<P> Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap . It may also be known as ship dismantling, ship cracking, or ship recycling . Modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to run . Ship breaking allows the materials from the ship, especially steel, to be recycled and made into new products . This lowers the demand for mined iron ore and reduces energy use in the steelmaking process . Equipment on board the vessel can also be reused . While ship breaking is sustainable, there are concerns about the use of poorer countries without stringent environmental legislation . It is also considered one of the world's most dangerous industries and very labour - intensive . </P> <P> In 2012, roughly 1,250 ocean ships were broken down, and their average age was 26 years . In 2013, the world total of demolished ships amounted to 29,052,000 tonnes, 92% of which were demolished in Asia . India, Bangladesh, China and Pakistan have the highest market share and are global centres of ship breaking, with Chittagong Ship Breaking Yard in Bangladesh, Alang in India and Gadani in Pakistan being the largest ships' graveyards in the world . The largest sources of ships are states of China, Greece and Germany respectively, although there is a greater variation in the source of carriers versus their disposal . The ship breaking yards of India, Bangladesh, China and Pakistan employ 100,000 workers as well as providing a large amount of indirect jobs . In Bangladesh, the recycled steel covers 20% of the country's needs and in India it is almost 10% . </P> <P> As an alternative to ship breaking, ships may be sunk to create artificial reefs after being cleared of hazardous materials, or sunk in deep ocean waters . Storage is a viable temporary option, whether on land or afloat, though all ships will be eventually scrapped, sunk, or preserved for museums . </P>

Which is the leading state in india in ship breaking industry