Fruehauf Cattle liner semi-trailers
Here are three examples of proto-typical straight floor cattle trailers built by Fruehauf in the 70's and 80's. This particular model was a reasonably common sight across the Canadian prairie provinces in that period, with some examples still floating about today. Heights and lengths would vary, with lengths up to 50' not being uncommon. heights varied from 11'6" O/A to the full 13'6" legal height. While some were single deck configurations, many would be set up with removable decking for livestock such as hogs or sheep.
In the examples here, the first one is 48' in length while the remaining pair are 50' long. The top pair have side vent covers to allow for both temperature control and re-configuring the trailers for dry freight operations.
The tractors shown attached to them are in order a 1967 IHC 4000, a 1984 Ford LT 9000 , and a 1976 Freightliner. There will be more on the trucks themselves at a later time.