The cost of the East-West Metro has been revised from Rs 4,875 crore to Rs 8,500 crore after a seven-year land logjam during which only 42 per cent of the project was completed.

The revised cost estimate with a Rs 3,625-crore increase was finalised a few weeks ago after the railways issued a work order to contractor Afcons for the stalled Howrah Maidan-Sealdah stretch of the project.

Sources said the cost escalation wouldn't have been so high had the Mamata Banerjee government removed encroachments four years ago.

The revised estimate doesn't include the compensation claims made by various construction companies.

Afcons, the infrastructure arm of Shapoorji Pallonji, has made a compensation claim of more than Rs 300 crore for encroachments keeping its men and machinery idle. Gammon and ITD, which are also involved in the project, have filed claims for the same reason.

Metro projects in Chennai and Bangalore too have had to battle cost escalation, but for reasons other than encroachment. The revised cost estimate for neither project exceeded 50 per cent of the original budget.

"In Bangalore, 9km was added to the 33km route. The original budget, calculated in 2007, was Rs 8,635 crore but the cost went up to Rs 14,845 crore after the expansion," said an official of Bangalore Metro.

In Chennai, several contractors were changed because of "poor performance", leading to an increase in the project cost from Rs 14,600 crore to Rs 20,000 crore.

"There were a few encroachment issues at the start but these were resolved quickly with the state government's help," said an official of Chennai Metro.

The East-West Metro, which will connect Sector V of Salt Lake with Howrah Maidan through the Hooghly, has already missed several deadlines because of land-related problems. The revised deadline for the first phase between Sector V and Sealdah is June 2018. Railway officials said the internal deadline for the second phase was 2020-21.

Revised cost estimates for four other Metro projects in Calcutta, all stalled for years, have yet to be calculated. Railway officials said the increase in cost would be steep for each of these projects.

An official involved in several mass-transit projects, including Delhi Metro, said a 100 per cent increase in cost would severely impact the financial viability of the East-West Metro.

"The projected returns had been calculated on the basis of the original estimated cost. This calculation will now go haywire, not to forget that the increased cost will be paid with taxpayers' money."

The stretch between Howrah Maidan and Sealdah hasn't seen any work since 2010. The state government objected to the original alignment because encroachers and hawkers at Bowbazar and Brabourne Road had to be removed. It was only in the middle of this year that the railways and the state government agreed on realigning the route, which alone has added Rs 770 crore to the original project cost, calculated in 2008.

Since the future of the project had looked uncertain until a couple of months ago, bids have only recently been invited for various contracts.

"The price of cement, iron and steel and other materials have gone up since the original cost was calculated. Every year, cost goes up by more than 30 per cent. More the delay, higher the cost," said a senior railway official.

The contract to manufacture rakes has also had to be reissued after Spanish company Construcciones y Auxiliar de Ferrocarriles opted out because of its cost-escalation claim being rejected.

Bangalore-based BEML Ltd, formerly Bharat Earth Movers Ltd, has won the contract, originally worth around Rs 770 crore. Officials said the revised cost, which is still being worked out, would be several times higher than the original.