decked bridge or ferry in nine minutes. This system has axle retraction arrangement, which facilitates complete retraction of the wheels inside the hull body during deployment and provides adjustable ground clearance during transportation.

Two or more such systems can be joined together on a river to form a continuous floating bridge. Inflatable floats have been integrated with the bridge superstructure for providing additional buoyancy and stability during floatation in water. The floats have compartments to minimize the buoyancy loss in case of puncturing. A low pressure (1.1 bar absolute) and high flow (20 m3 / min) pneumatic system has been used for inflation and deflation of floats. The operational control of the pneumatic system is PLC-based to get automation on safety during floatation. The AFFS has excellent aquatic mobility with the help of two pump jets, which give forward, reverse, lateral and yawing motion as well. The system has undergone extensive technical trials and has been evaluated successfully for bridge launching, ground mobility, floatation and pump-jet performance.




Mobile Power Generating System




Research 86 Development Establishment (Engineers) (R&DE) (Engrs) , Pune, has designed and developed

an engineering prototype of Mobile Power Generating System based on Variable Speed Drive Constant
Frequency and Voltage Output (VSCF & VSCV) Technology. This state-of-the-art technology programme has

been taken up to generate *power on moye'-essential for various mobile defence





applications. The Insulated Gate Bipolar Junction Transistor (IGBT) -based power conditioning unit, which works on double conversion technique, is the main feature of this system. Advantage over contemporary systems is its portable and lightweight nature as well as a digitally control based system enabling delivery of power to various types of loads. In this prototype, a variable speed drive in the range of 800-3000 rpm has been used as a prime mover to drive a 3000 rpm, 2 pole alternator controlled by a custom-built automatic electronic voltage regulator.






The variable frequency (14-50 Hz) and variable voltage (230-415 V AC) output

produced by the alternator, due to variable speed of prime mover is fed to power conditioning unit. Input AC voltage is diode rectified by 6 pulse converter and converted to high voltage (~600 Vdc) DC link using an IGBT-based boost converter. An AC to DC converter has been built with inbuilt active power controller that corrects the power input to near unity, irrespective of input voltage and frequency variation and makes use of soft start