1899. In 1923 the number of platforms was increased from six to eight by narrowing the platforms and removing the separate baggage platforms. In 1925 two new tracks were built between Helsinki Central and Pasila stations for service traffic. In the 1890s the Helsinki harbour rail was built from the Helsinki railway station through southern Helsinki to Katajanokka. Its use later decreased so much that it started to be gradually dismantled since the 1970s. It was finally completely dismantled in 2009 after the Vuosaari Harbour was completed. From 1969 to 1970 new tracks were built on the Rantarata railway between Helsinki Central and Pasila. In the 1900s, the Linnunlaulu cliff cut was subject to intense discussion for two times: first because of the construction of the Tikkurila city track and later because of the Leppävaara city track. The cultural value of the cliffs and villas at Linnunlaulu threatened to completely cancel the construction of the Leppävaara city track. Today the Helsinki Central Station has 19 platform tracks. Long-distance traffic and "proper" commuter traffic has been concentrated to the middle of the station. Traffic on the Kerava city track, as well as traffic on the eastern side of the Ring Rail Line mainly uses tracks 1 to 4, while traffic to Espoo and on the western side of the Ring Rail Line uses tracks 12 to 19. There are 10 tracks in total parallel with each other between the Helsinki Central and Pasila stations. Of these, the four eastern tracks belong to the Finnish Main Line, the two middle ones are service tracks used by the Ilmala depot, and the four western ones belong to the Rantarata line. The railway yard of the Helsinki Central Station has a total of 83 concentrated switches, of which 40 are simple switches and 43 are double-sided crossing switches. All of them are short 1:9 switches with a maximum allowed speed of 35 km/h. At peak traffic time, the Helsinki railway yard operates at the extent of its transport capacity. Thus even the smallest disturbances at the Helsinki railway yard can easily mess up the entire train traffic. The terminus form of the station building and its cramped location prevent the expansion of the current railway yard. The Helsinki City Rail Loop has been proposed as a solution for this problem, allowing commuter trains to be placed underground. On the other hand, another solution has