India designed warship technologies to boost Indian Navy preparedness
Indian Navy got a boost in its operational preparedness with the handing over of state of the art warship technologies for evading detection. Padmasri Dr A Sivathanu Pillai, Distinguished Scientist and Chief controller (R&D), DRDO Headquarters handed over the National Science & Technological laboratory (NSTL) developed products to Vice Admiral DSP Varma, PVSM, AVSM,VSM, Chief of Materials, Naval Headquarters. The ceremony was held at Manasi auditorium in NSTL, Visakhapatnam.
Dr. V. Bhujanga Rao, Director, Naval Science and Technological Laboratory said ” NSTL is involved in development of warship technologies useful for evading detection by enemy ships/submarines. These technologies are aimed for use in modern warships under design and construction. NSTL has nurtured these technologies in the recent past and is progressing strongly towards self reliance in this critical arena. Warship technology is a multidisciplinary field covering different aspects such as acoustics and electro-magnetics covering a wide band of frequencies. Hence an inter disciplinary and holistic approach has been adopted in developing these products. The Indian Navy acceptance demonstrates the technical readiness of NSTL systems and confirms the capabilities that could be realized by a variety of military and commercial customers.”
A lot of products have been deigned and developed by NSTL which includes acoustic enclosures, acoustic silencers, double stage vibration isolation systems, Radar transparent ladder, stanchions, camouflage screens, helo net frames and composite blowers among many others. All these products were subjected to extensive laboratory and shipboard evaluations. After successful evaluations, these products were accepted for induction into Indian Navy.
Some of the details of the products developed by NSTL is,
ACOUSTIC ENCLOSURE / HOOD
Acoustic enclosures for ship machinery are designed for noise reduction. Design of acoustic enclosures for shipboard machinery is a difficult task because of various constraints such as space, routing of pipes and harsh marine environment.
FEATURES:
•Panels with Steel and rock wool materials
•Achievable Insertion loss of up to 30 dB (A)
•Modular construction for ease of assembly
•Air circulators for heat dissipation
•Access for maintainability
•Importance to non-acoustic aspects such as ventilation, safety and Lighting
NSTL developed a shipboard acoustic enclosure for a 500 kW diesel alternator for application on board IN Ship. NSTL also developed acoustic hood for reduction gear lube oil pump of the ship.
ACOUSTIC SILENCER
Acoustic silencer is useful for noise control of intakes/exhausts of air/gas handling systems. These silencers need compactness while meeting performance requirements.
FEATURES:
•Parallel baffle type
•Baffles filled with sound absorbing materials
•Noise reduction in broadband frequencies
•Insertion loss up to 15 dB(A)
•Designed to stringent space and weight constraints
•Minimum pressure drop
A Parallel baffle type dissipative silencer for ventilation fan and gas turbine have been developed and installed by NSTL onboard frigate class ship. The silencers are working satisfactorily providing 15 dB (A) insertion loss.
TWO-STAGE MOUNTING SYSTEM
A two-stage mounting system (raft mounting) is employed where there is a demand for high structure-borne noise attenuation. The main objective of a two-stage mounting system is to reduce vibration levels from machinery to foundation, and thereby to reduce radiate noise levels from ship hull. The critical design aspects of the system are:
•Optimum mass of raft (intermediate mass).
•Design of suitable mounts for both stages for desired vibration reduction.
•Minimum height of the system for ensuring stability.
FEATURES:
•Double stage isolation for improved vibration isolation
•Vibration levels reduction up to 25-40 AdB// 1e-5 m/s2 over broad frequency range
•Appreciable reduction in under water noise
•Provision of limiters for lateral stability
NSTL has developed and installed a two-stage mounting system for shipboard HP air compressor. A significant vibration reduction (25 dB) has been achieved, which in turn leads to reduced radiated noise levels.
IR SUPPRESSION SYSTEM FOR NAVAL PLATFORMS
Naval Platforms IR Signature levels depend on uptake metal surface temperature and exhaust plume temperature. To minimize the IR signature levels NSTL has designed and conducted full scale tests with multi ring eductor Diffuser type IRSS devices for both Diesel and Gas turbines.
DE-IRSS devices designed for new construction frigates are proved for full scale operational conditions conducted at KOEL, Nasik. The device has achieved 90% signature reduction in IR bands. The item productionised & inducted into service for installation on new construction Frigates and Corvettes.
FEATURES:
•Cooling of exhaust gases, funnel etc for reduced IR signature
•Minimum back pressure, Ease of maintenance
•Design customized for different configurations of gas turbine and diesel engine exhaust systems
LOW-NOISE COMPOSITE BLOWER
On naval platform blowers of ventilating systems are one of the major noise sources. To reduce noise signature NSTL has designed a composite blower and tested for all environmental tests. Appreciable noise reduction achieved.
FEATURES:
•Blades & Casing made with composite
•Low Vibration and noise
•Shock withstandability
•Eliminates corrosion
COMPOSITES
Composites offer many advantages over other materials used in warships. Due to its high strength / weight ratio and low Radar Cross Section use of composite are recommended for new construction ship board applications. NSTL has designed and developed a number of composite products such as composite stanchions, Radar transparent ladders, RCS Screen, Helo safety net frames and pipes for ship board application. Toughening agents developed by NMRL have been used. These products were subjected to all tests for marine withstandability.
FEATURES:
•High strength/ weight Ratio
•Maintenance - free
•Non-corrosive
•Low RCS signature
•Can be tailored for desired characteristics
NSTL has been interactive with different DRDO sister labs, NGOs, PSUs, Educational and Research Institutions, various industries and fabricators for development of these technologies. DRDO Labs included NPOL – Kochi, NMRL – Ambernath, DL – Jodhpur, DMSRDE – Kanpur, RCI – Hyderabad, TBRL – Chandigarh etc. These labs successfully evaluated materials and systems, which were accepted and inducted into Navy for fitment onboard newly constructed modern war ships and some inservice ships of Indian Navy.
Vice Admiral DSP Sarma Chief of Materials acknowledged the determination spirit and willing mind to accept the challenges of defence scientists over these years in making the country strong enough to stand on its legs.
You must be logged in to post a comment.