Diesel locomotive break down. Hydraulic transmission for locomotives was developed in Germany. There is still debate over the relative merits of hydraulic vs. electrical transmission systems: advantages claimed for hydraulic systems include lower weight, high reliability, and lower capital cost. By the 21st century, for diesel locomotive traction worldwide the majority of countries used diesel–electric designs, with diesel hydraulic designs not found in use outside Germany and Japan, and some neighbouring states, where it is used in designs for freight work. In Germany and Finland, diesel–hydraulic systems have achieved high reliability in operation. In the UK the diesel–hydraulic principle gained a poor
Diesel-Zarlatti locomotive alone, but when running they were powered by a mixture of steam and compressed air. The steam was needed to prevent the cylinders icing up, because compressed air cools when it expands. Diesel-Zarlatti locomotive The Diesel-Zarlatti locomotive was a prototype railway locomotive, built in Italy in 1929, which adopted a hybrid diesel-steam transmission system. In the 1920s, there was a search for alternatives to the steam locomotive for railway traction, to reduce cost and improve efficiency. The main alternatives were railway electrification or the use of an internal combustion engine, such as the diesel engine. A disadvantage of the internal