Directive of the European Parliament and of the Council of 12 December 2006 laying down technical requirements for inland waterway vessels and repealing Council Directive 82/714/EEC (2006/87/EC) (repealed)

Article 6.03 Hydraulic steering apparatus drive unit

1. No other power consumers may be connected to the hydraulic steering apparatus drive unit. Where there are two independent drive units, such a connection to one of the units is however acceptable if the consumers are connected to the return line and may be disconnected from the drive unit by means of an isolating device.

2. Where there are two hydraulic drive units, a separate hydraulic reservoir is needed for each of the two units. However, double reservoirs are acceptable. Hydraulic reservoirs shall be fitted with a warning system that monitors any drop in the oil level below the lowest content level needed for reliable operation.

3. The pilot valve does not have to be duplicated if this can be actuated manually or by manually-controlled hydraulic actuation from the wheelhouse.

4. The dimensions, design and arrangement of the pipework shall as far as possible exclude mechanical damage or damage resulting from fire.

5. As far as hydraulic drive units are concerned, no separate pipework system shall be required for the second unit if independent operation of the two units is guaranteed and if the pipework system is able to withstand a pressure of at least 1.5 times that of the maximum service pressure.

6. Flexible piping is only permitted where its use is essential in order to damp vibrations or to allow freedom of movement of components. It shall be designed for a pressure that is at least equal to the maximum service pressure.