A railroad tie (generally known as a railway sleeper) is a rectangular object used as a base for railroad tracks. Ties are members generally laid transverse to the rails, on which the rails are supported and fixed, to transfer the loads from rails to the ballast and sub grade, and to hold the rails to the correct gauge. Traditionally, ties have been made of wood, but concrete is now widely used. Steel ties and plastic composite ties are currently used as well, although far less than wood or concrete ties. As of January 2008, the approximate market share, in North America, for traditional and wood ties was 91.5%, whereas the approximate combined market share for all concrete, steel, adobe (exotic hardwood) and plastic composite ties was 8.5%. Ties are normally laid on top of track ballast, which supports and holds them in place, and provides drainage and flexibility. Heavy crushed stone is the normal material for the ballast, but on lines with lower speeds and weight, sand, gravel, and even ash from the fires of coal-fired steam locomotives have been used. Approximately 3000 ties are used per mile of railroad track. The rails are traditionally joined to the track by a railroad spike rather than the substantial iron/steel chairs used in Europe. Concrete ties have become more common mainly due to greater economy and better support of the rails under high speed and heavy traffic. As concrete technology developed in the 19th century, concrete established its place as a versatile building material and could be adapted to meet the requirements of railway industry. Prestressed concrete is basically concrete in which internal stresses of a suitable magnitude and distribution are introduced so that the stresses resulting from external loads are counteracted to a desired degree. In reinforced steel concrete members, the prestressing is commonly introduced by tensioning the steel reinforcement. India’s infrastructure spending at present accounts for just 4 per cent of GDP, as compared to China’s 9 per cent. Physical infrastructure covering transportation, power and communication through its backward and forward linkages facilitates growth; social infrastructure including water supply, sanitation, sewage disposal, education and health, which are in the nature of primary services, has a direct impact on the quality of life. The feasibility of infrastructure projects in ports, roads, airports and railways with private-sector majority ownership is already evident. The government also expects a substantial increase in the share of private sector investments in infrastructure from 19 per cent in the Tenth Plan to around 30 per cent in the Eleventh Plan. The biggest increase in private participation is expected in roads (from 5 per cent to 36), ports (47 per cent to 74 per cent) and railways (less than 1 per cent to 20 per cent). The Planning Commission estimates that the remaining infrastructure investments will be funded by the central and state government. Thus there is a good scope to venture into this field for new entrepreneurs. Few Major players are as under: Alpine Housing Devp. Corpn. Ltd. Bangalore G P T Infraprojetcs Ltd. Kolkata Hindustan Prefab Ltd. South Delhi Indian Hume Pipe Co. Ltd. Mumbai