31. When they formed the Martin Fifth Wheel company Martin was president and Farr was named secretary. 32. Most of these terms are self explanatory, " motor carrier " or " fifth wheel ". 33. Now, they own a 30-foot " fifth wheel " 34. A small gasoline engine is mounted on a fifth wheel , or motor wheel, to drive the Flyer. 35. Walther started working on the design and engineering of fifth wheels and landing legs for semi-trailer trucks. 36. A significant feature was its patented fifth wheel coupling system which enabled a quick a flexible engagement. 37. Either the fifth wheel or the tow hitch takes up to half to load of the semi-trailer. 38. She felt like a fifth wheel . 39. Bush Hog mowers sometimes come with a small, pivoting fifth wheel mounted in the center behind the driver. 40. RV parks, many of them in the east Valley, brim with motor homes, fifth wheels and travel trailers.