ultracaps technology Other power sources In some places, other forms of power were used to power the tram. Battery As early as 1834, Thomas Davenport, a Vermont blacksmith, had invented a battery-powered electric motor which he later patented. The following year he used it to operate a small model electric car on a short section of track four feet in diameter. Attempts to use batteries as a source of electricity were made from the 1880s and 1890s, with unsuccessful trials conducted in among other places Bendigo and Adelaide in Australia, and for about 14 years as The Hague accutram of HTM in the Netherlands. The first trams in Bendigo, Australia, in 1892, were battery-powered, but within as little as three months they were replaced with horse-drawn trams. In New York City some minor lines also used storage batteries. Then, comparatively recently, during the 1950s, a longer battery-operated tramway line ran from Milan to Bergamo. In China there is a Nanjing battery Tram line and has been running since 2014. More recently in 2019, the West Midlands Metro in Birmingham, England, has adopted battery-powered trams on sections through the city centre close to Grade I listed Birmingham Town Hall. Compressed air Paris and Berne (Switzerland) operated trams that were powered by compressed air using the Mekarski system. Trials on street tramways in Britain, including by the North Metropolitan Tramway Company between Kings Cross and Holloway, London (1883), achieved acceptable results but were found not to be economic because of the combined coal consumption of the stationary compressor and the onboard steam boiler. Human power The Convict Tramway was hauled by human power in the form of convicts from the Port Arthur convict settlement. and was created to replace the hazardous sea voyage from Hobart to Port Arthur, Tasmania. Charles O'Hara Booth oversaw the construction of the tramway. It opened in 1836 and ran for 8 km (5 miles) from Oakwood to Taranna. By most definitions, the tramway was the first passenger-carrying railway/tramway in Australia. An unconfirmed report says that it continued to Eaglehawk Neck and, if this was so, the length of the tramway would have been more than doubled. The tramway carried passengers and freight, and ran on wooden rails. The gauge is unknown. The date of closure is unknown, but it was certainly prior to 1877. Hydrogen In March 2015, China South Rail Corporation (CSR) demonstrated the world's first