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
LMS diesel shunter 1831 converted to a mobile power unit, emerging in its new guise as MPU3 in November 1940. It was scrapped in August 1951. LMS diesel shunter 1831 No. 1831 was the first experimental diesel hydraulic shunter of the London, Midland and Scottish Railway (LMS) which pioneered diesel shunting in the UK. It was introduced in 1932, built at Midland Railway's Derby Works. It was nominally a rebuild of a Midland Railway 1377 Class 0-6-0T steam locomotive of the same number, built in September 1892 by the Vulcan Foundry. The frames and running gear of the original locomotive were retained. The experiment