"Saddle Tractor" ??? New term for a fifth wheel in my experience. (Or ninth wheel in this case.) I can see it though. It makes sense.

The German word is 'sattelschlepper' which literally means saddle hauler. Schleppen means pull, drag, haul The term 'fifth wheel' is also strange since it is also used when referring to something unnecessary/unwanted/in the wrong place: LINK "as useful as a fifth wheel under a carriage" The fifth wheel on top of the carriage is more useful than the fifth wheel under it / Robin

Thanks Robin, as I say that is the first time I have ever encountered that expression. The "turntable" for the front steering axle of a wagon or carriage IS called the "fifth wheel". If you place such a turntable on the rear of a bare wagon frame and then connect another wagon sans it's front axle, you just created a semi-trailer which is how the trucking industry came about. Not really sure how the negative interpretation for "fifth wheel" ever came about but I have heard that used as well.

The first uses of the negative form of the term is old, centuries old: may have originated as long ago as 1631, when Thomas Dekker wrote Match Me in London: "Thou tiest but wings to a swift grey Hounds heel, And addest to a running Chariot a fifth wheel." Known in French since 1535 (43 years after Columbus and 85 years before the Mayflower) In Latin it goes back to the 11th century: "Quem fastidimus, quinta nobis est rota plaustri" Thanks for the education about platform/wagon steering / Robin

The whole point is that the T-55 conversion is really cool and if only I could live to two hundred I would actually have time to build one. This talk of fifth wheels is rather funny...