According to some tractor tug experts, only the Voith Schneider cycloidal drive is a “true tractor” and z-drives don’t qualify. I don’t know whether that is a distinction really worth making. In any case, the Voith Schneider Propeller system, or VSP, is very interesting but because so few of them are in service in North America almost no one here knows how they work. They’re used for tanker escort and docking work in Alaska’s Prince William Sound, Washington’s Puget Sound, Louisiana’s LOOP facility, and the Placentia Bay terminal in Newfoundland.
Fortunately, Capt. Bill Brucato of the NY Tugmaster’s Weblog has just provided us with a gee-whiz demo site that shows exactly how it works in fine detail and even gives you the opportunity to play around with one a bit. Just click the lower link that says Open iVSP – Interactive VSP Program and have at it. There are also several links on the left sidebar with lots more info about the VSP if you want to learn more.
Thanks, Capt. Bill!