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Minehunter |
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VSPs for special mine-countermeasure vessels
The materials selected for vessels used on mine-countermeasure work are chosen to yield the minimum possible magnetic signature.
More than 90% by weight of the Voith Schneider Propeller consists of non-magnetisable material. If required, the magnetic components that are necessary for design reasons can be subjected to magnetic treatment before being fitted.
The components are dimensioned not only for the anticipated operating loads but also for potential shock loads due to exploding mines. The shock resistance of Voith Schneider Propellers has been verified by suitable blast impact tests.
Advantages of the Voith Schneider Propeller for mine-countermeasure vessels:
- The main and creep-speed propulsion systems are combined in a single unit.
- Since the propeller's size matches the power of the main propulsion system, the same size of propeller is available for creep-speed propulsion. In this case, the power requirement is very low, resulting in extremely low propeller loadings in relation to the very large wash area. Depending on the power requirement, it is therefore possible to reduce the speed of rotation even further. Noise levels are drastically reduced, the low noise emissions being achieved through the propeller's low-speed characteristics.
- There are no disturbances due to attachments such as shafts, propeller brackets, rudder drives or auxiliary drive systems. Only the thrust-producing blades project from the rotor casing, which ends flush with the surrounding external skin of the ship.
- There is rotational symmetry in hydrodynamic terms, with no disadvantaged direction with regard to the generation of noise.
- There are no changes in the noise characteristics when manoeuvring, because the Voith Schneider Propeller is a non steady-state propulsion system and therefore unaffected by changes in the direction of operation.
- The propeller thrust and hence the wash are not linked to the direction of the rotational axis. They can therefore be varied at will over a range of 360°. When braking, for example, it is thus possible to define an exclusion zone in order to minimise any disturbing influence on the sonar.
- During braking there is no tendency to draw in air, even when transome immersion is very slight, because the inflow is diagonally from below. This helps to minimise disturbing influences during manoeuvring.
- Adaptation to different operating conditions, such as open-water operation, creep-speed operation or towing is a simple matter.
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