Warship Technology: May 2018
The Indian Coast Guard recently commissioned the offshore patrol vessel (OPV) ICGS Vikram, the first OPV to be built by a private shipyard in India.
Vikram is the lead ship of a class of seven OPVs being built by the large Indian industrial conglomerate Larsen and Toubro (L&T).
The new Vikram class OPVs bear the names and pennant numbers once borne by the now largely decommissioned 74.1m, 1,200tonne former Vikram class OPVs that were built by Mazagon Docks and Goa Shipyard between 1983 and 1992.
The new OPVs are being constructed at L&T’s greenfield shipyard in Kattuppali, north of Chennai. The yard, along with an older one at Hazira on India’s West coast, are operated by L&T’s Defence Shipbuilding business unit.
The programme was awarded to L&T in 2015 with contract signing taking place on 30 March 2015. The contract stipulates a delivery timeline of 36 months for the first ship followed by deliveries of subsequent ships at six-month intervals according to L&T officials.
The seven-ship order was initially placed with Bharati Shipyard some years earlier. At the time Bharati is believed to have offered a 95m OPV design by Canadian design firm STX Marine (now known as Vard Marine). However, Bharati, which was also building 20 smaller interceptor boats (to a Dutch design) for the Indian Coast Guard, subsequently experienced severe financial troubles and entered bankruptcy in 2011. Subsequently, the OPV order was cancelled and retendered, with L&T emerging as the winner the second time around.
The Vikram class OPVs have been designed in-house at L&T’s Warship Design Centre at Manapakkam, Chennai to dual American Bureau of Shipping (ABS) and Indian Register of Shipping (IRS) certification standards. The L&T design team made extensive use of CAD-CAM and VR tools for the design of this OPV.
From the outset, L&T initiated construction of these OPVs in pairs, using modular construction methods. The Kattupalli yard has a L-shaped production line layout with some 20 production shops. Crucially, all fabrication and assembly work is undertaken in covered shops which permits weather independent, year-round operations say L&T officials. This is important in the Indian context as heavy rains during the monsoon season or high ambient temperatures typically impact production.
This shipyard’s block assembly shop can construct large blocks measuring up to 30m long, 30m wide and 15m high (moulded depth) and then partially outfitting them. These partially outfitted block modules are then moved to the blasting and painting shop and then to the final assembly hall where further outfitting takes place at the block level before the blocks are assembled to form the complete hull.
Each of the ships is assembled from seven hull blocks and two superstructure blocks. L&T commenced pre-production work in April 2015 – the steel cutting milestone for the first pair of OPVs, then known as yard number 45001 and 45002 – took place on 5 November 2015. This was followed by the keel laying milestone for the pair on 16 March 2016.
As the shipyard is fitted with a large shiplift and ship transfer system that can handle a 200m x 46m ship with a maximum weight of 21,050tonnes, L&T is able to complete a significant proportion of the build before the ship is launched. For example, Vikram was launched on 28 October 2017 when about 75% complete while the next ship, Vijaya was launched on 20 January 2018 with a completion rate of 85%, according to L&T. These are the highest such figures achieved by any Indian shipyard building OPVs to date.
Vikram had nearly completed its sea trials by mid-March 2018. These were followed by another sea sortie on 3 April 2018 for a series of high-speed runs ahead of a planned delivery on 7 April which was subsequently moved by two days to 9 April. The ship was commissioned into service on 11 April 2018.
What is particularly noteworthy is that the ship was delivered almost exactly 36 months after contract signing. No other Indian shipyard that is engaged in building naval ships has yet managed this feat for an OPV and the first-of-class ship on their first attempt.
The actual build period for Vikram from start of production (steel cutting) to completion of sea trials is about 29 months – which is by far the shortest build time for a 100m class OPV by any Indian shipyard – public or private – to date. In fact, L&T officials said that Vikram would have been completed two months earlier had it not been for cyclones in November-December 2015 and again a year later that disrupted the supply chain pipeline for at least two months.
Although the contract calls for delivery at six-month intervals, clearly these OPVs can be delivered more quickly, if required. At the same time, L&T officials said they are pacing the production of the ships to the critical path – that is, the Indian Coast Guards’ ability to induct many new platforms on schedule.
In comparison, L&T’s closest competitor is the public sector, Ministry of Defence-owned Goa Shipyard Limited (GSL) which also specialises in building OPVs. While GSL has progressively reduced the build period for similar sized OPVS from 72 months to 36 months over a span of five years, it has taken GSL several years to improve productivity and the build quality. In fact, GSL is set on reducing build times to 33 months for their current batch of five 106m OPVs. It has also been delivering ships ahead of schedule with minimal or zero defects since late 2015 but these schedules are often revised with timelines moving to the right.
On the other hand, the only other private sector shipyard engaged in building OPVs – Pipavav, now known as Reliance Naval Engineering under its new owners Reliance Group – has been struggling with building five OPVs for the Indian Navy. This project is now at least three years late. Although the programme has restarted, there are still concerns about the ability of the financially struggling shipyard to deliver these OPVs to the most recent set of timelines.
L&T has set a new benchmark for Indian shipyards engaged in naval shipbuilding to emulate. It remains to be seen if these yards draw the right lessons from L&T’s OPV project and raise their production efficiencies going forward.
The Vikram-class OPVs have a length of 98.2m, beam of 14.7m and a draught of approximately 3.6m. They have light displacement of 1,785.80tonnes, deep displacement of 2,147tonnes and net displacement is 2,911tonnes. They have a steel hull built of AH36 steel.
Powered by two MTU 20V 8000 M71L main engines driving two shafts with five-bladed controllable pitch propellers through two Siemens Flenders gearboxes, their maximum speed is 26knots with a range of 5,000nm at a cruising speed of 12-14knots. Siemens is a newcomer to the naval gearbox market in India and it is understood that their gearboxes have performed well during sea trials. The ships, like most newbuild Indian Coast Guard OPVs, also have a bow thruster for stationkeeping and ease of manoeuvring. Operations in up to Sea State 7 are possible thanks to the use of bilge keels and two
fin stabilisers.
The OPVs have a 22.8m x 14m helicopter deck and an integral hangar for one ALH sized helicopter although larger helicopters of up to 12-13tonnes can be staged but not hangared. They are fitted with L&T supplied helicopter haul down grid and a five-wire helicopter traversing system. The ships are also fitted with two davit-launched rigid hull inflatable boats. L&T says that some 95m2 of deck space can be utilised for pollution control purposes.
The new vessels have an integrated bridge system supplied by Sperry Marine along with X and S Band navigation radars from Sperry Marine. As with most Indian Coast Guard OPVs, their armament comprises a single CRN-91 gun mount with a 30mm cannon directed by an Fire Control System (FCS) as well as two 12.7mm heavy machine guns.
Indigenous content by value is not less than 60%, according to L&T. While L&T group companies supply many hull, mechanical and electrical equipment, like the two fin stabilisers and the integrated platform management system (IPMS) for example, some key propulsion systems like the shafting, propellers, gearboxes, and engines are imported.
With the induction of Vikram into service, the Indian Coast Guard now operates a fleet of 20 offshore patrol vessels including the lone survivor of the nine-ship legacy Vikram class, Vigraha which is likely to be decommissioned before long. The next of the new Vikram class units, Vijaya is expected to enter service around September-October 2018 or sooner.
