Vipac offers consulting services to governments, defence organisations, shipbuilders and owners in shipboard noise control, structural dynamics, underwater acoustics and sea trials testing.
The design and problem solving experience of Vipac’s staff ranges from small craft, such as patrol boats, motor yachts, tugs and charter vessels, to large ships such as bulk carriers, oil tankers, supply vessels, container vessels and also specialised craft such as research vessels, frigates, mine hunters, submarines and offshore platforms.
Shipboard Noise Control
Vipac’s acoustic consulting services are used for proposed and existing vessels to improve crew and passenger comfort, meet tender specifications and provide a marketing edge over competitor’s vessels. Through state-of-the-art structure-borne-noise modelling and empirical database information, complex predictions of noise levels can be made from the designers drawings. This allows the noise control treatments to be identified, optimised, costed and integrated into the overall planning of the vessel construction. In-house laboratory facilities are also available for the testing of acoustic treatments and materials.
Vipac’s engineers are experienced in underwater acoustics through projects concerning buoyant fibre towed arrays for surveillance and seismic exploration, fixed hydrophone arrays for vessel classification, and hydrodynamic noise analyses. Mechanical vibration (sensed as radiated underwater noise) has long been an indicator of the condition of mechanical systems and structures. It is now one of the principle design considerations in the detectability and survivability of military vessels. Vipac has worked on projects to minimise noise signatures from naval and ocean research vessels.
Sea Trial Testing
Vipac maintains a wide range of instrumentation, including sound level and intensity systems, hydrophones, multi-channel data acquisition systems, sophisticated multi-channel signal analysers and accelerometers, pressure and torsional transducers.
Ship Structures & Vibration
Vipac Engineers & Scientists offer consulting services in marine shock and shipboard vibration control. With offices located throughout Australia as well as Hong Kong, Singapore and Kuala Lumpur, Vipac has gained wide experience, ranging from simple machinery vibration measurements through to stress analysis, shock research and complex finite element modelling of ship hulls and structures for small to large vessels, and specialised craft like research or naval vessels and offshore platforms.
Shaft Power Measurement
Using miniaturised radio telemetry strain gauge data acquisition systems, Vipac’s engineers are able to measure instantaneous horsepower and R.P.M. on main propulsion or auxiliary machinery. This technique is extremely useful during performance trials, twin screw loading balancing, hull fouling determination, fuel consumption and engine loading measurements. This system requires only 8cm of exposed shafting, is unaffected by harsh marine environments and requires no shaft redesign or disassembly.
Torsional vibration in diesel propulsion machinery, whirling vibration of line shafting, and axial vibration of thrust blocks are all specific areas of ship design which require special attention to ensure safe and reliable operation. Vipac provides classification society approved design assessments and “T.V. analysers”, certification measurements and specialist investigation techniques to solve operational problems.
Predictive maintenance programs have the advantage of minimised maintenance costs, avoidance of catastrophic breakdowns as well as scheduling of overhauls and inventory. Vipac carries out periodic vibration surveys of rotating machines to define specific maintenance actions.
Hull and Structural Vibration
Vibration of ship hulls and structures present major design limitations to the design engineer. An understanding of these limitations is necessary to anticipate and control vibration levels that may have adverse effects on the structure of the ship and the comfort of passengers and crew. Vipac provides techniques such as finite element modelling for natural frequency calculations and stress analysis of hulls and attached structures. Prediction of vessel and structure characteristics allows changes to be made early in the design process to make constructional or equipment changes. Verification of computer models or solving of existing problems can be made using Modal and Response Shape analysis or by direct measurement of surface strains. Vipac maintains state-of-the-art structural vibration analysers and strain measurement equipment to provide efficient diagnosis of your dynamics problems.
Vipac’s engineers undertake applied shock research on transport equipment as well as shock simulation to help ship designers deal with the effects of shock resulting from underwater explosions. Numerical shock qualification of large defence equipment is also carried out as an alternative to MIL STD901 testing.