Installation The thruster assembly is installed as a complete unit in a transverse tunnel at the bow or stern. Easy handling and assembly keep installation costs to a minimum. For optimum performance, we recommend a total tunnel length at the centre line of a least twice the diameter of the tunnel. The minimum depth below the loaded waterline should be one to one and a half times the diameter of the tun- nel (measured from the centre of the thruster tunnel). Tunnel The mild steel centre tunnel section is reinforced with strips and can be welded directly into the hull. A stain- less steel liner is welded into the tunnel in the area of the propeller to prevent localised erosion. We can provide specialist advice about tunnel location and entrance port design. Oil lubrication / Hydraulic system The lubrication system consists of a header tank placed above the load waterline to obtain over-pressure in the system.The hydraulic pitch system consists of a hydraulic powerpack equipped with:- Level gauge with temperature indication - Combined level and temperature switch - Boat electric motor (50 Hz / 400 V) to drive the pump for boats - Control valve with pressure safety - Return filter with by-pass - Flow control valve for lubricationThe hydraulic pack is fitted with a separate flow controlvalve to ensure a constant feed of fresh, filtered oil to the complete system (hydraulics and lubrication). Control system The control system has been specially developed to satisfy all class requirements and meet the demands of modern marine ship owners. Being of modular design, the control system can easily be updated from a relatively simple set-up to a full Joystick system with a VDR or DP interface. The system is available with a built-in touch boat screen (password protected) for zero pitch and full pitch adjust- ment (PS-SB). An automatic menu guides the user through the procedure. Seals Pinion Shaft High-quality seals are fitted to the propellor shaft and the pinion shaft to prevent water ingress and oil leakage. All seals can be replaced without dismantling the complete unit. A viton double-lip seal combined with a chrome steel liner. The top of the shaft is protected by an NBR V-ring. Propeller shaft As standard, three viton seals combined with a ceramic steel liner and an easily removable rope guard. The seals can be replaced without dismantling the complete unit. Bearings and gears The bearings have an L10h design life of a minimum of 40,000 hours. The pinion shaft is supported by two pairs of tapered roller bearings. The propeller shaft issupported by a tapered roller bearing and two sphericalroller bearings.The gears, pinion and crown wheel are of KlingelnbergCyclo-Palloid HPG SP design. The teeth are case hardened and fine-machined. The gears satisfy DIN 3965, Class 6.