Comparison of producers of surface drive systems
Trimability – it is the main feature of surface drive, making it possible to fully use its potential. It is this feature that enables easy operation of the reverse gear, obtaining maximum speeds in different sea conditions and sailing in the shallows. Thanks to trimability we can eliminate or significantly reduce bouncing up the hull by waves. Surface drive on fixed shaft is perfect for obtaining maximum speeds in racing conditions on still waters, but it does not work well in changeable conditions mentioned above, or for military purposes.
Steerability – possibility of turning is achieved like in Z-type transmissions or overboard engines, via a turn of the shaft with propeller. The difference is, however, that due to shifting the turn axis towards the stern (moving the propellers away from the transom), manoeuvrability is much higher. The fact that there is no traditional stern, which has to be used in the fixed shaft, eliminates resistance and turbulence in water flow caused by the stern. Some producers introduce additional steering wheels for directing the water flow towards the propeller, but our experiments in the tunnel have shown that these make the propeller efficiency worse (they introduce turbulence in laminar water flow, which obviously results in efficiency loss).
Emergency steering – FH is the only producer that gives the third hydraulic pump as standard, which secures steerability in case of failure of the other pumps
Pre –wired installation – the client receives full cable bundles with connectors in the package, which facilitates assembly.
Propeller manufacturer – the propeller is the key element for the effectiveness of the entire system. FH is the only provider that has its own production and experiment facilities. Manufacturing of propellers is a complex process, starting from the design, through its moulding, treatment and subsequent tests in a special cavitation tunnel. Even if we use an identically looking propeller in the specific gear unit, this may lead to a dramatic fall in efficiency and frequently result in damage of the propeller and components.
Shock absorbers – the fact that vibrations carried by the drive are muffled significantly increases the comfort of use.
Electronic steering – the system communicates in all accepted standards, which makes it possible to use various electronic and hydraulic solutions. In addition we provide an automatic trim control system on request.
Tunnel tested – All FH drives and propellers are tested in a special cavitation tunnel, which cost over 1 million Euro to build. This enabled us to obtain full certification, necessary for commercial/ military uses.
Major class approval – as mentioned above, we are the only provider on the market that may be classified thanks to testing. We have ABS, BV and Lloyds classes.
Naval architecture – every design of a naval vessel requires holistic view on performance determined by the hull, the weight, its distribution, engines, gear units and drive with propeller. This requires advanced engineering expertise and considerable experience, which is why each design is assessed by a team of designers.
Warranty of performance – thanks to the holistic approach to drive systems, we are the only producer that offers the clients not only the standard production warranty, but also the warranty of performance.