  There was also a ramp right by it, for vehicular access to the platforms, which I used to drive up on when I was watching passenger trains.  So if an express reefer needed icing, which was probably a rare occurrence there, it wouldn't have been hard to do.  

Ron Merrick