Indian Defence Review

As terrorists get more sophisticated, they will endeavor to use the sea route to move fissile materials and “dirty devices” into maritime countries clandestinely using container bound shipments. It is therefore necessary to install smart sentinel wind/solar powered Radiation and Visual Detector Buoys to guard the channel fairway used by the ships of the command. This will enable the detection of all radio-active sources being shipped in and facilitate ships to be quarantined when necessary. Such detection should be an integral part of the Base security. The cost is small considering the possible catastrophic loss due to any contamination of the Base, the Fleet and the Port.

Salvage & Damage: Collisions and accidents do occur. These risk also needs to be adequately addressed so that the Integrity of the hull can be immediately assessed. This is best done when the Command has a specially trained Fleet Salvage and Diving Office with a Computerized system responsible for the stability, fire fighting, damage control, structural sea keeping response and underwater security of the fleet. This office should also be responsible for the visual capture of any associated damage to the Fleet, marine archeology and wrecks. It should be no surprise that such an organization in addition to its extensive Diving facilities will need a host of salvage equipment, surface and underwater vehicles. Additionally, an underwater security inspection and cleaning station and a real time panoramic visual camera system to display the state of any Hull and any corroded sites and damage to the ship and naval staff are essential.

The establishment of monthly statistics of ships in terms of Operational availability, distance sailed, wave bending Stress from stress gauge extrapolated to standard load condition also needs to be done regularly and analyzed. This information is of importance for correlating the strength of the hull with time. The cost of fitting a few strain rosettes under the Upper deck when the ship is on the ways or in dock at the time of construction is every small. Knowing the exact current load and stress, it is feasible to extrapolate the result to the standard wave Bending stress. Such data will help to establish the Command to monitor the degradation of hull strength on an annual basis thus enabling them to determine the limits of the operating envelope for different sea spectrums and damage profiles.

 If the Navy desires to implement a lasting improvement, we need to train a new cadre of hull technologists who understand the science of corrosion, surface preparation and paint.

Painting: Maintenance painting of the ships external hull done manually by brush from suspended staging under wet monsoon conditions has always been problematic. This is an expensive wasted effort which can never meet the Q. A standards of application required for modern epoxy and silicon paint systems. This is further compounded by the docking arrangements used. The use of side shores to provide a lateral constraint when the ship is in dock makes it impossible to erect any temporary shelters during painting of the ships external underwater hull. The practice of using side shores while dry docking stems from tradition; there are no side shores used when ships are launched on ground-ways.

Engineering protocol requires that the ship in dock be adequately supported against any lateral forces due to the hundred year maximum Seismic Earth quake/wind Loads for the zone, and the maximum unanticipated and unaccounted load shifts during refits. These transverse loads can be adequately supported by a set of anchored side blocks which then makes it practical to dispense with the side shores. If the ship sides are clear and accessible, it is then feasible to utilize power activated mobile screened staging between the ship side and the dock side to provide dry conditions during external painting. With the use of such mobile staging, infra red industrial heaters, fans and mobile controlled powered manual or robotic cleaning and spray painting machines, it is feasible to repaint a degraded epoxy surface to specification by locally isolating the Hull from the monsoon like weather. To do this, there must be adequate clearance of the ship in dock.

The older dry docks were designed for narrower ships with smaller Beam to length ratios. In recent years, this ratio has increased resulting in ships with wider beams. Because of this, the clearance of ships in these older Docks is often extremely small. Clearances of 4-5m, 10m and 2 meters for the side, tail and head respectively are absolutely necessary for good access by the maintenance teams. If external bottom painting is done correctly using current technology and use made of mechanical underwater robots for gently cleaning the slime film periodically, the dry Docking interval can be increased to at-least six years and more. To achieve this, it is also necessary that ships alongside do not berth in polluted shallow water. Such sea water being warmer adds to the fouling and corrosion threat. Sea water that has lower temperatures and is more neutral is preferable. This can be achieved if harbor dredging both capital and annual are planned and integrated into the overall requirements.

Conclusion

In some countries, maintenance has never been very popular or readily accepted as a necessary pre-planned expense. As proof, as one travels around, one has to look around at the variation in visible rust stains & cracks on buildings, trains, buses, vehicles and coastal ships. Hiding a rusted surface by a cosmetic coat of paint, as is often done before a VIP visit, is not the solution. If the Navy desires to implement a lasting improvement, we need to train a new cadre of hull technologists who understand the science of corrosion, surface preparation and paint. Since it is impractical to have a dual set of new and old maintenance standards, I hope that the younger generation will embrace the genesis of a new standard which will maintain and guarantee the operational integrity of our ships and public infrastructure against the ravages of corrosion, wear and tear.

If there is a total commitment to the systemic change suggested, it is feasible to increase the operational availability and extend the life of our ships hulls by at-least 25 percent and more. However, that will require a massive reformulation and training of the “construction” departments in both private and public shipyards and an investment in modern hull maintenance techniques, personnel and equipment. This expense will be miniscule compared to the improved readiness and longevity gained by the ships of the Fleet and the reduced CAPEX that will eventually follow. In addition, their survivability with age against fire and damage due to Action or Collision will undoubtedly also be better than ever before.