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 A six-cylinder, two-stroke, diesel engine built by Fiat-San Giorgio was installed. This engine produced 325 hp at 450 rpm and drove a rotary compressor, built by a Swiss company in Winterthur, which delivered compressed air at 8 bar pressure. A small naphtha-fired boiler with a heating surface of 52 square metres was also installed for the production of steam. Cooling water from the engine and compressor was fed into the boiler at about 70°C. For cold starting, the boiler was used to preheat the diesel engine. When the locomotive started from rest, the original steam cylinders were fed with steam