myaroslav
Today it is known as a general rule (with some exceptions, of course) that diesel vehicles under 1000hp perform better with hydraulic transmission, while for the more powerful electric powertrain usually suits best. But it took some time to receive this experience. In Soviet Union the hydraulic transmission concept was considered promising as being cheap and simple at the cost of slightly decreased efficiency. In 1959-1965 a relatively small series of less than 100 double unit #TG102 diesel locos was built in St. Petersburg (than Leningrad). Each unit was equipped with two 800 hp marine diesel engines. But the first approach lead into trouble. Diesels turned to be unreliable. Cardan shafts were oscillating. At least three manufacturers of hydraulic transmissions were tried including Voith, but no one performed well. The number of tested control systems was even higher. At least partly the root of problems was not in design itself, but in delayed spare part supply and unskilled maintenance used to deal with steam locomotives. To the late 1960s the experience was reached by both manufacturers and maintenance depots, but to this point it became clear that mainline locos needed up to 3-4 thousand hp per unit, and in that power range the economy stood on the side of electric powertrain. However, the way for building small power hydraulic locos was cleared. The most powerful of mass produced and generally successful types were 750-1200hp TGM4 and TGM6 shunters for industrial branches and 820hp TG16 for meter gauge network of Sakhalin island. A few TG102s survived. Two units are displayed in St. Petersburg railway museum, and one more body is stored. Some its equipment was supposedly used to restore the loco in museum. #trainspotting #diesel
