The original delivery schedule of the first submarine was December, 2012, with the remaining subs being delivered one every year.

 

The 1750 ton displacement Scorpene is 67 meters long and equipped with six 21 inch torpedo tubes that can launch 12 torpedoes or anti-ship missiles.

Scorpene submarines incorporate acoustic discretion and combat system performance technologies developed for nuclear-powered classes operated by the French Navy. They feature a modular design and excellent endurance. They are claimed to be one of the few medium-displacement designs suitable for extended ocean patrol duties.

The Scorpenes made at MDL will be equipped with Exocet SM39 missiles capable of being launched from its torpedo tubes.

A proposal to fit an additional section in the submarine for vertically launched Brahmos missiles was shelved with the Navy preferring an AIP unit instead.

The Indian Navy has asked MDL to equip the fifth and sixth boats with Air Independent Propulsion, which will require the addition of new section. 

During his visit to India with French President Nicolas Sarkozy in December 2010, DCNS CEO Patrick Boissier said that if a contract were to be placed on DCNS by next year, AIP systems could be integrated into the fifth and the sixth submarines rolling out of MDL in 2018.

The four Scorpenes launched earlier could be retrofitted under an upgrade program.

The Navy is also looking at an indigenous AIP kit under development by DRDO.

On April 13, 2013, the French ambassador to India, Francois Richier, told the press that the first of the six Scorpene subs on order would be rolled out by 2014.

“September 2018 is when the last boat would be due for delivery. The first may take a longer time than originally planned, but when the entire project is completed, the delay would be no more than nine months,” he said.

“The structural and regular outfitting [laying of pipe and cabling] of the first Scorpene has begun and the second is soon to follow suit. Now we are absolutely on track to meet the new contractual provisions. The teething issues are way behind us. Supply of material and armament is steady and the steel comes from France, but ironically, DCNS, the company originally manufacturing Scorpenes, buys it from ArcelorMittal.”

MDS has set up a new workshop and launching platform to fast track Scorpene construction.

“From the fourth submarine onwards, construction will concurrently take place in two yards. Which means you will have two lines of construction, which will be fully operation when P75-I commences.”

Admiral Malhi asserted that the termination of collaboration between Spanish Navantia and French DCNS — the developers of Scorpene — had not affected the yard. “We have people from Spain here as part of the ToT agreement carrying out their contractual obligation.”

In a written reply in parliament on March 14, 2011, Defense Minister Shri AK Antony said that the first submarine is now scheduled to be delivered in the second half of 2015.

In early April 2010, NDTV quoted Retired Vice Admiral H S Malhi, Chairman and MD, Mazgaon Docks Limited, as saying deliveries will now start from 2014.

"We have had delays due to various reasons. I expect the first submarine to be delivered in four years time. That is 2014 - 2015. That's a delay of 2 - 2/12 years. There were certain issues to be addressed with the government and the owner. These issues have now been sorted out and we are placing orders for various equipments." 

Speaking in the parliament on Monday, July 20, 2010 Indian defense minister AK Antony said:

The construction of the first, second and third submarine commenced in December 2006, December 2007 and August 2008 respectively. As per the contract signed with Mazagaon Docks Limited (MDL), the first submarine is scheduled to be delivered in December 2012 and thereafter, one each every year till December 2017. On account of some teething problems, absorption of technology and delays in augmentation of industrial infrastructure and procurement of MDL purchased materials (MPM), slippage in the delivery schedule is expected. The delay in scheduled delivery of submarines is likely to have an impact on the envisaged submarine force levels.

In February 2010, during DEFEXPO 2010, DCNS in a press release stated:

The first pressure hull of the first submarine is now completed and the structures are well advanced.

DCNS will complete the delivery of combat system equipment for the first submarine this year, the following ones will be delivered one every year 

In June 2009 it was reported that the project had fallen 2 years behind schedule and France had hiked up the price of some key components resulting in a per boat price increase from $500 million to $600 million.

"Going in for three more Scorpenes is one way out of the logjam over P-75I, with Navy and MoD yet to agree on the shipyards to execute the project. The French companies will charge hefty amounts for the ToT (transfer of technology) packages for the three more Scorpenes,'' the TOI source said.