Indigenous Destroyer Construction – A Giant Technological Leap

PNS ASLAT, a F22P class destroyer, is expected to be commissioned this month (April 2013). What makes this event significant is that it would be the first destroyer to have been constructed in Pakistani yards, no mean achievement in itself. The first three vessels of the same class, namely PNS ZULFIQUAR, SHAMSHEER and SAIF, had been constructed in China by the Hudong Zhonghua Shipyard.

Naval architecture is a general term that encompasses all aspects from designing to maintenance during the entire life cycle of a marine vessel. While planning the construction of warships, this term takes on a meaning of its own. For one thing, warships are very complex platforms employing a wide array of sensors, weapons and communication systems. A warship also needs a high degree of stability, a task made difficult by having most of its weapon systems, radars and satellite communication antennae mounted high on the ship. An interlinked system of fuel and water tanks is artfully designed and effectively utilized to maintain balance.

Construction of a warship necessitates the use of high quality and high strength tensile steel to make it robust enough to absorb shocks and better resist damages inflicted during battle. All individual compartments, which in the case of a destroyer like PNS ASLAT exceeds 300, are required to be water-tight to enable them, as well as groups of compartments, to be sealed to contain damages below the water-line in particular, such as that generated by mine or torpedo hits. A warship is required to maintain variable speeds to fulfill various mission criteria, which coupled with its desired level of maneuverability, translates into a complex propulsion, propeller and rudder combination.

Karachi Shipyard and Engineering Works Ltd, an autonomous public limited company under the Ministry of Defense Production, which was entrusted with the destroyer construction project, is no stranger to warship construction. Starting with the construction of a coastal logistics vessel PNS GWADAR in the early eighties, it went on to construct a missile craft PNS SHUJAAT in 1995, a huge 4000 ton floating dock in 1996 followed by the fabrication of a pressure hull for the Agosta 90B submarine, its most technically challenging feat till that time. Since 2000, it has continued to build various auxiliary and missile craft for the Pakistan Navy.

Constructing a destroyer, however, which is a far more complex platform, was a different ball game altogether, necessitating intricate and minute planning and skillful execution. An agreement for the acquisition of four F22P destroyers was signed in 2005, but once the decision to undertake the construction of the fourth of the class indigenously was made, planning began in earnest. The foremost requirement was to carry out a material upgrade of the yard, without which such a complex undertaking was unthinkable. Apart from the addition of sophisticated workshop machinery, a grit blasting and painting set-up needed for undertaking the said work in a controlled environment had to be built up from scratch.

The next most important thing was capacity building. A core team of engineers and workers had to be trained in modern workshop construction methodology and shipbuilding techniques to be able to effectively supervise and pass on the skills learnt to the vast bulk of the workers employed in the project. Construction began in earnest in March 2009 by cutting the specialized steel used in such constructions through an equally special numeric controlled water plasma cutting machine, the task taking a period of 8 months to accomplish.

Modern ship-building makes extensive use of what is called block construction. Multi-deck segments of the hull and superstructure, 91 in all in this case, were prefabricated in various places within the shipyard, grit blasted and painted under controlled conditions prior being transported to the slipway where they were lifted into place. The process is not as simple as it sounds, as the out- fitting work, apart from the placement of machinery and equipment on shock-absorbing foundations, also entailed the installation of more than 10,000 pipes, 16.5 km of cable, 69000 cable connections and 6000 pieces of ventilation ducting. Modular construction techniques, which rely on pre-installation of all equipment, pipes, cables and other components within the blocks to facilitate assembly and subsequent repairs whenever needed, are being extensively employed these days.

Once the ship was successfully launched in June 2011, the combat systems were installed and integrated. The functioning of the various systems was then fully optimized through a laborious process known as setting to work. On completion of installation, integration and STW of all the equipment, the vessel was put through its paces in a series of arduous trials at harbour and at sea. A warship is designed to function in a harsh marine environment and the optimal functioning of all its machinery, equipment and sub-systems under such trying conditions has to be ensured prior acceptance. The harbour and sea acceptance trials thus took a period of over 18 months to accomplish to the satisfaction of the end user, the Pakistan Navy.

With the vessel soon to join the Pakistan naval fleet as the newly-commissioned PNS ASLAT, it is a time for introspection and planning for the years ahead. A lot has been accomplished and yet much more needs to be done if we are to derive optimal benefit from the enterprise. Using history as a guide, we find that the United States shipbuilding industry, which accounted for as much as 90% of the total global production during the Second World War years, soon lost its prime position to newer players like Europe in the sixties and seventies, Japan in the eighties and to South Korea and China in the current century, owing to higher production costs and an unwillingness to subsidize. By contrast, most developed countries prefer to undertake warship construction on their own, by declaring all such constructions as a strategic industry.

Just as South Korea built its economic success story around its shipbuilding industry by drawing on the extensive technological capability and enormous downstream benefits that it generated, Pakistan can only pride itself on its achievement if it manages to take a giant share out of the 70% of the net value of a ship which is normally outsourced to a network of suppliers and sub-contractors. This it can only do if it goes into series production, which would hopefully lead to the development of an efficient and effective local supply chain and herein is some food for thought.

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