The viscosimeter to be suitable for the following modes of operation, all controlled via IAMCS:a) Automatic Marine Diesel Oil Modeb) Automatic Heavy Fuel Oil Modec) Automatic change over between fuel types Viscometers to be arranged such that read-out of F.O. viscosity in engine bus rail is recorded in E.C.R. Viscosimeters, by control of heaters or coolers, to control fuel oil viscosity to within the range 2 - 17 mm 2/sec. (cst) when oil is at engine fuel pumps/injectors.- One (1) viscometer with controller of the electronic PID type. The viscosity control is backed up by a temperature control. In case of viscosity control failure the system is to switch-over automatically over to temperature control.. The unit is to use the “torsional vibrating rod” principle. The steam valve is to be able to be positioned manually remotely via IAMCS.- One (1) mixing/vent tank between the feed pump discharge and the booster pump suction for each group of engines , with low level switch indicated in IAMCS..Tank is to be of suitable size for duty required and to be heated and insulated.Tank to have connection to:a) Feed pump dischargeb) Boost pump suctionc) Return from engine fuel raild) Relief valve, drain valve and air/oil release valve to heavy fuel oil and diesel oil service tank.