- steam heater of 100% of required capacity for the served engines at 100% MCR to ensure the correct temperature and viscosity of the fuel oil. The heater is to be of the shell and tube type with steel shell and tubes and is to be fitted with automatic oil temperature electric control valve, operated by a viscometer.- Electric heavy fuel pre-heater, to serve as stand-by is to be installed , capacity to be sufficient to satisfy the fuel oil flow required for one 14 V engine at 100% MCR and a fuel delivery temperature of 155 deg C. The el-heater is to be arranged with four banks of heating elements and is to be provided with thermostatic control.. One in number fully automatic viscosimeter to install in module discharge pipe. The viscosimeter to be designed for full flow, in-line installation and is to be of the vibrating rod type comprising a vibrating rod or of magnetic coil principal type both linked to a built on electronic unit to control either steam or electric heaters, regulating valves, etc. The unit to have a resolution of plus or minus 0.1 Cst.